OPERATION C ARE; REP AIR ^AUTOMOBILES r I r The Livingston Radiator is not an imitation of, but a wonderfully effi- cient improvement over, the square tube type. Scientifically and practically correct in prin- ciple and construction. The lapped, seamed, swaged edges of our patented tubes produce thin edges to the air ducts, resulting in a frontal area of only J3% of the total as against the 50% usually found in the square tube type. IF YOU DOUBT THIS, FIGURE IT OUT FOR YOURSELF C. Live circulation in horizontal as well as vertical water channels. See cut. Equal circu- lation in all tubes. C The lapped, seamed edge is the strongest possible construction. C All water in moving contact with entire radiating surface. C. Sixty-four square inches of radiating sur- face for each square inch of frontal area. CL Combined area of water passages equal to 15 square inches. C, The radiating section and frame built of separate units, then assembled. C. All rivets protected on the interior by a flexible metal covering. C. All joints of frames reinforced by brass castings of proper shape in addition to long laps. C, Absence of spacing wires permits the lightest known construction. C. The great strength, lightness and efficiency especially adapt these Radiators to aeroplane work. LIVINGSTON RADIATORS MF6.CO.,INC. 312 West 52d Street, New York City I THE ECONOMY OF IT The possibility of spring breakage is removed as soon as the TRUFFAULT-HARTFORD SHOCK ABSORBER is put on a car. The ravages of vibration, the racking it causes every bolt, nut and part, cease. In actual figures the use of the Truffault-Hartford decreases depreciation through wear and tear 50 per cent. That's the economy of it. It is a matter of dollars and cents to have your car Truffault-Hartford equipped. If you cannot have a set put on at the factory, have it done at the garage. The motorist who looks to comfort and economy must realize the absolute necessity of having his car Truffault- Hartford equipped. A car that is jarred is necessarily racked, and constant racking means a quick finish. The Truffault-Hartford Shock Absorber absorbs the jolt; it absorbs the vibration; it nullifies the discomfort to the car's passengers. Its use makes the car run smootherjast longer. It saves your feelings, saves your pocketbook. THREE MODELS: Standard, 160 Intermediate, $45 Junior, $25 Price includes fittings for making the application to any car. HARTFORD SUSPENSION COMPANY E. V. HARTFORD, Pres. 158 Bay Street, JERSEY CITY, N. J. The Operation, Care and Repair of Automobiles EDITED FROM THE FILES OF THE HORSELESS AGE By ALBERT L GLOUGH REVISED EDITION Copyrighted, 1910, by THE HORSELESS ACE COMPANY Published by THE HORSELESS AGE COMPANY MOTOR HALL 254 West 54th Street New York City IGNITION. It is a matter of common experience that a large proportion of the attention required in the care and maintenance of automobiles is de- manded by their ignition apparatus. In order to be able successfully to cope with the difficulties arising from failures of ignition it is desirable not only to understand the general construction and mode of action of the various pieces of ignition apparatus, but to possess a working knowl- edge of the cardinal principles of electricity and magnetism. The follow- ing elementary considerations are therefore presented. General Electrical Principles. Electricity is a form of energy that makes itself manifest to the senses by its mechanical, thermal and chemical effects. For most practical pur- poses it may be regarded as a fluid that flows through bodies of certain materials called conductors as water flows through pipes. Just the same as water in flowing through pipes encounters a frictional resistance, so an electric current in flowing through a conductor encounters a resistance. The frictional resistance of a certain pipe to the flow of water through it depends upon the length and diameter of the pipe and upon the rela- tive smoothness of its bore. Similarly, the resistance of a conductor to the flow of electricity through it depends upon the length and cross sectional area of the conductor and upon the material from which the conductor is made. The best conducting material is the precious metal, silver. Copper, however, in its pure state is nearly equally conductive, and is the best conductor from a commercial standpoint. Iron offers about eight times the resistance of copper, and is used to some extent in practice where the greater bulk of the conductor is of no consequence and the greater tensile strength of iron is an advantage, as in telephone and telegraph lines. The conductivity of a material is the inverse of its resistivity; that is, if a material has a high conductivity, it has a low resistivity, and vice versa. All materials conduct electricity to some extent, and all are, there- fore, conductors in one sense. However, some are such poor conductors that their conducting power is entirely negligible for all practical pur- poses. These very poor conductors, which are of as great importance in the industrial application of electricity as the very good conductors, are called insulators. Among the best insulating materials are glass, porcelain, hard rubber, ebonite, niica and silk. In the present articles electrical phenomena will be explained by hydraulic phenomena that is, phenomena of flowing water which are familiar to everyone. Almost every electrical phenomenon can be thus explained in simple language easily comprehended by the lay mind. Water flows under the influence of the force of gravity from a higher point to a lower, provided there is an unobstructed path for the flow between these two points. The flow is then said to be due to a difference of level between the two points. Similarly, an electric flow or current in a conductor is due to a difference of electrical level or a difference of potential, as it is known technically. In nature water is continually raised by the process of evaporation, and in a similar manner high electrical potentials are occasionally created by meteorological processes. In practice, however, if we want water at a high level in order to create a flow, we usually find it necessary to raise it there by means of a pump. Similarly, if we desire to produce a high electrical potential in order to obtain an electrical current, we must make use of an apparatus capable of creating a difference of potential. Such an apparatus is ordinarily called a source of electromotive force. The terms "difference of poten- tial" and "electromotive force" are almost synonymous. They bear to each other about the same relation as "difference of level" and "pressure" in hydraulics. As is well known, a certain difference in water level cor- responds to a certain definite pressure per square inch, so that for many purposes "difference of level" expresses the same thing as "pressure per square inch," although fundamentally these terms express different things. This difference between the two electrical terms is particularly to be noted: If there is simply a difference of potential between two points, this is wiped out as soon as the points are connected by a conductor; but if there is an electromotive force active between them, the difference of potential will be maintained between the points, even if they be con- nected by a conductor. The two factors which control all hydraulic phenomena are the pres- sure of flow and the rate of flow. In a waterfall, for instance, the power depends upon the number of feet of fall, and also upon the number of gallons or tons of water per minute passing through the fall. Similarly the power in an electric circuit depends upon the pressure (electromotive force) and on the rate of flow (current) in the circuit. In order that an electric current can flow at all these two conditions must be fulfilled : (1) there must be a complete or closed circuit of conducting material; (2) a source of electromotive force must be incorporated in this circuit. Electricians generally distinguish between static electricity and current electricity. There is in reality only one kind of electricity, the distinction being based upon the fact that phenomena in which extremely high electric pressures and very small quantities of electricity are involved are rather different in their manifestations from those in which both the pressure and the current are of normal value. Electrostatic effects are really effects of extremely high electrical pressures. As the quantities of elec- tricity involved in electrostatic phenomena are extremely small, the power involved is small, and these phenomena can be produced by means of frictional electric machines and induction machines as used by physicians and for experimental work, these machines being generally turned by hand. Sparks produced by such frictional machines were used for igni tion by some of the early gas engine experimenters, but as these machines are not now used for this purpose we need not consider them any further. Every conductor has a certain capacity for storing electricity, as every vessel has a certain capacity for storing a liquid. The electrical capacity of a conductor, however, does not depend upon its cubical contents, but upon its surface area. The amount of electric charge that can be stored in a certain conductor depends also upon the pressure at which the charge is supplied to the conductor and upon the surroundings of the conductor. When it is desired to store a comparatively large charge such a charge, for instance, as is involved in an ignition spark use is made of what is known as an electric condenser. A condenser in its simplest form consists of two thin sheets of conducting material, separated either by a thin layer of air or of some other insulating material. The capacity of such a condenser depends upon the surface area of the sheets, on their distance apart (the closer together they are the greater the capacity), and on the nature of the separating material, which is called the dielectric. Among the best dielectrics are mica, glass and paraffin. Commercial condensers are built up of a large number of sheets of conducting material (usually tinfoil) separated one from the other by a sheet of insulating material (usually paraffined paper or mica), alter- nating sheets of conducting material being connected together to the same terminal post of the condenser, so that all the even sheets are connected to one terminal post and all the odd ones to the other. The capacity of such a condenser is proportional to the number of plates. If the two terminals of such a condenser are connected to the two terminals of a source of electromotive force, a charge flows into the condenser, the amount of the charge being directly proportional to the pressure of the source of electromotive force and to the capacity of the condenser. When the source of electromotive .force is disconnected from the con- denser, the charge remains in the condenser, and if the pressure of charge was sufficiently high, by connecting a conductor to one terminal of the condenser and bringing its other end near the other terminal of the con- denser, a spark will pass at this gap and the condenser will be discharged. Detailed descriptions of condensers will be given later on. Chemical Effects of the Electric Current Units of Measurement Ohm's Law Chemical Generators. When the ends of two wires connected to a source of electromotive force are inserted into a glassful of slightly acidulated water, a current will pass through the water from one wire to the other and gas bubbles will form and rise from the surface of both wires. Acidulated water is thus a conductor of electricity. The gases formed at the surfaces of the two wires are hydrogen and oxygen, the components of water. In mak- ing this experiment it will be observed that the quantity of gas given off at the two wires (called in this case electrodes) is not the same. The hydrogen is given off in much greater quantity than the oxygen, and as the oxygen is evolved at the positive pole or the wire where the current enters the liquid, and the hydrogen at the negative pole, where the current leaves the liquid, this apparatus admits of determining the direction of flow of the current. Conductors which in conducting a cur- rent are decomposed by it are called electrolytes. Electrolytes include many solutions of metallic salts. One of the most familiar electrolytes is a solution of copper sulphate. When this solution is decomposed in the electrolytic bath, metallic copper is deposited on the negative elec- trode and gases accumulate on the positive electrode. In all electrolytic work the metal radical of the electrolyte travels with the current through the bath and is deposited on or liberated at the negative electrode. The rate at which either component of a given electrolyte is liberated depends directly upon the current strength, and the decomposition of electrolytes therefore lends itself, by weighing the deposit of metal ob- tained in a certain time, to the measurement of current strength. The unit in terms of which the strength of electric currents is expressed is the ampere, which is the current necessary to deposit 0.00113 gram of silver per second from a bath of silver nitrate in water. It will be noticed that this unit of current is based upon the metric system of measurements, and so are all electric and magnetic units. The above constant, 0.00113, is called the electrochemical equivalent of silver, being the amount liberated by one ampere in one second. Each element has a different electrochemical equivalent, and those metals which, like copper, form two sets of combinations have two electrochemical equivalents. The electrochemical equivalent of copper in cupric combinations is .000327 and in cuprous combinations .000654. OHM'S LAW. Before proceeding any further we must make mention of a most simple and widely applicable law of electric phenomena named, after its discoverer, Ohm's law. It is to the effect that the current in an electric circuit is directly proportional to the electromotive force active in that circuit and inversely proportional to the resistance of the circuit. In other words, if all three factors are expressed in units of the same system, the current is equal to the electromotive force divided by the resistance. Ohm's law is generally written as follows: E. M. F. Current = Resistance. There are two variations of this equation which may be deduced directly from it; they are, E. M. F. = Current x Resistance ; E. M. F. Resistance = Current. We have seen how current can be measured and how the unit of measurement, the ampere, has been determined. The unit of resistance, the ohm, is the resistance of a column of mercury of one square millimetre cross section and 106.3 centimetres in length, at the temperature of melt- ing ice. The temperature is here specified because the electrical resistance of most conductors increases with an increase in temperature. The unit of electromotive force, the volt, is that electromotive force which will cause a current of one ampere to flow through a resistance of one ohm. Just as in mechanical motion against a friction heat is developed, so heat is generated whenever an electric current flows through a circuit. In both cases the heat produced represents a loss, unless the mechanical movement or the electric current is produced for heating purposes. In an electric circuit the heat produced in overcoming the resistance is pro- portional to the square of the current and to the resistance, which may be expressed as an algebraic equation by H = C 2 R. This principle is also sometimes employed for measuring electric currents, in combination with the law that heat expands all bodies. ELECTRIC GENERATORS. There are two sources of electromotive force or current in general commercial use. In the first type, known as chemical generators or bat- teries, the electric current is produced by the combination of certain chemical elements, thus transforming the chemical energy stored up in these elements into electrical energy. In the second class, called mechanical generators, the electric energy is induced in wires by the motion within a magnetic field of some rotary part to which mechanical energy must be applied. In the latter case, therefore, mechanical energy of motion is transformed into electrical energy. We will first consider the former kind of generators. The simplest form of chemical cell consists of a rod of zinc and a rod of copper immersed in a bath of dilute sulphuric acid. When the upper, exposed ends of the two rods are connected by a wire, a current will flow from the copper rod through the wire to the zinc rod, and as a current makes always a complete circuit, it flows inside the cell from the zinc rod to the copper rod. The copper rod is called the positive pole and the zinc rod the negative, because the current flows from the copper and returns to the zinc. There is, of course, a certain chemical action going on inside the cell to which the current is due, and this chemical action is the combination of zinc with the sulphate radical of the sulphuric acid, forming zinc sulphate which goes into solution. If at the end of a period of activity the cell be examined, it will be found that the zinc has been "eaten" away, and if the electrolyte be then evaporated the familiar white powder, zinc sulphate, will remain. The copper rod does not take any active part in the generation of the current, and serves only as a terminal for collecting the current from the electro- lyte. It is not consumed and may be used indefinitely, while both the zinc and electrolyte are consumed and must be renewed from time to time. The copper rod may be advantageously replaced with a rod of gas carbon. A cell in which zinc is reduced to zinc sulphate gives an electromotive force of about iJ/2 volts, irrespective of the size of the cell. The size of the cell determines, however, the current that may be taken from it, and as the power in an electric circuit is equal to the product of the electro- motive force and the current, the electrical power obtainable from a cell depends upon its size, as would be expected. POLARIZATION. The above described simple cell is never used in practice, for the reason that if a considerable current is taken from it its power soon decreases. The generation of the current breaks up the sulphuric acid into a sulphate radical which combines with the zinc, and nascent hydro- gen which accumulates on and adheres to the copper or carbon electrode. It prevents a proper contact of this electrode with the electrolyte over its entire surface, thus increasing the internal resistance of the cell, and also sets up a counter electromotive force, thereby reducing the current which the cell will furnish with a given outside resistance. This phe- nomenon is known under the name of polarization. It can be prevented by the addition to the cell of some chemical substance which readily combines with nascent hydrogen. Such chemicals are nitric acid, bichro- mate of potash, manganese dioxid^, etc., which are known as depolarizers. These depolarizers combine with the hydrogen as fast as it is generated, and thus allow of the electric generation going on continuously. Magnetism. A magnet is a body which has the power of attracting certain other bodies called paramagnetic. The most important paramagnetic substances are iron and its various combinations. Nickel and cobalt are also slightly paramagnetic, but do not possess this property to a sufficient degree to affect their commercial values. There are two kinds of magnets, viz., permanent and temporary magnets. The former retain the power of attracting paramagnetic (magnetic for short) substances permanently, while the latter retain it only so long as a magnetizing force is applied. Permanent magnets can only be made of hardened steel, tungsten steel being the best for this purpose, because it retains the magnetism best. In practice permanent magnets are usually found in two forms, bar magnets and horseshoe magnets. When a magnet is freely suspended it takes up a certain definite posi- tion. A bar magnet (Fig. i), for instance, will point substantially north and south. The end of the magnet pointing toward the north is called the north, or positive, pole, and the end pointing toward the south is called the south, or negative, pole. Every magnet, of whatever shape, has these two poles, and if a magnet is broken into two or more pieces each piece again has a north aad a south pole. The reason a magnet takes up a certain definite direction when freely FIG. I. BAR MAGNET. suspended is that 'the earth itself is a permanent magnet, having its mag- netic north pole in the regions near the North Pole, and its magnetic south pole opposite, and it is a law of magnets that poles of unlike sign attract and poles of like sign repel each other. The force of attraction and repulsion is equal to the product of the strength of the two poles, respectively, divided by the square of the distance between them. As there is an attractive and repulsive force between magnets at a distance from each other, and an attractive force between a magnet and an unmagnetized magnetic body, it is obvious that the magnetic force of a magnet pervades the surrounding space. It is also found by experi- ment that at any given point in the surroundings of a magnet the at- tractive or repulsive force has a definite direction. If a small magnetic needle, freely suspended, be brought close to the north pole of a large bar magnet and then be moved away along the path indicated at any moment FIG. 2. HORSESHOE MAGNET. by its direction, it will finally arrive at the south pole of the bar mag- net. This experiment has led to the conception of magnetic lines of force which emanate from the north pole of a magnet and pass through the surrounding atmosphere to the south pole. The space sur- rounding a magnet in which there is an appre- ciable magnetic effect is called a magnetic field. The lines of force which pass through the atmosphere from the north pole to the south pole pass through the magnet from the south pole to the north pole, thus forming a com- plete circuit. Magnetic lines of force follow very much the same laws as electric currents. The total number of lines, which corresponds to the current, depends directly upon the "mag- neto motive force" of the magnet and inversely upon the magnetic resistance of the circuit. The magnetic resistance is much greater for the air portion of the cir- cuit than for the steel portion, and this explains the superiority for many purposes of the horseshoe magnet (Fig. 2) over the bar magnet, as in the horseshoe magnet the length of the magnetic path through the air is relatively short. In order that a permanent magnet may well retain its magnetism the magnet must be very long in proportion to its cross section, its poles must be close together and the opposed polar surfaces must be relatively large. The lines of force extending between the poles of a magnet may be well illustrated by a simple experiment. A magnet is laid on the table and at a short distance above it is held a sheet of white paper soaked with molten paraffin, which paper is shaken while a bagful of fine iron filings is slowly poured onto it from a certain height. Each iron filing arranges itself with its length in the direction of the lines of force, and when the experiment is completed a perfect map of the magnetic field is obtained, as shown by the accompanying diagram (Fig. 4). A permanent magnet may be produced by drawing a piece of hard- ened steel over one pole of another permanent magnet. This method, however, does not give very satisfactory results, as magnets thus made are not very powerful. The method now generally employed is that known as electric magnetization (Fig. 3). By bringing a magnetic needle into the vicinity of a conductor carry- ing an electric current it will be found that the needle tends to set itself at right angles to the direction of current flow, thus indicating that an electric current has a magnetic effect. In fact, a conductor carrying an electric current is surrounded by circular magnetic lines of force. The magnetic effect of a current can be made very powerful by forming the conductor, or wire, into a coil of many turns, in which case all the lines -of force pass through the coil and return on the outside. Such a FIG. 3. ELECTRIC MAGNETIZATION. coil behaves exactly like a magnet, and when freely suspended takes up a position with its axis extending north and south. The magnetic strength is proportional to the number of turns in the coil and the cur- rent flowing through it. If a hardened steel bar or horseshoe is inserted into the coil while the current is flowing it becomes at once magnetized, and by using a large number of turns in the coil and a strong current a very powerful magnet can be thus produced. After the bar or horse- shoe is withdrawn or the current is stopped it retains a considerable por- tion, though not all, of the magnetism thus imparted to it. It is a permanent magnet. The strength of permanent magnets de- creases in the course of time, and is very detrimentally affected by shocks and heat. If, instead of a hardened steel bar or horseshoe, one of soft iron or steel had been inserted into the coil, an even stronger magnet would have been obtained, but the magnetism of such a piece of soft iron or steel immediately vanishes almost com- pletely when the current is stopped or the piece is withdrawn from the coil. Tem- ?//)'!{ porary magnets are thus made from soft wrought iron, steel or cast iron. They are of very great importance in the genera- tion, control and application of electricity. It may be added that in the case of elec- tric magnetization the polarity of the re- sulting magnet always depends upon the direction of flow of current through the coil. If the coil be regarded as a screw and the current flows through it in the direction the screw is turned, then the north pole will be in that direction toward which the screw would advance. . ' A THE HORSELESS ME FIG. 4. MAGNETIC FIELD OF HORSESHOE MAGNET. EIectro=Magnetic Induction. When a magnet is inserted into or withdrawn from a coil (Fig. 5), an electromotive force is induced in the coil, and if the coil forms a closed circuit a wave of current is caused to flow through it. The electro- motive force lasts only so long as the relative position of the coil and the magnet is changing, and its direction is opposite for approach and recession. By closing the pircuit of the coil through a current indicator or galvanometer, the current impulses as the magnet is brought nearer to *or removed farther from the coil can be directly observed. The same effect can be secured by substituting for the magnet a coil through which a current from some outside source, such as a battery, is flowing. By placing the two coils with their axes coincident and approaching and separating alternately, current impulses will be generated in the second coil, although this coil has absolutely no connection with the other coil, which receives its current from an outside source. This effect is known as electro-magnetic induction, and was discovered by Faraday in 1831. 10 E HOUSELESS AGE FIG. 5. ILLUSTRATING ELECTRO- MAGNETIC INDUCTION. When a magnet is placed with jts axis coinciding with that of a coil, at a slight distance from the coil, some of the lines of force emanating from the poles of the magnet will pass through the coil and return on the outside, thus looping the spires, turns or convolutions of the coil. When the magnet is brought nearer the coil the number of lines of force passing through the coil increases, and when the magnet is moved far- ther away from the coil the number of lines of force passing through the coil decreases. The total number of lines of force emanating from the north pole and returning to the south pole of the magnet remains the same, but as the magnet approaches closer to the coil an increased pro- portion of the lines link the convolu- tions of the coil, and it is this link- ing or cutting of magnetic lines of force by electric conductors which is the cause of the phenomenon of electro-magnetic induction. When- ever an electric conductor moves in a magnetic field at an angle to the magnetic lines of force, so as to cut these lines, an electromotive force is induced in the conductor, and if the conductor forms a closed circuit a current is caused to flow in it. The electromotive force induced depends upon the rate at which lines of force are cut. If 100,000,000 are cut per second, the electromotive force is one volt. SELF INDUCTION. When a current is flowing through a coil of wire a magnetic field is set up in the surrounding space, as has already been explained. If now the current is stopped the magnetic field will, of course, also cease. Now, the effect upon the coil of the removal of this mag- netic field is exactly the same as if the field had been due to an outside magnet ; in other words, an electric impulse is in- duced in the coil by the very dying out of the cur- rent in it, and this im- pulse is in the same direc- tion as the current in the coil. The result is that when the circuit is broken to stop the current, the decrease in the current adds momentarily to the electromotive force active in the circuit, and a visible spark, or even an 6. MAGNETIC FIELD OF SOLENOID. arc, is generally formed at the break. This phenomenon is known as self induction. Owing to the self induction of a circuit, the current in it, therefore, tends to continue when the circuit is broken; but the self induction also opposes the rise of a current when the circuit is first made. Self induction therefore opposes any variation in the current flowing in a circuit, being similar to the property of inertia of matter, which opposes any variation in the motion of a body. MUTUAL INDUCTION (Fie. 6). Now, suppose that two coils are mounted side by side, with their axes coinciding, one being connected to a source of current and the other closed upon itself. If the coils are very large in diameter and relatively flat, approximately the same number of lines passes through both. If now the current in the one coil is stopped, and the magnetic field in conse- quence ceases, both coils are cut by the same magnetic lines, and the same inductive effect is produced in both. The effect in the coil carry- ing the current is, as already explained, called self induction, while that produced by this coil on the other coil is called mutual induction. In the latter case there is a transference of electric energy from one coil to the other without there being any conductive connection between the two. It was stated above that the electromotive force induced in a conductor is proportional to the rate at which lines of force are cut. If the con- ductor is formed into a coil of many turns and is brought into a mag- netic field in which a certain number of lines of force passes through it, every line is cut a number of times equal to the number of turns in the coil. In order, therefore, to produce a high electromotive force by electro-magnetic induction we require, first, a strong magnetic field; second, a coil of many turns; third, means for varying the number of lines of force interlinked with the coil as rapidly as possible. In such an arrangement of two coils in inductive relation to each other, the one which is connected to the source of current is called the primary coil, and the other one the secondary. The combination is called an induction coil, or a transformer. It is used in practice for varying the electromotive force of a circuit. If the primary coil consists of a few turns of heavy wire, and the secondary of numerous turns of fine wire, the electromotive force induced in the secondary upon making or breaking the primary circuit is much greater than the electromotive force of the source of current supplying the primary coil. Of course, not all the lines of force produced by the current in the primary coil pass through the secondary coil, and in order to reduce the leakage as much as possible the coils must be placed close together. To produce the strongest magnetic effect a soft iron core must be placed inside the two coils. FIG. 7. RULE FOR DIRECTION OF INDUCED CURRENTS. From the foregoing it will be seen that an electric current can be produced by mechanically moving a conductor in a magnetic field in such a direction as to cut the lines of force. When a current is thus pro- duced there is a certain resistance to the motion of the conductor. The direction of an electromotive force thus induced may be found from the following rule: Extend the thumb, index finger and middle finger in directions at right angles to each other (see Fig. 7). If the-'index finger indicates the direc- tion of the lines of force and the thumb the direction of motion, then the middle finger will indicate the direction of the induced electromotive force. Elements of the Jump Spark Ignition System. THE SPARK COIL. There are essentially two methods of electric ignition for hydrocarbon motors, viz., jump spark ignition and touch spark, or make and break ignition. In the former system a spark is caused to jump the gap between the ends of two slightly separated fixed electrodes inside the cylinder, insulated from each other, while in the latter system the spark is formed between relatively movable terminals in the cylinder wall, which are first brought in contact for a moment to close the circuit and allow the cur- rent to flow, and then rapidly separated. The former is also known as the high tension system and the latter as the low tension. The high tension system of ignition in its simplest form consists of the following apparatus: A source of current (battery or mechanical generator), an induction coil, operated by the source of current, for producing extremely high pressure electric impulses on the principle of electro-magnetic induction ; an interrupter, or timer, operated by the motor, for actuating the coil at the proper period in the cycle of opera- tion of the motor; a spark plug, which is secured into the combustion chamber wall of the engine, and the electrodes of which are connected to the secondary winding of the coil. The simplest form of spark coil or induction coil, known as a plain coil, is built about as follows : A core is made of soft annealed iron wires (about No. 20 B. & S. gauge) from one-half to three-quarters of an inch in diameter and about 6 inches long. Over this core is slipped a spool of insulating material (hard rubber or composition), on which is wound first the primary winding of the coil, which consists of several layers of about No. 18 B. & S. gauge silk insulated magnet wire. After the primary wire has been all wound on and the ends have been properly brought out through the heads of the spool to be connected to binding posts thereon, a layer of insulating material is applied over the primary wire, and the secondary winding is then wound on. This consists of about No. 36 B. & S. gauge single silk covered magnet wire, the amount used varying considerably with the different manufacturers. When all the wire has been wound on the ends are brought out to binding posts, the coil is soaked in shellac dissolved in alcohol and baked, or in melted paraffin or a paraffin compound, and allowed to cool. It is then placed 13 FIG. 8. DIAGRAM OF INDUCTION COIL. in either a cylindrical hard rubber shell or in a prismatic hardwood box, according to the use to which it is to be put. The proportions of these coils vary greatly. For motor- cycle use they are made long and of small diameter (iox2 l / 2 inches, for instance), while for some other purposes short and thick coils are found more A diagrammatic representation convenient (4x6 inches, for instance), of an induction coil is given in Fig. 8. According to S. P. Thompson it requires about 10,000 volts to jump a gap of one-sixteenth of an inch in the atmosphere. The electrical resistance of an explosive charge under compression is several times as great as -that of the atmosphere, and hence, though the spark plug ter- minals are usually only one thirty-second of an inch apart, the coils are wound to give a spark from one-half to three-quarters of an inch long in the atmosphere. This, according to Thompson's rule, requires from 80,000 to 120,000 volts maximum pressure. With a coil constructed as described above, a jump spark may be produced for demonstrating purposes as follows (Fig. 9) : Connect the ends or leads of the second- ary winding to fixed insula- tors and bend the ends so they are from one-sixteenth to one-eighth inch apart. Connect one end of the pri- mary winding to an electric battery, and with the other lead of the primary winding brush against the other ter- minal of the battery, as in- dicated. When the contact is broken there will be a spark both at the point of rupture in the primary cir- cuit and at the gap. An electric impulse is also in- duced in the secondary circuit when the primary circuit is closed and the current flowing in it gradually rises to its maximum value, but this impulse is too feeble to cause a spark to jump across, the gap. Only the impulse induced in the secondary during the dying out of the current in the primary is utilized. The electromotive force induced in the secondary winding varies substantially as shown in the curve, Fig. 10. While the current in the primary winding rises to a maximum an im- pulse is induced in the secondary winding in the opposite direction to that flowing in the primary circuit, and while the current in the primary de- creases an impulse is induced in the secondary in the same direction as the FIG. 9. ILLUSTRATING EXPERIMENTS WITH INDUCED CURRENTS. THE HORSELESS AGE FIG. 10. CURVES OF IMPULSES AT MAKE AND BREAK OF CIRCUIT. THE HORSELESS ACE FIG. n. CURVE OF OSCILLATING DISCHARGE. primary current. Theory and experiment show that the reverse impulse in the secondary during the break in the primary has about twice the maximum value of the direct impulse during the "make," but lasts only about half as long. The quantity of electricity in other words, the product of the average current by the time is the same for both im- pulses. Under certain conditions of self inductance and capacity in the secondary circuit the dis- charge is of an oscillatory nature; that is, a charge passes through the circuit first in one direction, then in the other, gradually di- minishing in value, as indi- cated in Fig. ii. It does not appear to be known whether the conditions in the average high tension spark circuit are such as to cause such an oscillatory discharge. A coil used as illustrated by the above described ex- periment will only give feeble sparks for its size, for the following reasons : The inductive effect of the primary winding on the secondary depends upon the rate at which the current in the primary winding decreases or dies out. If a strong inductive effect is to be produced in the secondary the current in the primary must stop suddenly. But this is prevented by the self induction of the primary coil, which has a tendency to pre- vent the current from decreasing. The direct result of this is that as the primary circuit is broken a spark appears at the break, which simply means that the current continues to flow after the break has occurred, dying down comparatively slowly, and the inductive effect on the secondary winding is small. The spark at the break in the primary circuit is even larger than that in the secondary circuit, and as this primary spark serves no useful purposes, but, on the contrary, quickly eats or burns away the contact points, such an arrangement is obviously defective. The whole trouble is evidently due to the self inductance of the primary circuit, and the effect of this self inductance must therefore be overcome in some manner. This is accom- plished by means of a condenser. An electric condenser (Fig. 12) is a device which will absorb or hold an electric charge in about the same manner as a jug holds a liquid. Every conductor of elec- tricity forms a condenser, and its capacity for holding charge depends upon its surface. A condenser is therefore made of electrically con- THE HORSELESS AGE FIG. 12. DIAGRAM OF CONDENSER. FIG. 13. CONSTRUCTION OF CONDENSER. ductive material formed into such shape as to present the greatest possible surface for the least amount of material. The usual method of constructing an electric condenser is as follows (Fig. 13) : The conducting material used is tinfoil, of which a large number of sheets are prepared, all cut to the same size. These are placed one on top of the other, with a thin layer of insulating material, usually two sheets of paraffined paper, between. Numbering the successive sheets of tinfoil serially, all sheets of even number are connected together, and all sheets of odd number are connected together, these connections form- ing the terminals of the condenser. The condenser is then connected across the break in the primary circuit. The action of the condenser is as follows: When the circuit is broken and the current begins to die down, an "extra current" is produced by the self induc- tion in the primary circuit, but this extra current, in- stead of forcing its way across the gap, passes into the condenser, charging it, thus avoiding the spark at the break. Of course, the condenser ^^ ^Jft^^^^^^ THE HORSELESS AGE must be of such capacity as to just neutralize the in- ductance of the primary circuit. Capacity is, in fact, an "antidote" for self inductance, and neutralizes all its effects. If the capacity just balances the self inductance, the current in the primary will die down almost instantly, and consequently a high pressure will be induced in the secondary winding. The self inductance that must be . neutralized by the capacity of the condenser is not only that of the primary winding of the coil but that of the whole pri- mary circuit. In the practical use of a coil we require a device which performs the function corre- sponding to the brushing of the primary lead against the battery terminal by hand in the above described experiment ; that is, making and then rap- idly breaking the primary cir- cuit. Such a result may be produced by the use of a timer as shown in Fig. 14, where F is the end of a shaft run by the engine at one-half the speed thereof, E is a cam secured to this shaft, formed with a raised face; B is the support for the pivoted make and FIG. 14. MAGNETO TYPE TIMER. 16 break arm C, and is electrically connected to one side of the electric cir- cuit; H is a platinum-indium contact point adjustably attached to the free end of the pivoted arm C, and I is another platinum-indium contact fastened to the end of an adjusting screw fixed in the insulated support J, which carries the other circuit connection ; K is a spring which tends to hold H and I in contact. With the cam in the position shown in the figure, the electric circuit is closed, the current passing by a wire attached to J, through the contacts I and H, into the pivoted bar C, and thence through a wire to the external circuit. When, however, the shaft turns so that the raised portion of cam E strikes the block carried by the face of pivoted arm C, the latter is moved upon its pivot and the contacts H and I separate abruptly, breaking the circuit through the battery and primary coil and producing a spark at the plug in the secondary circuit. It is here considered that the engine is of the four cycle type and passes through one cycle during two revolutions of the crank shaft or one revolution of the cam shaft F. Hence there will be one spark per cycle, or every two revolutions of the engine, as is required for ignition. The cam E is secured to the shaft in such a manner that the spark occurs just before the beginning of the power stroke, after the charge has been admitted to the cylinder and compressed therein. Provisions are, how- ever, made for allowing the time of ignition to be varied with relation to the engine cycle. The shell L is mounted concentric with the cam E, and is so arranged that it can be rocked one way or the other by means of a link and lever attachment operated by the spark timing lever. It is obvious that by moving the shell and its connected parts in the direction in which the cam rotates the time of ignition is retarded, and by moving it in the opposite direction the time of ignition is advanced. The mechan- ism here shown is protected by an aluminum cover, held to the base plate by thumb nuts. The timer here shown serves well as an illustration, but is not the type commonly used in battery ignition, as it holds the electric circuit closed so long as to be very wasteful of batteries. It is, how- ever, the form used in connection with the high ten- sion magneto, and will be referred to again under that head. THE SPARK PLUG. Another element in the make-up of a simple jump spark system is the spark plug. A typical form of plug is shown herewith (Fig. 15). It consists of a central rod A, which is clamped into a porcelain insu- lator B, which, in turn is clamped into a metal housing in two parts, C D. Asbestos gaskets^ or washers are interposed between the metal and p'orcelain to pre- vent cracking of the latter, due to unequal heat expan- sion of the two materials, and also to give a gas- tight joint. The outer shell C is provided with a screw thread, and screws into the wall of the combustion chamber. The rod A and the shell C carry at their FIG. 15. TYPI- inner ends short lengths of platinum or nickel alloy CAL SPARK wire, which are bent toward each other and come to PLUG. within a distance of one thirty-second of an inch of each other. The central terminal A is provided at its outer end with a binding screw E. The simple jump spark system here referred to is completed by an electric switch, which admits of opening and closing the circuit at will. The various parts comprising the ignition outfit are now connected together electrically, as shown in the diagram (Fig. 16). It will be noticed that the current from the battery flows through the primary of the coil, from which it is led by a wire to the timer, and from the timer it returns through the switch to the battery. One terminal of the secondary winding of the coil is connected to the spark plug, and the other is grounded, and as the outer shell of the spark plug is in contact with the mass of the engine, and therefore grounded, the secondary circuit is complete except for the one thirty-second inch gap at the spark plug terminals. FIG. 16. DIAGRAM OF SINGLE CYLINDER JUMP SPARK CONNECTIONS. The action of the outfit may now be easily understood. Every time the timer suddenly breaks the circuit an electrical impulse is sent through the primary of the coil, and a high tension electric impulse is thereby induced in the secondary winding of the coil, which impulse causes a spark to jump at the spark plug terminals. Instead of producing the spark by the abrupt breaking of the circuit by the mechanical action of the timer in the manner similar to that just described, spark coils intended for ordinary battery ignition are now usually fitted with magnetic vibrators. This device acts to break and make the primary circuit with great rapidity so long as the timer keeps the circuit closed and produces a spark at each break. Fig. 17 illustrates a simple form of this device fitted to an ordinary boxed coil. One end of the primary winding is connected to the binding post P 2 on the end of the case, and the other leads to a metal block B secured to the end of the case. To this metal block is screwed a flat steel spring C, having riveted to its outer end a small cylindrical block of soft iron D, called the armature. This armature D is located exactly opposite the end of the soft iron wire core A, and is normally held at a little distance from the core by the 18 steel spring C. The steel spring C is spanned by a brass yoke E secured to the end of the coil box by means of screws. This yoke is drilled and tapped at its centre to receive the contact screw F, which can be adjusted in it and locked in adjustment by the check nut Fi. The two platinum tipped contact points are normally pressed together by the spring C. The yoke E is connected to the primary binding post Pi by a wire. Now suppose a battery to be connected to the two posts Pi- and P 2 . The positive or carbon terminal of the battery may be considered to be connected to Pi, in which case the current will enter at this terminal. As indicated by arrows, it will flow through the wire connection to the yoke E, through the contact screw F, across the contact at the points to the contact spring C, to the metal block B, through the primary winding of the coil to the binding post P 2 , and from there back to the battery. As soon as the current begins to flow through the primary winding of the coil it magnetizes the soft iron wire core A, and the latter attracts the armature D and the outer end of the spring C, thereby drawing the contact point on the spring away from the point of the contact screw F, and interrupting the primary circuit. The flow of current through the FIG, 17. MAGNETIC VIBRATOR. primary winding is thereby stopped, and an electric impulse induced in the secondary winding, and if the terminals of the latter are sufficiently close together a spark will jump across the gap. As soon as the current in the primary winding ceases the core A loses its magnetism, and the armature D and spring C are returned to their original positions by the spring force of C, and contact is estab- lished again between the platinum point on the spring C and the point of the contact screw F. The current then flows again through the primary winding, the armature D is again attracted, and the circuit broken at the contact points, which gives another spark in the secondary. This process, or cycle, requires only an extremely short time, less than the one-hundredth part of a second, and is repeated indefinitely as long as the source of current is connected to the primary binding posts Pi and P 2 . The rapidity of the break and of the vibration of the spring C can be varied by adjusting the contact screw F. 19 THE HORSELESS AGE FIG. 18. DIAGRAM OF COIL WITH VIBRATOR AND CONDENSER. By varying the adjustment of the contact screw, not only is the num- ber of sparks in a given time varied, but also the strength of the indi- vidual sparks. Suppose, for instance, that the contact screw F is screwed so far out that the spring C merely bears against the point of the contact screw when at rest. Only the slightest force is then required to draw it away from the point of the screw, and the circuit is broken as soon as the current begins to flow in the primary and long be- fore it reaches its maximum value. But if the current in the primary winding only attains to a small value, the inductive effect in the secondary can only be small, and only a small spark is produced. Owing to the self induction of the primary winding of the coil a con- denser must be connected across the vibrator, as shown in Fig. 18, to prevent abnormal sparking at the vibrator contact points. This condenser is sometimes placed in the bottom of the coil box, as here shown, some- times wrapped around the coil, as it were, and sometimes put up in a special box, the idea in the latter case being to facilitate repairs to either the coil or the condenser. ADJUSTMENT OF COIL VIBRATORS. Unless the vibrator of a coil is adjusted properly unsatisfactory opera- tion of the engine is likely to result. If it is so adjusted that it allows an unnecessarily large current to pass, the batteries which operate it will be exhausted prematurely and the platinum-iridium points will rapidly be worn away, becoming so rough as to fail to make a good contact, when the spark will become irregular and the engine begin to miss explosions. Most coil manufacturers furnish instructions as to the cur- rent strength which their coils should pass in order to secure reliable sparks with low compression and high compression engines, respectively, and if a certain fraction of an ampere is recommended for use with a certain coil, the best procedure is to connect in circuit with the coil a low reading ammeter and adjust the current to the required value. Most modern vibrators are n'ow fitted with a single screw adjustment, the turning of which so as to bring greater pressure between the vibrator contacts increases the current taken, and vice versa; The correct adjust- ment is to be found by varying the set of this screw. In the absence of an ammeter a fair adjustment may be made by starting the engine and slowly reducing the pressure between the contacts of the vibrator by means of the screw until ignition begins to become irregular, and then turning the adjusting screw slightly in the opposite direction until reliable firing has recommenced. As the vibrator points wear away slightly in ordinary use, it occasionally becomes necessary to adjust them a very little closer upon any sign of missing on the part 20 of the engine which is attributable to the ignition. After extended use the contact points are likely to become burned into a rough form and require to be smoothed. For this purpose a piece of emery cloth or a small abrasive stone specially prepared for this service is preferable. The direction of the current through the vibrator should always be from the screw or stationary contact to the vibrating contact, rather than in the opposite direction, so that the point of the screw, which is the more readily replaceable part, may be the portion to suffer the more wear. The Spark Plug. (ALBERT L. CLOUGH.) The very widespread adoption of the jump spark method to the igni- tion of automobile motors has raised the spark plug to a position of great importance and consideration in the automobile world and has led to the expenditure of a vast amount of time and thought upon the per- fection of this small but supremely important adjunct of motor car operation. PRINCIPAL PARTS. In its essential features, the jump spark plug is a device of extreme simplicity,, consisting of but three necessary parts, namely: A metal shell capable of insertion into the combustion chamber of the motor, a hollow bushing of insulating material adapted to fit the metal shell in- ternally, and a metal spindle adapted to fit the hole in the insulating bushing and provided with a discharge terminal upon its inside end and means for clamping the lead wire upon its other extremity. These three portions, together with accessory parts designed to fasten the construc- tion together and to render it gas tight, form all the constituent parts of any jump spark plug, but the variations in material employed, in the form and arrangement of the parts and in the method of manufacture afford an almost endless variety and furnish an interesting study to one who cares for automobile details. CONSTRUCTION OF METAL PARTS. The construction of the outer shell and of the inner spindle is not a matter of particular interest or moment, the shell being manufactured of iron along practically the same lines as ordinary pipe fittings are pro- duced, while the spindle or electrically alive portion is usually of brass or steel rod bearing the live discharge terminal on one end and a thread for the connecting screw on the other. It is, however, upon the material and form of the insulating bushing that the ingenuity of the spark plug designer is mostly lavished. Upon the integrity as a non-conductor of the insulating bushing abso- lutely depends the operation of the plug, and a minute crack in the material of the bushing is sufficient to allow an escape of the current through it, instead of between the sparking points, and to cause a cessation of the ignition. CAUSES OF INSULATION FAILURE. Failure of the insulation usually takes place from one of the three following causes: The insulation becomes covered with a conducting coating which allows the current to escape quietly over the surface of the bushing from the spindle to the shell. The bushing may break, allowing the current to discharge through the crack, or the insulation may become impregnated with conducting matter, rendering it of doubt- ful quality as a dielectric and allowing of an escape of current through the material of the bushing. A great deal of effort has been expended in attempts to minimize the liability of one of these accidents happening. Breakage of the bush- ing seems to occur either from some mechanical shock or from internal stresses occasioned by a difference of temperature existing between dif- ferent parts of the insulating tube the inner end, in the combustion chamber, being very hot and the outer end, in the open air, being com- paratively cool. The more brittle the insulating material may be, the more danger there is of the insulation becoming cracked. Porcelai" is particularly prone to failure by cracking, although the best quality, which is especially employed for spark plug bushings, is exceedingly fine grained, hard and mechanically resistant. In order to minimize the danger of cracking from unequal heating, the bushing is sometimes made sectional, so that the portions inside and outside of the cylinders may expand independently. In order that plugs which make use of porcelain insulation may be capable of being repaired after the porcelain is cracked, they are generally arranged so as to be readily refitted with new bushings. Spark plug bushings built up of mica are from the nature of the material quite free from the liability of becoming cracked from blows or from unequal expansion by heat. SOOTING OF INSULATOR SURFACE. Prevention of the failure of spark plugs due to a conducting surface being formed over the insulating material has proved a problem of great importance and difficulty. If an explosive mixture is employed in the cylinders which contains an excess of gasoline vapor, there must neces- sarily be some gasoline each stroke which is not perfectly consumed. The result of the imperfect combustion of a hydrocarbon is the freeing of carbon in the form of lampblack, and some of this rrtinutely divided and conducting material deposits upon the insulating surfaces and allows of the passage of a "sneak" current, which prevents the disruptive dis- charge at the plug terminals. Then, too, if an excess of lubricating oil is employed in the cylinder, some of it is sure to splash upon the end of the spark plug, and as the temperature of the plug is likely to be higher than the decomposing point of the lubricant, a carbon deposit will result. The extreme heat to which the spark plug end is exposed is likely to ultimately deteriorate the end surface of the insulation. Porcelain loses its glaze after considerable service and presents a rough surface, generally of a slightly pinkish or yellowish hue. This unglazed surface seems to catch the carbon deposit more readily and is not easily cleaned. PREVENTION OF SOOTING. Many expedients are in vogue intended to prevent this carbon deposit or to minimize its effect, and it seems rather strange that so much effort is directed toward this end when it is perfectly practicable to remove the cause of sooting, and far more effective than treating the symptom after it has manifested itself. A perfect mixture will not deposit a particle of soot upon any kind of spark plug, and a plug may be run almost indefinitely without fouling in a cylinder having a proper quality of gas and judicious lubrication. If one-half the attention which is paid to the manufacture and use of non-sooting plugs were expended upon car- buretor adjustments and oil feeds, a better condition would probably be the result. Of course, if a bad mixture has to be used, sootprool plugs are valuable in so far as they deserve this designation, but "remov- ing the cause" is the only truly logical course under such circumstances. THEORY OF ANTI-SOOTING PLUGS. The methods by which the insulation of plugs is claimed to be pre- vented from fouling are based upon theories, some of which are very difficult of demonstration and are regarded with more or less skepticism by those who have given thought to the matter. The most common con- struction designed to effect this end is the use of a cavity between the outer shell and the inner spindle; that is, the bushing is arranged so as not nearly to fill this space, which may extend quite deeply into the sparking end of the plug. The live terminal is ar- ranged at the mouth of this cavity and may be a point brought into juxtaposition with the outside shell, or it may be a circular plate, nearly filling the mouth of this chamber (Fig. 19). The insulating bushing is gen- erally not brought out flush with the sparking terminals, and is thus protected to a certain extent from splashing oil. It is claimed that during the compression stroke a small portion of the working charge is forced into the cavity above described, and that when the spark is produced this part of the mixture is first ignited and expands, rushing out of the enclosed space so violently as to preclude the possibility of any carbon deposit taking place. Another theory of the protected ter- minal or explosion chamber plug is that the gases which are in the base of the cavity of the plug very seldom change, are practically inert and non-explosive, while the gas at the tip of the plug is fresh and easily ignited, and, as the dead gas which envelops the end of the insulating bushing, at the bottom of the cavity, does not burn, it can deposit no carbon, and thus the end of the bushing remains clean. Until we know more about the behavior of the gases inside an internal combustion motor we may not be in a position to state with assurance just how the so called non-sooting plug performs its function, but it is hardly to be doubted that there is some advantage in a plug having a free space between the shell and the spindle with the insulation some- what withdrawn into this chamber. MINIMIZING SURFACE LEAKAGE. The leakage effect due to sooting is reduced in many forms of plugs, by the expedient of increasing the superficial extent of the insulating material which intervenes between the shell and spindle. This forces the leakage current to travel over a greater length of carbon film, and materially reduces the loss of energy due to this cause. By forming FIG. 19. SPARK PLUG WITH AN- NULAR GAP. the end of the insulation with deep corrugations concentric with the spindle, the sneak current is constrained to follow a circuitous path and is much reduced. Many plugs now manufactured seem to embody in the form of the bushing end the idea of increasing the path of escape of the sneak current. Plugs used to be constructed with the bushing end perfectly flat and interposing the minimum superficial distance between the shell and the spindle, but one sees very little of this construction at present. Spark plug bushings sometimes fail in their insulating properties through becoming impregnated with carbon containing material. When this occurs the bushing becomes unreliable electrically and sometimes the defect is very difficult to locate. Porcelain, so long as it retains its glaze, is practically free from this absorbent quality, the deposit upon it being entirely superficial and easily wiped off. Lava, which is an unglazed stone, is somewhat absorbent, although not seriously so. MICA INSULATION. The mica bushings which are used for spark plug insulation are gen- erally built up of washers cut out of sheet mica and assembled upon the spindle, which generally has previously been given a wrapping of sheet mica. As it is not considered good practice to use a cement for the purpose of binding these washers together to form the bushing, the pressure produced by the parts of the plug themselves is relied upon to consolidate the mica sheets into a solid body (Fig. 20). It is claimed, how- ever, by those who are averse to the use of this material, that oil works in between the laminae of the mica and is carbonized by the heat; also that the carbon deposit from a bad mixture is not entirely superficial and cannot be completely wiped off. They claim that the electrical defects which develop in mica bushings are insidious and difficult of detection, while those arising in the use of porcelain are obvious, and readily located. GASTIGHT JOINTS. The joint between the shell and the porcelain bush- ing is generally made gas tight by means of a copper- asbestos washer, which is forced between an external shoulder on the bushing and an engaging internal one on the shell. When a mica bushing is used for insula- tion, it may be formed on a taper and the shell may be formed in a corresponding conical shape internally so that the two parts make a perfect joint when forced together. The joint between the spindle and the bushing is sometimes sealed with cement. SPARK TERMINALS. As the discharge terminals of spark plugs are subjected to a high degree of heat, they are generally made of some alloy of platinum, although silver, german silver and some special cheap alloys are made use of. The material used is probably a far less important consideration than is gen- erally believed. About the only requirements are that the points shall FIG. 20. MICA INSULATED SPARK PLUG. 24 be of material which shall not oxidize or fuse away too rapidly, and that they shall be of ample strength mechanically so as not to be disarranged as regards their sparking distance when the plug is being screwed in place. If the discharge points are too fine or sharp, there may be some diminution of the disruptive character of the spark, due to a brush discharge. In cleaning a plug, the insulating surfaces separating the spark points should be gone over with a small stiff brush moistened in gasoline. The very hot discharges produced by modern magnetos call for the employment of special plugs having extra heavy sparking terminals which resist the melting action of the very energetic spark or arc which is pro- duced. The length of the spark gap allowed in these plugs is less than that used in battery plugs, being not far from one sixty-fourth inch as a rule. CONTACT SPARK PLUGS. In the contact spark system the entire igniter, comprising both the stationary insulated contact and the moving, grounded portion, is usually adapted to fasten to and cover, by means of a ground jointed, bolted flange, an aperture upon the side of the combustion chamber, the con- tacts of the igniter projecting inwardly into the combustion space. The Timer. In every high tension ignition system there is required a device for closing and opening the primary circuit at the proper instant, with respect to the cycle of the engine, this device being called the timer, and has previously been briefly referred to. The timer determines the exact point or period in the cycle of the engine at which ignition occurs, and permits of varying this point at will while the engine is in operation. Every timer consists of a stationary part and a rotary part, the latter being driven from the engine at one-half the engine speed in the case of a four cycle, and at full engine speed in the case of a two cycle motor. One of the parts is provided with contact blocks, or segments, equal in number to the cylinders of the motor, while the other part is provided with a single contact brush or arm adapted to pass over and make contact with all the contact blocks in one revolu- tion of the device. The principle of the timer may probably be best illustrated by the sketch Fig. 21, which shows a brush contact timer for a single cylinder engine. In this figure A is the motor cam shaft (or a separate shaft which is driven at the same speed), to which is fixed a disc B of insulating material, having a metallic segment C embedded in its circumference, the -^^ _^"THE HORSELESS AQE segment being electrically connected to the shaft A by the screw holding FIG. 21. SIMPLE TIMER. it in place. Against the surface of the disc B bears a wire gauze or similar brush D in a brushholder E clamped in the circular housing F of the tinier, this housing being made of insulating material. To the brush- holder E may be fastened an electric connecting lead as shown. It will be readily understood that when the segment C passes under the brush D there is connection from the brushholder E to the cam shaft A, which shaft is, of course, in metallic connection with the engine structure and therefore grounded. The arrangement of the parts may, of course, be THE HORSELES6 AGE FIG. 22. PRIMARY CIRCUIT CONNECTIONS. reversed ; that is, the segment may be carried by the annular housing and the brush in a holder on the shaft. The primary circuit of the ignition outfit is now made up as follows (Fig. 22) : One of the primary binding posts P of the coil is grounded (as indicated at G) and the other is connected through a small switch B to the battery, from the other terminal of which a wire is led to the timer. The whole primary circuit can now be easily traced. So long as the brushholder is stationary contact always begins and ends with the cam shaft in certain definite positions, which positions, of course, corre- spond to definite periods or points in the cycle of the en- gine.- In order to allow of varying these points the hous- ing of the timer is mounted so it can be rocked around its axis, and provided with a lug from which a linkage connects to a small lever convenient to the operator, usually on the FIG. 23. DIAGRAM SHOWING PRINCIPLE OF SPARK TIMER. will be readily seen that when the timer housing is moved in the same direction as the rotary part of the timer rotates the spark is retarded, as then the rotary part must move farther before contact is established and broken, while if the housing is rocked in the direction opposite to the motion of the rotating part the spark occurs earlier or is advanced. TIME OF CONTACT. The time during which the circuit remains closed depends upon the angular width of the contact segment, upon the speed of revolution of the motor, and to some extent upon the shape of the contact brush. As the consumption of electric energy is directly proportional to the time of contact, the segment should be as narrow as possible. The minimum width is determined by the rate of vibration of the coil vibrator and by the maximum running speed of the motor. In timers made for the market the segment is sometimes made as wide as one-eighth the circumference. Among important detail improvements in timers is the provision of ball bearings for carrying the timer housing upon the driving shaft, whereby the necessity of frequent lubrication is obviated" as well as the tendency of the timer to become "wobbly," through wear of its bearings, which is the most frequent cause of irregular operation. Another important improvement consists in the provision of sliding connections with the contact terminals, thus obviating the bending of the wire connection every time the timer is advanced or retarded, which is a frequent cause of breaking of these connections. As shown in Fig. 24, the ar- rangement consists in mount- ing metallic contact sectors on a board back of the timer (the dashboard, for instance) of such angular extent as to cover the terminal in any point of its range of advancing and retarding motion. The contact terminals are fitted with spring pressed ball or cylinder con- tacts, which bear against the inner surface of the segments. The timer may, of course, be FlG 24 ._TiMER WITHOUT MOVING WIRES. located in any position to which it is convenient to establish driving connection from the motor and electric connection -from the coils. In modern four cylinder cars the pre- ferred location is at the top of a vertical shaft, driven from the cam shaft at or near the rear of the motor. The front of the timer is usually protected by a cover, frequently of aluminum, which is readily detachable, but provided against accidental loosening. Fig. 25 represents a type of timer which is in very general use, and which possesses the advantage of wearing very slowly in use. It con- sists of the fibre shell A, which is mounted upon a bearing running upon the timer shaft K. The collar C keyed to shaft K is fitted with a pro- FIG. 25. ROLLER CONTACT TIMER. j action in which pivots the arm E, and it also carries another projection L, to which is attached one end of the spiral spring H, the other end of which is attached to the long arm of lever E, and acts to press its other end, which carries a pivoted roller G, against the inside periphery of the timer shell A. The steel contact B, which is electrically connected to the binding post F, is set into the inside periphery of the timer shell, flush with its surface. D is a lug to which the ignition timing linkage is attached. As shown in the figure, the steel roller G is rolling over the fibre surface of the timer shell and no contact is made, but when, through the rotation of shaft K, the roller reaches B, the contact is established, the coil acts and a spark is pro- duced. As here shown, the arrangement is that for a single cylinder engine, but to adapt the timer for use with multicylinder engines con- tacts and binding posts identical with B and F are provided equal in number to the cylinders of the motor and equally spaced about the in- ternal periphery of the shell, so that the roller may contact with them at equal angular periods. As the action of the .roller upon the inside face of the timer case is of a rolling nature, there is very little likelihood of the parts rapidly becoming worn. THE CARE OF TIMERS. The inside of the timer should be kept perfectly clean, and should be lightly lubricated with good oil. (Some recommend packing the timer case with grease.) If the track upon which the brush, roller or other moving part runs becomes irregular through use, it should be trued up in a lathe. The wires should be kept tight in their binding posts, and should be examined for breakage. Good results need not be expected from a timer the shell of which is loose and "wobbly" upon its shaft. SECONDARY COMMUTATORS OR DISTRIBUTORS. Up to this point we have been dealing with systems in which the primary circuit is alone interrupted, and which require a separate coil for each cylinder of the engine. In the distributor the secondary current is also commutated and only one induction coil is used for the whole engine. A primary timer forms a part of the device and makes and breaks the circuit of the coil primary as many times in each two revolu- tions as the motor has cylinders. Upon the same shaft carrying the primary timer is the distributing device for the secondary current, so designed that when a contact is made in the primary circuit the induced secondary current is conducted to the proper cylinder. The advantages of this system over the more common method of employing separate coils for each cylinder are twofold. As there is only one set of wearing parts, whatever wear occurs will affect the timing of all cylinders equally, and consequently a perfect relationship is maintained at all times. Again, the character of the spark in all the cylinders must be identical. This system has come into rather extensive use of late, and will be further described under the head of "Ignition Connections.'" The Dry Cell Battery. (JULIAN C. CHASE.) The source of the ignition current used in many one and two cylinder cars, and indeed upon some four cylinder machines, is the dry cell. The principles upon which this useful agent depends were discovered years ago, and for some considerable time nothing radically new has been applied to its construction. Nevertheless, the best dry cell of today is, in points of capacity per pound of weight and longevity, greatly superior to the best dry cell of five years ago. This result has, in no small measure, been brought about by the demand of the automobile designer for a source of electrical energy which shall be at once compact, light, reliable and durable. ESSENTIAL PARTS. In general, the dry cell consists of three principal parts, viz., a zinc element, a carbon element, and an exciting fluid or electrolyte; and two secondary parts, viz., a chemical depolarizer and an agent for holding the electrolyte, by being saturated with it. In order to have a flow of electric current it is necessary to have what is known as a difference of potential, which, to use a classical comparison, corresponds to a difference in height of two bodies of water or two parts of a body of water. The strength of flow of the electric current depends upon the amount of this difference of potential, just as the strength of the natural flow of water between two points depends upon the difference in height between these points. Zinc, as such, has a given potential or electrical height when placed in an acid bath, as have also carbon and all of the other elements. When the two elements mentioned are placed together in an acid bath the potential of carbon is found to be greater than that of zinc, and if the solution be that which is most commonly used, this difference, when measured electrically, is found to amount to approximately 1.5, volts. As the cell itself must form a part of the circuit through which it delivers a flow of current, and as the amount of current which passes through a given circuit at a given voltage or pressure is dependent directly upon the resistance in that circuit, it is evident that the larger the cell, and consequently the lower its internal resistance, the greater will be the amount of current which flows through the circuit. (It is assumed, for purposes of illustration, that the external resistance in the circuit is lower than the internal resistance of the cell.) Further, the larger the cell the greater the amount of the material present capable of yielding electrical energy, and, at a fixed rate of consumption, thfc longer the period of time required to exhaust it. COMPOSITION OF ELECTROLYTE. The exact composition of the electrolytes used in the dry cells of today is in most cases known only to the manufacturer of the cell. They all, however, contain a large percentage of chloride of ammonia, or sal am- moniac, as it is commonly called, as their principal part. Good results have been obtained by the addition of certain other chemicals which tend to stimulate the electro-chemical action and to alter the character of the surface of the zinc so that it becomes less prone to local action caused by inequalities in the metal, which, through a slight difference of poten- tial, cause local currents to flow from one part to another of the element, and in a measure destroy the electromotive force of the cell. It was soon found that when nothing more than the two elements and an electrolyte was employed, the current produced in the wire would at once become lessened, and soon disappear entirely. This condition of affairs is explained by the fact that during the electro-chemical action a large quantity of hydrogen is generated at the carbon element. This clings to the carbon and, as it is a bad conductor of electricity, cuts off to a large extent the flow of current through the cell, and also sets up a local action within the element itself. Polarization is the name given to this destructive action, and many means, both mechanical and chemical, have been employed to overcome it. It is now customary to introduce into the construction of the cell a chemical depolarizer giving off oxygen. The oxygen so produced combines with the hydro- gen as it is generated, and overcomes its de- structive effect. CONSTRUCTION OF CELL. Fig. 26 shows a sectional view of a dry cell of the type used most commonly for ignition pur- poses in automobiles. The letter Z in this sketch denotes the zinc element of the cell, which in this case also forms the container or cup enclos- ing the whole cell. This is the first part made in the process of manufacture of the cell, and is nothing more or less than a can of chemically pure sheet zinc with soldered joints. Next within this can, and in contact with it to the greatest possible extent, is the material which holds by saturation the exciting fluid or electrolyte (A). It may be a lining of blotting paper, straw board, a paste, or, in fact, any material or composition capable of holding the exciting liquid as a sponge holds water. It is essential, of course, that it be not affected mechanically or chemically by the solution which it holds or by either of the elements of the cell. Its office is of a purely mechanical character, in that it merely provides a means of holding the solution and of preventing it from spilling or leaking. The carbon element C'is placed in the centre of the cell, and between it and the absorbent lining is packed tightly a granulated or partly pow- dered composition M made up of carbon flour and black oxide of manga- nese, saturated with the exciting fluid, the oxide of manganese being present as the chemical depolarizer. A sealing compound is then poured THE HORSELESS ACE. FIG. 26. SECTION THROUGH DRY CELL. over the top of the cell to hold it together and to prevent the moisture within from evaporating. The carbon element may be of any of a number of different forms, but there are certain shapes which for one reason or another are most desirable. Fig. 27 shows the THE HORSELESS AC ,O 3 FIG. 27. TYPES OF DRY CELL CARBONS. three forms in most common use. Each has points of su- periority when all things, in- cluding cost, are considered. INTERNAL RESISTANCE. When we consider that the cell itself forms a part of the circuit through which it must force an electrical current, it is evident that a good electrical contact be- tween the various parts of the cell is as essential as good contacts in the exter- nal circuits. It is desirable therefore to have on the car- bon plug or pencil as large a contact surface as possible, and to have this surface of such shape that the vibra- tions and shocks to which the cell is subjected will not tend to loosen the carbon element from the surrounding compound. In order to insure the longest possible life for a cell, it is, of course, necessary to place it in a position on the car where it will be subjected to the least amount of vibration and jar. Evidently this point is not appreciated by a large number of automobile designers. It is also evident that the cell should not be placed where there is any considerable amount of heat, as in that case evaporation will be increased and the moisture within the cell will gradually disappear, with the result that the strength of current given off will accordingly diminish. SHORT CIRCUITS. The effect of a short circuit, so called, or, in other words, a discharge of the cells through a very low resistance, as by placing a piece of metal across their terminals, is to induce polarization at a very rapid rate, and to generate hydrogen so fast that the proper amount of oxygen is not obtainable to assimilate it. Great care should therefore be taken that this short circuiting does not occur, as a cell is never so good afterward, be the length of time during which it is short circuited ever so short. The ordinary automobile battery is usually made up of from four to six cells, having the zinc of one cell connected to the carbon of the next one to it. The effect of this method of connecting is to build up the voltage or pressure, and consequently to require a smaller amount of cur- rent to do the same amount of work. SERIES AND MULTIPLE CONNECTION. In order to explain why, when several cells are connected together in this manner, a greater pressure is obtained, we may refer to Fig. 28 here- with, and to a fact previously mentioned. It has been stated that zinc and carbon when placed in an acid bath show a difference of potential equal to 1.5 volts, the potential of carbon being the higher. There is caused, therefore, by each cell a drop, as it were, of a given length. Referring to the diagram, Fig. 28, it may be considered that the cur- rent starting at d (the carbon of the first cell) drops in cell i to Zi (the THE HORSELESS ACE FIG. 28. POTENTIAL DIAGRAM. CELLS IN SERIES CONNECTION. zinc of the first cell, which is on the same level with C, to which it is directly connected by a short wire. In cell 2 another drop occurs, from C 2 to Z 2 , which is equal to the drop in cell i. In this way, it will be seen, the total drop through which the current passes and the pressure result- ing from this drop is equal to the drop caused by one cell multiplied by the number of cells. When cells are connected in this manner they are said to be "in series." It can also be seen that if the carbon of cell I is connected with the carbons of all the other cells, and the zinc to the zincs of the other cells (Fig. 29), the total drop will be equal to that of only one cell. The effect, however, will be to prac- tically make one cell four times as l ar S e as eac h f tne f ur so connected. From this method of connecting the cells, which is termed "multiple," increased amperage capacity is obtained and consequently a longer life for a given current output. c c c THE HORSELESS AGE FIG. 29. CELLS IN MULTIPLE CONNECTIONS. Cells connected as in Fig. 30 are said to be arranged in multiple series. The voltage of the combination shown is that of six cells and the amper- age that of two cells. This method of grouping cells is often resorted to when the current output of a single set of cells becomes less than required. When con- nected as shown each set of six cells is called upon for but one-half of the total cur- rent demanded. There seems to be a gen- eral belief that a dry cell, like a storage battery, is charged with so many ampere-hours, and that the amperage read- c c C TH HOR C sdESS AG c f ing of the cell will indicate what this capacity is. In FIG. 30. CELLS IN MULTIPLE SERIES other words, if a cell regis- CONNECTION. ters 15 amperes on an am- meter, that this fact shows that within that cell is a given amount of current which can be taken as required. This belief is erroneous. Prac- tically the only thing indicated by an amperage reading is the internal resistance of that cell at that particular instant. In no way is length of life of the cell disclosed. By reducing the amount of depolarizer and increasing the amount of carbon flour, the initial amperage of a cell can be increased, but the length of life is thereby decreased, as polarization will set in so much sooner. It is well known to battery makers that the introduction of cer- tain other substances, such as graphite, into the cell will increase the initial amperage, but the length of life is thereby shortened. Experience has shown that an increase of initial amperage beyond a certain limit is not desirable, as it indicates an improper proportion of the ingredients. A cell of th standard dimensions (6 inches x 2*4 inches) which registers from 15 to 22 amperes is apt to be better than one which registers over 22 amperes. CAPACITY AND DISCHARGE RATE. The efficiency, as it may be called, or the total amount of electrical energy obtainable from a cell per pound of its total weight is, roughly speaking, inversely proportional to the rate of current consumption. It is desirable, therefore, in order to obtain the longest life, to so adjust the external circuit that the least possible amount of current be consumed in obtaining the desired results. Periods of rest are also beneficial, con- sequently when possible two sets of cells should be used, with a combina- tion switch so that either of these may be thrown into circuit, or both together in a series-multiple arrangement. In order to obtain the best results from the use of dry cells it has been found that series-multiple arrangements should be used. It has been demonstrated, for instance, that four sets of four cells each, con- nected in multiple to make a battery of sixteen cells, will give much more extended service than will the same total number of cells used in suc- cessive batteries of four cells each in series. Some estimates indicate 33 that over double the service is obtainable from the sixteen cells used as one battery than from the use of this number of cells four cells at a time. Multiples of two and three sets of four cells also show decided advantages in economy over the use of a single series. For one and two cylinder engines the smaller number of multiples may be advisable, and for four cylinder motors multiples of four are preferred. These series-multiple combinations may be obtained put up in so called wireless battery boxes, the connections being made by automatic contacts in a very secure and convenient manner. The Storage Battery or Accumulator. (E. B. FAVARY.) On account of its constancy of voltage, large current output and capa- bility of being recharged when exhausted, the storage battery is very generally supplanting the dry cell as a source of ignition current wher- ever battery current is regularly used. The treatment here presented refers not only to accumulators used for ignition purposes, but also to those employed in the propulsion of electric vehicles and in the lighting of vehicle lamps. In order to thoroughly understand the treatment and repair of accumu- lators, or storage batteries, it is first necessary to know what a storage battery is and its behavior during operation. The ordinary storage battery consists of two sets of lead plates one positive, the other negative immersed in dilute sulphuric acid. The posi- tive contains peroxide of lead (PbOa), the negative spongy lead (Pb). The plates can be easily distinguished by their color, the positive being chocolate brown and the negative light gray. There are two different types of storage batteries on the market, the Plante type and the Faure type. In the Plante system the peroxide and the spongy lead, called the active material, are produced upon and out of the lead plates themselves by electrical and chemical processes. The Faure electrode often called the pasted plate type, and now much less used than formerly consists of a cast metallic grid composed of antimonious lead, to which the active material in the form of lead oxide is applied mechanically. The plates are inserted side by side in a vessel containing dilute sul- phuric acid, and are connected to the positive and negative poles of a dynamo, or some other convenient source of electricity. On the passage of current the plates joined to the positive pole are converted into peroxide of lead; those joined to the negative are reduced to pure spongy lead. The advantage of the Plante system is that the plates are more durable, and that the active material is not so liable to "shed" or drop away from the plates, while the advantage of the Faure system consists in the greater capacity per unit of weight. When charging the battery, i. e., when a current from the dynamo is passed through the battery, the voltage of the latter gradually rises until a maximum is reached. When discharging, the voltage gradually dimin- ishes until it attains a minimum value. Fig. 31 shows the charge and the 34 discharge curves of a cell, and it can be seen that they consist of three parts. On charge the voltage rises quickly at first; then it stays nearly constant at about 2.27 to 2.32 volts, and the third part represents the end of charge, when the voltage rises rapidly to about 2.6 or more. On discharge the voltage drops rapidly to about 2 volts ; then it remains reasonably constant until the battery is nearing exhaustion, when it will commence to fall rapidly to about 1.8 volts, and if the discharge is not stopped at this point it will very rapidly sink to zero. This rapid fall in voltage at the end of discharge is chiefly due to the formation of sulphate on the surface of the plates, which prevents the electrolyte from entering into the pores of the active material, and thereby causing the electrolyte enclosed in the pores to turn to water as the SOj is abstracted from the sulphuric acid. On charge, when the voltage attains about 2.3 volts, the evolution of gas commences ; when 2.5 volts is reached the battery is usually fully 2.6 2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 / j ^ __ Cha ge - ' ^* - - "^ / V DlscK, *ge - -^ N \ \ THE H ORSELE S *QE 1 2 3 * 5 e 78 Hours. FIG. 31. CHARGE AND DISCHARGE CURVES. charged, and the charging should be stopped. The voltage, however, does not always indicate the state of charge. A cell may show 2.5 volts on charge, and yet quickly drop in voltage to 1.8 on discharge, owing to a loss in capacity; however, this will be described later under "Diseases and Remedies." When the charging circuit is broken the voltage first drops rapidly and then gradually to about 2.12 the exact value depending on the tem- perature and the acid density. On the commencement of discharge the voltage drops still further, and rather rapidly to about 2.05, and then gradually within a short time to about 2 volts. Here it will stay approxi- mately constant, dropping only very slowly until it reaches about 1.9 volts, after which the rapid decrease commences. 35 If the discharge is carried too far, or if the battery is kept standing discharged, the plates will be covered with a certain amount of lead sul- phate. The presence of lead sulphate on the plates is the most common disease of storage batteries. It is brought on by a number of causes which will be mentioned later. Lead sulphate is white in color, and has a very high resistance, and if the elements or plates be covered entirely with it as would happen if the battery should be discharged to zero, and left standing in this condition they would become worthless, for it is almost impossible to reduce pure lead sulphate to spongy lead or peroxide of lead. Therefore a battery should not be discharged below a point which permits the formation of an excessive amount of sulphate; the proportion of lead sponge and peroxide remaining must be sufficiently large to keep down the resistance of the cell in order to permit the passage of the charging cur- rent, and thus the regeneration of the battery. The lowest point of discharge for batteries used for electric ignition, or for other purposes where a comparatively small amount of current is required, is 1.8 volts. Batteries used for electric automobiles, where a heavy current is used, can be discharged to 1.75 volts, or even below this value; for when the discharging current is stopped the voltage will increase again several tenths of a volt. It should be understood that "charging" a battery does not signify that any electrical energy is given to the plates or stored in them as electrical energy. It means only that a chemical transformation is taking place, producing a voltaic couple similar in its general behavior to an ordinary primary battery. In practice this chemical transformation is usually pro- duced by an electric current; however, lead sponge and peroxide can be manufactured by purely chemical means, and if applied to two lead plates or grids a fully charged storage battery would be produced. Therefore a charged cell is one in which the positive plate is covered with peroxide of lead, and the negative with spongy lead, and if a certain amount of lead sulphate is produced on the plates a discharged cell would result. Thus the only bearing the electric current has on the question of charge and discharge is that it is employed as a reducing agent in one direction, and a product of chemical transformation in the other. ELECTROLYTE. The electrolyte used in storage batteries should be sulphuric acid made from sulphur, and not from pyrites, as the latter may contain injurious substances. The acid should be diluted with the amount of pure distilled water that is required to bring it to the proper density. If the water is not soft or free from lime, it should previously be boiled. The acid must be diluted in a separate vessel of acidproof material, like lead, glass, etc. Care must be observed in mixing, on account oi the heat generated. The acid should be poured slowly into the water (never the water into the acid), stirring well at the same time. Use about twenty-eight parts acid to loo parts water, and let cool before taking a hydrometer reading. The specific gravity of the electrolyte varies in different types of batteries from 1.200 to 1.250. In batteries used for electric ignition the density does not exceed 1.230 as a rule, while in electric automobile batteries 1.250, or even more, is not unusual. The specific gravity of the electrolyte increases continually during the charge. However, fresh electrolyte put into a cell 36 will not commence to increase in density for a considerable time after the charging has started. The durability and the operation of a battery depend greatly upon the density of the electrolyte. High specific gravity acid facilitates sulphata- tion and deterioration of the plates; on the other hand, the electromotive force of a battery increases with the acid density. The voltage of a cell, however, is also dependent upon the internal resistance and the tempera- ture. Fig. 32 shows the variation in resistance of electrolyte for different densities. As seen, the resistance is lowest between 1.200 and 1.250. Com- mercial acid is of 1.835 specific gravity, while pure sulphuric acid (H 2 SO) is of 1.842. The internal resistance of a cell tends to increase the applied voltage of charge, and decreases the useful voltage of discharge, thereby Ohms. 10 THE HORSELESS AGE 10j 20^ 30% 40% 5df 60% 70% Percentage in weight of 1.842 acid in mixtures. Sfiecific Gravity.- 1.069 1.135 1.224 1308 1.309 1.502 1.614 FIG. 32. RESISTIVITY OF SULPHURIC ACID SOLUTION. causing a loss of energy. But the internal resistance is not only dependent on the electrolyte, but also on the thickness and porosity of the active material. Temperature variations are also important; a rising temperature decreases the charging voltage, while the discharging voltage is increased. The electrolyte also affects the capacity and durability of a battery. The capacity per pound of element for automobile batteries varies from 4 to 6.5 ampere hours. As a rule the durability will be greater the less the capacity per pound weight. If the capacity per pound of cell is high, the layer of active material must be thick, the amount of electrolyte small, and therefore its density high. The two latter conditions tend to shorten the life of a battery. .57 The plates of a battery must be covered with electrolyte; if on account of evaporation the level of the solution falls below the top of the plates, pure water should be added and not acid. It is only seldom required to add dilute acid, and that is because of the abstraction of the SO* on dis- charge, which combines with the active material to form lead sulphate, thus effecting -a gradual diminution of the acid density. DURABILITY. The principal factors affecting durability are : (1) Quality of active material. The quality of active material must be such that it can expand and contract without shedding ; that is to say, without dropping particles from the plates. In order to fulfill these conditions the material must be com- paratively hard (the spongy lead is slightly softer than the peroxide), tough and porous, and have a low specific gravity. (2) The rate of charge and discharge. The rate of charge per unit of plate area- should be within moderate limits. The current should be so proportioned that it requires about eight hours to charge stationary or electric ignition batteries, and four hours for electric automobile batteries. In this case the concentration of the acid in the pores will also be within moderate limits, the contraction of the active material slow, and, therefore, not harmful, as the material has time to adjust itself gradually to the changing conditions. When the rate of charge is too rapid the voltage of the cell will rapidly rise (without being fully charged), because of the higher concentration of acid in the pores, which is unable to diffuse out into the surrounding electrolyte. A high rate of charge requires also a higher charging voltage, which means more energy. Therefore a high rate of charge is detrimental to the life of plates, the efficiency of the battery is lower, and if there is much sul- phate present, the temperature of the cell will be increased. For the above mentioned reasons it is also desirable to keep the rate of discharge within safe limits, as practically the same thing occurs on charge as on discharge. Yet a high rate of charge is more harmful, as in this case the active material is contracting 'and may pull away from the grid. When the rate of discharge is too rapid polarization* is also increased, and helps in reducing the voltage of the battery. Besides, the acid is too highly diluted in the pores of the active material, thereby lower- ing the electromotive force rapidly, and thus ending the discharge more quickly. The electromotive force (E. M. F.) of a cell is the voltage (V) plus the internal resistance (R), multiplied by the current (C) ; that is: E. M. F. = V+(RxC). When a cell is exhausted or discharged, the current may be compara- tively high at the commencement of charge, but should be low toward the end when the evolution of gas begins. (If the charging current is too high the evolution of gas will commence long before the cell is charged.) (3) The maximum permissible rise in voltage on. charge. Under ordinary circumstances the charging should be stopped when the voltage of the cell reaches 2.5 volts. However, it is well to over- * When a battery is discharged at a very high rate the violent reaction that takes place produces an excessive amount of gas at the negative plates, which keeps the elec- trolyte away from the plates. This is called polarization. 38 charge now and then to about 2.65 volts (when the electrolyte assumes a strong milky color) in order to completely rid the plates of sulphates that may have formed. Accumulators used for ignition purposes should be overcharged not oftener than every two or three months, those used for traction purposes at about every twenty-fifth charge. A too frequent or continuous overcharge is deleterious to the plates, as the gases formed inside the pores of the active material may cause the latter to crack or "shed" in forcing their way out. The gases may also get between the active material and the grid, thereby decreasing the contact between them, and consequently facilitating sulphatation greatly, as will be explained presently. The active material may break or peel off by virtue of its too great change in volume, due to the absolute reduction of sulphate. (4) The maximum permissible drop in voltage on discharge. One of the most important factors regarding durability is probably the minimum voltage to which a cell is discharged. If the discharge is carried too far it may result in (a) oversulphatation ; (b) too great a change of volume of the active material, causing buckling, shedding and breaking, and (c) the excessive dilution of acid in the pores of the active material, inducing a corrosive electrolytic action. (5) Time elapsing between the end of discharge and beginning of charge, or vice versa. Whenever possible a battery should be charged immediately after it has been discharged, as otherwise sulphatation will take place, increasing in amount with the time elapsing between discharge and charge. If a cell is fully charged -and permitted to stand idle for a considerable time it will discharge itself by leakages and local action, and the active material will in this case, too, become sulphated. (6) Density, quantity and purity of .electrolyte. If the density of electrolyte is too high sulphatation is facilitated ; besides, it affects the internal resistance, as can be seen from Fig. 32. If the quantity of electrolyte is too small the density of the acid in the cell, and especially in the pores of the active material, becomes too low; and, as is well known, the electrolytic decomposition of highly dilute acid has a corrosive effect, shortening the life of the plates. Impurities in the acid generally tend to corrode and deteriorate the plates, and fill up the pores of the active material, thereby decreasing the capacity of the battery. (7) Temperatures at which cells are operated. A battery should not be operated at a temperature higher than 100 Fahr. High temperatures induce a more rapid chemical action, the pores of the active material become larger, and there is a greater tendency for sulphatation. (8) The separation of plates. The positive and negative plates must be properly separated, otherwise leakages or short circuits can form between the plates, producing internal discharge. The latter condition obviously leads to sulphatation. (9) Amount of lead in plates. (Plante type.) In the Plante type batteries the amount of lead in the plates influences the life of the cell. As the active material sheds or disintegrates, the lead exposed to the electrolyte is gradually reconverted into active material by 39 the charges. Therefore, the life of the cell is at an end when the lead available for conversion into active material is used up. DISEASES AND REMEDIES. (1) Loss of capacity. After a battery has been in use for some time it may be found that on charge the voltage will rise to 2.5 volts more rapidly than previously, and on discharge drop more rapidly, the charge and discharge to take place at a normal rate, of course. In a case like this the capacity of a battery has decreased. To remedy it the first thing to do is to give a good overcharge, say, to 2.7 volts, for the reduction of the sulphate on the surface of the plates. If this does not improve the capacity materially, or if no sulphate can be seen on the surface of the plates, the reasons are: (a) Some of the active material may have fallen off the grid. This can easily be detected when lifting the plates out of the cell, or drawing off the electrolyte. If this is the case the grid or the portions only of the grid which are defective should be repasted as described under "Care and Repair." (&) The pores of the lead sponge may be clogged with sulphate; sulphate may have formed between the grid and the active material, or the pores of the latter may have contracted. To remedy this the battery should first be discharged, and then the polarity of the charging current should be reversed; that is, the positive of the dynamo or the source of current used for charging should be connected to the negative terminal of the battery, and the negative of the former to the positive of the battery. Currents should then be sent through the battery in this reversed direction. The voltage will first drop down to zero, and then slowly rise again to 2.5 volts, as the spongy lead of the negative is con- verted into peroxide, and the peroxide of the positives to spongy lead. The charging curent should then be stopped, the electrolyte poured away, and the cell filled with acid of the proper density. After this the poles of the charging current are reversed again, and current is sent through the battery in the original direction until it is fully charged, when it will be found that the capacity has been brought back to its normal value. The current used during the reversal and the consequent charge should be approximately one-half the normal charging rate of the battery, (c) The plates may not be covered with electrolyte, in which case the amount of active material not immersed will be idle, and a corresponding decrease in capacity the result. The remedy, of course, is to add water or dilute acid as required. Besides, if active material is exposed to the atmosphere it will harden and oxidize (this is especially the case with the negative plates), when it will require several charges and discharges before it is reduced again. (2) Fraction and buckling of plates. This is due to excessive or unequal expansion, or to an unequal dis- tribution or formation of active material. It may arise from too high a rate of discharge, or from carrying the discharge down too far, or else the distribution of current over the plates was not uniform, thus discharg- ing certain portions too rapidly or too far. For the latter reason buckling can also take place at normal rates of discharge, that is, if the active material is not formed or applied to the plates uniformly; under this condition buckling is due to defective plates. Buckling may also occur 40 if the discharge takes place at high temperatures, whereby the capacity, and consequently the formation of sulphate, is increased, thereby bringing about a greater voluminous change of the active material than occurs at lower temperature. If the buckling is due to defective plates the remedy would be not to carry the discharge too far or discharge at too high a rate. (3) Shedding of the active material. "Shedding" takes place within limits in all pasted plate batteries, owing to the greater expansion and contraction of the active material which the grid cannot follow, and to the rapid release of gases at high rates of charge and on overcharge. Shedding in greater measure may be due to defective active material; that is, to active material that loosens from the grid, or that is improperly formed or applied to the plate. The remedy for too much shedding is to charge at lower rates. Decrease the amount of the normal charging current about 30 per cent., do not overcharge (stop at about 2.4 volts), and do not carry discharge too low (not lower than 1.85). If the plates have not been provided with envelopes by the manufacturer originally, a good plan is to provide them at the sign of increased shedding, in order to increase the life of the battery. (See under "Care and Repair.") (4) Oversulphatation. Oversulphatation or the injurious kind of sulphatation differs from the normal sulphatation of charge and discharge in that it is almost irreducible. If present in a battery it causes loss of capacity, shedding of the active material, buckling of the plates, an increased internal resist- ance, and consequently a lower efficiency and increased temperature with the passage of current. If the amount of sulphate present is too great a current cannot be sent through it, for pure lead sulphate has a very high resistance. However, if sufficient lead or lead oxide be left, per- mitting the absorption of electrolyte, and thus decreasing the resistance, the normal action of charge and discharge will take place. Oversulphatation arises from overdischarge or from high rates of discharge, either on the entire surface of the plates or only on certain portions of them. Overdischarges, besides arising from exaggerated dis- charges through external circuits, may be due to (a) short circuits between plates, (fc) local action and leakage, and (c) loosening of the active material which is discharged but not traversed by current on charge, there- fore becoming overdischarged. High rates of discharge may also cause the formation of a layer of sulphate on the externaLsurface of the active material, thereby preventing the inner portions from participating in discharges. This causes the action to take place on the outer surface of the plate, resulting in over- discharges of the outer layer of the active material, and thus in the formation of the injurious sulphate. If the active material has become loose, and is not in close connection with the grid, electrolyte would penetrate between the two. In this case the surface of the active material nearest the grid becomes overdischarged, and thus a layer of sulphate is formed on this inner surface of the active material. If the plates are oversulphated there is a tendency to injurious volumi- nous changes of the active material, causing breaking and shedding, and 41 buckling of the plates. Local actions and short circuits will also cause overdischarge, and consequently sulphatation. As sulphate is white in color, its presence can be recognized by the lighter color. If it has gone very far pure white flakes of sulphate will cover the plates, or their affected portions. A good method of treatment for oversulphatation is to charge the battery for a long time at such a rate that the temperature of the electrolyte does not exceed 100 or 102 Fahr. In this way the sulphate is gradually reduced. If there is a thick layer of sulphate between the grid and the active material, so that current cannot be sent through, the plates should be renewed or repasted. Short circuits can be prevented by keeping the cells clean ; that is, by not allowing sediment to accumulate at the bottom of the cell, between the plates, or on the separators. If a number of cells are connected in series, and one cell alone shows signs of sulphatation, and it is not convenient to take it away from the others, it may be kept in on charge, but should be cut out on discharge. By thus charging the cell a few times, without discharging, the overcharge will be sufficient to reduce the sulphate. If it is desired to reduce the sulphate quicker the cell may be left in on discharge, but its polarity reversed. In this way the discharging current of the battery will pass through the defective cell as a charging current. It should be remem- bered, however, . that cutting out one cell decreases the voltage of the battery 2 volts, and if its polarity be reversed and the cell left in on dis- charge, it will take another 2^/2 volts, making a total decrease of 4^ volts. In case of electric automobile batteries, having forty or more cells, this drop of voltage is usually permissible. Sulphatation may also be produced by internal discharge of the cell due to "local action." (5) Internal discharge. Discharges take place sometimes in the same plate, due to different potentials between the active material, or certain portions of it, and the grid or metallic impurities in the grid. This discharge is called "local action," and obviously it decreases the capacity of the battery. Local action is often due to impurities and sulphate deposited in the pores of the lead sponge. The remedy is to use pure electrolyte and keep the plates well covered. (6) Reversal of negatives. This may happen when there are several cells in series, and one loses its capacity for some reason or other. On discharge the defective cell, will go down to zero before the others are discharged, and as the discharge proceeds the current will flow through the defective cell in a reverse direction, thus reversing its polarity. The remedy is to charge the cell in the right direction until the lead sponge of the negative is brought back to its natural condition; that is, until the color of the negative plate is light gray. The reason for the loss in capacity of the defective cell should be ascertained and remedied. (7) Loss in voltage. This is due to an excessive amount of sulphate on the plates, which must be reduced by a continued overcharge. The cause of sulphatation should be found and removed. (8) Corrosion of the plates. 42 Corrosion and deterioration of the plates take place to a limited extent in all batteries, due to the action of the acid and the electrolytic decom- position. However, the corrosion or disintegration sometimes takes place more rapidly than is natural, and this may be caused by the chemical action due to the decomposition of highly dilute acid in the pores of the active material. This occurs whenever the discharge is carried too far; or, in the case of plates having a thick layer of active material, where it occurs when the rate of discharge is high. Another cause for rapid deteriora- tion is the presence of lead dissolving acids in the electrolyte, which attack the plates and thus permit the forming process to continue. It can be recognized by a constant decrease in capacity of the cell, and the remedy is to substitute fresh electrolyte free from injurious substances. THE CARE AND REPAIR OF STORAGE BATTERIES. Voltage reading should be taken now and then, and the acid density of each cell measured with a hydrometer in order to keep informed as to the condition of each. The hydrometer should be flat, so as to pass between two adjacent plates, and the acid should be stirred before taking a reading, as the density may be different at top and bottom of the cell, if the voltage or the acid density is lower in one cell than in the others, it will generally indicate local action or short circuits. When the electrolyte is of higher density than normal, owing to evaporation, it should be brought to the proper density by the addition of pure water, or highly dilute acid. When such an addition is necessary, it is best to pour it through a rubber hose or glass tube extending to the bottom of the cell. If this is not done the water, being lighter in weight, will remain on the top or mix very slowly with the acid. After a battery is discharged it should not be allowed to stand idle for any length of time. If conditions are such that it is impossible to recharge immediately, the discharge should not be carried further than 1.85 volts. If the battery is not used for some time it should be fully charged until the acid assumes a milky color; besides, every three or four weeks a small additional charge should be given until the evolution of gas begins. If, however, the battery is not required for a long time it should be fully charged at a slow rate, then partially discharged; after- ward the electrolyte should be drawn off, and the plates thoroughly washed in running water, and then left standing in pure water for twenty-four hours, changing the water several times. After this the water can be drawn off and the plates permitted to dry. In this condition they can be kept a long time without injury. When again required, the cells need only be filled with electrolyte and recharged to 2.65 volts at the normal rate. When making connections it is of the utmost importance that the proper polarities are joined together. An easy method for finding the polarity is to take two pieces of lead wire, hold them in a cup or other receptacle filled with dilute sulphuric acid, and connect their ends to the two live wires. After the current has been permitted to flow through them for a few minutes the lead wire connected to the positive pole will be brown, and that of the negative light gray. The polarity can also be found by the use of a voltmeter which reads only one way; that is, one in which the controlling magnet is permanent. The trouble of "shedding" of the active material in Faure's system, 43 or the pasted plate system, can partly be overcome by the use of envelopes. In case particles of active material should loosen from the grid the envelopes would hold them in place, and so prevent them from leaving contact with the grid or falling to the bottom of the cell, thereby causing short circuits between the plates. Generally, it is only necessary to provide the positives with envelopes, though sometimes the negatives must also be covered. Envelopes have been made of hard rubber, celluloid, asbestos cloth, glass wool and pyroxylin. Pockets or cases made of hard rubber or cellu- loid, into which the plates can be slipped, have been found very efficient and durable. Glass wool, that is, glass in a finely divided fibrous state, is sometimes packed between the plates and works very well, the mass being sufficiently porous to absorb enough electrolyte, and therefore offer- ing no obstructions to the electro-chemical action. When a great deal of the active material has fallen off the grid, or when the plates are entirely covered with sulphate and its reduction is impossible, it is necessary to repaste the plates. Almost all active mate- rials are made of lead oxides, usually red lead for the positive plates and litharge for the negatives, to which dilute sulphuric acid of about 1.140 degrees specific gravity is added to form a paste. The paste, which should not be too soft, but rather stiff (as little acid being used as possible), is then applied to the grid. After the paste has been applied to both sides of the grid it should be subjected to pressure, in order to fill every pore of the grid. Manufacturers usually use rubber rollers for this purpose. However, the author has found that by using two pieces of strong plate glass, placing the pasted grid between them, applying pressure with the hands to the top glass plate, and moving it around in a circular motion, very good plates can be produced. Some manufacturers claim that a very durable active material is pro- duced by mixing red lead and litharge for the positive and negative plates, respectively, with sulphuric acid and glycerine. In mixing, equal parts of concentrated sulphuric acid and glycerine are mixed first. After letting this mixture cool, twice the amount of water should be added, i. e., two- thirds of the complete mixture will be water. After the grids are filled with the paste they are allowed to dry for one or two weeks, according to the thickness of the active material. After being fully dried the plates are assembled in the cells and charged and discharged a few times, after which they are ready for use. To completely form the plates, i. e., to convert all the oxide of the negative plates to spongy lead (Pb), and that of the positives to peroxide of lead (PbO 2 ), by the liberation of oxygen and hydrogen, requires about 100 hours and 70 hours for the negatives and positives, respectively. The flow of current must not be too high, about 6 amperes per square foot of plate, considering both sides of each plate. When assembling plates together, or making any lead joints between the lugs of the different cells, the two pieces to be joined should, when- ever possible, be flowed or burned together. This method consists in bring- ing the ends to be joined to such a high temperature that the lead melts and flows together, forming a lead weld. Where many lead joints have to be done it is best to make use of the hydrogen blowpipe, as the hydro- 44 gen flame has the special property of not soiling or oxidizing the lead. However, where only a few joints are necessary, an ordinary gas blow- pipe, or else an electric arc, may be used. When the amount of work to be done is very small the joints can be made by soldering. It might be mentioned here that no flames should be brought near the battery when the cells are giving off gas, as there is great danger of explosion. A most plates in present use are of the formed rather than of the pasted' type, a renewal of a cell, after its capacity has become irremediably very low, entails the purchase of new plates, new positives being generally required first, and new negatives at considerably longer periods. Care and Charging of Ignition Accumulators. (ALBERT L. CLOUGH.) Storage batteries intended for ignition purposes generally consist of two, three or four cells in hard rubber jars electrically connected, and car- ried in an acidproof case (Fig. 33). As each storage cell gives about 2 volts, the two-cell combination develops 4, the three-cell combination 6, and the four-cell 8 volts, and thus take the places, respectively, of primary batteries of four, six and eight cells approximately. These storage bat- teries are generally rated by their manufacturers in ampere hours, and the charge may be considered as exhausted when sufficient current has been withdrawn to reduce the voltage of each cell to 1.8 or 1.7 volts, which in the two-cell combination would be equivalent to 3.4 or 3.6 volts total, in the three-cell battery to 5.1 or 5.4 volts, and in the four-cell bat- tery to 6.8 or 7.2 volts. When the battery is newly charged, its voltage per cell may be considerably in excess of 2 volts, possibly 2.3 or even 2.5 volts, but it soon falls to about 2 volts and remains thereabouts dur- ing the greater part of the discharge. Cells should al- ways be recharged as soon as the voltage has fallen to 1.7 volts. INSPECTION OF CELLS. Owing to the fact that ignition storage cells are gen- erally sealed in their contain- ing cases, it is not easy to inspect them. There is, how- ever, almost always a means provided for replenishing the liquid in case of loss through spilling or evaporation. There P IG . 23. TYPICAL IGNITION ACCUMULATOR is always a removable filling (NATIONAL). plug, and generally a vent is 45 provided in this plug which allows of the escape of the gases that are formed during the action of the cell, but which will not readily allow of the escape of liquid through jarring of the cell. The filling plug should occasionally be taken out and, if liquid has been lost through spilling, it should be replaced with dilute sulphuric acid of the proper specific gravity. If the loss of liquid has been entirely due to evaporation, it should be replaced with pure water. Pure water rather than acid should be added, unless it is positively known that there has been loss of acid. At all times the upper edges of the plates should be well covered with liquid. In case an ignition storage battery during discharge fails to deliver its usual amount of current, or loses its charge rapidly when idle, it is usually a sign that it is internally short circuited with active material which has been loosened by severe jarring or through a short circuit. The best thing to do in such a case is to send the battery to its manufacturer for repairs. CORROSIVE EFFECT OF ACID. The connections between the individual cells of a storage battery should be entirely of lead and protected from the acid fumes which are constantly present, by some acidproof paint. Indeed, the acid spray which is produced by storage batteries when charging or doing hard work is very destructive to any metal surfaces in its vicinity. A coating of vase- line over the binding posts and over other bright metallic parts in close proximity to the cells tends to obviate this difficulty. A good storage battery ought to withstand a very large number of charges and discharges, if it is intelligently handled, but at the end of a season's hard work, or if it is not to be used for several months, most manufacturers recommend that it be fully charged, then partially dis- charged, the plates taken out, washed most thoroughly with pure water, dried and laid carefully away. The acid may be saved in glass bottles and the jars cleaned of all sediment. ^ CHARGING MEANS. The question of charging and charging facilities is a most important FIG. 34. MOTOR GENERATOR CHARGING SET (WESTERN ELECTRIC) 46 one to automobilists contemplating the use of storage batteries. As pre- viously stated, the direct or continuous current is absolutely necessary for this purpose, and is not always readily obtainable, as the alternating cur- rent is almost universally used for public supply outside the great cities. If one does not reside in one of the large cities where the Edison cur- rent is available, and no mercury arc rectifier is available, recourse may perhaps be had to some private direct current plant in a hotel, apartment house or other public building, or to an electric light station where the direct current is still produced by the exciters which magnetize the fields of the large generators. Occasionally one may chance upon the owner of an electric vehicle who has a motor generator plant (Fig. 34) for charging his own batteries. If not, a small direct current magneto or dynamo intended for ignition purposes may be set up and connected for power driving for charging purposes. Wherever the direct current is used for lighting at a voltage of 100 to 125 volts, the charging of a stor- age battery is a very easy matter and, in fact, where the 200 to 250 volt system of direct current distribution is used the same procedure may be followed, although the charging will be a more wasteful process. The only electrical apparatus necessary is a series current tap or charging plug with its attached wires (Fig. 35). This current tap is merely a plug which screws into the socket of an ordinary incandescent lamp, in place of the lamp itself. This plug carries a socket into which the lamp may be screwed, and also two screw connections to which wires may be at- tached for connection to the battery. When so connected, the battery is placed in series with the lamp; that is, the same current passes through the lamp and bat- tery successively, and its volume will be dependent upon the candle power of the lamp which is used, being about one-half ampere with a 16 C. P. lamp, about i ampere with a 32 C. P. lamp, and about FIG. 35- CURRENT TAP FOR 1 34 amperes with a 50 C. P. lamp at no CHARGING IGNITION Accu- volts. The charging current may thus MULATOR FROM LIGHT- be regulated and the light from the ING CIRCUITS. lamp made use of during charging. The connections may be such that the current passing through several lamps may be utilized and charging at 3 to 5 amperes effected. TESTING FOR POLARITY. It is of the first importance that the current be sent through the battery in the proper direction, otherwise the cells will be detrimentally discharged instead of being charged. The direction of the current will depend upon which one of the binding posts of the battery is connected with a certain one of the wires coming from the current tap. In order to determine the correct connection, either one of two methods may be used. A strip of red litmus paper may be moistened with water and the ends of the two wires placed in contact with it a short distance apart. If then the current is turned on at the key of the socket, with an incandescent lamp 47 screwed into the plug, a blue stain will be produced in the test paper under one or the other of the two wires. The wire which produces the stain should be attached to the binding post of the battery which is marked negative or . The other wire should, of course, be connected to the positive or + binding post of the battery. In case no litmus paper is at hand, the ends of the two wires may be immersed in a tumbler of acidulated or salted water and held slightly separated. When the current is turned on, small bubbles of gas will be seen rising from the submerged ends of the wires, but in very much larger quantities from one wire than from the other. The wire which gives off the most gas should be attached to the battery binding post marked nega- tive or , and the other wire to the -f or positive battery terminal. The length of time in hours which a battery should be left charging under this arrangement is generally given by the manufacturers for each size of lamp employed for the charging resistance or for any given amperage. When the number of hours prescribed is nearing an end, it is well to watch the battery, and when, upon withdrawing the filling plugs, the cells are found to have begun to "boil" quite energetically, they may be considered as charged and the current may be cut off. CHARGING CONNECTIONS. When batteries are charged from the exciter at an electric light or power station it will generally be under the supervision of a skilled attendant who will use a larger charging current and complete the job in a comparatively short time. In charging from a small ignition gen- erator, a magneto or a shunt dynamo should be chosen, and it should be run at a speed at which it will generate nearly 6 volts, if a 4 volt battery is to be charged. An ammeter should be included in the circuit and also a length of moderate sized iron or German silver wire, to act as a rheostat. The polarity of the generator should be determined by the red litmus paper test, and the generator wire which produces the blue stain should be connected to the negative battery terminal. The connections should not be made until the generator is fully up to speed and generating, and the current as shown by the ammeter should never exceed the rated charging current as given by the manufacturers, but may be as much less as the capacity of the generator may require. If too much current flows, a greater length of resistance wire may be included in the circuit and vice versa. In case no other means of charging is available, ignition accumu- lators may be recharged from gravity or other primary batteries, by recourse to the following procedure (Frank Berry, Jr.) : As the voltage of a storage battery for ignition purposes is usually 6 volts, with a capacity of about 60 ampere hours, it will be found very inexpensive and convenient to procure about seven gravity cells, such as are used in telegraph work (8x12 inch size). The solution for these batteries consists of about 3 pounds of Milestone per cell, the solution to cover the zinc at the top of the cell. Connect the wire leading from the copper element in the bottom of the cell to the zinc in the neigh- boring cell. When the seven cells have been thus connected attach the copper terminal of the gravity battery to the positive terminal of the storage battery. Great care should be taken in this, as a mistaken connection would cause the current to flow through the storage battery the wrong way, which would injure it. Leave the gravity battery in circuit with the storage battery until it is fully charged, the most satisfactory way being to allow the gravity battery to charge the storage battery overnight, as the charging current is compara- tively small and will not injure the storage battery, if ordinary care is taken. More rapid charging can be effected by the use of several sets of seven cells, each connected in multiple. It is advisable when the storage bat- tery is fully charged to siphon off the bluestone solution from the gravity bat- teries until they are again required, in which case the same solution may be used, as the elements of the gravity bat- tery decompose when they are not in use. The cells may, however, be kept charged, if frequently required, the cir- cuit being maintained closed. An outfit like the above would cost possibly $6, and it has the advantage that it can be used anywhere at any time by the average person. Nearly all well equipped garages make a business of charging ignition accumulators, and many of them employ the mercury rectifier (Fig. 36), which is a device for changing an alternating current into a continuous one of suitable voltage. When this apparatus is not used a low voltage dynamo is generally employed. Rectifiers are now very generally to be found as part of the equipment of private electric vehicle garages. The above instructions relative to ignition storage batteries also apply, in the main, to the larger batteries of from 80 to 120 ampere hours capacity, now used to light tungsten bulbs in the head, side and tail lamps of cars. FIG. 36. MERCURY ARC RECTIFIER (GENERAL ELECTRIC). Magnetos and Other Mechanical Ignition Generators. (ALBERT L. CLOUGH.) It is of the greatest importance that the supply of ignition current .be of an unfailing nature, and that it be independent of external sources. The magneto being operated by the vehicle motor itself, and capable of providing a liberal supply of electrical energy so long as the engine is in motion, has come to be generally regarded as a more desirable ignition source than the battery. Both the primary and the storage cell require 49 replenishment at somewhat frequent intervals, it being necessary period- ically to renew the former and to recharge the latter. The magneto requires no such attention, it being only necessary to maintain it in opera- tive condition, a minute fraction of the power developed by the motor being converted into the required supply of electrical energy. For this reason, and others, the use of the magneto has become ex- tremely widespread, and it is today the most important feature of the ignition field. The synchronous magneto being the most important type, it will be described first. Such a magneto is invariably of the alternating type ; that is, it gives impulses of alternating direction, and is thus not compli- cated by any commutator the collection of the current from the armature requiring only the simplest arrangements. Since this type of magneto produces a succession of regularly alternating electrical impulses separated by points of zero electrical activity, dependent upon armature position in respect to the field, it is necessary to drive it at a speed bearing a certain definite relation to that of the motor, in order that the periods when a spark is desired shall correspond with the periods when a sufficient volt- age is being developed, as otherwise the sparking instant might corre- spond with a zero point of ^electrical generation. Thus all magnetos of this type must be geared, or otherwise precisely driven by the motor to be sparked, and it is usual practice to so proportion the gear ratio between generator and engine that a certain electrical impulse will correspond in time to the ignition instant of one cylinder, and the next impulse to that of the next cylinder, and so on. While the current delivered by the magneto is alternating in di- rection, so far as a single ignition is concerned, the current is unidirectional, the current for each spark corresponding with the crest portion of a single wave of the alternating current. A synchronous magneto may be either of the rotat- ing armature type or of the inductor type, but whether it be of one or the other type the electrical impulses which it generates always depend upon a more or less sudden withdrawal of the magnetic lines froni the wire coil, which, under certain condi- tions, pass through it from one pole of the permanently magnetized field magnet to the other. It is a cardinal principle of electrical induc- tion that when such a with- THE HORSELESS QE FIG. 37. MAGNETO DIAGRAMS. drawal of magnetism from a coil of wire takes place an electromotive force is developed within the wire. The two types of magnetos differ in respect to the manner in which this change of magnetic condition is brought out. OPERATION OF ROTATING ARMATURE MAGNETO. Fig. 37 represents diagrammatically a magneto of the bipolar rotat- ing armature type with the permanently magnetized field, the H shaped soft iron armature core and its wire armature coil. The direc- tion and path of the lines of magnetic force from pole to pole of the field magnet are also shown in different positions of rotation of the arma- ture. In diagram a, Fig. 37, magnetism is represented as passing through the soft iron armature, the heads of which are in close proximity to the field magnet poles and threading through the armature coil. In diagram b the armature has rotated to the point at which its heads are just passing out of proximity to the pole faces, and thus breaking the magnetic path between the field poles. At this point magnetism is rapidly being dis- charged from the armature, and a sudden generation of electrical pressure is taking place in the armature wire, which impulse persists during a considerable period of rotation, gradually decreasing in magnitude. When the armature reaches position c its core again forms a path for the passage of magnetism from pole to pole and it again becomes highly charged, but in the opposite direction. When the position d is attained the magnetism is again discharged with the production of an electrical pressure in the wire as at position b, although of opposite direction. Thus in each revo- lution of the armature two electrical impulses are produced, of sudden rise and considerable amplitude, with two periods between them, during which the armature winding is inactive. If a magneto of this type is to be used to spark a four cylinder engine its armature must be rotated at the speed of the motor. If the motor is of the six cylinder type the arma- ture speed must be one and one-half times that of the engine, and with an eight cylinder motor twice the engine speed. Since in this type of magneto the winding is in rotation, in order to collect the current, one end of the winding must be grounded to the armature shaft and the other brought out through shaft insulation to a metal pin upon the end of which a stationary brush makes electrical contact. THE INDUCTOR TYPE. In one common form of the inductor type (Fig. 38) the wire coil A is stationary, being set into a recess in the pole pieces. It is circular in form and of square cross section, and its plane is perpendicular to the axis of the driving shaft B. The soft iron inductor C, which is rotated by the shaft, is of such a form that as it rotates the direction of the magnetic lines threaded through the coil A is alternately from right to left and from left to right, the change of direction being effected with the utmost abruptness, and at each such change a powerful electrical impulse is generated in the coil. The change of direction of the magnetic flux through the inductor, and hence through the coil, is dependent upon the position relative to the stationary pole pieces of the two sector shaped soft iron projections of the inductor D and E, which run very closely to the pole pieces. These projections are upon opposite sides of the coil A, Si E being shown toward the end of the shaft which is driven from the engine and D upon the other end of the shaft. When projection E is passing the N pole piece (away from .the observer), and projection D passing the S pole piece (toward the observer), the direction of the flux is necessarily from the N pole piece into projection E, through the body of the inductor and coil A from right to left. When, on the other hand, D is passing the N pole piece and E the S pole piece, the direction of the flux is still toward the observer, but it has to enter projection D from the N pole piece, pass through the body of the inductor, this time from left to right, and out through projection E into the S pole piece. It is thus seen how the direction of the flux through the coil is reversed twice each rotation of the inductor. The chief advantage of the inductor type lies in the fact that the winding is stationary and requires no moving connections. Both the rotating armature and the inductor type magnetos, as described, produce two relatively low tension impulses per revolution, the electrical pressure generated being comparable with that from an ignition battery. Just as with the battery system of jump spark ignition, two things THE HORSELESS IGE FIG. 38. INDUCTOR TYPE MAGNETO (REMY.) are required to enable the magneto to generate a sufficient pressure to cause a spark at the plug gap, viz., a means for suddenly rupturing the low tension primary current from the magneto winding and a fine high tension winding of many turns placed within the influence of the mag- netic field of the ruptured primary current ; in other words, a transformer or step-up coil arrangement. The make and break device, as shown in Fig. 14, is typical of the type most used upon synchronous magnetos. The shaft F in the figure is that carrying the rotating armature or the inductor. When used as a magneto make and break for engines of two or more cylinders the cam is fitted with another projection similar to E and diametrically opposite 52 to it, so that the primary circuit is broken twice each revolution. The period of the break is adjusted so as to take place when the value of the current impulse to be broken is near the maximum. Synchronized magnetos are divided into two classes dependent upon the location of the high tension winding, viz., the high tension and the low-high tension types. In the high tension magneto the fine wire, high tension coil is wound in close juxtaposition to the low tension coil, in which the magneto im- pulses are generated, so that both coils are in the same field. In the case of the rotating armature high tension magneto the high tension coil is usually wound directly over the low tension coil upon the shuttle shaped core, being very carefully insulated therefrom. One end of each coil is usually connected together and grounded, while the free end of the primary or low tension winding goes to the make and break device, and the free end of the secondary to the high tension distributor of the magneto. In the inductor type of high tension machine the secondary or high tension winding is wound over or closely upon one side of the primary winding, the two coils forming a single unit with insulation between them. The connections are the same as in the rotating armature type, except that the leads are stationary, no moving contacts being required, since both coils are fixed. The other class of synchronous magnetos is known as the low-high tension type. Here there is no high tension winding within the influence of the machine's magnetic field, and the magneto proper generates a low tension current only. The transformer is here a separate unit, usually attached to the dash of the car, although it may be attached to the frame of the magneto. In the low-high tension magneto the current from the generating coil, after passing through the make and break points, is conducted to one side of the primary winding of the step-up coil, the other side of which is grounded. One side of the high tension winding is grounded and the other side is led to the distributor upon the magneto. In both the high tension and the low-high tension types switches are provided to throw the magneto in and out of action. The usual method of cutting off the ignition is by short circuiting the primary winding of the machine. As in the case of battery ignition apparatus, a condenser is provided con- nected around the make and break contacts in order to intensify the spark and prevent burning of the contacts. The only other essential of the synchronized magneto is the high ten- sion commutator or distributor. In point of^ fact, such a magneto may be regarded as an example of the single coil and distributor system, with a single spark per ignition, the place of the battery being taken by a low tension magneto generator. As applied to the magneto, the distributor or secondary commutator consists of a base or shell of insulating material, upon the face of which are mounted metallic segments, so placed as to be swept by a rotating metallic brush carried by the distributor shaft, which latter is usually placed above and parallel to the armature shaft of the magneto and driven from it by gears. The metallic segments on the distributor face are equal in number to the cylinders of the motor to be ignited, and from 53 C K.S i- 2 S "| S 3 B. H i-ih-S il-M^ h- 1 o.^^ *" -ao^ja u int and the switch contacts are opened and closed. This may be due to any one of three causes, (i) The battery may have failed; (2) there may be a break or unreliable contact some- where in the primary circuit, or (3) there may be a short circuit in the primary which allows the current to take a short cut without passing through the coil. RESERVE BATTERIES. (i) Every car ought to carry two distinct sets of batteries, one of which should at all times be kept fresh and in perfect condition. If this is the case, the act of switching to the reserve battery will demonstrate at once whether or not the difficulty is one due to weak battery power. If ignition is immediately resumed after switching over, the trip can, of course, be completed with the good battery, but one should not neglect to replace the defective one at the very earliest moment. In case, through any neglect, neither battery is known to be in perfect order, or in the very rare instance of but one battery being carried, in the absence of an ammeter, rough tests of battery strength may thus be made: A piece of wire a couple of feet long may be taken and its ends momentarily touched to the free zinc and carbon terminals of the battery. If the cells are in good condition, the flow of current ought to be enough to make a bright spark sufficient to cause the end of the wire to smoke. In case no spark is obtained in this way, or only a very feeble one, the battery may be considered as imperfectly contacted or weak. If there is no spark at all, it may be that some individual cell is internally open circuited, or that the wire connecting some cell with its neighbor has been broken or makes a bad connection in its binding posts. Wire sometimes breaks and is held from falling apart by its covering. Such a break may sometimes be located by bending the wires in various 80 directions by the hand and if a particular point in the wire is noticed which seems especially flimsy the conductor may be broken there. It will naturally occur to one to tighten all binding posts and to look especially for any sign of corrosion around the connections, which, if found, should be scraped off and clean connections made. If the battery still fails to give any current whatever, the engine should be set on the sparking position, and one should take the test wire previously alluded to and search for the break in the circuit, by touching its ends simultaneously to the two terminals of each cell, thus cutting each cell in turn out of circuit. If the particular cell which is thus being tested be the offending one there will be a spark at one or the other end of the test wire. By simultaneously touching the ends of the test wire to adjacent terminals of neighboring cells, each connecting wire between cells may be suc- cessively cut out of circuit, and if the break be located in one of these a spark will occur at the test wire when it is applied. AMMETER TEST. In the event of the battery's giving a weak spark when tested as a whole, it will probably have to be condemned, but if one has a pocket ammeter at hand it may be worth while to test the condition of each cell successively by attaching the two terminals of the instrument to its carbon and zinc terminals successively. If any one cell shows a strength very much below the others, it may be cut out of circuit with good results. Should no particular cell be found weaker than the others, the batter)' will have to be given up as useless. PARALLELING BATTERIES. If both batteries of the car are found hopelessly weak, as a last resort they may be connected in parallel, thus demanding only half the usual flow of current from either one. Sometimes one can get home through resorting to this expedient. As usually arranged, a wire leads from the free zinc terminal of each battery to one of the two points of the switch, and the free carbon terminals of the two sets are wired together, or it may be that the polarity is just the reverse. In either case, a wire con- nected to the two battery terminals from which run the wires to the two switch points will put the two sets in parallel. Some cars have switches which provide special means for paralleling the two batteries. (2) A break in the continuity of the primary circuit may occur at any one of the following points: (a) at the timer; (&) at the vibrator (if one be employed); (c) in the primary winding or connections; (d) in the battery switch; (?) in the wiring. DEFECTS IN TIMERS. (a) Timers are usually of either the roller contact type or of the commutator and brush type, and one may test the timer by throwing on the battery switch and simultaneously touching with the two ends of the test wire the binding screw of the timer and the timer shaft, or some part of the engine. This should cause a spark at the test wire and a buzzing of the vibrator if the trouble is in the timer contacts. With a multiple cylinder engine, each timer binding post may be tested in this manner. 81 POOR CONTACTS. When the engine is cranked over, the timer contacts should be seen to press firmly together at the correct points, the attachment of the wires to their binding posts should be demonstrated to be clean and firm, and the timer must not be loose enough on its shaft to allow any possibility of its motion breaking the connection. DIRTY CONTACT SURFACES. In the commutator and brush type of timer a moving brush or roller travels over the internal surface of an insulating cylindrical shell having contact segments set into its surface at proper intervals for each cylinder to be sparked. These timers are not very prone to failure, but occa- sionally the stationary contacts may become fouled with dirty oil or metal dust, or worn down below the surface of the insulation. In the latter case the insulation will have to be turned or filed down to make the surface true. The spring which forces the moving brush or roller into contact with the segments must be of the proper tension to secure positive action. Dependence upon pivots to carry the current may properly give rise to suspicion. All binding posts should be tried for tightness. A timer which is "wobbly" upon its shaft is almost sure to give trouble, especially at high speeds, and should be repaired so as to run true. COIL VIBRATORS. (&) The coil vibrator is rather a troublesome little piece of apparatus. To determine whether it is at fault, carefully place the engine on the sparking position, and with the test wire simultaneously touch the sup- port of the vibrator and the arch which carries the adjusting screw. If a spark be obtained, the trouble is in the vibrator contacts or in their adjustment. The adjusting screw is easily removed and its platinum smoothed up. If the vibrator itself can be removed from its support, this should be done, and its contact put in condition. If it cannot readily be taken off, it may be smoothed by a thin file or emery cloth. The screws which hold the vibrator to its tack support should be tight, and the adjusting screw should be left firmly clamped in its thread by means of the set screws usually supplied. VIBRATOR ADJUSTMENT. Vibrator adjustment is a matter of experiment. Two screws are gen- erally (but not always) provided for this purpose, one which determines the upward spring of the vibrator and the other the platinum tipped contact screw. In general it may be said that the spring adjustment should be so set as to cause the vibrator to make a positive contact be- tween the vibrator and the contact screw to insure the electric circuit, but it should not have an excessive tension, as then the electro-magnetism of the core may be insufficient toxlraw down and cause vibration, and too great a current will be usedV The nearer the position of rest of the vibrator is to the core of the coil, the stronger will be the field, and the spring adjustment should be so made as to take account of this. The engine should be set upon the sparking point, the switch thrown on and the contact screw turned back and forth until the buzz of the vibrator is energetic and gives forth a perfectly even sound. The adjust- ment may be tested by opening and closing the switch very rapidly with the engine in the sparking position. If the vibrator responds infallibly 82 to instantaneous contacts of the switch it will probably work properly even at high engine speeds. A GOOD METHOD. A good method of vibrator adjustment is the following : Take the secondary wires out of their connections to their plugs and place the ends of, each of them about a quarter of an inch from some part of the engine or engine frame. Then adjust each vibrator until the sec- ondary discharge will set on fire in the shortest length of time a sheet of tissue paper held between its secondary wire and the engine. If a spark will light tissue paper almost instantly it may generally be relied upon for ignition of the charge. This manner of making the adjustment will secure a very hot spark, but not necessarily economy of battery. Special instructions on this sub- ject are presented in the section of this book devoted to the coil vibrator. (c) A break or burn-out in the primary winding of the coil is so unlikely as to hardly require mention, but the connections of the coil terminals to the binding screws on the case of the coil, or to the vibrator, may have become loosened. An inspection of them will not be amiss. BATTERY SWITCHES. (rf) It is unfortunately true that battery switches often make imper- fect contacts, owing generally to reliance having been placed upon spring portions of metal which gradually lose their resiliency or break com- pletely. In switches of the plug type the spring fingers with which the plug makes contact may have been bent out of a position of positive engagement, may have become dirty or corroded, or their connecting wires may have become loosened. Switches of the three-point variety for two sets of battery, which have a pivoted contact on the lever arm, sometimes make a poor contact at the pivot, owing to wear or loss of spring in the little brushes which are supposed to preserve the contact. The lever arm may lose its spring after long use and make an uncertain contact with the battery points. In general, defects in switches are due to spring failure. BREAKS IN CONDUCTORS. (c) Positive breaks in the wiring are more easily found than partial breaks which are held in uncertain contact by the insulating covering of the conductor. Any particular wire which is under suspicion of being entirely broken, or "open," may be tested by placing the engine upon the sparking point, closing the switch and touching with the ends of a test wire the two points to which the suspected wire is attached. If the current begins to flow when this is done the wire may confidently be condemned. A wire which has in it a partial break, or a break held together by the insulation, may sometimes be tested out by freeing it from its supports and bending it sharply at successive points along its length the engine being on the ignition point and the switch on. When the defective point is bent an indication of imperfect continuity will probably be given by the making and breaking of the current. Points where the wire is sharply moved or bent in the operation of the machine, places at which it is abraded or strained by coming into contact with moving parts of the car, and points where the wire is fastened to binding posts by screws 83 which may be set up sufficiently hard to cut it off, should be very closely inspected. If there is any part of the wire which seems especially limp when handled a break may have occurred there. The wires leading to the timer are the only portions of the wiring which are necessarily loose and subjected to bending, and very often a wiring break will be found at this point. Solid wire breaks more easily than cabled or stranded conductor, but when the latter becomes broken the defect is more difficult of location. Small wire having very stiff, thick insulation is very likely to be broken when sharply bent. PRIMARY SHORT CIRCUITS. (3) A short circuit in the primary wiring may be detected as follows: Disconnect the wires where they enter the coil primaries and leave them out of contact with anything. Then touch the switch momentarily upon each of its two battery points, and if the slightest spark appears at the switch contacts (assuming the batteries not to have been run down), there is a short circuit. If this test is not considered conclusive, any electrician with a magneto testing generator can determine in a few minutes whether there is any contact between wires which should be insulated one from the other, or any short circuit between a wire and "ground," as the engine and connected metallic mechanism is called. "GROUNDS" IN PRIMARY. Short circuits from a wire to ground are generally caused by the wearing away of its insulation through contact with some metallic por- tion of the engine or connected parts. A moving part will rapidly cut through any insulation and produce a ground. Muddy water soaking into wire having inferior insulation will produce a partial short circuit or ground to a metallic body upon which the wire rests, but such a ground may require the magneto test for its detection. Wet wires of poor insulation may also leak to one another if held closely together. A short circuit may generally be removed by clearing all wires of contact with any metallic bodies and by pulling each wire away from others which have hitherto been in contact with it. If the battery is kept connected during this process, and the short circuit is complete, or "dead," the exact location of the defect may be made manifest when it is disturbed by the presence of a spark. If all wires are kept dry and away from other conducting bodies short circuits need not be apprehended. DEFECTS IN SECONDARY CIRCUIT. (B) Consider a defect in the secondary circuit evidenced by a failure of ignition when the coil vibrators are working regularly and energetically, and everything in the primary circuit has been inspected and approved. The defect may be any one of the. following: (i) An open circuit or short circuit in the coil secondary; (2) an open circuit or short circuit in the secondary wiring: (3) a defective plug. (i) The secondary wires should be detached from their binding posts on the coil, and a short piece of wire connected by one end to one of the secondary binding screws. Its other end should be brought to within about one-half inch of the other secondary post. Assuming that the battery is all right, and the vibrator working properly, the coil should throw a perfectly continuous discharge from the end of the wire, hot enough to ignite a sheet of tissue paper almost instantly. If the dis- 84 FIG. 59. SPARK PLUG TESTER WITH PLUG IN PLACE. charge does not take place, and a pronounced crackling or sizzling can be heard from within the coil, or if the discharge is intermittent while the vibrator is buzzing regularly, it is likely that the coil secondary has broken down. SPARK PLUG TESTS. A spark plug tester (Fig. 59) may be used to ad- vantage in this test. This device consists of a small chamber with a glass window, into which may be screwed a spark plug. Means are provided by which an air pressure may be pumped up in this chamber in order to reproduce the conditions of gaseous pressure under which the plug sparks in practice. If one of these testers is at hand a plug which is known to be in per- fect condition should be screwed into it and the pressure pumped up. The short wire above mentioned should be attached to the plug terminal and the tester placed in contact with the other secondary post. A perfectly con- ^ ,J I tinuous, "fat" spark of an intense brilliancy should be rj the result, and, if so, the coil secondary may be con- sidered as intact. In fact, defects in first class coils very seldom develop, and one should not hastily come to the conclusion that the coil secondary is at fault, but should be sure that all other more likely causes of failure have been eliminated. Of course, if there are decided noises to be heard, indicating a discharge within the coil, or smoke is seen coming out of the coil case, trouble is evidently present. Defective coils can, as a rule, be successfully repaired by the manufacturers only. SHORT CIRCUITS IN SECONDARY. (2) A short circuit in the secondary wiring may sometimes be detected by removing its connection from the spark plug and allowing the end of the wire to remain within about half an inch of the plug ter- minal. When the coil is operated under these conditions a discharge may sometimes be seen or heard leaping from the secondary wiring to some conducting portion of the car. Reinsulating the defective portion of the v wire, or removing it from proximity to conducting bodies, is the natural course of procedure. If the foregoing test yields inconclusive results the secondary wire may be entirely disconnected from the coil and from the plug, and a temporary wire held free from all conducting bodies connected between the two. If .the spark is satisfactorily obtained with this test wire the regular secondary wiring may be assumed to be faulty. Sometimes, upon examination, it may be found that the secondary wire has become dis- connected from the spark plug, or has become broken. The remedy for this is obvious. Water splashed upon the secondary wire will often short circuit it, unless it is very carefully insulated, and water splashed upon the external insulating surfaces of a spark plug will short circuit it until it has been dried off by the heat. USE OF PLUG TESTER. (3) Testing out a plug can be successfully accomplished only by the 85 use of the spark plug tester. All attempts to determine the condition of a plug by sparking it in the open air under atmospheric pressure are per- fectly futile. The gas between the points of a plug under the conditions of use is considerably compressed, and gas at this pressure offers a very great resistance to the passage of the discharge, compared with the atmosphere at its ordinary pressure; therefore, the discharge, if it takes place in the cylinder, might find an easier path through a film of soot or a crack in the porcelain than through the resistant gas between the points, while in the open air the path between the points would be far less diffi- cult than through a carbon deposit or a minute defect in the insulation. A failure to spark properly when tried in the tester indicates that the plug is short circuited, and a new plug should be tried. Sometimes the only fault with the plug is that its sparking points are in contact, so that no spark is possible, and, on the other hand, the points may have been placed so far apart that the voltage of the coil is insufficient to cause a dis- charge through the highly compressed charge. A little over one-thirty- second of an inch separation between the spark points may be considered correct in the absence of explicit instructions from the manufacturers. TEMPORARY REPAIR OF PLUGS. If a spark plug is short circuited and no spare one is at hand, and if it still remains short circuited after it has been thoroughly cleaned exter- nally of all carbon or oil, it should be taken apart, care being exer- cised not to break the asbestos washer which usually packs the joint between the insulation and the outside shell.' When taken apart the internal insulating surfaces can be cleaned, and if the porcelain is not cracked the plug should work properly upon being reassembled. If the packing is destroyed in the process a temporary packing of string or paper may last long enough to carry the machine home. Even in case of a cracked porcelain, thick shellac forced into the break and well dried out will sometimes cause the plug to work properly, for a time at least. Hydrometers and Their Use in Connection With Automobiles. The hydrometer is an instrument for determining the density of liquids, and is an indispensable adjunct in the care of storage batteries, as it furnishes a means of determining the density of the electrolyte. It is also of great assistance in testing the quality of gasoline and in prop- erly compounding non-freezing solutions. To be able to express the density of a liquid in definite terms it is necessary to have a standard density, and for this is taken the density of distilled water at 60 Fahr. Water under these conditions is said to be of unit specific gravity (the terms "density" and "specific gravity" are here .used interchangeably). The specific gravity of other liquids may then be determined in the following manner: Weigh off 1,000 grains of distilled water at 60 Fahr. ; then take an equal bulk of the liquid the specific gravity of which is to be determined and weigh it; its weight in grains divided by 1,000 will be its specific gravity. For instance, chemically pure sulphuric acid equal in bulk to 1,000 grains of water weighs 1,845 grains; hence, the specific gravity of sulphuric acid is 1.845. It is, however, not very convenient to accurately measure and weigh a quantity of the liquid the specific gravity of which is to be deter- mined, and the same object is accomplished much more readily by means of a hydrometer. This instrument is based on the law of floating bodies that such bodies will displace a volume of the liquid in which they float equal to their own weight. If the liquid tested is of low density or low specific gravity a greater bulk of it is required to equal the weight of the floating body, and the latter therefore sinks deeper into the liquid, so as to displace more of it. On the contrary, if the liquid tested is of high specific gravity a smaller bulk of it is equal to the weight of the floating body and the latter sinks into it less deeply. Hence the depth to which a floating body sinks into a liquid is an indi- cation of the density of that liquid. The hydrometer consists of a glass tube, with a bulb at one end and a stem of small diameter at the other. The bulb is filled with lead shot, in order to make it heavy and cause the tube to float with the stem pointing straight upward. Upon the stem are inscribed division marks from which the density can be read off directly, in terms of one of a large number of different scales. The only two scales which interest the automobilist are the so called specific gravity scale and the Baume scale. HYDROMETER SCALES. The zero point for the specific gravity scale is found by placing the instrument in distilled water at 60 Fahr., and making a mark on the stem where it emerges from the liquid. Other points on the scale can be determined by preparing liquids of different densities salt solution, for instance determining their specific gravity by weighing and meas- uring as described above, placing the instrument in these liquids and marking the specific gravity of each liquid on the stem where it emerges from that liquid. Some of the liquids which require to be ' tested as to their density are lighter than water, while others are heavier. Petroleum and all its products, alcohol, benzine, etc., are all lighter than water. Salt solu- tions, acids, etc., are heavier than water. In the United States the specific gravity scale is largely used for expressing the density of liquids heavier than water; it is used exclusively for testing the density of storage battery electrolyte. This scale is certainly the easiest to understand for the layman. The objection made to it and the excuse for the many other scales are that the use of four figures in expressing a density is confusing and annoying. THE BAUME SCALES. There are two entirely different Baume scales, one being used for testing liquids heavier than water, and the other for liquids lighter than water. These scales are due to Antoine Baume, a French chemist, and were originated in 1768. The Baume scale for liquids heavier than water is only rarely used. It was obtained as follows : The zero point was first determined by immersing the instrument in distilled water at 60 Fahr. Then a solution of sodium chloride (common salt) was made containing 15 per cent, of salt and 85 per cent, of water, and the point to which the instrument sank in this solution was marked 15 degrees. The distance between the zero mark and the 15 mark was Baume Degrees, o Specific Gravity. I OOO Baume Degrees. 8 i 1 .007 2 I 013 10 3 I O2O ii .... 4 I.O27 12 ... . . . . 5" . I O34 13 6 I 041 14 . . 7... . 1.048 IS... divided into fifteen equal spaces, and the graduation continued beyond the 15 mark. This scale is used on hydrometers for testing the electrolyte of certain primary cells. The following table gives a comparison of this scale with the specific gravity scale: Specific Gravity. 056 063 070 078 086 094 101 109 The Baume scale for liquids lighter than water is of more interest, as it is used in this country for testing gasoline and other oils, although in France, where this scale originated, the gravity scale is now used for this purpose. This scale (Baume) is obtained as follows: The point to which the instrument sinks into distilled water at 60 Fahr. is marked 10. The point to which the instrument sinks into a 10 per cent solu- tion of sodium chloride (common salt) is marked zero. The space between these marks is then divided into ten equal divisions and the graduation continued beyond the 10 mark in the same manner that is, the whole stem is divided into linear divisions equal to one-tenth the distance between the zero and 10 marks. Baume only made hydrom- eters showing up to 50, as at that time no lighter liquids were known or in use. But as the light distillates of petroleum, including gasoline, are lighter than 50 Baume, the scale has recently been extended to 90. The table on this page gives a comparison of that part of this scale which is likely to be useful to the automobilist in testing gasoline, with the specific gravity scale. It will be seen that the two scales vary in opposite directions that is, the smaller the specific gravity of the liquid, the greater its Baume test. This is certainly somewhat confusing to the novice. A specific gravity of .700 corresponds to nearly 70 Baume, and as this is about the density of the gasoline generally used for automobiles, there is con- siderable chance for confounding the two scales when speaking of the density of gasoline. Baume Degrees. 64 Specific Gravity. 724 Baume Degrees. 71 Specific Gravity. 602 65 720 74 680 66 717 7S 68 <; 67 711 76 682 68 700 77 670 69 706 78 67 <; 70 7O2 70 672 71 600 80 660 72... .DOS RANGE OF SCALES. In order to make hydrometers compact and easy and accurate to read they are provided with only a small range of scale readings, and instru- ments are made specially for specific purposes, such as testing gasoline, alcohol, storage battery electrolyte, etc. The average density of gasoline is about 70 Baume, and a scale ranging from 60 to 80 Baume is quite sufficient for a gasoline hydrometer. The density of the electrolyte in a lead storage battery varies approximately between 1.200 (at charge) and 1.120 (at discharge), so that an instrument graduated from 1.050 to 1.300 will be quite suitable for this purpose. A calcium chloride solu- tion made by diluting one part of saturated solution with one part of water has a specific gravity of 1.22, and the density should never be allowed to exceed 1.30 to 1.32, so that a storage battery hydrometer may also be used for testing non-freezing solutions Fig. 60 shows a typical gasoline hy- drometer for automobile purposes. The scale on the instrument has a range ex- tending from 60 Baume to 82 or 85 Baume. The instrument is contained in a flannel bag, enclosed in a glass test- ing jar, and is enclosed in a nickel plated carrying case, 4^ inches long ty I inch diameter. This case permits of carrying the instrument in the tool box without danger of injuring it. There is also now being made a hydrometer combined with a thermometer on the same stem, to allow of readily making corrections for variations in temperature. TEMPERATURE CORRECTION. The density of every liquid varies with the temperature, and to ascertain the character of a liquid by its density FlG - 60. GASOLINE HYDROMETER. the latter must be taken at a specified temperature 60 Fahr. Heat expands the gasoline that is, makes it less dense and, therefore, if a hydrometer reading be taken at a temperature above 60 Fahr. the liquid tested will show a lower density that is, a higher degree Baume than at the normal temperature, and vice versa. For every eight degrees the thermometer is above 60, one degree should be subtracted from the reading of the hydrometer, and for every eight degrees the thermometer is below 60, one degree should be added to the Baume degrees. HYDROMETER SYRINGE. Fig. 61 herewith shows a hydrometer syringe for use in connection with automobile storage batteries. Automobile storage batteries, both those used for propulsion and those for ignition purposes, are entirely closed, except for a small filling hole in the cover, into which a perfo- rated hard rubber plug is screwed. It is impossible to insert a hydrometer into the cell and read it, as, in the first place, the plates are very close to- FIG. 61. STORAGE BATTERY gether, leaving no room between them for the instrument ; besides, as the cell is always of hard rubber, it would be impossible to read the instrument if it could be inserted. The only way of making a hydrometer test is, therefore, to draw some of the electrolyte from the cell and place the instrument in it. This is done very readily and in a very cleanly manner by means of the hydrometer syringe shown herewith. First the vent plug is unscrewed from the -cover of the battery cell, and the tip of the syringe is inserted through the hole, with the rubber bulb of the syringe compressed. Then the bulb is re- leased, the syringe partly fills with electro- lyte, and the reading of the instrument can be taken through the wall of the syringe. The bulb is then compressed again, which ejects the electrolyte from the syringe back into the cell. The tip of the syringe need not be taken out of the cell, and there is there- fore little chance of spilling any of the acid on one's clothes, etc. In storage battery work there is no necessity for such fine readings as in testing gasoline, and it is not customary to make corections for variations in tem- perature. In the sub-figure in Fig. 61 is shown a special tip furnished with the hydrometer syringe for adjusting the liquid level in the cells. By resting the closed end of HYDROMETER SYRINGE. the tip on the electrodes and allowing the bulb to distend, any excess acid can be removed. 00 CARBURATION. The maintenance of the proper supply of gaseous fuel for the engine of a motor car may properly be regarded as the problem requiring, next after ignition, the greatest exercise of care upon the part of the operator. A few facts relative to the fuel employed will therefore be presented, a brief treatment of the principle of the carburetor will then be given and the derangements to which it is commonly subject will then be discussed. Gasoline. (ALBERT L. CLOUGH.) NATURE AND DERIVATION. The light product of petroleum, known in this country as gasoline and abroad as petrol, motor car spirit or motorine, is employed, in its varying grades, as fuel, in all internal combustion oil motors that form their explosive mixture without thorough preliminary heating of the hydro- carbon. Such motors comprise practically all automobile engines in use at the present time. The source of gasoline is the first, or lightest, of the three "fractions" into which crude petroleum is divided by the process of distillation, and the term is applied to products differing somewhat in specific gravity and composition. The first fraction of the distillation comprises the volatile, ethereal portions of the petroleum; the second, the more stable liquid portion, mainly kerosene, and the third, the very heavy or solid components lubri- cating oils, paraffine, vaseline and others. The difference in their boiling points, as always in the process of fractional distillation, forms the means of separation of the many substances which petroleum furnishes. In the process of petroleum distillation the crude oil from the wells is placed in large stills of boiler iron and heated by a fire beneath. The vapors which pass from the still through the vapor pipe are led to the condenser, where they resume the liquid form under the influence of the cold water circulating about the condenser pipes. The first or light frac- tion of the distillation, which is separated from the portion yielding kero- sene by a merely arbitrary line of demarcation, is called crude naphtha, and its components vary in specific gravity from 90 B. to 62 B., or lower. This liquid is the source of commercial gasoline and its allied fluids. This naphtha may then be further treated in steam heated stills and further fractionated. The two most volatile products thus obtained, cymogene and rhigolene, do not concern the motor car user, as they boil 91 at temperatures below that of the air. Next comes a liquid called gaso- line, but which is very much lighter than that used for motor power purposes, having a density of 88 B. to 86 B. The next fraction, some- times known as boulevard gas fluid, but more often as .680 or 76 gaso- line, is the stove gasoline of commerce, and is the fuel most commonly used in automobile motors. Next in order of density comes the 73 to 68 liquid, sometimes known as benzoline or prime city naphtha, but frequently vended as gasoline and suitable for automobile use, except in surface carburetors in cold weather. It is more commonly supplied as gasoline than the 76 article. Below this in volatility and the densest of the series is benzine of 62 density, which is used as a solvent in var- nishes and for similar purposes. These trade names mean very little and are very loosely used, and the specific gravities of these various liquids are subject to considerable variation. Of late, on account of the enormous increase in the demand for gasoline to be used as automobile engine fuel, there has been a strong tendency to utilize a greater proportion of the crude naphtha fraction for this purpose, with the result that the denser portions of the fraction are now more largely present in the gasoline being vended. DENSITY TESTS AND STANDARDS. Ordinarily, in asking for gasoline, one secures a fluid testing at about 68 B. Fortunately, in modern carburetors, in ordinary weather, almost any grade of petroleum spirit will serve as fuel at least temporarily. The only way of ascertaining what quality of gasoline is being obtained is by testing it with a hydrometer intended for use in liquids lighter than water. Hydrometers are not expensive and can be obtained from almost any instrument dealer. The construction of the hydrometer, its principles and the method of its use are fully treated in an earlier portion of this work. Nearly all petroleums yield, upon distillation, some gasoline suitable for motor use, but there is a great difference in the proportion derived from the various crude oils. Pennsylvania petroleum averages to yield not greatly more than from 8 to 10 per cent, of its bulk of gasoline suit- able for this purpose, and the Russian oil and shale oil yield even less. Asphalt base oils are very low in gasoline. It is thus seen that the gasoline supply is strictly limited by nature and should be carefully conserved if the price is to be prevented from becoming prohibitive. The future of the internal combustion oil engine must depend largely upon the possibility of the successful utilization of alcohols or of petroleum products that are denser and thus less restricted in supply. COMPOSITION AND PROPERTIES. Gasoline of a certain specific gravity varies widely as to its boiling point, as it is itself complex and capable of fractionization. It begins to boil at about 120 Fahr. and is completely evaporated at about 250 Fahr. Its composition is also quite indefinite, but it may be regarded as a mix- ture of hydrocarbons of the methane or paraffine group, of the general formula C n H 2 n + 2 . Hexame CeHi 4 and Heptane CTH, with their iso-com- pounds, probably constitute a large part of the gasoline used in automobile .engines. 92 Gasoline spontaneously evaporates at all temperatures down to the Fahrenheit zero or thereabouts, and its vapor forms explosive mixtures with air in a somewhat wide range of proportions. In a series of experi- ments conducted with 76 gasoline with the temperature of the air at 65 to 68 Fahr., it was found by Redwood that mixtures of saturated vapor and air in proportions ranging from 5 to 100 to 12.5 to 100 were explosive. With the proportion of n parts of saturated vapor to 100 parts of air the explosion was most violent. The heat of combustion as figured from the percentage composition of the liquid and sometimes stated as the potential energy contained in it is based upon the complete oxidation of the carbon and hydrogen which it contains. In practice, however, the combustion is not complete and results not only in the formation of water and carbonic acid, but in the production of carbon monoxide and of unsaturated hydrocarbon com- pounds which are partly responsible for the odor of the exhaust. In case of gasoline becoming accidentally ignited, it is useless to try to quench the flame with water, as the oil will float upon it and continue to burn. Dry sand is very effective as an extinguisher for these fires and should be kept constantly on hand where gasoline is stored or used. Chemical extinguishers are also effective against gasoline fires. The Storage and Handling of Gasoline. (N. B. POPE.) Probably the most important consideration in connection with the handling of fuels and the cars themselves is the proper ventilation of the garage. This should be looked after both on account of the danger from an accumulation of explosive gases and because of the poisonous nature of the exhausts from motors. In handling inflammable liquids, as far as possible, they should be kept away from the air. Safety cans of various sorts have been designed with a view to reducing the danger as much as possible, and some one of them should always be used where frequent handling is required. A can recommended by the Board of Underwriters is constructed substantially and arranged to automatically seal itself under all conditions. Fig. 62 shows a section of the pump and filling valve of this device. The delivery pipe is arranged to telescope into the pump when not required, and to swing in any direction for convenience in use. The check valve of the pump is shown by A in the sketch, near the outlet. In action it is lifted into its socket out of the way by the flow of the oil, but at other times is held to its seat by its own weight. Its location per- mits it to serve the double purpose of check for the pump and an automatic seal on the can. The filling valve C is closed by a stout spring, except when for the purpose of filling it is opened by pressure on the stem D. This provides a self closing filling aperture and a means for returning the drip from the pump back into the tank. Where the consumption is sufficiently great, or the source of supply at all remote, so that it becomes necessary to have on hand large 93 quantities of fuel, special provision must be made for permanent storage, with due regard to its isolation. Handling inflammable liq- uids involves a twofold danger, first, from the igni- tion of the liquid or its vapor from spark or flame, and, second, from explosion as a result of fire from an outside source, as, for in- stance, the burning of a neighboring building. Safety may be secured by affording ample ventila- tion to storage room, and by excluding from it all arti' ficial light and making pro- vision to draw only such amounts as are needed for immediate use. The isola- tion of the supply is a more difficult matter, especially in the cities, but can be accomplished by burying the tank beneath the ground, or locating it in a stone or brick vault or pit, closed with fireproof doors. It should be borne in mind that gasoline evaporates at all temperatures, and that the inflammable gas is being given off in the coldest weather as well as in summer, though not in as great quantities. To minimize the danger from an accumulation of vapor, as well as to prevent any possibility of a dan- gerous pressure being formed, the supply tank and its enclosure must always be kept where a free circulation of air is possible. The proper location of the supply and method of drawing from it depends largely on circumstances. Wherever it be possible it is best to bury the tank under ground, at a point at least as far from buildings as the insurance regulations require, and pipe the outlet to a brick or zinc lined closet, well ventilated and drained. This may also prove very serviceable as a stock room for lubricants, waste, etc. The supply may be pumped from the tank or forced to the desired point by air pressure. When it is impossible to store under ground a fireproof vault may be used and the supply maintained in wooden barrels. But this is not a good method unless the supply is to be used very rapidly, because the necessary ventilation tends to shrink the wood and thereby increase the amount of evaporation or leakage from the barrels. All empty barrels should be removed from the premises at once, as they are always more or less saturated with oily residuum and are apt FIG. 62. SAFETY GASOLINE STORAGE TANK. 94 to give off inflammable gases, even after they have been lying empty for some time. It is better 10 make the arrangement more permanent, using a metal barrel or tank and piping it in a substantial manner, with due care to avoid leakages, to the point where the liquid is to be used. A glycerine drum may be xTHE HORSELESS OE X made for the purpose and FIQ 6 TANK BL:KIED UNUERGkoUND QUT- fitted with suitable piping SIDE, WITH CONNECTION TO PUMP IN- SIDE BUILDING. and a pump must be ob- tained. The latter is shown in Fig. 63. Another good outfit is fitted with a measuring pump, which may be set to deliver any desired amount, from a half pint to several gallons (Fig. 64). Another convenient way to draw off the fuel is to use compressed air. This is very simple in a station where a com- pressor and tank are al- ready in use for pumping tires. A three-way cock must be arranged in the pressure line, as shown in Fig. 65, to insure ventila- tion when no oil is being drawn. In this diagram A is the air pressure sup- ply pipe, B the three-way cock, D the pressure line to the pipe, C the pressure relief pipe, E the gasoline suction line, G the gaso- line delivery pipe, and F t h e gasoline shut-off valve. Commercial gasoline is a blending of several dif- ferent petroleum distil- lates proportioned to se- cure the desired specific gravity. Hence the com- position varies from lot to lot, and the test alters slightly from day to day sometimes, owing to the separation of the constituents. Because of the uncertainty of the commodity, as well as its known propensities, it is never safe to handle it anywhere in the vicinity of open flame. Safety FIG. 64. BOWSER GASOLINE SYSTEM WITH MEASURING PUMP. demands that no open flame lights be used, and that elec- tric wiring be insulated with extra care where gasoline or naphtha is much used. In this connection it should be said that all ventilating pipes leading to tanks and vaults should be protected by wire gauze to prevent any possible communication of fire. The principle of complete insulation must be carried out in the machine as well as in the stable, as a flood- FIG. 6S.-GASOLINE SUPPLY PIPING. ing carburetor or a Ieak y P^ may cause its destruction at any moment, as it is impossi- ble to predict just where or when a critical mixture will be found in the vicinity of the muffler, commutator or a lamp. Filtering Gasoline. (FRANK N. BLAKE.) It is of prime importance that all gasoline be carefully filtered when it is put into the tank of an automobile, and as this is quickly and easily done there is no excuse for neglecting this most reasonable precaution. Fine wire gauze, cloth and chamois are used for filtering gasoline, and prob- ably all three materials do the work fairly well, but acting on the principle that whatever is worth doing is worth doing well, it seems best to use chamois for this purpose; it is certain that neither water nor dirt will go through chamois, though gasoline flows through it with surprising freedom. A common method of using chamois is to spread it over a funnel and then pour the gasoline through it, but this way is open to objections; the leather lies against the funnel and hinders the free flow of gasoline, and this occasions a waste of time and also of gasoline through evapora- tion. The next time the filter is used the dirt strained from the gasoline the last time it was used will be washed into the tank, unless care is taken to always use FIG. 66. WIRE GAUZE GASO- the right side of the filter. At any rate, LINE STRAINER (BREEZE). 96 both funnel and chamois are liable to be dirty, unless they are put away and kept more carefully than is commonly done. COMBINED FUNNEL AND FILTER. A good funnel and filter combined is made by taking a tin can or pail of suitable size and provided with a shut-over cover, and suspending a circular piece of chamois in it by sewing it to a wire ring fitting the inside of the can and held near the top by three little tin lugs soldered to the inside of the can ; a spout soldered into the bottom at the corner and provided with a cap completes the device. The chamois should bag down, but not quite touch the bottom of the can. The cover keeps the filter clean, and to a considerable extent prevents the evaporation of the gasoline which is left in the leather, and the cap on the spout contributes to the same end. This filter works very rapidly, as there is a large area to the filtering medium and it all hangs clear of any obstruction, besides having considerable pressure on the lower part when the filter is kept nearly full. This filter is convenient to carry if you are traveling beyond the capacity of your tank. Of all things, one should be most careful not to get dirt or water into the tank while away from home, and it is not only less trouble to have your own filter-funnel always at hand, ready to use, but it is also far safer to use it when taking in gasoline at all sorts of places, in prefer- enee to the dealer's funnel, which may be both wet and dirty. His measure may be wet and his gasoline dirty, but if they are, no harm will result if the gasoline is poured through your filter. CONVENIENT SIZE OF FUNNEL. A can 4 inches in diameter and 4 or 5 inches deep is a good size to use, and, of course, is less bulky to carry than a larger one. A larger one is more convenient for pouring into from a full gallon measure, though the smaller one does very well unless some part of the car is in the way. Filtering funnels of copper or galvanized iron and equipped with removable chamois strainers are to be had of supply dealers. These are made in various sizes, the larger ones being more convenient and quicker acting, although not so readily carried upon a car. GASOLINE SEPARATORS. x In Fig. 66 is shown a gasoline separator or strainer intended' to be inserted in the fuel pipe between the tank and the carburetor. The con- nection with the tank is by the threaded union on the left hand side of the figure, and that to the carburetor upon the right hand side. Drops of water or solid particles gravitate into the central standpipe through the bottom hole thereof and thence into the drain cock fitting, which, when opened, allows them to escape. The gasoline passes down into the standpipe through the upper hole therein, thence into the body of the separator and upwardly, through four thicknesses of fine wire gauze, shown in section in the diagram, out to the carburetor. Most cars are fitted with a strainer of this character. The Gasoline Carburetor. The source of the mixture of gasoline vapor and air, which forms the fuel charge of the engine, is called the carburetor or vaporizer. Gasoline is one of the liquids which have a very low boiling point and 97 which are constantly evaporating, even at ordinary temperatures, and saturating the air with which they are immediately in contact with their vapor. The office of a carburetor is merely to rapidly bring a large body of air into intimate contact with a quantity of gasoline in the form of spray, and to effect the evaporation of the latter by the former, and supply the resulting gas to the engine. Such control of the air and gaso- line supplies must be 'at all times maintained as will cause the result- ing mixture to contain the two ingredients in proper proportions. There must be no undue preponderance of air, as in that case, even though the mixture should ignite, its temperature and useful expansion would be reduced by the excess. On the other hand, there should not be too much gasoline vapor, as fuel would be thrown away, unburned or decom- posed into soot, on account of there not being enough air to consume it. As ordinarily constructed a carburetor consists of the following essential parts : ' the float chamber and its float and needle valve, the vaporizing chamber, and the standpipe with its spraying nozzle. Gasoline is supplied from an elevated tank or under artificial pressure to the float chamber A (Fig. 67), in which the liquid is maintained FIG. 67. CARBURETOR WITH SUPPLEMENTARY AIR VALVE. at exactly a constant level, independent of demand, through the auto- matic action of the float B and needle valve C, which act in much the same manner as does the ball cock in the domestic bathroom tank. The vaporizing chamber D is usually a vertical passage generally of a more or less double conical section and cast in one with the float chamber. Its upper end E is connected to the suction pipe which leads to the inlet port of the engine. From the lower portion of the float chamber a small pipe F leads into the vaporizing chamber, and, turning, rises ver- tically in its centre and forms the standpipe G. This pipe has a very small bore, and supplies the gasoline for the mixture. Its upper end is at nearly the same horizontal level as the liquid in the float chamber, so that gasoline is always ready to flow from it. The form of the out- let of the standpipe is such that when gasoline is emitted it will be broken into fine spray. 98 Near its lower end the vaporizing chamber is usually contracted for an important reason, to be described later, and near its upper end is located a valve, called the throttle H, which serves to regulate the amount of mixture which goes to the engine. In the pipe which leads from the float chamber to the spraying nozzle L is usually a needle valve I which serves to regulate the supply of gasoline. The action of such a carburetor is as follows : During the suction stroke of the piston a partial vacuum is created within the cylinder, and, as the inlet valve is opened, this suction causes air to enter at the lower end of the vaporizing chamber or through an air pipe connected thereto. This air has to pass the contraction at K in the lower portion of the chamber which has already been referred to, and is thereby somewhat throttled or rarefied, so that there is a slight degree of vacuum formed in the space around the spraying nozzle. Since the surface of the liquid in the float chamber has upon it the full pressure of the atmosphere, gasoline is energetically squirted through the spraying nozzle, in the form of a mist, to fill the partial vacuum. This spray becomes intimately mingled with the air, and the mixture passes the throttle H and thence through the intake pipe and valve to the cylinder. When the needle valve regulating the gasoline supply is correctly set, the entering air will be nearly uniformly impregnated with such a pro- portion of gasoline as to be perfectly explosive, no matter whether the engine is drawing gas rapidly or slowly; for if it is not drawing mix- ture very rapidly the vacuum produced around the standpipe will be very slight, and the flow of liquid through the spraying nozzle will accordingly be quite moderate, while if a high rate of gas supply is demanded, the entering air will be considerably contracted, quite a strong vacuum will be formed, and gasoline will be sprayed energetically. In point of fact, however, this inherent self regulating property of a carburetor of this kind is not complete, and there is a tendency for mixtures containing too much gasoline to be produced when the demand for gas is great. A carburetor unprovided with any means for rectifying this tendency is called a simple carburetor, and a carburetor provided with means for its correction is called "automatic." This means of automatic correction of the quality of gas furnished is known as the auxiliary air valve and may take the form of a spring closed poppet valve such as shown at M. When the demand for gas is small, sufficient air for the mixture will enter at K and the vacuum at D will be insufficient to unseat the poppet valve M, against the pressure of the spring. When the demand for gas becomes considerable, so great, in fact, that not enough air would be furnished through K in proportion to the gasoline sprayed, the vacuum becomes sufficient to unseat the poppet valve and a sufficient amount of auxiliary air enters through N to meet the demand and maintain the quality of the mixture. With a further increase of gas demand the poppet valve opens still further, its rate of opening with increased gas demand being so adjusted by increas- ing or decreasing its spring tension as to secure the desired quality of gas throughout the range of throttle opening and speed variation of the motor. Various arrangements of the automatic air supply are resorted to in different carburetors, but they all have the same intent, that of 99 adding supplementary air to the mixture as the gas demand increases. The necessity for so doing is on account of the following considerations : DEPENDENCE OF MIXTURE ON SUCTION. The action of a gasoline jet comes under the laws of discharge from orifices and the admission of air under the laws of the flow of gases in pipes. The force which causes the flow is the same for both air and gasoline, viz., the suction in the inlet pipe. The rate of discharge from an orifice is always proportional to the square root of the pressure pro- ducing it, and the velocity of air at any point in a pipe one end of which is in communication with the atmosphere is also proportional to the square root of the suction at this point. Both of the components of the com- bustible mixture seem therefore to vary with the suction in the same proportion, viz., as the square root of the suction. However, the flow of gases in pipes is a rather complex phenomenon, and the velocity of flow past any given point is no measure of the actual rate of flow or the amount of gas or air passing this point in unit time, because the air in its progress through the pipe expands, and the velocity increases from point to point along the pipe. The higher the speed of the air the less its density, and consequently the actual rate of flow of air varies less rapidly than the square root of the suction. In other words, while the speed of the air past the spray nozzle and the speed of gasoline flow from the nozzle are always proportional, the density of the air decreases as the velocity increases, and hence the quantity of air by weight varies less rapidly than the quantity of gasoline. There is a second reason why the feeds of air and gasoline do not vary in the same proportion when the suction varies, and that is that an initial suction is required to lift the gasoline to the mouth of the nozzle, before spraying can begin at all, the normal level of the gasoline in the nozzle being kept at some distance below the mouth. Only the slightest suction is required to draw air through the inlet pipe, but there is a certain minimum suction below which no gasoline will be fed, and this is the reason why when the engine is started by turning it over by hand, when the suction is naturally very weak, it is necessary to first "flood" the carburetor by holding down the float. The effect of the initial suction required to raise the gasoline to the mouth of the nozzle on the proportions of the mixture for different intensities of suction is well shown by the following consideration. Taking no account of the variation in density of the air passing the nozzle, the flow of air is pro- portional to the square root of the suction, and the flow of gasoline to the square root of the suction minus the pressure required to lift the gasoline to the mouth of the nozzle. The ratio of gasoline to air varies therefore as the square root of the quotient of the suction minus a con- stant, by the suction, and this value naturally increases as the suction increases ; hence the mixture becomes richer the greater the suction. The auxiliary air valve instead of being under the influence of a single spring, as in Fig. 67, may be controlled by two springs which act successively a weak spring which resists the first motion of the valve that takes place at relatively low gas demands, and a stronger spring which comes into action during the greatest gas demands. This arrangement is adopted in order to secure more perfect compensation. FLOATING BALL AIR VALVE. Instead of employing a spring controlled poppet valve for this pur- pose, it is becoming quite common to make use of a series of balls of graduated diameter held to their seats by gravity. As more auxiliary air is required for the mixture, the increased suction tends to raise these balls and to allow of the admission of air between the balls and their seats. The sizes of the balls are so chosen that they rise from their seats in such numbers and in such order that approximately the correct amount of additional air is admitted. This arrangement permits of the elimination of springs and their adjustments. VENTUEI TUBE. It is becoming quite common to make the cross section of the vaporizing chamber that of the frustra of two cones, with their smaller ends joined together, the jet being located at or near the contraction thus formed. A vaporizing chamber of this form is known as a Venturi tube, and its action is such as to tend toward the more correct proportioning of the fuel and air which go to form the mixture. The vaporizing chamber shown in Fig. 67 is somewhat of this form. PREHEATING THE CHARGE. In order sufficiently to vaporize the rather heavy grade of gasoline now used so that it shall enter the cylinder in a truly vaporous condi- tion with the air rather than in the state of minute liquid particles borne in the air stream, it has become necessary to provide means for furnishing artificial heat to the carburetor. This is accomplished in two ways : (i) By taking a part or the whole of the air for the mixture in a heated condition by gathering it from a point where it has been warmed by the exhaust pipe, and (2) by surrounding the vaporizing chamber of the carburetor with a- jacket through which circulates the hot water from the radiator. In method (i) the warmed air possesses a greater capacity for gasoline than does cold air, and in method (2) the heat entering the vaporizing chamber through its walls helps supply the large call for heat required to supply the latent heat of vaporization of the evapo- rating fuel. A great proportion of the carburetors now in use are fitted with some means of heating them, the water jacket being the most ap- proved method. Artificial heat is more necessary in cold than in warm weather, and means are often provided for cutting off the heat supply when the air temperatures are high. Another expedient resorted to for the purpose of securing com- plete evaporation of the gasoline is that of mechanical agitation of the mixture. Fig. 67 A represents the "Homo," THE HORSELESS GE FIG. 6;A. "HOMO" FUEL MIXER. a mechanical device intended to render more homogeneous the mixture furnished an engine. It consists of a fan, placed in a chamber, which is interposed be- tween the carburetor and the in- take pipe. This fan is mounted on ball bearings, and is caused to rotate rapidly by the incoming gas stream.- As it does so it subjects the mixture to energetic agitation, which is claimed to result in a breaking up and vaporization of any entrained gasoline, and in an improvement in the vaporous na- ture of the mixture. The fan carries a network of galvanized iron wire, which is claimed to be essential to the breaking up of the gasoline drops. VAPORIZING TUBE CARBURETOR. In order that the supply of artificial heat shall prove effective in bringing about complete vapori- zation, the warmed surfaces should be of large extent, and a form of carburetor known as the "vapor- izing tube" type is being intro- duced to embody this idea. Fig. 68. Here F is the float chamber, N the standpipe, T is a hot water jacket of considerable length (here shown cut off) which encloses the long vaporizing tube (shown within it). The auxiliary air is admitted at the upper end of the vaporizing tube, which carries a nearly saturated mixture that is in contact with the hot walls of the jacket for a considerable distance. Up to this point we have spoken only of the automatic carburetor in which the necessary auxiliary air is admitted by the automatic unseating of a poppet valve or a series of balls. THE" MECHANICAL CARBURETOR. However, the mechanical carburetor, so called, is in quite extensive use. In this type the throttle valve is mechanically connected by means of a suitable adjustable linkage, with a valve controlling the air supply so that as the gas demand increases with the opening of the throttle, the amount of air admitted is also increased. (Fig. 69.) By a careful propor- tioning of the parts and a proper adjustment thereof the mixture furnished by such a carburetor may be made quite satisfactory. FIG. 68. VAPORIZING TUBE CARBURETOR. 102 FIG. 69. MECHANICALLY CONTROLLED CARBURETOR (FRANKLIN). VARYING THE GASOLINE SUPPLY AUTOMATICALLY. Instead of relying en- tirely upon the expedient of admitting additional air as the gas demand in- creases, and thus securing a uniform mixture, some carburetors are fitted with a mechanical arrangement actuated by the throttle mechanism which auto- matically increases the amount of gasoline passing the spraying nozzle as the gas demand increases. (Fig. 70.) Here the throttle valve arm carries a flexible metal segmental track A, which can be adjusted more or less in a direc- tion in and out of the plane of the paper by means of the adjusting cams C C so as to have a FIG. 70. SCHEBLER CARBURETOR WITH AUTO- curved profile. Upon this MATICALLY VARIED GASOLINE SUPPLY. 103 track runs the roller B, the movement of which, in a direction away from or toward the observer, serves to change the opening of the gasoline needle valve at various portions of the throttle range, in such a manner as to make the mixture meet the requirements. MULTIPLE JET CARBURETORS. It is often a very difficult matter to secure, at all times, a suitable FIG. 71. DOUBLE JET CARBURETOR (STEARNS). A, float chamber; B, float valve; C, flooding valve; D, bell crank for operating same; E, pull rod; F, auxiliary spray nozzle; G, main spray nozzle; H, valve at inlet to auxiliary spray chamber; I J M, throttle valve; N, valve at inlet to main spray chamber; L, bell crank for operating throttle; K, rod transmitting motion of same; O, outlet of carburetor. mixture for large multicylinder engines capable of very great variations in speed. In such cases instead of employing a single gasoline jet two or three jets may be used, the jets being brought into action successively as the gas demand is increased. At very low throttle openings but one jet is active, and this may be so adjusted that a sufficiently rich mixture 104 to operate the engine at a very low speed, and to render Starting easy, may be secured. As the engine speed increases the second and, in some cases, a third jet are also brought into action, thus furnishing the additional fuel required in more exact amounts than can be secured if one jet only, with its single adjustment, is depended upon. The method of successively bringing the jets into action is to successively uncover them and thus expose them to the engine suction. This may be done by the movements of shutters controlled by the throttle action, by the automatic lifting of shutters or by other equivalent means. Carburetor Troubles and Their Remedies. (ALBERT L. CLOUGH.) The earburetor, when well adapted to the motor which it is to supply, and given a correct initial adjustment, is one of the least troublesome elements of the automobile mechanism. Ordinarily it will perform its service continuously and uniformly for long periods of time without requiring attention, and it is too often blamed for faults in engine opera- tion which should be attributed to defects in the ignition system. In searching for the cause of irregularity of action in an automobile motor, the sparking arrangements may generally be profitably scrutinized with the utmost care before investigation proceeds to the carburetor. Of course, there are certain symptoms which point at once to carburetor trouble, such as black smoke in the exhaust, or fouled plugs, but in cases where there is no obvious sign, such as the above, the carburetor may wait for its inspection until all electrical features have been most minutely examined. Faithful as the carburetor usually is in the performance of its prescribed duty, there are certain derangements to which it is subject, the same as with all mechanisms. GASOLINE LEAKS. Every user of an automobile should be very watchful concerning the possible development of gasoline leaks on his car, and an occasional glance under the machine, when it is at rest, with the engine stopped and the gasoline still turned on, may prove profitable. Gasoline leaks are to be avoided not only on account of the loss of valuable fuel, but on account of the fire danger which they involve. A glance under the supply tank will at once show whether it has become leaky, through the opening of its seams, by jarring, or whether the union connecting the gasoline pipe to the tank is leaking or not. The tanks of some low grade machines are made of galvanized iron. When this is the case the drops of water which are almost inevitably taken in with the fuel remain upon the tank bottom and finally rust it through. When a leak due to this cause has developed it is practically no use to solder it, as other holes will appear in a few days. The tank might as well be discarded and one strongly made from heavy gauge copper substituted for it. How TO PREVENT LEAKS. The gasoline pipe may well be examined for leaks, as mav be the union which connects it to the carburetor float chamber. This pipe should have sufficient slack in it to prevent its being strained under any conditions, and 105 may well comprise a coil, of one or two turns, to render it flexible under the strains of service. It should not be so placed as to come in contact with any other part of the mechanism which might abrade and in time nick it, so as to cause it to leak. If either of its unions is found to leak, it should be disconnected, the ground surfaces wiped perfectly clean and given a coating of white soap, which will be found to stop light leaks. If, however, this expedient is ineffectual, the bearing surface will have to be ground in with fine emery and rouge or whiting, or a new union supplied. The soldered connections of the gasoline pipe to its unions will bear watching from time to time. REPAIR OF LEAKY PIPES. A leaking or broken gasoline pipe is a rather annoying accident to be met with on the road, but it may be temporarily repaired by cutting out the leaky portion and joining the severed ends by means of a short length of rubber tubing of suitable size, the connecting ends of the rubber being held by wire winding to their respective ends of the copper pipe. In the absence of a soldering iron for making a permanent repair, or of rubber tubing, one may be able to drive a few miles with the following make- shift: Take narrow strips of cloth, torn from a handkerchief, soap them well and wind tightly over the junction of the broken ends, which should first have been filed off squarely; then take adhesive tape and wind firmly over the cloth, beginning at quite a distance beyond it in each direction. PUNCTURED FLOATS. When the car has been at rest for a short time with the gasoline left turned on, there should be no drip from the carburetor. If it is found that gasoline is still dripping from a float feed carburetor, it requires attention. Some manufacturers are now using cork for the material of their floats, as being more reliable than the hollow metal ones. These latter sometimes develop minute leaks, partially fill with liquid, and lose so much of their buoyancy that the gasoline level in the float chamber is main- tained above the level of the top of the spraying standpipe. This permits a constant loss of fuel when the car is standing. The presence of liquid inside a metal float may at once be detected by the sound when it is shaken, but the leak through which it entered is usually so minute that the liquid cannot escape through it, and is too small to be detected by the eye. If the float is heated slightly, so as to partially vaporize the liquid within it, and the flame of a match is passed over the float's surface, the hole will be discovered by the ignition of the issuing vapor. After mark- ing the leak a hole should be punched in the float with an awl to allow of the egress of the contained liquid, and both holes should then be carefully soldered. Cork floats, if they become gasoline soaked and lose their buoyancy, should be dried out and carefully shellacked. IMPERFECT SEATING OF GASOLINE VALVE. If the float is found tight and in good condition the cause of the con- stant flow of fuel is probably the failure of the needle valve to seat tightly under the influence of the float. Unless the carburetor is mounted with the float chamber truly horizontal, this is very likely to happen. The leak may usually be stopped by grinding this valve into its seat with a little whiting, or even grinding the seat and valve 1 together without any abrasive, 106 holding the needle and seat in their true relative positions and giving them a motion of rotation with moderate pressure. No FLOW OF GASOLINE. Sometimes, instead of an excessive supply of gasoline passing the carburetor, little, if any, will flow, even when the carburetor is flooded in the accustomed manner. It may be that a sufficient quantity of impurities has gathered upon the wire gauze filter, which is usually placed in the supply orifice of the float chamber. This may be opened to inspection by freeing the union of the gasoline pipe to the chamber and the gauze can then be readily cleansed. ' Some impurity may have worked its way through the gasoline passages and become lodged in the needle valve or other measuring device which allows the gasoline to reach the mixing point. In this case the needle should be entirely withdrawn and cleaned, and its seat flushed out by causing gasoline to run through it freely upon depressing the float. "There is no need of losing the adjustment in doing this, as after the set screw which locks the adjustment is loosened the needle may be turned down to a completely closed condition and the number of turns required may be noted. This will give the necessary data to make it easy to effect the old setting when the parts are put together. In order to avoid the possibility of foreign matter finding its way into the passages of the carburetor, it is well to occasionally draw off the float chamber through the plug in the bottom, which is always provided. By depressing the float when the plug is out, gasoline may be flushed through the chamber, carrying with it all remaining sediment. GASOLINE SHOULD BE STRAINED. In regard to this matter of impurities in gasoline, it may be said that all trouble arising from them may be averted by the use of a chamois filter in the funnel when the tank is filled. This will stop not only solid particles, but will successfully exclude all water which the gasoline may contain. There is a great deal of talk about gasoline containing water, as if the two liquids were capable of being mixed, so that the water became impossible of detection and likely to affect the running of the motor in some obscure manner. Water, as the well informed motorist knows, will no more mix with gasoline than it will with oil, and if any water is present in a vessel of gasoline it will be perfectly apparent in the form of globules collected on the bottom. If the gasoline tank be filled from a can having a faucet, there will be no danger of water escaping from the filling vessel with the gasoline, as the former will seek the bottom of the can below the level of the faucet. If the tank is filled from a measure, the water, if any, is readily seen on the bottom, but if the gaso- line is poured in from a can which has no faucet, the water, if present, is likely to be emptied out with the gasoline, but will be caught by the chamois strainer if one be used. Fine solid particles or dissolved gummy sub- stances are the impurities in gasoline which are most difficult to guard against. Water is easily avoided, as it is so easily detected. Some gaso- line tanks are fitted with a settling pocket, which forms the lowest point of the tank. Water and solid particles are supposed to gravitate into this, and it should be drawn off occasionally by means provided therefor. The gasoline outlet from the tank is sometimes fitted with a strainer, and occa- sionally this should be cleaned to prevent its becoming clogged. 107 FREEZING OF CARBURETOR. When water is allowed (through carelessness) to enter the float cham- ber, it creates special trouble in cold weather. It will settle into the recess in the bottom which forms the guide of the float stem and when it freezes will prevent the action of the float. If it enters the passage leading to the jet it will stop it up completely when it congeals, as it may readily do under favorable conditions. Most carburetors take in their air through some sort of a strainer, with the intention of excluding from the engine particles of dust and other materials. Sometimes this strainer is a fine wire gauze, and sometimes it is a loosely woven fabric. These strainers need cleaning occasionally so that the air may not be unduly throttled. A fabric strainer may be washed in gasoline and all foreign material thus removed. When a carburetor is rather small for the gas which it has to supply, it becomes very cold while in operation, as the heat called for to effect the evaporation of the gasoline is more than that available from the entering air or than can be secured through the metal of the carburetor from the outside air by conduction. The metal of the carburetor is very often reduced in temperature to a point below the dew point of the surrounding air and a large amount of water condenses upon it. Under extreme con- ditions the moisture is deposited in the form of white frost, which evi- dences a temperature within the carburetor low enough to preclude the successful use of low test fuel and possibly to affect the intimacy of the resulting mixture even when high test gasoline is employed. If any water is present in the float chamber, it will be likely to freeze and disturb the action of the carburetor. The methods of supplying artificial heat have been described in an earlier portion of this chapter, and should be resorted to when more heat appears to be required. ADJUSTMENT. As to the matter of adjustment, only general statements can be made, as there is so great a variety of carburetors on the market. One adjust- ment, however, and the most important one, is common to them all, namely, that of the needle valve which regulates the flow of fuel to the spraying jet. Carburetors which possess automatic air valves or air valves which are interconnected with the gasoline valve vary in their individual arrangements so widely that the following of the directions which accom- pany them is the only practical course. The main point in the handling of almost any carburetor is this adjustment of the gasoline supply. A good method to effect it is as follows: Be sure that the ignition apparatus is in perfect order. Open the muffler, or, still better, disconnect it, so that the exhaust flame may be seen. See that the spark is set not earlier than the dead centre and that the throttle is open a little and, with the gasoline adjustment open a fraction of a turn, the gasoline supply valve open and the carburetor flooded ; have the engine cranked by another person while the gasoline adjustment is being opened very gradually. When explosions commence and the engine is fairly running, the adjustment should be so regulated that the engine shall give an exhaust flame of a deep, rich blue color. If its color is a lurid red, accompanied by black smoke, it is evi- dence that too much gasoline is being fed, while if the exhaust flame is 108 small and pale almost a yellowish green there is an excess of air. The sound of the exhaust will also give the practiced ear some idea of the quality of the mixture. Where the charge is too rich the 'Sound is more like a puff than like a detonation ; when too weak, it is sharp, but with a hollow, low tone, and when the mixture is correct and the exhaust un- muffled, the sound has the peculiar indescribably sharp "smacking" sound of beating together two pieces of wood. ADJUSTMENT OF AUTOMATIC CARBURETORS. If -the gasoline adjustment is made with a nearly closed throttle the latter should now be opened widely. With an "automatic" carburetor the mixture should still prove correct at this higher speed, but it may be actually too rich, in which case provision for the entrance of more air through the automatic valve or mechanically controlled auxiliary inlet should be made. Adjustment should not be regarded as perfect until a good mixture is obtained at all degrees of throttling, as judged by the character of the exhaust flame and the activity of the engine. With many carburetors which are not fitted with automatic air supply, the best that can be done is to secure such an adjustment as wil] give a perfect mixture at full throttle opening, even though it is slightly defective under nearly closed throttle. Making the carburetor adjustment with the engine run- ning light is far from satisfactory. With full throttle opening the motor speeds up to a rather distressing extent, even when the spark is somewhat retarded, and this racing is not particularly good for it. The running condition during which it is most imperatively desirable that the mixture should be perfect is when the engine is operating under fully opened throttle and heavily loaded, as when climbing a considerable grade on the high gear. Also, when the engine is racing it is very difficult to detect a single missed explosion, and one is always in doubt after a .test of a motor running light whether it will do good work at low speeds. ADJUSTMENT FOR FULL POWER. If the motor is not too large this difficulty may be met by arranging a crude brake, formed of a piece of board or plank held forcibly in contact with the face of the flywheel. When this brake is in application the motor speed may be kept very moderate, even under full throttle, and with the usual spark advance, and conditions for adjusting the carburetor may thus be realized which somewhat approximate to practice. The engine is not so badly "racked" when running under this brake control, missed explo- sions are easily detected at the lowered speed and some idea can be gained as to whether the motor is "pulling well." Instead of resorting to a makeshift brake of this kind the car may be securely jacked up, the high gear thrown in and the brakes applied sufficiently to slow the motor to a moderate speed. This practice is only recommended for very short trials, however. One thing which should be remembered : That it is more essential to have a carburetor so adjusted as to enable its motor to pull hard on low speeds and under severe loads than to race madly when light. Some idea of the correctness of adjustment may be gained by run- ning the motor with nearly closed throttle and spark not earlier than the centre, and then suddenly opening the throttle, closing it again almost immediately. If the speed of the motor "picks up" instantly and rapidly, 109 and there is no choking, missed explosions or popping back, it is likely that a usable adjustment has been attained; but one can never be sure of this until the car is tested out upon the road under various conditions of grade and speed. The following additional suggestions, part of which are due to Frank S. Hanchett, may be found useful: If the ignition system is shown to be in working condition, the trouble is almost certain to be with the carbureting system. The engine receives either too rich a charge, too poor a charge or no charge at all. If the charge is too rich, continuous cranking will produce an occa- sional weak explosion, and such an explosion will be followed by a cloud of black smoke emitted from the muffler, which is a positive indication' of too rich a mixture. If, on the other hand, the mixture is too poor in gasoline vapor, continued cranking is likely to produce no result whatever. In order to make sure of the cause of the trouble it is necessary to intro- duce gasoline into the cylinder through some other than the regular channel, and this is probably best accomplished by holding a rag saturated with gasoline over the opening of the air inlet to the carburetor. Let one man hold the rag while another does the cranking, and if poor mix- ture is the sole cause of the trouble an explosion will certainly be obtained in this way. Some caution is, of course, necessary in handling the rag. Partly closing the air inlet by the hand may also sufficiently enrich the mixture as to cause an explosion. Another method of introducing gaso- line by hand is with an oil squirt can through the air inlet, or a hole drilled for the purpose in the pipe between the carburetor and the engine, and which is afterward closed by a plug. CAUSES OF OVERRICH MIXTURE. If the symptoms show too rich a mixture, the problem is to discover to what the excess of gasoline in the air is due. With most carburetors it is necessary to "prime" the carburetor before starting the engine, which operation consists either in depressing the float by means of a plunger extending up through the cover of the float chamber, to allow the gaso- line to rise in the float chamber above the level at which it is normally maintained by the float, or in creating an air pressure in the float cham- ber by means of a conveniently located rubber bulb, with rubber tube connection to the chamber. The reason why priming is necessary for starting is that when the engine is turned over by hand the motion is much slower, and the suction consequently much weaker than under con- ditions of normal operation, and if an approximately full charge of gaso- line is to be drawn in, the level in the spray nozzle must be higher than normally, or some gasoline must be forced from the spray nozzle into the bottom of the mixing chamber. Now, it is evident that there may be such a thing as excessive priming. A novice operator may hold the float down until the gasoline runs out of the spray nozzle and fills the bottom of the mixing chamber, especially if there is no drain hole at the bottom of the chamber, as is the case with some carburetors. If the gasoline is of a light grade, and the temperature is warm, an overrich charge will be obtained, and the motor will be difficult to start. The remedy is to keep cranking the motor until the excess of gasoline is pumped out. The trouble is a temporary one, and is completely removed as soon as the engine starts up. A too rich mixture may also be due to throttling of the air inlet in some manner. For instance, the mouth of the air inlet tube is often covered by a wire screen, and this may have become clogged with mud or other matter a trouble which is, however, not likely to be encoun- tered in a modern car with an apron underneath or the air inlet pipe may accidentally have been turned in such a manner that its opening is almost closed by some other part of the engine or car. Although cork floats are not subject to springing leaks like metal floats, they are liable to a similar failing in that the coating applied to the cork to render it impervious is liable to wear off in places, allowing the cork to soak full of gasoline, thus becoming much heavier, and consequently, losing in buoyancy, giving rise to flooding. This trouble can be over- come by taking the float out of the carburetor, allowing it to dry, and applying to it several coats of shellac dissolved in alcohol, each of which must be quite dry before the next is applied. When the motor persistently refuses to start and the ignition system is shown to be intact, the chances are that the mixture is too poor or that the engine draws in nothing but pure air. One of the most frequent causes of this trouble is that the driver has forgotten to fill the gasoline tank, or that it has run dry in the course of the journey. An interruption due to this cause is often very perplexing, as the driver usually feels cer- tain that he has attended to the filling before starting or has given orders to have the tank filled. Many amusing incidents of long extended hunts for the cause of some apparently deeply hidden trouble have occurred when there was nothing at the bottom of the whole thing but a little forgetfulness. As it is easy to ascertain whether there is any gasoline in the tank, it is always advisable to do this when the indications are that no explosive vapor is fed to the engine. The test must, of course, be of such a nature that its indications are conclusive. For instance, it is no sign that there is no lack of gasoline if some of the fluid flows out of a drain cock at the bottom of the float chamber or at any other low part of the gasoline system, because the engine would "die" long before the gasoline came down to this level. Supposing, however, that the tank contains plenty of gasoline, then the passage for the gasoline from the tank to the spray nozzle must be blocked at some point. It may be that the driver has simply forgotten to open the valve in the gasoline pipe line if the trouble is experienced shortly after starting out, but otherwise there is likely to be some obstruction either at the needle valves, at the strainer or at the spray nozzle. On more than one occasion a weak engine has been made strong by simply opening up the vent hole in the tank filling plug or drilling one where none was provided, as with no vent the gasoline is held up by the forma- tion of a partial vacuum above it, and will not flow to the carburetor freely enough to make all the gas needed. Another point in the gravity system is the liability of stalling on a steep hill when the gasoline becomes low in the tank, on account of the lack of fall from the tank to the car- buretor, but the wily driver overcomes this by simply backing his car up the hill, thus putting the tank at a higher level than the carburetor and giving the gasoline the needed head. In case gas pressure feed is used, carbon particles held in suspension by the burnt gases must be guarded against by passing the gas through a fine mesh strainer. The line strainer for the gasoline is usually placed either at the bottom of the carburetor float chamber or in a special strain- ing device. It is always so arranged that the straining screen can easily be taken out and cleaned, and this should be done at intervals. A very hard thing to discover sometimes is the cause of a loss of pres- sure in the pressure feed style of gasoline delivery, when it arises from a number of small leaks in the tank seams or air pipes, and where none of the leaks are large enough to locate by sound or feeling. In such a case as this, if the pipes, seams, etc., are painted with soapsuds the leaks will disclose themselves by forming bubbles wherever there is an escape of air. Occasional washing out of the tank will assist in keeping the carburetor in good working order by removing the small particles of scale and dirt which accumulate and preventing them from getting down between the carburetor float valve and its seat. The location of strainers, if any, in the gasoline pipes should be ascertained by the operator and a fre- quent examination of the same made, as their clogging will seriously interfere with the efficiency of the flow. If a stoppage be located in the gasoline pipe, and no means be at hand to take the pipe down, the trouble may frequently be eliminated by forcing air through it with the tire pump until the air can be heard bubbling through the gasoline in the tank. Simply holding the end of the air hose against the delivery pipe makes a tight enough joint for this purpose. When this is done it is advisable to allow sufficient gasoline to escape from the pipe to thoroughly flush out the dirt which has been loosened up. In that type of carburetor where the spraying nozzle is placed in a mixing chamber which is entirely separate from the chamber containing the float there will generally be two or more small holes found in the bottom of this mixing chamber, placed there for the purpose of allowing any accumulation of gasoline which might come from a leaking float valve to drain away. These drain holes must be kept open ; otherwise, should the carburetor flood badly while standing the gasoline will find its way into the cylinder and crank case in fluid form, destroying all lubricant with which it comes in contact and laying the foundation for an accidental explosion. A further source of trouble may result from the use of gasoline of too heavy a grade, especially during the winter months. The Baume test of the gasoline changes one degree for every eight degrees (Fahrenheit) change in temperature, so that a gasoline which shows 70 Baurae at the standard temperature of 60 Fahr. is only 65 at 20 Fahr. The effect of low grade gasoline in a carburetor is that the buoyancy of the float is increased, and the fuel is maintained at a lower level in the spray nozzle, consequently a smaller charge of gasoline is drawn into the engine. The remedy consists in weighting the float or in adjusting the float valve so as to shut off the supply at a higher level in the float chamber. If neither of these methods is practicable there remains the possibility of over- coming the difficulty by increasing the suction around the spray nozzle by reducing the area of the air passage around the nozzle or of the air inlet. Care must be used in keeping all joints of the mixture pipe between the carburetor and engine cylinder tight. Mysterious cases of engine miss- ing fire can frequently be traced to leaks in this pipe, the vibration of the machine causing the leaking joints to open up, at times to such a degree that enough air will be drawn through them to dilute the gas until it loses its ability to explode. Soldered joints are especially liable to this trouble, and with them it will sometimes be found necessary to take the pipe down to locate the trouble, as with the engine standing still and the pipe bolted in place the looseness will not show. Defective gaskets at the inlet pipe connections or worn inlet valve stems may also lead to such leaks. Back firing in the carburetor is often attributed to the use of too weak a mixture, but it is also likely to be caused by some portion of the combustion space being raised to such a temperature that the incoming gas becomes ignited before the inlet valve closes. An extremely late position of the spark is likely to aggravate this effect. If the inlet valve sticks open, through weakness of its spring or any similar cause, back firing is likely to result. Fuel Consumption as a Criterion of a Car's Condition. (ALBERT L. CLOUGH.) The proportion of the amount of fuel used to the mileage traversed furnishes a valuable indication of the condition of a car. The number of miles which a car will cover, carrying a certain load over a certain road, per gallon of gasoline burnt, will at once inform its owner, who has given consideration to his special case of the fuel question, whether or not it is performing as well as usual. Sudden changes of condition in the car, evident losses of power, manifested in decreased speed and hill climbing power, are readily noticed as they occur and may usually be traced to their sources by characteristic symptoms. On the other hand, the gradual deterioration in the condition of a car which comes about through extensive use may be hardly noticeable from day to day, but may amount to a very material difference in the quality of its running during a period of several months. JUDGMENT UNTRUSTWORTHY. One can hardly be sure, on any given day, that one is opening the throttle just the same amount in order to secure a certain speed or hill climbing power on certain roads as was required to give the same results several weeks or months ago. The loss of power may have been so gradual during the period that the increase of gas required has been imperceptible from day to day, but, in point of fact, the added amount of fuel gradually called for may be very considerable. Furthermore, an operator can hardly be expected to remember for several weeks or months just how much the lower gears were required in order to traverse a cer- tain road with a certain load, and he is thus usually unable to compare the performance of his car on that trip with its actions when covering 113 the same ground at a later date. The judgment of the operator is, indeed, quite unreliable in determining the question of condition during long periods of time. Very often an owner beginning to drive a new car is quite impressed with its speed and power, but after a little while he becomes used to it, its capabilities seem more ordinary to him, and he often thinks it is not doing as good work as it originally did. If he drives or rides much on other cars of higher power, when he resumes the con- trol of his own car he often does so with other and higher standards of performance in mind, and is likely to regard the work of his own lower powered vehicle in an unflattering light. If, however, an automobilist knows exactly what was his mileage dur- ing a certain trip, at a certain speed at the beginning of his season, he has a measure of the car's performance with which he can at any time compare its later condition, if he drives the vehicle over the same route, under nearly the same conditions of load, road surface, speed and quality of fuel. If the later test shows a greater consumption of gasoline he may be sure that the car is in some way or ways less well conditioned than it was at the time of the first run. GASOLINE AND MILEAGE RECORDS. If a car is equipped with a trip odometer it may be set at zero each morning that the car is to be used, and if a record of the daily mileage obtained from it is kept upon a calendar pad, and with it is made a record of the quantity of gasoline required to just refill the tank at the end of each day's run, data will be collected for determining the daily mileage per gallon that the car is making. An occasional glance at the figures obtainable from these records will show whether the fuel economy of the car remains satisfactory or is decreasing. The mileage obtainable from a gallon of gasoline on ordinary country roads varies roughly from 6 or 7 in the case of large six cylinder cars to 20 or upward in the case of light cars with engines of good effi- ciency and direct and economical transmission. Experience has shown that about 15 miles on a gallon is not far above the average figure for the ordinary four cylinder, five passenger car under normal conditions. Loss OF FUEL ECONOMY. If a user begins to feel that his car is not doing quite as good work as formerly, and finds by consulting his fuel figures that while previously the vehicle has been covering 15 miles per gallon it is now traveling only 12 miles per gallon, he may be reasonably sure that his suspicions con- cerning the car are well founded and that it is, in fact, "out of tune." In an automobile which is out of condition the excess of gasoline consumed is accounted for by the necessarily wider throttle opening required to give the desired speed and by the increased proportion of the distance which is traveled on the lower gears, which ordinarily waste much more fuel than does the direct drive. When increased gasoline consumption, as well as the driver's observa- tion, indicates that the car is "out of fix," it is usually found that there are quite a number of things simultaneously a little in need of attention, and the problem of setting matters right is sometimes quite elusive and complicated. A single defect, which is complete, or very bad indeed, 114 usually demands immediate remedy, but a "complication of diseases" result- ing in "general debility" is often difficult of treatment. LEAKAGE OF FUEL. Before drawing any conclusion from the rate of gasoline consump- tion, it is well to determine that no leakage of fuel is taking place. Occa- sionally the float needle valve becomes slightly leaky through the roughen- ing of the conical valve surfaces due to constant vibration or on account of small foreign particles lodging therein. The leakage may not be suffi- cient to cause any loss of gasoline or flooding of the vaporizing chamber while the engine is running, but may be sufficient in amount to lead to a constant slow dripping while the engine is stopped. As it is the practice of many users not to shut off the gasoline supply from the tank when the car is left standing, there may be an escape of fuel in this manner, amount- ing in time to a very considerable amount. The gasoline will usually evaporate from the floor or be absorbed by the road without forming any noticeable puddle, and unless the carburetor be very closely watched the leak may continue undetected for a long time. The unions on the gasoline pipe which connect its respective ends to the tank and the car- buretor float chamber may have become loosened and leaky, and there is always the possibility of a slight split having developed in the gasoline pipe. Considering the danger that is inherent in gasoline leaks, it is sur- prising that the fuel system does not receive more careful attention than is generally bestowed upon it. Loss OF COMPRESSION. If no gasoline leak be found the figures showing a reduced mileage per gallon are to be trusted as evidence that the car will bear a careful inspection. In the regular use of a car there usually occurs a very gradual loss of compression, the progress of which is not at all evident to the sense of feeling when the motor is cranked, because the change is so slow. The piston rings wear so that their ends do not come together, they lose their resiliency or are stuck in their grooves by an accumulation of car- bonized oil. Then there is a tendency for valves to gradually become leaky through long use. The exhaust valve particularly is likely to become warped by the intense heat of the escaping charge or to scale or pit, and thus in time to seat very imperfectly. All these actions result in a lack of tightness on the part of the cylinder, and, while the volume of gas drawn into it during each suction stroke is as large as ever, there is an escape of fuel during both the compression and explosion strokes, a reduction of the pressure and a diminution of power generated during the cycle. In other words, a portion of the fuel taken from the carburetor is thrown away into the muffler and crank case and the rest is used uneconomically. DERANGEMENT OF VALVE MECHANISM. Another cause of progressive decrease in fuel efficiency and of power is the gradual decrease in the exhaust and inlet valve lift, due to the wearing down of the surface of the exhaust cam, wear of the pin in the roller follower and lost motion in the valve operating rocker arm, if one is used. The wear of the valve stem end and the push rod end and of other parts, if they are not carefully hardened, contributes to this back- lash. The result of this reduced exhaust valve lift is to throttle the out- "5 going gases and to produce a back pressure which is subtracted from the pressure of explosion, and while the same amount of fuel is burned at a given throttle opening, the production of power is naturally reduced. The same reduction of life, due to wear of the operating parts, may affect the inlet valve as well, with the result that a lessened charge is admitted to the cylinders and less power produced per stroke, but this defect pro- duces the same effect as throttling and has not much influence upon fuel economy. MUFFLER BACK PRESSURE. In the same connection as the reduction of exhaust valve lift may be mentioned the progressive choking of the muffler which sometimes occurs if its passages are contracted and if an excess of oil or a bad fuel mix- ture is habitually used. The carbon deposits in the muffler passages give rise to an excessive back pressure and an inevitable loss of power and of fuel efficiency, and, as the accumulation is quite gradual, this source of trouble is likely to be overlooked. There is at all times more or less carbon dust floating in the exhaust and also vapor from the oil of the cylinders. These two, the carbon and the oil smoke, combine and form a sticky, greasy deposit on the plates or tubes of the muffler, especially around the perforations, decreasing their diameter and eventually choking them up to such an extent that the back pressure developed will cut the speed and power of the machine down 50 per cent, or more. In such cases the plates in the muffler may become so heavily coated that on holding them up to the light only a glimmer can be seen here and there through the holes. If the plates, after being scraped and washed with gasoline, are coated with stove blacking or plumbago and boiled oil, the oil being applied first and the plumbago rubbed into it, and excess of cylinder lubrication is avoided, the muffler will go much longer between cleanings, as the smoother the plates and the dryer the exhaust the less chance there is of the carbon sticking. No single defect is more surprisingly productive of poor fuel economy than a weak spark due to insufficient battery power or to vibrators which have lost their proper adjustment through long use. A considerable period may elapse after the spark ceases to be per- fectly efficient before it actually begins to fail to produce an explosion, and during this time the charges are very imperfectly ignited, the initial pressure in the cylinder is abnormally low, and consequently the power developed is very unsatisfactory. A considerable portion of the charge, when ignited by a weak spark, seems to escape unburned or only partially oxidized. The deterioration in the quality of the spark, being quite gradual, may not be realized by the operator or identified as a cause of trouble unless close account is kept of the fuel consumption. Then, too, there may be missed explosions which escape notice. CARBURETOR OUT OF ADJUSTMENT. There is always a chance that the carburetor gasoline adjustment may have changed on account of the loosening of the set screws, or that the air admitting poppet valve in the carburetor air inlet may be prevented from acting because of having been fouled with mud. A bad mixture and consequent low fuel economy will be the result. A great change in tem- perature or the use of the car in a much higher or lower altitude may 116 render the original gasoline adjustment imperfect and prove to be the cause of wasted fuel. WASTE IN TRANSMISSION. The above mentioned defects, which may be the causes of observed wastefulness of fuel, affect the production of power; in. other words, the engine. But sometimes wastefulness in applying the power may account for the increased consumption of gasoline. A driving chain is likely gradually to stretch and become very much out of pitch with the sprockets, thus wasting in friction a considerable amount of power. There may be lack of lubrication somewhere which may not be serious enough to give immediate notice, by heating or sticking of the parts, but still prove a serious "drag." Brake bands or shoes may fail to entirely part contact with their drums when released, and reverse and low speed bands may be dragging. LUBRICATION. Theory of Lubrication. (J. W. G. BROOKER.) Lubrication is the art of making things work smoothly. Lubricants minimize the friction existing between two surfaces when one slides or rolls over the other; but they set up friction themselves, our engines having to overcome two classes of friction the friction arising from the metal surfaces sliding over one another, and the internal friction of the lubricant. The first we call solid friction, the second fluid friction, and it is the aim of all engineers to reduce the first to nil and the second to a minimum. The nearest approach to this ideal is obtained by the use of an oil bath containing a fairly fluid lubricant and with, of course, accu- rately made bearings. The ideal condition is one where the sliding sur- faces are completely separated by a film of lubricant. Like other ideals, it is never attained, so that for all practical purposes we have compound friction a friction due to the action of surfaces partly separated by a fluid in which there is solid friction where the bare surfaces touch one another, and fluid friction where the lubricant intervenes. In may be well to briefly enumerate a few laws of solid and fluid friction. First, as to solid friction. Increasing the pressure increases the fric- tion; increasing the comparative roughness of the surfaces increases the friction. Distribution of the load over a larger area of bearing does not decrease the total friction, but it lessens risk of abrasion and seizure. Friction is greater between soft than hard metals, and is greatest at the beginning of motion. In practice, it is better to let a hard work against a soft metal, making provision for the easy renewal or repair of the latter as it wears. Now as to fluid friction. It is independent of the pressure, it is directly proportional to the area, varies approximately as the square of the velocity and is influenced by the viscosity. Between the solid sliding surfaces the fluid may be regarded as con- sisting of a series of superposed layers, each moving at a speed propor- tional to its distance from the fixed solid surface. The topmost plane of fluid is carried along by and moves at the same speed as the moving solid surface, the lowest plane remains stationary, the intermediate move little or much, according to their distances from the solid surfaces. Now, it is this sliding of the planes of lubricant over each other that constitutes fluid friction. The more viscous the liquid the greater will be the resistance to motion; the ease or lack of ease with which the layers slide over one another is a direct measure of the viscosity of the lubricant. Viscosity is the property by virtue of which the lubricant forms a com- paratively thick film between rubbing surfaces I say thick, but in reality these films are measured in thousandths of inches. The more viscous the 1x6 lubricant the greater is the pressure which can be sustained, but at the same time unnecessarily high viscosity creates unnecessary fluid friction and the viscosity of the lubricant should therefore be in proportion to the pressure which it will have to sustain. ROLLING VERSUS SLIDING FRICTION. It is of interest to compare these actions with those for a ball bearing, in which it is customary to consider the whole of the load to be carried by one ball. With an average five-sixteenth inch to. three-eighth inch ball the working pressure may vary from 500 to 1,500 pounds between the points of contact. Converted, this means many hundred thousand pounds to the square inch, as compared with a few hundred pounds per square inch in the case of plain bearings. In rolling friction the balls or rollers act in a manner closely analogous to the lubricating medium of a plain bearing by keeping the working faces apart. If it were possible to make a ball or roller bearing with absolutely no sliding friction, i. e., entirely rolling friction, the use of a lubricant would be unnecessary. However, there is always a little sliding between the balls or rollers themselves or between them and the cage employed to keep them in position, and it is to minimize this that a lubricant is neces- sary. Ball or roller bearings undoubtedly minimize the sliding friction of a plain bearing. One of the functions of a lubricant is to overcome or neutralize acci- dental variations of the smoothness of surfaces. Although almost infini- tesimal in magnitude, these cause variations in the friction, which are always tending to produce overheating, and it is solely a matter of chance when these tendencies preponderate over the lubricating effect of the oil. A light oil lubricates as well as a viscous one when all is smooth, but when a minute irregularity occurs, such as grit or rough places on the surfaces, heat is generated locally, the oil becomes too thin, and there is a risk of seizure taking place. By the use of a plentiful supply of viscous lubricant this risk can be considerably reduced. A new engine under- lubricated will seize much more readily than one well run in. There are three other conditions to meet which a viscous lubricant is necessary, viz., great pressure, slow speed and high temperature. The reasons are so obvious from what has been already said that it will be wasting time to dwell on them. PHENOMENA OF SEIZING. Seizing can always be traced to a failure of the lubricant to keep two metal surfaces adequately separated by a film of oil. Either the oil may- be too thin or the pressure between the surfaces too great, or there may be no lubricant there at all. When the two surfaces come into close contact under considerable pressure much work has to be done to get one to slide over the other; the work expended in overcoming the friction is translated into heat, and the heat thus produced raises the temperature of the bearing, and the molecules of metal at the two surfaces, spurred into greater activity, diffuse from the shaft into the brasses or from the piston into the cylinder wall and vice versa. This tendency to diffuse or weld is so great that when two metals with carefully cleaned and polished sur- faces are very strongly pressed together and left for several weeks at the atmospheric temperature molecules from one are found diffused through- 119 out the other. This migration is immensely facilitated by a rise in tem- perature equivalent to an increase in the velocity of the molecules. Under suitable conditions the interlocking may be so great that it is impossible to separate the surfaces intact again. When the seizing is incomplete, and the metals continue to slide over one another, the surfaces, especially that of the softer of the two, are scored, and even if checked at this stage by stopping the engine or by a copious supply of oil, the repair of the damage is an expensive matter. Scoring and seizing are facilitated by high temperature, high pressure and close fitting (remember that a close fit at a low temperature becomes a much closer fit at a high temperature). Hence we arrive at the main features determining a suitable lubricant; it must withstand the maximum pressure and the maximum temperature which it will have to meet and preserve, as far as possible, an unbroken film between the sliding surfaces. TESTING LUBRICANTS. The following are the chief properties which a lubricant should possess to be efficient: Enough body or viscosity to keep it between the rubbing surfaces at their maximum temperature and pressure. The greatest fluidity consistent with the required viscosity. Good capacity for transmitting heat. (It is one of the uses of a lubricant to transmit or carry off the heat generated by friction; the larger the supply of lubricant the better is this effected, which is another argument in favor of an oil bath.) No tendency to change in the air. Freedom from mineral or fatty acids likely to corrode the surface of the metal. High temperature of vaporization and of decomposition and low freezing or "setting" point. Freedom from grit, water and other foreign matter. EFFECT OF HEAT ON LUBRICANTS. The first effect of heat on a lubricant is to considerably reduce its viscosity. The temperature of the cylinder wall in an air cooled engine averages from 250 to 300 Fahr., and in a water cooled engine from 180 to 250 Fahr. At the higher of these temperatures the lubricant is about as thin as water or kerosene, and splashes just as readily. The following table shows roughly the change of viscosity with rise of temperature: Temperature, Fahr 75 110 Time of efflux in seconds ". . 740 no If there be an adequate supply, even in this state it is capable of pre- serving a good film, between piston and cylinder, and it is not till tempera- tures of 400 up to 500 Fahr. are reached that danger arises. At this stage a good deal of the oil is turned to vapor and is no longer useful as a lubricant. Unless copious supplies are pumped in to make up the loss, the piston will seize, especially if it is a close fit in the cylinder, owing to the absence of the protective film which keeps the metal surfaces from touching. I have just said that at a high temperature the oil is evaporated, and, therefore, passes out of the exhaust with the burnt charge. That is only partly true; the truth of it varies with the quality of the oil used. If you have a well refined pure oil 99 parts in 100, say, are evaporated and do no damage; the one part is carbonized that is to say, decomposed by the heat. It is solid matter in a very fine state of division ; a portion of it will go out of the exhaust with the gases, the rest will be deposited on the walls of the combustion chamber and on top of the piston. In the case of oil containing notable quantities of impurities, the proportion car- bonized is very much greater, and the deposit in the cylinder head grows more rapidly. It has sometimes been stated that the lubricant has to withstand the heat of the explosion. Now, that is erroneous. There is no lubricant in existence capable of successfully standing a temperature of 1,500 Cent, to 2,000 Cent, or 3,000 Fahr. to 3,500 Fahr., which is the average tempera- ture of the explosion at its hottest point. The lubricant is always at the same temperature as the cylinder wall, and it is this factor which governs the choice of an oil. The size of a cylinder is of some account, because a big cylinder means a big piston and a correspondingly heavy pressure between them. If an abnormal piston speed, either very fast or very slow, is employed, that must be taken into account ; but, as a rule, piston speed need not be considered, so we are narrowed down to cylinder tem- perature as the chief question to be studied. With an efficiently water cooled engine, an oil of moderate viscosity and volatility can be used; in fact, a good quality gas engine oil will frequently serve. But we must discriminate between a single cylinder and four or six cylinders ; the latter engine, with its smaller and cooler cylinders, less pressure on crank pins and shaft, etc., and higher average speed of running, is best served by a thinner lubricant than the slower speed single cylinder engine. The same applies with even more force to single and multi cylinder motorcycles. With one cylinder, particularly if it is of 3^/2 horse power to 4 horse power, a very viscous and resistant lubricant is required; for the four cylinder better results would most probably be obtained with an oil recommended for water cooled engines ; for a twin cylinder an oil inter- mediate between the two should be used. Automobile Lubricants. (ALBERT L. CLOUGH.) The choice of lubricants of suitable quality for use upon the various wearing surfaces of an automobile is a matter of the utmost importance and has more bearing upon the length of life of the mechanism than any other consideration. Any employment of poor or unsuitable oil or any failure of the lubricant to actually reach the wearing surfaces results in a rapid destruction of the parts involved, while the constant use of liberal quantities of lubricant of appropriate qualities delivered exactly where the friction is produced results in the attainment of a remarkable degree of longevity by the moving parts which are so treated. Important as is the subject of lubrication in all its details, and definite as are the respective results which spring from good and bad practice in this regard, it is a curious fact that there is hardly any domain of mechanical knowledge the subject matter of which is more obscure, inexact and inapplicable to individual cases than that of lubricants and lubrication. TESTS DIFFICULT. Lubrication is not a particularly fascinating subject and very few people willingly give their attention to it. Furthermore, it is a very long, tedious and doubtful undertaking to determine the lubricating properties of an oil under any given circumstances, and the only manner in which it can be done successfully is by experimenting with the particular fluid in question under conditions of actual use or in an oil testing machine in which actual conditions are as closely reproduced as possible for a pro- tracted period of time. Naturally, there is comparatively little oil testing undertaken, and that which is performed is usually carried out by oil manufacturers or by large industrial or transportation companies who are enormous users of lubri- cants. The information gathered by the former is in a measure turned to the advantage of the consumer, but that collected by the latter is gen- erally kept secret. There are such a large number of combinations of conditions under which the use of oil is required, involving differences in pressure, speed, temperature and other factors, that the lubrication of each new mech- anism is in some respects a separate problem. Furthermore, while the chemical and physical properties of an oil may be determined with considerable accuracy by means of laboratory tests, the art of lubrication doesn't seem to be sufficiently exact to enable it to be stated with confidence that an oil which combines certain chemical and physical characteristics will be the best lubricant under certain specified conditions. Experience in the use of a certain oil is the only source of really valuable information regarding it, and data of this kind the con- sumer is forced to accept upon hearsay, upon the say-so of the manu- facturer or some user, rather than at first hand. Slight as is the value of the individual judgment of the ordinary small user of oils, there are certain facts the knowledge of which may be of help to him in his selection of lubricants. The theory of action of lubri- cants has already been discussed in these columns. SELECTION OF OILS. For use upon any particular bearing an oil of such thickness should, be used as will just effectually resist the "squeezing out" tendency due to the maximum pressure which acts between the surfaces. This will render the loss in friction due to moving the oil upon itself less than would be the case if a more viscous lubricant were employed. When choosing an oil of appropriate viscosity or body, it is to be remembered that temperature exerts a most important effect on this property. An oil which at ordinary temperatures would prove amply viscous to resist squeezing out might, if heated materially, become so thin as to be quite unfit for its purpose and might, on the other hand, become so nearly solid upon a considerable reduction of the temperature as to lose its power of spreading and thus covering and protecting all parts of the bearings. One important requirement of a good oil is this, that its degree of viscosity should change as little as possible with temperature variations. MUST BE NON-CORROSIVE. In order that a lubricant shall not exercise a corrosive effect upon the bearing surfaces upon which it is used, it must not only be devoid of free acid or alkali, but must be innocent of materials which, through the action of heat, oxygen or moisture, may develop corrosive materials. Free acid may occasionally be present in carelessly prepared oils, having been introduced during the process of manufacture, but its presence hardly need be apprehended in mineral oils of reputable manufacture. Animal and vegetable oils, under the influence of conditions met with in use, are ultimately decomposed into glycerine and fatty acids, which latter are exceedingly destructive to brass and bronze and somewhat less deleterious to iron and steel. Pure mineral oils are not thus decomposed in use and are hence greatly to be preferred. One statement may confidently be made : No animal or vegetable oil or grease, either pure or in combination with mineral lubricants, should be habitually used upon any part of an ordinary automobile. In the case of a gasoline automobile there are, roughly, five separate lubrication problems involved : (r) Cylinder lubrication. (2) Shaft bearings, including those of the engine and change speed gear. (3) Gear faces and chains. (4) Wheel and axle bearings. (5) Miscellaneous bearing surfaces. CYLINDER LUBRICATION. The choice of an oil for use in the cylinders is the most important of all automobile lubrication questions. Probably the safest course for the individual owner to pursue is to use the oil recommended by the manu- facturer of the particular car in question, until some oil known to be superior is found. There is, however, hardly any danger in using a suit- able grade of any oil which has attained an extensive reputation, is gen- erally carried in stock by dealers and which is manufactured by a reliable firm. Such an oil would hardly have reached a position of popularity if it were objectionable. ROUGH TESTS. It is usually futile to experiment with small samples of new cylinder oils, as the results are generally entirely inconclusive. Not enough oil is usually supplied to suffice for a test of adequate duration, and the ordi- nary user is not in possession of the apparatus necessary to conduct a really critical test. The rough observations which an ordinary user can make upon a new oil might include the apparent power delivered by the engine, the character of the exhaust, effect upon spark plugs, cooling water evaporated, extent of carbon deposits produced, and some similar crude data which could be of no great value. Furthermore, he who is not supplied with scientific testing apparatus can never be sure that a supply of oil ordered by sample is honestly filled, especially if it comes from an obscure manufacturer. It is good policy, therefore, to "stick" to the oil that has given fair satisfaction, especially if of a well known brand, as one is likely to be able to secure it of uniform quality at a great many widely separated points. When one is using a cylinder oil of fairly satisfactory character, it is well to bottle a sample and place it away for reference. It may be compared with a similar sam- ple of each new lot of the same lubricant when received, in order to demonstrate the correct filling of the order. Such simple tests as taste, smell, color under different lights, and viscosity as judged by the behavior of the fluid when the bottle is inverted,- are not without their value in determining whether one is receiving that which one has paid for. '123 REQUISITE QUALITIES. Among the qualifications of a good cylinder oil are the following: First and foremost, it should be purely mineral in its origin and free from any admixture of animal or vegetable substances. It should pos- sess sufficient body to serve its purpose when at a temperature consid- erably in excess of 212 Fahr. say at 250 to 300 Fahr. It should not have lost too much of its viscosity at this temperature, nor should it waste away perceptibly through evaporation if maintained at this heat for a number of hours. As to the flash temperature or "flash point" the temperature at which inflammable vapors begin to be given off authorities differ regarding its importance as a specification in fixing the qualities of a cylinder oil. It is admitted that it is impossible to produce an oil which will not be burned if it is actually brought to a temperature anywhere near that of the explo- sion. It is impossible also to produce an oil which will not be flashed if it reaches the temperature of the centre of the piston head or that of any other portion of the mechanism which is unprovided with cooling means. If an oil is used which will withstand without decomposition the temperature of the water jacketed portions of the cylinder and remain unaltered upon the surface forming the piston travel, it is about all that can reasonably be expected. The temperature of the outside of the cylinder walls in normal operation never exceeds 212 Fahr., and it is prob- able that in cases where the cylinder walls are thin and the water circula- tion good the temperature of the inside wall is less elevated than one might infer. At any rate, it has been found that an oil possessing a flash point in the neighborhood of 450 Fahr. certainly not in excess of 500 Fahr. appears to serve very well. There is apparently no object in going any higher, and some valuable qualities are likely to be sacrificed in making the attempt. The oil which is fed to the cylinder is finally evaporated, if not decom- posed, but not until it has served its object. Some of it may be ejected with the exhaust still in the condition of oil, but a part of it is apparently decomposed or "split" into a mixture of other hydrocarbons. It is very desirable that the oil may be ejected before its decomposition has so far advanced as to result in the freeing of carbon in the form of a lampblack, and it is possible chemically to favor the attainment of this condition. A cylinder oil should possess a satisfactory "cold test" that is, it must withstand a large reduction of temperature without becoming too viscous to feed properly or too thick to be longer amenable to the spreading ten- dency due to capillary action. The elimination from the oil of hydrocarbon compounds of a waxy or paraffinelike character much lowers the point at which the oil "freezes," but it is a decidedly difficult matter to combine in a single oil the some- what antagonistic qualities of a good degree of viscosity at very high temperature and a satisfactory degree of fluidity when very cold. This difficulty is very well met by the employment of two grades of oil, a thicker one for summer and a thinner one for winter use. "FLASH" AND "COLD" TESTS. If one happens to possess a high range thermometer, it is a very easy matter to gradually heat a sample of cylinder oil in a small dish over 124 a gas burner. At no time in the process should there be noted any odor indicative of tallow or other organic matter being a constituent of the oil, and the lubricant should not become too thin or watery at any tem- perature below 300 Fahr. The flash point may be roughly determined by reading the thermometer just as an inflammable vapor begins to be given off as shown by presenting a flame near the surface of the liquid. By the use of ice water or of a freezing mixture composed of ice and salt, a sample of oil may be cooled until it just ceases to be fluid, when a reading of the temperature will give a rough idea of its cold test. PROPER COLOR. Cylinder oil for gas engine use should be perfectly clear, and its color by transmitted light should be an amber, while by reflected light it may appear fluorescently green or blue. In direct sunlight or under the arc lamp this fluorescence is particularly marked. Oil which does not show it is either not of mineral origin or has be'en tampered with by a chemical process. CARBONIZATION. This subject is an important one in the operation of modern vehicle engines. If too much oil or oil of an inferior quality be used incrusta- tions in time form upon the surfaces of the combustion space, the piston heads and the valves and their seats, which are composed of carbonaceous materials derived from the oil, soot from the fuel which may be imper- fectly consumed, and fine sand and other materials drawn in with the air through the carburetor. These incrustations, when accumulated in sufficient quantities, and rendered incandescent by the burning charge, lead to premature ignition, pounding of the engine, loss of power and wear of the bearings. Compression is reduced by the failure of the valves to seat properly, fuel is thereby lost and the engine further loses power. Cooling is also somewhat interfered with. It is of the utmost importance that an oil be used which is known to possess a minimum tendency to deposit these carbon incrustations and that no excess of the same be employed. By so doing the necessity of decarbonizing the parts may be greatly deferred. BEARING OILS. As nearly all modern vehicle motors are lubricated throughout includ- ing cylinders, piston pins, connecting rod tips and main and cam shaft bearings from the same supply of oil, little need be said upon this subject. If a grade of oil suitable for the cylinders be used in the engine, it will be found also to be suitable for the bearings. GEAR Box LUBRICANTS. Since, in the majority of cases, the shaft bearings of the change speed gears and the gear faces are lubricated from the same bath of lubricant contained in the gear case, the shaft bearings must almost of necessity be oiled with a lubricant adapted to keep the gear faces in quiet operation with a minimum of wear. The same thing may be said of the bearings and gear faces in the differential case. GREASES. The use of greases for the lubrication of the less important auto- mobile shaft bearings is now very general. Their use is very attractive 125 on account of the cleanliness with which they may be applied, their free- dom from any tendency to drip from the bearings and the convenience with which they may be carried about. There are on the market lubri- cants of the consistency of grease which are known as solidified oils, non- fluid oils, and so forth. These greases are claimed to be entirely mineral in their origin and are excellent lubricants. It is almost universal prac- tice to supply these lubricants from compression grease cups which are given a turn or two by hand whenever convenient, and the grease thus forced into the bearings under considerable pressure. A bearing requires to be specially prepared to fit it for grease lubrica- tion. Greaseways of liberal depth leading from the admission hole should be cut in the bushings to convey the somewhat immobile lubri- cant to all parts of the frictional surfaces. A grease of a considerably less degree of solidity should be used during cold weather, otherwise bear- ings supplied with it become very "stiff." In general, it may be said that if a pure mineral grease be chosen the lubricating value of the materials of which is equal to that of fluid oil, and if this semi-solid material can be made to permeate all parts of the frictional surfaces, its use should possess decided advantages over the employment of liquid oils. Greases with which are incorporated a certain proportion of graphite are considerably used. FOR GEAR FACES. For the lubrication of gear faces quite a viscous oil is required one that will not be pressed from between the engaging teeth of the gears in ordinary use. Gears being usually enclosed in an oiltight case, it is cus- tomary to allow one or more of the larger ones to dip in this heavy oil and to splash it over the faces of the others. If "an oil of exceedingly high viscosity is used and the gears are allowed to dip almost their full radius, a very considerable amount of power may be wasted when running at high speeds. It is generally sufficient to have, say, two gears dip rather lightly into the liquid. As there is no high temperature to be resisted by the lubricant, a mineral oil of a relatively cheap grade may be employed successfully. Oils suitable for this use and known as gear case oils are upon the market. As a rule, the heavier grades of these oils are preferable, and steam engine cylinder oil is recommended by some manufacturers. GREASE IN GEAR CASE. The practice of placing greases or other solid lubricants in the gear case instead of a liquid oil is rather questionable. The solid lubricant is forced or worn away from contact with the rapidly revolving gears, and it is only when the car is still and the temperature high that the grease will again settle around the moving parts and re-lubricate them. De- pending for lubrication upon any material which cannot spread or move under the influence of gravity or capillarity is hardly a safe proposition. However, an admixture of grease with cylinder oil, resulting in a proper consistency, makes an excellent lubricant. CHAIN LUBRICATION. For the chains it will be found that an immersion of an hour or two in gear case oil after they have been thoroughly cleaned with kerosene will perfectly lubricate the pins. The chains may then be wiped off 126 externally and, after putting them in place, a liberal coating of graphite grease may be given the blocks or rollers and the sprocket teeth. Graphite grease is usually a lime soap with a certain admixture of mineral oil into which has been incorporated finely divided graphite. In some cases a non-fluid oil which has been filled with graphite is used. ANTI-FRICTION BEARING LUBRICATION. For the lubrication of the ball or roller bearings, so generally used for the support of the front wheels and the rear axles of automobiles, a pack- ing of non-fluid oil, filling the space in which the balls or rollers travel, is usually adopted. This packing has the advantage of not escaping rapidly from the bearing. The rolling action of the balls or rollers keeps it well distributed, and, as this type of bearing does not need a large amount of lubrication in any event, the results are most satisfactory. If the balls or rollers are contained in a cage, the interstices of this may be filled with the compound, which will last for a long time. A bearing of this kind furnishes an instance where a semi-solid lubricant may be used to very great advantage. MISCELLANEOUS BEARING SURFACES. Grease, fed from compression cups provided with spring retained caps, is generally used to lubricate all the minor parts, such as spring hangers, brake parts, rear axle bearings, parts of the steering gear and the shafts of the operating devices. Where grease cups are not provided spring closed oil retainers are generally employed. Almost any good machine oil will serve at these points, but the average motorist will use cylinder oil in order to avoid keeping on hand more than one grade of fluid lubricant. GRAPHITE. Although the lubricating qualities of this material are undoubted, it cannot be said to be in very general use upon automobiles. Graphite greases or oils containing graphite in suspension are some- what used in gear cases, and the greases in grease cups. The mixture of a small proportion of graphite with cylinder oil has been found by some users to secure excellent engine lubrication and to permit of economy in the use of oil. Some trouble has been experienced by others arising from the short circuiting of the spark plugs by the graphite. In the deflocculated or minutely subdivided form, known by the trade name of "Oildag," graphite seems to be giving good satisfaction to a considerable number of users when mixed with cylinder oil in suitable proportions a reduction in the amount of oil required being claimed. CONCLUSIONS. In closing, let stress be laid upon a few points, among which are the following : Do not employ anything but purely mineral lubricants if it can possibly be avoided. Take special pains to follow the advice of the manufacturer of your particular car in regard to the cylinder oil best adapted to be used upon it, if such advice seems to be sincere and unbiased. Adopt, if possible, a brand of cylinder oil of established merit, which can be obtained anywhere and of uniform quality. If practicable, adopt a grade which is not unsuitable for general lubri- 127 eating purposes, and thereby preclude the necessity of carrying more than one grade. Do not discard the use of liquid oil in favor of greases until it has been demonstrated that it may be done without danger. Use the best grade of grease and be sure that there are means provided to insure its spreading properly throughout the bearings. It pays to be conservative in the matter of lubricants and not experi- ment too much. Methods of Engine Lubrication. (ALBERT L. CLOUGH.) Practically all modern engines are furnished with their oil supply by some positive mechanical means, the operation of which starts and stops with the engine, and in most instances the distribution to tht various parts of the oil supplied is wholly or in part effected by the splashing action of the moving parts, which results in a mist of finely divided oil that pene- trates to all frictional surfaces. By far the most commonly used system is the self contained circulating system. In this system a positively driven pump, usually of the gear or of the eccentric type, is mounted within the crank case and operated by gears from the half time shaft. In fact, the pump is usually an integral part of the engine structure. This pump ordinarily draws its supply of lubri- cant from an oil reservoir which is generally cast in the lower half of the crank case. Oil is generally delivered by the pump to pipes leading to each main bearing of the crank shaft and sometimes of the cam shaft, and in some cases the piping is supplanted by channels cast into the walls of the engine base. A large oversupply or "flood" of lubricant is thus furnished to each main bearing and the excess escapes therefrom and falls back into the reservoir. A strainer is provided in the pump suction which pre- vents all foreign particles from being circulated. Various methods of oiling other parts of the engine may be made use of in this system. The crank shaft may be provided with channels leading from each bearing to their neighboring crank pins, and centrifugal force may be relied upon to carry the lubricant to the connecting rod tips, or the oil in the engine base may be carried at such a height that the rod tips dip into it, pro- ducing a splash which lubricates the reciprocating parts. In some cars channels are provided in the connecting rods and piston pins, up through which oil is carried from the crank pins by virtue of its inertia on the down strokes of the rods and the pins and the cylinder walls thus lubri- cated. As a rule the splash or mist of oil in the crank case is at least partially relied upon for cylinder and piston pin lubrication, as a con- siderable part of the flood of oil escaping from the bearings is generally caught and thrown about the inside of the engine. In this system a gauge is frequently attached to the crank case to indi- cate the oil level, an accessible filler tube is provided therein, and a reserve supply tank is commonly provided from which the supply in the crank case may be periodically replenished. Oftentimes the supply from the pump, or a part of it, is carried through a telltale on the dash, which gives visual indication of the working of the pump. This method of circulating oil in large quantities around the bearings seems rapidly to he growing in favor and has the merit of keeping the bearings cooled and the shaft oil floated in a nearly ideal manner. In Fig. 72 is diagrammatically represented such a system, in which A is a gear pump driven from one of the engine shafts by gearing, which delivers oil from the reservoir C through pipe B to the filter D. From the filter the main portion of the oil flows through the sight feed manifold E and through pipes F to the three main bearings of the motor. The rest of the supply passes through pipe G to the timing gear case. As the excess of oil escapes from the main bearing it falls into the partitioned crank case bottom H, where it is caught by the connecting rod tips and thrown up against the cylinder walls, also oiling the pistons and the piston pins. The accumulation of too great a depth of oil in H is pre- FIG. 72. SELF CONTAINED CIRCULATING SYSTEM OF LUBRICATION (ROYAL). vented by the escape of the excess through the standpipes KK, which return the surplus to the reservoir C, with which the pump suction is connected. M is an oil gauge showing the height of the oil supply in the reservoir, and which also serves as a draw-off cock. N is the reserve oil tank from which the supply in C may be replenished by opening the cock O. FORCE .FEED MAGAZINE LUBRICATORS. In the regular force feed system the oil supply is carried in a reser- voir usually located under the hood, where the oil may be kept warm. Within the reservoir are a number of small pumps drawing their supply from the oil about them. The delivery of each pump is connected by a copper tube with some point requiring lubrication, such as a cylinder wall, a main bearing or the timing gear case. Each pump is adjustable as to the amount of its delivery per stroke, the usual rate of feed being from 129 one to three drops, and often the oil delivered by each pump is passed through a telltale or sight feed glass, from which it flows to its destina- tion by gravity. All the pumps are commonly driven from a single shaft that passes through the lubricator reservoir and which receives its motion from the engine through gearing. A very slow motion is imparted to the pumps by means of worm gearing, or some equivalent arrangement, interposed between the shaft and the pump itself, so that one stroke of the pump is equivalent to quite a number of turns of the motor. Instead of a single pump for each feed there may be two provided, the first being an adjusta- ble measuring pump, which delivers oil to a second pump that forces it to the bearing under pressure instead of feeding it by gravity. Or there may be a single elevating pump capable of elevating the total supply required by all the feeds into a header from which the oil flows through adjustable sight feeds to individual pumps, which force it through separate THE HORSELESS AQE FIG. 73. MECHANICAL LUBRICATOR WITH ONE MASTER PUMP FOR ELEVATING OIL AND ONE PUMP FOR EACH FEED. A, master pump for forcing oil through tube B to distributor C; D, sight feeds; E, tubes from sight feeds to pumps F for individual feeds; G, driving worm shaft; H, worm wheel; I, "fingers" for operat- ing individual feed pumps; J, spring for individual feed pumps; K, oil delivery; L, oil gauge. leads to the bearings and the cylinder walls. When furnished to the cylinders check valves are provided at the points of delivery to prevent the explosion pressure from forcing the oil back through the delivery tubes. A lubricator of the last described type is depicted in Fig. 73. Occasionally a combination of the force feed lubricator system and the splash system of distribution is adopted, the oil level in the several crank case sections being maintained by the feed from a lubricator of this type, and the oil being splashed about by the action of the connecting rod ends. 130 EXHAUST PRESSURE FEED LUBRICATORS. Sometimes the pressure of the exhaust gases is applied to a body of oil contained in a tight reservoir to force the lubricant through pipes to the various friction producing parts. The pressure comes on with the start- ing of the engine and ceases soon after it is stopped, so that the system is fairly automatic. It is, however, very little used at the present time. On some very small cars the gravity flow from an elevated reservoir is depended upon to maintain a sufficient lubricant supply to the crank case where distribution' is effected by the splash method. Hints on Lubrication of Motor Cars. (ALBERT L. CLOUGH.) Failure of proper lubrication is admittedly the most common cause of injury to automobile mechanisms, and it is especially to be noted that these injuries most often occur in the early use of a machine before the operator thoroughly understands the demand for oil existing in its different moving parts, or even understands what the parts themselves are, where located, and how supplied with lubricant. It has too often been the case that in the first or second trip with a new machine some damage has resulted from faulty lubrication, and it is certainly too bad to take chances with a new machine which may lead to permanent injury and a great deal of expense through failure to properly provide for its oiling. After a machine has been operated for some time its lubrication becomes habitual with the owner, and there is very little chance of damage resulting under these circumstances. Sometimes the instructions for oiling furnished with a new car are rather meagre, and it seems to be an occasional fault in the literature received from the manufacturers that they make the oiling operations appear very easy, apparently with the idea of impressing the owner with the slight amount of care required by the machine. However, very good oiling instructions, accompanied by clear diagrams, are now the rule. It would be a wise precaution if, upon the receipt of a new machine, the owner should first become acquainted with every detail of the lubri- cating mechanism ; not only with every part which can possibly require lubrication, but to become thoroughly familiar with its oil supply, to note its required rate of supply and not be contented with the mere fact that oil is supplied, but be sure that the oil actually reaches the point of use through the appropriate pipes or channels. Where the oil pursues a devious path in reaching the bearing one should be satisfied that the oil channels are all clear and free. NECESSITY OF PROPER LUBRICATION. There are a great many different points of attention about an auto- mobile, failure to attend to which will result only in inconvenience and not in damage and loss; but the matter of lubrication is one the neglect of which is sure to be serious. Instances are by no means uncommon of cars of reputable makes being nearly ruined by lack of lubrication. STUDY THE LUBRICATING SYSTEM. It requires some self restraint to forego the pleasure of operating a newly received vehicle before looking it over mechanically, but this slight sacrifice is certainly warranted in the better understanding of the vehicle and its needs, which will come from a careful inspection with the aid of a first class mechanic, or, still better, an operator of the same make of vehicle. If one would surely avoid injury to the vehicle at the start, with its effect upon all its future operation, he certainly should look to the oiling mechanism before operating the car at all. There is one thing which makes toward conscientious lubrication, and that is the provision of convenient FACILITIES FOR HANDLING AND STORING oils and a good light to enable the operator to definitely ascertain whether his oil is going to the right point. Sometimes the difference between con- venient oiling arrangements and inconvenient ones will be sufficient to determine whether the machine receives any oil at all, and possibly deter- mine the fate of some part of its mechanism. It is good judgment to have lubricating oils kept in receptacles from which they can be pumped or drawn without the necessity of pouring from a heavy can. They are much more cleanly when kept in this manner and the cans provided with small drip pans. A stable may well be equipped with squirt cans of the most convenient forms to reach the most inaccessible parts of the mech- anism, and small funnels, grease and oil guns should be provided, as, in case oiling is made convenient, there is less liability of its being neglected. AN INCANDESCENT LAMP on a flexible cord is almost necessary to examine the lubrication of con- cealed parts of the mechanism. A machine which is easily accessible in all its parts is likely to have a longer life than one otherwise constructed, on account of the greater probability of its receiving proper lubrication. The lubrication of a machine in which the parts are crowded or which cannot be readily exposed to view is almost sure to be neglected, unless its owner is more conscientious than the average. If adjustable oil feeds from a mechanical or pressure lubricator form a part of the equipment, these feeds should be kept accurately adjusted and the oil leads be kept from clogging and frequently inspected for possible breakages or disconnections. Where the circulating system is in use for engine lubrication the strainer should be frequently cleaned, the recommended amount of oil always should be carried and the supply in the reservoir should never be allowed to become stale or fouled with foreign particles, but should be drawn off at frequent intervals. The oil level in change speed and differential cases should be carefully maintained at the correct height, and the lubricant should be replaced before it becomes unduly dirty. ONLY ONE QUALITY OF OIL. It is a great convenience to be able to use one quality of oil for all the requirements of the machine, both for cylinder lubrication and the oiling of other moving parts. This practice is perhaps not scientific, but is fairly successful where a good oil is chosen, primarily of such quality as to be successful in the cylinder. This should be found suitable, when 132 mixed with grease, for the gears of the transmission, for the clutch and for all other parts requiring a fluid lubricant. If one could have only one oil to carry on a tour it should certainly be a good cylinder oil. GENERAL LUBRICATION. No mechanical part of an automobile which moves upon another part, however obscure that part may be, should be left without lubrication. All such parts should be identified and their needs satisfied. All grease cups and spring oilers should receive attention, and if there are moving parts not so provided oil should be supplied to them in some manner, either through the holes sometimes drilled for this purpose or by squirting oil, as best one can, between the frictional surfaces. Such parts as control device linkages, parts of the brakes, torque and distance rods, parts of the steering gear and spring hangers should receive careful attention. In general, it may be said that nothing should be taken for granted in the lubrication of an automobile. The plugs designed for the drawing off of the spent oil from crank and gear cases should be carefully looked after to see that they cannot drop out while running. If an undue amount of oil drips from any particular point of the machine it may indicate either that the supply is excessive, that means for retaining it are not proper, or that the oil is too thin. Thick oil, on the whole, gives little trouble from working out of bearings, especially when everything is hot. A great many "pointers" in regard to the lubrication of a machine are likely to be obtained when cleaning it. The "wiping off" of a machine is a duty which no one having the instincts of a mechanic will shirk, as the dust which an excess of oil on the outside surfaces of the wearing parts is constantly collecting proves very injurious to the mechanism. How to Locate Abnormal Friction in the Moving Parts. (ALBERT L. CLOUGH.) It not infrequently happens that an automobile motor is blamed for a loss of power with which it is not justly chargeable, the fact of the case sometimes being that there is an unusual drag imposed upon the engine owing to some portion of the car having developed an abnormal fric- tional resistance through lack of lubrication or some other cause. This supposed lack of power is generally first realized from the development of an inability to surmount certain grades on the high gear which have customarily been negotiated by it with comparative ease; or it may make itself felt by its becoming necessary to open the throttle wider than usual in order to gain a certain speed upon the level. Before assuming that the engine rs weak it is well to try the experi- ment of pushing the car by hand, both backward and forward, over the level stable floor, with clutch and brakes in their released positions and noting whether more effort than usual is required. In order to judge of this one should become accustomed to the amount of force normally required to move the vehicle under these conditions. If the car has sliding gears, the experiment should be tried with the "high" in engage- ment. Then, too, a 'little attention paid to the action of the car while coasting, free from the engine, may be of value in this connection. If 133 the machine fails to run by gravity as far as usual upon a certain grade under ordinary road conditions, something may be binding and holding the vehicle back, producing an effect which, under other conditions, might not unnaturally be attributed to loss of engine power. GEAR SETTING FOR COASTING. When a machine with sliding gears is allowed to coast, the gears should either be thrown out of mesh that is, into the "neutral" position, so that none of them are turning at all or, still better, as far as the present pur- pose is concerned, should be placed in the "high" position, so that they may be revolving at a minimum speed and thus consuming the least possi- ble amount of power. Careful attention paid to the force required to push the car and to its coasting ability will generally enable one to discriminate between faulty operation due to a weak engine and sluggish action of the car due to unusual frictional resistance. LOCAL HEATING A GUIDE. If there is reason to believe that some moving part is demanding an abnormal amount of power, it becomes necessary to locate the difficulty. Just after the machine has come in from a brisk run one may sometimes determine where the difficulty is by searching for signs of heat by means of the hand feeling the front and rear bearings and those of the counter- shaft, the brake bands, drums and shoes,' the clutch drums and bands, if a planetary gear is used, and the bearings of the change speed gear shafts, as well as the bearings of the shaft drive (in case one is employed). BLOCKING CAR UP. It is a still better arrangement to block the front wheels clear of the floor (securely, so that there shall be no danger of the machine running away) and to run the car for a considerable length of time on the high gear and then feel for evidences of heat at the points above enumerated. The front wheels may be jacked up and spun by hand and any lack of freedom in their motions noted and corrected. Perhaps their ball or roller bearings may be in too tight adjustment, a ball may be broken or a cone may have proved soft and become badly cut, or lack of sufficient lubrica- tion may be the only trouble. A good opportunity will also be afforded to see whether the chain is running freely, without any tendency to ride the sprockets either on the forward or reverse motions. When blocked up the engine ought not to be slowed down perceptibly when the high speed clutch is engaged, except at the instant when the connection is made. Any large loss of engine speed may be taken as an indication of the presence of unusual friction. In case any evidence of heat is found in the rear wheel or axle bear- ings, it may be due to defective adjustment, broken balls or rollers or to lack of lubrication, and the cause should at once be removed so that the rear axle will spin freely. DRAGGING BRAKES. If the brakes are found to become heated, an adjustment may usually be found which will secure the complete freeing of the braking surfaces when the brakes are off, and still not prevent their effective engagement when applied. A dragging clutch band of a planetary gear is likely to become evident when the machine is jacked up, as motion may be com- 134 municated to the wheels although the clutch is nominally thrown out. This is a matter of adjustment which can usually be handled without much difficulty. If lubrication has not been continuously furnished to the shafts of the change speed gear, they will waste a great deal of power, and this will also be the case if the gear case is too full of viscous lubricant. In machines employing sliding gears the manual power required to spin the rear wheels with the gear shifter in its neutral position and with the shifter on "high" may both be noted, and some idea gained as to whether the gear shafts are running as freely as ought to be expected. EXCESSIVE ENGINE FRICTION. Internal friction in the engine may also be a cause of the faulty per- formance of the car. If, with the relief cocks open, the motor does not crank with perfect freedom, even after a hard run, it may well be that, although it develops its full power, a considerable proportion of it is wasted in overcoming piston or bearing friction. The main bearings or those of the secondary shaft may be dry, or their shafts may have become sprung through some accident. Possibly the supply of oil to the pistons may be insufficient, in which case the loss of effective power may be almost complete, and easily detected by the rapidity with which the cooling wafer boils away. Copious lubrication is the obvious remedy for these difficulties. In general, it may be said that frequent attention to the easy running qualities of the car as a wheeled vehicle, and to the freedom of move- ment of the engine and all shafts related to the transmission of the power, often results in clearing the motor of an unjust imputation of shirking its duty. It may also have the result of greatly reducing the fuel bill, adding considerably to the life of wearing parts and of increas- ing very noticeably the speed and hill climbing power of the car. A good practice is to push the car by hand over the stable floor on each occasion when it returns from a run, both forward and backward, and also to crank the engine over a few times. In that way such a degree of famil- iarity in regard to the car's running qualities is achieved that any changes therein are immediately noticed. 35 TIRES. In the operation of an automobile the outlay for pneumatic tire^s is ordinarily much larger than any other single item of expense, and it is, furthermore, in great measure modified by the degree of care bestowed by the user upon this part of the equipment. The subject is thus of the first importance. In the following pages most of the instructions offered refer to the clincher type of tire, but are, in general, applicable to the mechanically fastened tires which are now rapidly being adopted upon motor cars. It is to be remembered that the two classes of tire are identical in prin- ciple and material, subject to the same accidents, affected by the same conditions and differing essentially only in the method of attachment. Attaching and Detaching Clincher Tires. Although the exact method of procedure in any given case is dependent largely upon conditions peculiar to that case, such, for instance, as the ease with which the tire can be reached under the mud guards, etc., and the climatic conditions under which the work must be done there are FIG. 73A. FIG. 74. certain general rules which should be followed, and possibly some "use- ful hints," based on practical experience, which may be taken advantage of to make the attaching or detaching of clincher tires a task less burden- some. Before any effort is made to detach a tire it is essential that absolutely all of the air pressure within the tire be released. This can best be done by removing the plunger completely from the valve, by means of the miniature screwdriver or spanner formed in the end of the valve cap. The alternative of holding the valve open with a pointed instrument is 136 more laborious, and not nearly so efficient, either in point of time con- sumed or in the thoroughness with which the air is expelled. Next remove the nuts from the retaining studs and valve stem, and push the studs and the stem through the rim and, if possible, entirely clear of it, using a small rod to complete the operation. If the studs are only partially released, they are apt to seriously interfere with the clearing of the shoulders on the shoe from beneath the edges of the rim. When all nuts are removed and the shoe cleared, grasp the tire with both hands, the thumbs pressing against it near the outside edge of the rim. Pull the top of the tire outward, and at the same time press inward with the thumbs against the lower part to clear the tire beneath the edge of the rim (Fig. 73A). Next, as part of the same operation, push the top of the tire in toward the car and down toward the bottom of the opposite wheel, until a space is visible between the tire and the rim of the wheel (Fig. 74). Continue this operation completely around the periphery of the tire before attempting to use the levers. It is usually possible to apply greater strength in this manipulation if the wheel rests on the ground, and the axle should therefore not be jacked up until the operation is completed. While pushing the top of the tire in toward the car with one hand, insert the end of a lever between it and the rim, after the manner shown in Fig. 75. Push the lever down until it assumes a horizontal position and thereby raises the edge of the tire from the rim. While holding thus with one hand, insert the end of a second lever in a similar manner at a point not more than 4 inches from the first. Push down the ends of both levers until the edge of the outer shoe slips out clear from the rim. Remove one lever, and in order to prevent the tire from springing back into position again, hold the other lever in the vertical position by grasping a spoke with the same hand. Insert the free tool FIG. 75. beneath the edge of the tire again and pry off another short length. The smaller the length of tire cleared from the rim each time, the smaller will be the physical exertion necessary to accomplish it. If it is desired to repair or replace the inner tube, it is doubtful if much time or labor is saved by removing simply the outer edge of the shoe. In fact, it is desirable for many reasons to remove the. tire com- pletely. It is accomplished comparatively easily after the first edge is detached, and a more careful inspection of the inside of the shoe is pos- sible when it is off the rim. Again, there is less likelihood of pinching or creasing the inner tube while replacing. If the tube is caught either between the rim and the outer shoe, or between the outer shoe and a retaining stud, in the manner shown in Figs. 76 and 77, trouble is sure to result, and if the tube is carefully fitted within the shoe and partially inflated while the shoe is completely detached, there is less chance for this "pinching" to occur than there is when the tube is worked little by 137 little into the shoe as it remains on the rim. Only a very slight inflation is necessary, and if too great a pressure is pumped up the operation of attaching is made more difficult. On replacing the tire, first insert the valve stem in its proper hole and work the shoulders on the tire in under the edges of the rim for a distance of about 3 inches on each side of the valve. Run the nut on the valve stem down to the rim so that the valve is held in its proper position. Turn the wheel until the valve is at the lowest point and then lower the jack so that the wheel touches the ground and is pre- vented from turning easily. The retaining studs nearest the valve stem can be fitted with their heads in the proper position between the lips, as they may be called, of the outer shoe and the inner tube. They can be directed into the holes in the rim as the tire is pushed on in both direc- tions up to the top of the wheel. The other studs should be placed in the rim and held from falling out by running the nuts on for a few threads. In some cases it is possible to work the two studs nearest the FIG. 76. FIG. 77. valve stem through the rim far enough to catch the nuts before it is necessary to resort to the levers. This should be done when possible, as it will, of course, prevent them from working out of position again. They should not be drawn tight, however. Little by little the shoe should then be worked on to the rim with the aid of the levers, first the inside edge, then the outside edge. Fit the heads of the retaining studs into their proper places before working the shoulders of the shoe under the edges of the rim, taking care that the inner tube is not "pinched." Fit the portions of the tire between the bolts under the edges of the rim after the portions at the bolts have been so fitted. The nuts on the retaining studs should then be run up lightly with the fingers and the tire fully inflated. Hammer well with a lever to insure the proper fitting of the tire at all points, and finally set up the nuts on the retaining studs reasonably hard, using a small wrench for the purpose. The Care of Tires in Use Wear Due to Faults in Car. Even with careful operation the tire item will form a goodly portion of the total expense in the operation of a car, and through carelessness and inattention it may easily become as great or even greater than all 138 the other running expenses added together. It devolves, therefore, upon the motorist to give the tires every consideration, and to apply every means calculated to prolong their life. Natural wear, of course, can- not be altogether prevented, but as unnecessary wear may result from many causes, a study into these causes should prove beneficial and enable the observer to take remedial measures, and to avoid such wear by constantly watching for its causes. Unnecessary wear of the tires may be caused in many different ways, but results from nothing more fre- quently than an improper condition or adjustment of certain parts of the car. These usually are not found in a car when new, but develop as the machine is used. IMPROPER ALIGNMENT OF WHEELS. By far the most prevalent of these causes is the improper relation- ship of the steering wheels, due to the bending of the steering arms or of the connecting rod between the wheels, either of which will make it impossible to bring the wheels into planes parallel with each other and with the longitudinal centre line of the frame of the car. A drag- ging of either one or both of the tires of these wheels over the ground will result, which will rapidly wear the outside layer of rubber on the outer shoe at the tread portion or point of contact with the ground. If the plane in which the wheel rotates is not parallel with the line of motion of the car as a whole, the tendency of the wheel to travel in two directions at the same time causes this dragging, and the wear will occur in lines across the tread at an Bangle equal to the angle of error in the position of the wheel. If it is discovered that the steering mechanism is in the condition indicated above, great care should be taken to accurately locate the cause of the trouble before any effort is made to rectify it. Even if a steering arm is bent, it is possible to bring the wheels parallel with each other by adjusting the connecting rod, but such correction holds only for travel in a straight line, and as the steering angle has been disturbed, dragging and wear will occur in turning corners. In such a case the steering arm should be brought to its proper position, and the connecting rod, if it is not bent, will then bring the wheels into their normal position. If the front axle shifts on the springs, so that one side is nearer the front end than the other, it will become impossible to bring the wheels parallel with each other when the car is traveling in a straight line, and wear on the tires will result, the same as in the cases cited above. In this case the wheel bearings will be in line with the axle which position is the only one in which the wheels are parallel with each other only when the wheels are out of parallel with the frame of the car and not pointed for travel in a straight line. In holding the car in this direction a sort of compromise is reached between the two wheels, and the dragging which causes wear occurs. ALIGNMENT OF REAR AXLE. The rear axle should also be maintained in a position at right angles with the longitudinal centre line of the frame. A slight variation may cause increased wear on the driving tires, while a considerable varia tion will throw this wear on to the tires of the steering wheels. This will result from the fact that in order to move in a straight linr 139 the car must travel "crab fashion," with the front and rear wheels not tracking. To correct the effect on the steering, a turn must be given to the steering wheels, and they will therefore be thrown out of parallel. If the car is fitted with chain drive, and has a distance rod at each side, great care should be taken in adjusting these, to see that they are taken up or let out the same amount, so that the relative position of the axle will not change. In the case of cars fitted with bevel gear drive, it sometimes hap- pens that the clips over the springs become loosened, with the result that the axle shifts along the springs unevenly. Any such "shifting" should, of course, be corrected before the clips are tightened again. MUD GUARD BOLTS. Many tires have been injured by being cut by the bolts by which the guards over the wheels are attached. If insufficient clearance is pro- vided at the start; if the springs settle from long use, or if the guard supports become bent, it may happen that these bolts will rub the tire as the springs work up and down under a heavy load. Such wear is very rapid, and a single -run may ruin a tire. It is most apt to occur when the car is loaded to a considerable degree beyond the normal, either with passengers for a short run, or with baggage for touring. It is, of course, true that the guards should not strike the tires, even if the springs be forced down to the absolute limit, but such, unfortunately, is not always the case. EFFECT OF BRAKES. The condition of the brakes has much to do in an indirect way with unnecessary wear on the tires. In some cases the brake which is habitually used is so located that the braking action is transmitted through the differential and distributed evenly between the two road wheels. Braking shocks are consequently divided, but even so, if the conditions of the braking surfaces or the means of applying the braking effort are such that a gradual braking effect cannot be produced, the wheels will come to a stop sooner than they should, and will skid along the surface of the road, much to the detriment of the tires. Emergency brakes are usually fitted to the hubs, and are used much more than their name would imply. They should, therefore, be taken into consideration in a discussion of this sort. Their action is not bal- anced by the differential group, and it is, therefore, necessary to pro- vide some other means of doing this. If an equalizing device is fitted to them, the braking tension is distributed evenly between the wheels ; but if the braking surfaces are of different character, due to the pres- ence of grease or grit, the braking effect will vary accordingly, and one wheel will be retarded quicker than the other, and will therefore receive practically the whole of the braking shock. These surfaces should be kept in as nearly the same condition as is possible, and if no equalizing device is supplied, the length of the rod or cables connecting to these brakes should be such that the pressure applied to the brake handle is divided evenly between the two brakes. EFFECT OF GRIPPING CLUTCH. Another cause of unnecessary wear on the driving tires, which is peculiar to the gasoline car, is what is called a "gripping" clutch. If 140 through faulty adjustment, an improper condition of the frictional sur- faces, or a poor controlling device, it is impossible to allow the clutch to grip gradually, the shock which is transmitted through the entire trans- mission system, due to this sudden seizing, is finally delivered at the tires, and, besides subjecting them to a sudden strain, which tends to tear the rubber from the fabric, may cause them to skid and thereby wear at the point of contact with the ground. EFFECT OF OIL. The construction of some cars and the carelessness of the owners of some others make it possible for oil to reach the tires and accumulate thereon. It is undoubtedly unnecessary to state that oil is extremely injurious to rubber, and if its reaching the tires cannot be prevented, its accumulation should not be permitted. Enclosed live axles are very often filled too full of oil, with the result that when an incline in the road is reached it works out through one outside bearing and down the spokes to the tire. To remove oil from a tire, the safest method is to first wipe it off carefully with a dry cloth, and after this rub the parts, which were covered, with French chalk. The chalk should be dusted onto the cloth and rubbed vigorously over the tire. Some Causes of Abnormal Wear. The operator should always try to avoid the shocks of a sudden start or a quick stop to save not only the tires but other parts of the car as well. The tires are usually the yielding members which absorb the greater part of these shocks, and are therefore the greatest sufferers. If the coefficient of friction between the wheel and the ground is suf- ficient to keep them from "skidding," they are submitted to tremendous strains tending to tear apart the rubber and the fabric in the outer shoe. If skidding occurs the wear on the tread is dependent upon the condi- tion of the road surface. In ordinary operation a single violent stop or start does not ruin the tire, but each one weakens the outer structure of the cover to an extent and hastens the end of the tire's usefulness. The tires are also subject to unusual strains in turning at speed, the side strains thus created pending to tear them from the rim and to "skid" them sidewise over the road, both of which actions are, of course, detrimental. An important cause of wear on the tires of cars that are fre- quently stopped in the course of a run a doctor's car, for instance is the rubbing of the wheel against the curbing. This will wear off the outer covering of rubber at the point of contact, and allow water to get at and rot the canvas beneath. In such cases there is also greater danger of bending the rim in places, in such a manner that it will pinch the shoulder of the shoe and possibly cut into it. EFFECT OF SHARP STONES. Running over roads covered with small, sharp stones is very detri- mental to tires, and small bits are almost sure to be cut from the pro- tecting coating of rubber, and in some cases the covering may be cut through to the fabric. It is largely due to such causes that "blisters" 141 appear on outer shoes. The only effective cure for them is re-vulcaniza- tion, and as this is a relatively expensive operation the prevention deserves every consideration. It is safe to say that more tires have been hopelessly ruined by driv- ing that "last mile" while they were in a deflated condition, due to a puncture, than have been by punctures themselves. The fabric may be torn from the rubber, the shoulders torn at the bolts, and the valve stem pulled out of the inner tube. It is far better, if it really is impos- sible to repair the tire on the road, either through lack of time or of the proper tools and appliances, to remove the tire completely from the rim and to drive slowly and carefully in this manner to the nearest harbor of refuge. There are records of many miles traveled with a piece of rope serving the purpose of a tire, but the advisability of attempting such "makeshift" measures depends entirely upon the con- ditions peculiar to the case, and cannot therefore be discussed in a general way. STEERING WHEEL TIRES. A large proportion of drivers bring much unnecessary wear upon the tires of the steering wheels by twisting the wheels about before the car has been started. Tremendous strains are thus brought upon the steer- ing mechanism, the tires are ground into the road surface, and the outer covering of rubber is worn off to a greater or less extent. Ordinarily a sufficiently sharp turn can be made by turning the wheels as the car starts to move, and turning them while the car is stationary is entirely unnecessary. The grinding, if it does occur, is then distributed over a larger section of the tire, and its evil effects are accordingly reduced. CARE OF SPARE TIRES. Proper treatment is as essential in the case of spare tubes as in that of the tires in actual use, as when the extra tubes are needed they must be in perfect condition. It often happens that spare tubes are carried about for a considerable time before being put on the wheels, and dur- ing this period they must be protected against all deteriorating influences. Rubber deteriorates from various causes. Light, heat and oil all have a destructive effect on it, and, besides, it is, of course, subject to mechanical injury. To put an inner tube uncovered into a boxful of loose tools, oil cans, etc., is only a little better than throwing it away. The tools will chafe and the oil rot it, so that if it holds air at all when inflated it may soon burst under the weight of the car. Extra inner tubes, to be carried safely, should be first rubbed well all over with French chalk and folded carefully and tied not too tightly with wide tape. They should then be placed in a bag made of soft, water and light proof material which has also been carefully dusted inside with French chalk. This bag should then be carried in some part of the car where it will not be subjected to heat or come in contact with oil. The French chalk will prevent chafing between different parts of the tube and between the tube and the bag. If string is used to tie the tube it is likely, if drawn sufficiently tight, to hold the folds together so that there can be no rubbing between them, to cut into the rubber and stretch it considerably at one point, with injurious results. After a tube has been carried a reasonable length of time, it is well to refold 142 it so that the creases will come in new places. A spare tube deteriorates most quickly at the sharp bends caused by the folds. EXTRA OUTER SHOES. Extra outer shoes, if not carried on the car, should be stored where they are not open to the attacks of the enemies of rubber and fabric- light, heat and dampness. If carried on a car, it becomes necessary to keep them covered in some way, so that they may be protected against all of these, and against dust and chafing as well. There are now on the market covers specially made for this purpose. It is possible to obtain very good results from a winding of rubber cloth, but the cover will be found much more satisfactory, all things considered, particularly in point of appearance. Wear Due to Faulty Conditions of Tire Itself. While it is undoubtedly true that the average motorist has much to learn in regard to the proper treatment and care of pneumatic tires, it is also true that a very large part of what has been written on the sub- ject may be summed up in the phrase "Use common sense." The properties of rubber are to an extent apparent, and if its peculiari- ties are kept constantly in mind by the automobilist, he is not likely to injure his tires in handling them. If he asks himself as each problem presents itself, "Can this in any way injure the rubber or fabric, or affect their proper adhesion?" he is quite certain to arrive at the correct con- clusion. Herein lies the application of common sense. No book has been made large enough to contain all the detailed "don'ts" which might be set down and should be followed if the life of the tires is to be pro- longed to its absolute limit, and if such a book were written it would be simply an elaboration on common sense as applied to motor tires. Practical experience has shown that excessive wear on tires is com- monly produced by a set of causes which have their origin in the con- dition in which the tires are kept, and the frequency with which this sort of wear is found makes it possible to set down and discuss herein the more common of these causes without fear of appearing to be indulging in a statement of self evident facts. IMPROPER ATTACHMENT. Improper attachment of the tire to the rim is certain to result in trouble before many miles have been covered. In an earlier section it was explained how the inner tube might be caught between the shoe and the rim, or between the shoe and a retaining stud. The results of such pinching are obvious. The portion of the tube near that which is caught is subjected to increased strains while in a stretched condition, and the tube will soon burst or tear at the point of pinching. It may happen that the outer shoe is not caught properly between the rim and a bolt. If such be the case, damage to the shoe may result, and, in the case of many tires, the inner tube may blow out through the space between the shoe and rim near the improperly set bolt. BENDING OF RIM. If, for some reason, the edge of a rim becomes bent in any way, the dent should be removed as soon as discovered, for, if the bend is 143 inward, a greater pressure is brought upon the shoulder of the shoe at that point, and any chafing- will wear the outer protecting cover and weaken the shoulder at that point. If, on the other hand, the bend is outward, there is chance for water, oil and sand to work in between the tire and rim. Water tends to rot the canvas in the shoe, to rust the rim and to destroy the rubber, and sand to aggravate wear on the shoe. EFFECT OF RUST. Iron rust, as is well known, rots canvas very quickly, and for this reason water should be kept from reaching the rim. Assuming that the rim is clean, as, of course, it should be, when the tire is attached it may be kept so indefinitely if proper attention is given to the wheels. The retaining bolts and locking nuts on the valve stem should be carefully inspected at intervals, to make sure that they are drawn sufficiently tight to prevent any water from working in through the holes in the rim. If they are not tight, it is possible for water to work in between the rim and shoe, which, besides causing a certain amount of rotting itself, will soon rust the rim, and this rust will rapidly increase the rate of decay. The possibility of water reaching the rim also arises if the tire is not properly inflated. The rusting usually starts at the very edge of the inside of the rim, and if the faulty conditions which made its beginning possible are not corrected, it will spread until it has reached the canvas, through which it will travel rapidly. If a rim has become rusty, even though merely in small spots, such rust should be carefully removed with emery cloth, and the inside of the rim given a very light coating of lacquer, thin shellac or white lead paint. It is well to remove the tires from the rims at reasonable intervals, make a careful inspection of the inside of the tire and of the rim, and correct any faulty conditions before serious harm may come from them. LOOSE RETAINING BOLTS. Loose retaining bolts may be responsible for more trouble than that caused by letting water into the tire. If the bolts do not clamp the shoe securely to the rim, the latter may "creep" and thereby bring a strain upon the valve stem which will tend to tear it from the tube. They also stimulate wear on the inner edge of the shoe and may cause a chafing of the inner tube. The tires of the driving wheels require particular attention in this regard, as the driving effort will tend to increase the "creeping." In the case of the tires on the steering wheels, any slackness of the bolts may, if the tire is not sufficiently inflated, permit of a certain amount of play between the rim and shoulder, and in nego- tiating curves at any degree of speed there is increased likelihood of a tire becoming detached for at least a portion of its length, allowing the inner tube to burst out. Insufficient inflation of a tire has certain other evil effects besides those mentioned. Under the weight of the vehicle, a partially inflated tire takes the shape of a flattened arch the curvature of the outer ends of which varies in acuteness inversely as the pressure within the tire. As the wheel revolves, this bending, as it were, of the tire in contact with the ground causes an unequal stretching of the combined rubber and canvas in the outer shoe which tends to tear them apart. Insufficient inflation also increases the liability of puncture, as a larger area of the 144 tire surface is in contact with the ground and exposed to puncturing influ- ences. The liability of bending the rim is also increased. PRESSURE OF INFLATION. Much theorizing has been done on the subject of proper inflation pressures, but when all is said and done there is only one final test which is of any practical value. A tire should be pumped up until it is capable of holding its shape, and yet does not transmit every small shock to the axles. This may seem a bit indefinite, but it is as accurate a statement of proper tire inflation pressure, all things considered, as can be given. The pneumatic tire is intended to absorb all small road shocks. If it is too highly inflated it will not do this, and if it is insufficiently inflated it will not hold its shape under the weight of the car, and the results set down herein will follow. In pumping air into a tire an ounce of com- mon sense is worth a column of pressure tables. However, tire manu- facturers generally furnish data as to the inflation pressures which they recommend which are sometimes of assistance, and tire pressure gauges, which are very convenient, are to be had of supply dealers. There is an evident lack of appreciation among motorists of the impor- tance of having small cuts which extend through the outer layer of rub- ber on the outer shoe sealed up as soon as possible. Water and sand get into such cuts and will in time cause blisters which gradually increase in size until an extensive repair is necessary. The water will also tend to rot the canvas. It is well known that in a long run the tires become considerably heated. This heating is caused largely by the frictional action between the outer shoe and the air chamber. To avoid it to a degree, French chalk or talc or pulverized graphite should be rubbed over the inner tube before it is inserted in the shoe; this acts as a lubricant and reduces the friction between the two surfaces to a minimum and consequently diminishes the amount of heat generated. Hints on Tire Maintenance. (CHARLES E. DURYEA.) Very frequently a weak spot in the fabric, caused by water getting in or possibly by a faulty splice or similar defect, manifests itself by a slight swelling, and this the owner should notice, diagnose and repair, for if neglected the weak spot will grow larger, causing the tire to increase in cross section at this point with correspondingly increased strain on the fabric and the certainty of quick further damage resulting in a burst, which will probably tear a large hole in the air tube as well as in the casing. Probably the worst abuse to which tires are subjected is wrong infla- tion. Under excessive inflation every weak spot in the tire is needlessly strained and it is not uncommon for them to burst when standing still in the garage because of this abuse. On the other hand, tires are constantly used with insufficient infla- tion, with the result that striking a stone or street crossing at speed bumps the rim perceptibly, bends the casing sharply, and often pinches 145 a hole through the air tube. Air tubes that have seen much service frequently show bruises extending part way through and in some instances completely through, to the wonderment of the user who fails to find the expected nail that caused his trouble. Inflation troubles can be easily avoided by glancing at the tire where it supports the load. If it is too hard it will not show that it is carry- ing a load. If it is too soft it will look as though carrying too much. If properly inflated it will widen under the load about one-eighth of an inch for each inch of tire sectional diameter. For example, a 3 inch tire under load should measure about 3^ inches at the widest part at the bottom. A 4 inch tire should measure 4 l /2 inches. It may be that these measurements can be improved upon and that slightly lessening them o'r increasing them, according to the locality, speed at which the vehicle is driven, and similar influences, would be better, but for a general rule they are probably as nearly correct as anything. It is not enough that the user should know that the tires are prop- erly inflated, but he should see that they remain so. To insure this, one of the first things to be done when the vehicle comes in should be to examine the tires and see if they need attention, for if repairs are needed they should not be left until the vehicle is wanted, but should be attended to at once, in order that they may be completed by the time the vehicle is to be used. If they need inflating this should be done so that the vehicle may have some time to stand properly inflated before being used, in which event it may be seen whether or not they are hold- ing up properly. It is well known that a small puncture may not leak at all when the pressure gets below a certain point, so that a leaky, half inflated tire may stand all night in that condition and not be appreciably softer next morning. It may be inflated properly when the vehicle starts out, only to leak down almost immediately to its original condi- tion and be damaged, just because the needed inflation was not given long enough before using to permit the leak to be observed. It is also well known that the valves commonly used cannot be depended upon to hold air themselves, but that the flimsy soft rubber gasket provided in the cap and forced against the narrow edge of the valve tube is the actual holding agent in most cases. There is no certainty that this cap can be screwed down tight enough to hold without being cut, roughened or otherwise damaged, and therefore no certainty when a tire has been inflated that the valve cap is in condition to hold the inflation. This is another reason why the inflation should be made a sufficient time before using to determine whether or not there is a leak. Of course, this can be determined by testing with a glass of water, the valve tube being at the top of the wheel, so that it may project down into the water and permit escaping bubbles to be seen. Very few people will take this trouble to insure that everything is right, so the practice x of inflating the tires properly when the vehicle first comes into the place and then noting their condition when it leaves is the only safe one. One should make sure, by frequent testing, that the pump is all right. It is quite common to test a pump by holding one's thumb over the out- let nozzle while a light stroke is made with the other hand. This, in 146 reality, proves but little. What the pump will do at a pressure of a few pounds is of no consequence to a man in trouble on the road. He wants a pump capable of doing its full duty at the pressure required to prop- erly inflate his tire. The only certain way to insure this is to use the pump that is in the vehicle for the purpose of inflating the tires of the vehicle. In the absence of this a sealed or blind valve can be attached to the pump, and then one or more good, strong strokes, as would be required for proper inflation, should be made. This will show whether there are any leaks. Many times a pump will have such a flimsy cup leather that under pressure this leather will reverse and refuse to work. Sometimes the rubber hose will leak at the connections or blow off completely or cause other little troubles not much in themselves, and easily fixed at a garage, but decidedly aggravating when the operator has need for a serviceable pump under unpleasant circumstances on the road. Extra valves and caps should always be carried. The user can do much to avoid unnecessary damage by seeing that the floor of his stable (and grounds) is free from needless obstacles liable to damage tires as the vehicle is moved about. An overturned jack, for example, may present the sharp, square corner of a metal base, which, if driven over without noticing, would almost certainly do dam- age. Nails or small tools used in crating or other work should not be allowed to remain on the floor, and the curbstones at the entrance should not have sharp corners. When the vehicle stands but a short while and under more or less constant inspection, the tires need not be given any special attention. If, however, the vehicle is left on dead storage and kept where the tires are not inspected it is advisable to largely reduce the air pressure and also to jack up the wheels, so that if the air does leak out the tires are not flattened and caused to crack where sharply bent. The vehicle should not be in a damp place, for this is not only bad for the mechanism and wood work, but the moisture is absorbed also by the upholstering. The fabric of the tires may also take up some of this moisture, which is detrimental. On the other hand, light and heat are injurious to rubber, and tires last longest in a moderately cool place. If they can be stored in a cool room, not exposed to direct sunlight and kept very lightly inflated, so as to preserve their shape, no other attention need be given nor can anything better be done. If a powder of any kind is needed to keep the rubber from sticking to other things, talc (French chalk) is the proper substance. If the tires are left inflated hard the fabric is unnecessarily strained, and if perchance there is a wrinkle in the air tube it may crack at this point in time. Partial deflation largely removes these possibilities. If left deflated wrinkles or sharp bends are formed, with the probability that the rubber will crack at these places when put back into its normal position. It is a fact that both oil and water wet the surface of a tire and serve to lubricate any cutting edge or puncturing point that may strike the tire, so on this account, if for no other reason, oil and water should be kept oflf the tires as much as possible. The wise driver will avoid mud holes and wet surfaces for this same reason. 147 Tire repairing is a large subject and one difficult to cover exhaustively. Small cuts in a tire casing may easily be fixed by a portable vulcanizer such as are now to be had. Many users stop small cuts by cutting a piece of rubber till it fits closely and then cementing the same in place. The weakened spot likely to result in a blowout can be remedied by cementing a piece of canvas on the inner side of the casing. This treat- ment will also cure for a short while a large puncture or even a small burst pending the time when it can be properly repaired by vulcanization. Tires should be watched for rim cutting and the cause removed. Generally it will be found that either the tire is run too soft or that it does not fit the rim, or that the rim is rough. In case it does not fit, a little canvas along the portion that is chafing will frequently stop the trouble. If rough, the .rim should be smoothed with a file or sandpaper and painted or varnished to prevent recurrence. Constant care is the price of good results with pneumatic tires, but as something cannot be had for nothing, things are usually worth the labor they cost. Road Repairs of Pneumatic Tires. The thoughtful automobilist will always carry spare inner tubes on his car, and to him a road repair will usually mean the insertion of another inner tube. But as it sometimes happens that in a single run the number of punctures is greater than the number of inner tubes carried, it may become necessary for even the most careful to put a damaged inner tube into condition to hold air. With skill and experience, it is possible to effect repairs of extremely bad punctures, but to insure success in even the simplest case, it is essential that certain simple rules be followed religiously. For the smallest puncture, a patch 2 inches in diameter should be used. The surface of the tube should be thoroughly cleaned for a space of at least half an inch larger in diameter than the patch to be applied, by first rubbing hard with a bit of waste or cloth, moistened with benzine or gasoline, until all traces of chalk or sulphur have been removed, and then slightly roughing up the surface of the rubber with very fine sand paper. It is best to use the prepared patches which are procurable from the tire makers, but if a patch cut from an old inner tube be employed this should be carefully treated on the under side in the manner indicated above, and the edges beveled, as shown in Fig. 78. It is bet- ter to cut the patch of circular shape, as a square patch will start to come off compara- tively easily at the corners. Cover the patch and cleaned space on the tube with a thin coating of high grade, heavy rubber cement (inferior grades are worse than useless), and allow it to thoroughly dry; then apply a second coating. When the second coating has become "tacky" (i. e., not moist, but will 148 THE HORSELESS AOE FIG. 78. TIRE PATCH. stick to the fingers when touched) the patch can be applied. Hammer it well with a bit of wood and allow it a minute or so in which to "set" before pumping air into the tube. It is most important that the sur- face of the tube and the patch be cleaned thoroughly. If this is not done, failure is almost sure to ensue. It is also necessary to wait until the cement is quite dry and "tacky" before applying the patch. A moment spent in waiting at this point of the operation will save many repairs later on. The treatment of cuts and gashes in inner tubes is a more difficult matter; but many cases are on record wherein cuts several inches in length have been successfully closed by carefully following the rules set down above, the operation, of course, being carried on on a larger scale than would be necessary for a small puncture. If good cement is used, the surfaces are thoroughly cleaned, and adequate patches are applied, a very bad injury may be healed, and the tube used for many miles. Some motorists obtain good results in patching inner tubes from the use of the acid cure process, which employs the vulcanizing effect of chloride of sulphur. It is claimed that patches cemented by this process stick better than when cement alone is used. If the injury to the inner tube results from some internal trouble, such as the pinching of the tube between other parts of the tire, no attention need, of course, be given to the outer shoe, further than to make sure that the conditions which caused the injury to the inner tube are eradicated; but if a nail has punctured it, or it has been cut by a sharp stone, or the like, and no spare shoe is at hand, it is necessary to give it attention, the amount depending upon the extent of the injury. In the case of a nail puncture the hole in the outer shoe should be covered by sticking on a bit of the prepared canvas, which the tire makers can supply, in order to prevent water and grit from working in be- tween the inner and outer tubes. To do this, the same rules must be followed as in the case of applying a patch to the inner tube. Use wood alcohol, benzine or gasoline in limited quantities to re-, move the French chalk or talc which may be present. Water will not dry readily and will therefore prevent the patch from sticking properly. Furthermore, it will rot the canvas if the hole is sealed so that it cannot entirely evaporate. As a further precaution, a small amount of cement should be carefully worked into FIG. 79- the hole from the outside. In cases of cuts which extend through the outer shoe, a strip of canvas sufficiently wide to cover the cut completely and to extend beyond on each side, and long enough to catch between the shoulder of the outer shoe and the rim, should be fitted on the inside of the shoe before the inner tube is inserted (Fig. 79). This strip should fit closely to the inside of the shoe, and it is well to attach it to it for at least a 149 part of its length, by using cement. The object of this strip is to pre- vent the tube from blowing out through the cut, and it should there- fore be drawn sufficiently tight when the tire is attached to the rim to form a supporting band about the tube. Emergency inner shoes or patches of leather or other materials adapted to this use are, to be obtained. In replacing the tire the inner tube should be rubbed well with talc or French chalk, or with graphite, and inserted, if possible, in such a manner that the patch will not come against the cut in the shoe, and care should be used that the loose ends of the canvas strip are securely caught between the shoulders of the tire and the edges of the rim. THC HOftSCXtSS AGE FIG. 80. THE SLEEVE IN PLACE. FIG. 81. TIRE STRAP. After a slight inflation, a leather sleeve, such as is now on the market for such purposes, should be laced tightly about the tire and the rim at the point of injury, a,s is shown in Fig. 80, and when this is done the tire may be fully inflated. If a strap be used in place of the leather sleeve it should be wound about the tire and rim in the manner shown in Fig. 81. Each winding should overlap the previous one, and the winding should be done in such a direction as will bring the uncovered edges toward the rear of the car when the strap is at the top of the wheel. The sleeve or strap, when properly applied, not only affords a sup- port to the injured shoe, but also prevents dirt and water from work- ing into the cut, and an aggravation of the injury by the contact of the wheel with the ground. The Tire Repair Outfit. A substantial tire repair outfit is a necessary part of the equipment of any car. It is a great waste of time and effort to attempt to repair a damaged automobile tire without the aid of good sized levers and large patches, and the experienced operator is therefore quite willing to give to tire implements a good proportion of the available space in his tool box. There are many appliances which may be included in a repair set as "luxuries" which are well to carry if they do not occupy space that ISO might be employed to better advantage ; but there are a few which are "necessities," and for these space must be provided. There should be at least two, and preferably three, metal levers of not less than a foot in length, an inch in width and a quarter inch thick, slightly tapering at one end. I q] S] ^ ~ v They m ay be of any of a I gj- d _jE ) J number of common shapes, but experience has shown that those illustrated in Figs. 82 and 83 meet re- quirements in a very satis- factory manner. The lever FIGS. 82 AND 83. CLINCHER TIRE TOOLS shown in Fig. 82 is useful in holding up the outer edge of the shoe while the valve stem or a retaining bolt is being put in place, as shown in Fig. 84. The tool shown in Fig. 83 is helpful in detaching a casing which has rusted to its rim, and in forcing it back into place. Much could be said on the subject of cement. It is a substance which varies much in quality, -but none but the best is good enough for tire repair work. It is useless to spend time with inferior grades, as the difference in price is not nearly proportional to the dif- ference in adhesive qualities. It is well to have on hand at least a half pint of heavy black cement in an airtight tin can. The small tubes put up for the bicycle trade do not hold a sufficient quantity, and the cement employed is far too light for this heavier class of work. An assortment of prepared rubber patches of various sizes can be obtained from nearly all tire makers. They are specially treated on the under side, so that they will stick well, and are usually circular in shape with beveled edges, so that they are not easily torn off. It is well to carry also a good sized piece of rubber from a discarded inner tube, from which patches of irregular shape can be cut if necessary. For patching holes in the outer shoe, two or three pieces, about a foot square each, of prepared canvas, such as the tire manufacturers can supply, should also be included. It is light and can be folded to occupy very little space, so that it will cause no inconvenience, while an abundance of repair material may prove extremely handy in case of an accident to a cover in an out of the way place. A sheet or two of sandpaper is necessary for use in cleaning and roughing up the surface of the rubber before the cement is applied. Talc or French chalk should be rubbed over the inner tube before it is inserted in the shoe, as it acts as a lubricant, and prevents to a considerable degree the heating of the tire caused by the frictional action between the outer shoe and the air chamber. A wooden box of tubular shape about i inch in diameter by 6 or 7 inches long, having a screw top, will hold a sufficient amount of powder for several applications. THE HORSELESS AQE FIG. 84. Of late, powdered graphite has been very highly recommended as a substitute for talc for lubricating the inside surfaces of casings and the outsides of inner tubes. Its use does not harm the rubber and it appears to be a much better lubricant than talc, as tires treated with it heat much less, and there is thus less energy wasted and less liability incurred of patches becoming detached. It is best applied from a com- mon squirt can, from which the graphite may readily be ejected in the desired quantities. The powder is then thoroughly rubbed into the rubber with the ringers or a brush, where it stays better than does talc. If thoroughly applied it tends to prevent rusting, and thus renders easier the removal of the tire. When the outer layer of rubber on the tire shoe becomes cut through, it is necessary to prevent dirt and water from working into this cut; and in extreme cases, when the fabric is also cut, it is necessary to give to the tire at this point an external support, to prevent the bursting through of the inner tube. The leather or rawhide sleeve shown in Fig. 85 accom- plishes both these objects ad- mirably. As is clearly shown in the sketch, it is so con- structed that it conforms to the shape of the tire, and can be fastened tightly about it by means of the hooks and lacing shown. It is, of FIG. 85. TIRE SLEEVE. course, possible to obtain the same results for a time by the use of a strap which may be wound about the tire, but the leather sleeve is more substantial, and when properly applied will permit of running on a badly damaged tire for many miles. Blow-out patches or reinforcements made of leather or other materials and intended to be inserted between the inner tube and the casing are also considerably used. It is well, also, to include in the kit extra valves, washers and caps for the valves, and one or two extra retaining bolts. A round rod about 6 inches long, of such diameter that it will pass freely through the bolt holes in the rim, will be found handy in pushing these bolts free from the rim when a tire is to be detached. These sundries do not take up any great amount of space, and may be found to be well worth the room they occupy. Whenever a repair is made, the tire requires to be pumped up again and a tire pump must therefore constantly be carried. A strong, well made pump, even if it costs a little more than would seem to the uninitiated to be a reasonable price for such an implement, will soon pay for itself in the satisfaction it gives. In inflating an automobile tire to its proper pressure the pump is subjected to tremendous strains, to withstand which it must be strongly made. It should be filled with not less than 2 feet of the heaviest and best of rubber tubing, to the end of which should be attached a coupling of generous pro- portions. 152 Home Tire Repairing and Vulcanizing. (O. H. V.) A large number of automobile owners have their own repair shops, some of them well equipped to do all the ordinary repairs, with one exception, and that the one most likely to occur, a tire repair. A vul- canizer in a private repair shop is a money saver, for a man with ordinary ability can soon learn to make a repair to an outer casing or inner tube that will save him a lot of time, trouble and expense. A vulcanizer can be purchased outright, or if one is mechanically inclined and has the necessary tools he can make it. Steam vulcanizers are used in nearly all cases now, as they are easier to regulate than dry heat and not so apt to "cook" or scorch the work. A vulcanizer (Fig. 87) consists of a cast iron box with one or more channels or grooves in it to receive the molds or forms used in repairing. The box can be made in one piece by using a core box and leaving core supports, which serve for vents in the casting as well, and can afterward be tapped and plugged, or it can be made in two pieces and bolted together with either a ground joint or gasket between. If the casting is cored it should have means provided for cleaning it out, as lime and sediment will form and impair the heating qualities. A gasoline burner is used to generate heat, and a safety valve, a steam gauge and a filling cap should be attached to the vulcanizer, as it is nothing more than a cast iron steam boiler. Of course, in large repair shops and factories a regular steam boiler is used and steam conveyed to the vulcanizer in a pipe. The pressure used is about 70 pounds per square inch, as this gives the required heat to vulcanize rubber. The molds (Fig. 86), which are made of cast iron and in halves, are made the size and shape of a segment of the tire, and of course every size and style of tire requires a different mold. A small cut in an outer casing can be vulcanized on a flat surface, but if the repair is large or the fabric torn, a mold should be used to prevent the tire from getting out of shape. The pre- paring of a job for vulcanizing is what requires the time, as each layer of cement should be thor- oughly dry before the next one is put on, otherwise it will not stick. The cement used is crude Fj( ._ ^_^ QW FOR VULCANIZING. rubber, cut or dissolved in benzol. To vulcanize an inner tube that has been cut or blown out, clean it around the blowout with sandpaper or emery cloth, or wipe it off with a cloth wet in gasoline, then put powdered soapstone inside the tube at the cut to prevent the cement from sticking the tube together; then apply a coat of cement to the outside of the tube around the edges of the blow-out and allow it lo dry naturally. Then take a crude rubber patch or a patch with a crude rubber coating on one side, which can be purchased from supply houses, and coat it with cement and allow it to dry. While they are drying unscrew the filjer cap on the vulcanizer and 153 pour in water until about half full, then screw in the plug and put gasoline in the burner and light; when steam shows seventy on the gauge regulate the fire to hold it there, and when two or three coats of cement have dried press the patch on the inner tube firmly, working from the centre to the out- side; sprinkle a little soapstone on the vulcanizer, put on the tube with the patch next the plate or top of the vulcanizer and lay a weight on it, or tighten the top by means of the lever and weight with which some vulcan- izers are fitted, or with a screw for flat work, and let it cure from thirty to sixty minutes and the rubber and cement will be united. To repair an outer casing in which there is a cut that goes through the fabric, grind away the ouler rubber down to the fabric and around the cut, apply cement the same as on inner tube inside and out, cut out a patch of fric- tion cloth or prepared canvas the size needed, coat with cement, and when FIG. 87. SMALL STEAM VULCAN IZEK. dry stick it inside the casing, after giving it several coats of cement. If the cut is a large one, apply the prepared canvas on the outside and build up the required number of layers of fabric, each having been coated thoroughly with cement. Then apply the crude rubber of sufficient size to replace the amount ground off and place in the mold, with an air tube inside the casing; then put the mold in one of the channels provided for it and cure. A little practice will soon produce results, and in many cases a tire can be saved to months of usefulness by the timely application of the vulcanizer. The air tube is to hold the casing in shape in the mold until it is vulcanized. ELECTRIC VULCANIZERS. For small jobs of vulcanizing, and especially for the vulcanization of tires by owners themselves, the electric vulcanizer (Fig. 87A) is in 154 quite general use. Here the heat is furnished by the etectric current obtained from the regular lighting circuits (either direct or alternat- ing) through a flexible cord at- tached to a lamp socket. The heat is developed in conductors embed- ded in the metal of the vulcanizer and may be regulated to any desired degree a thermostatic device auto- matically throwing the current on or off as required to maintain the required temperature. These vul- canizers are so devised as to enable repairs of inner tubes to be made, cuts upon the tread to be vulcanized while the shoes are in place, and the repair of blow-outs to be effected by inserting the vulcanizer within the shoe, the heat being applied from inside. On account of their small size, and the fact that no fire or steam pressure is required, these vulcanizers are handy and safe. FIG. 8;A. -ELECTRIC VULCANIZER. ( AUTO- ELECK-TRICK. ) Quick Detachable Tires. While the clincher tire of bicycle size left little to be desired, as it could easily be removed and replaced, practically without tools, and punctures could be readily repaired, the increase in size of the clincher tire required to adapt it to heavy automobile uses rendered the process of removal and replacing very much more difficult, requiring a great deal of physical exertion. A large variety of tire tools were in- vented to facilitate the removal and replacement of the tire cover, but with the large sizes FIG. 88. MIDGLEY. O f t j res commonly used on modern touring cars the opera- tion remains still a very arduous task. In the course of time it became recognized that whatever advantages the clincher rim might possess for tires of small section, it was certainly not the acme of perfection for large tires. To lessen the difficulty of removing the tire, a type of rim which may fitly be described as a separable rim made its appearance on the market some years ago. So far as we are aware, the first rim of this kind to be actually marketed was the "Peter," made in Ger- many, which made its appearance about 1903. In the separable rim one of the sides or beads of the rim is bolted to or otherwise secured 155 HOUSELESS IOE FIG. 89. MARSH. to the rest of the rim and can be removed after taking out the bolts, after which the tire may be slipped right off without the exertion of much physical force. A large variety of methods for joining the separate bead to the main portion of the rim have been developed. One difficulty experienced with this type of rim results from the tendency of the parts to rust together, so as to make it almost impossible to remove the bead. Of course, no trouble need be experienced from this cause if the rim is properly attended to in time, and the success of the separable rim depends, therefore, largely upon the person taking care of the car. MIDGLEY RIM. One of the first separable rims to be placed on the American market was the Midgley rim, which is manufactured by the Hartford Rubber Works Company, Hartford, Conn. Referring to Fig. 88, A is the main portion of the rim, secured to the felloe C, and B is the locking rim. The rim is here shown as set for standard clincher tires. It is also adapted for use with Dun- lop detachable tires, rubber filler being inserted in the left hand or inner bead and the ring B reversed when this type of tire is to be fitted. The locking ring is locked or drawr* together by the turnbuckle D, which is provided with right and left hand threads and turned by means of a spiral FlG - 90. GOODRICH. gear meshing with the gear in- tegral with the threaded shaft. By the use of a special crank provided for the purpose the turnbuckle is turned, thus separating or drawing together the two ends of the ring B, as desired. To remove a shoe, the two ends of the locking ring B are separated by the turnbuckle until the side opposite can be pulled out of the groove. The ring is then lifted up to remove the turnbuckle and the shoe slipped off. To replace the rim B, the turnbuckle is first inserted in the socket, the rest of the ring shoved into place, and by the method already explained the two ends are drawn together until the ring is tight in its groove. As this turnbuckle is practically irreversible with respect to the separating tendency of the ends of ring B, it cannot work loose. THE MARSH SEPARABLE RIM. This rim is made by the Diamond Rubber Company for use with all standard clincher tires. A (Fig. 89) is the rim secured to the felloe E. The two rings B C are removable, and C is held and locked into position by the internal expanding ring D. This ring is locked by an oval wedge 156 FIG. 91. GOODYEAR. on the spring clip F, which rests in an oval shaped slot cut in the locking ring. To re- move the ring the wedge on clip F is first sprung out, and the right hand end of the lock- ing ring sprung downward and past the other end, which re- leases the ring. The slip ring C can now be removed, and then the shoe. To replace the ring, C is slipped into place and -one end of ring D started. The rest of the ring is then expanded to place and the wedge snapped into its seat. THE GOODRICH RIM. This rim is made for any standard clincher tire. In Fig. 90 A is the rim, secured to the felloe C, and B the detachable rim with which is incor- porated the locking device. At each end of the ring B is formed a hooked lug integral with it, which hooks into the slot E and locks in the following manner: The left hand lug D 1 is first slipped into the outside part of the slot E and drawn down or toward the observer until the hook engages with the rim, and the dowel pin G is central with a hole in B, which insures locking. The rest of ring B is shoved into place and with a special tool with pins, engaging with holes F F, the right hand end of the ring is drawn up until lug D 2 FJ- 92. FIRESTONE. can be slipped into the inside half of the slot E in the direction of arrow 2. The ring is now drawn together, and lug D 2 can be drawn outward in the direction of arrow I until the two lugs are in the same slot, when the ring is locked. Lug D 2 cannot slip back into the other half of slot E and thus come off, because a clip on the valve stem spreads the beads of the tire apart and holds the locking lugs into the outside half of slot E. To remove the shoe, the dust cap of the valve stem is loosened, which releases the clip. The beads are now free and the right hand end of B is shoved in until lug D 2 releases, when the ring can be pried out and the shoe removed. THE GOODYEAR SEPARABLE RIM. This rim, made by the Goodyear Tire and Rubber Company, is adapted for use with either clincher or detachable tires, by the special shape of the slip rings which permit of reversal for the particular type used. A rim A (Fig. 91) is secured to the felloe of the wheel. The two slip rings B C, owing to their peculiar shape, can be reversed. In the figure they are shown set for a detachable tire. The locking device is a contracting ring D, the normal diameter of which is that of its groove, and it is held in place by its contraction and the pressure of the shoe against B. To remove the ring D, one end of it is pried out of the groove and the rest of the ring can then be worked out, which releases the slip ring B, which can now be removed. To replace the ring the reverse operation 157 is performed, the locking ring being simply sprung into place. The pressure of the shoe against the slip rings holds all parts in firm contact. The Goodyear Company uses a special de- tachable tire with the rim, with a woven wire tape embedded in the bead. When the tire is inflated this tape, on account of its weave, is said to shorten and to exert a pressure of nearly 1,000 pounds to the square inch, thus preventing creeping. FIRESTONE SEPARABLE RIM. These rims, the product of the Firestone Tire and Rubber Company, are constructed with two sets of rings for use with clincher or detachable tires as desired. Fig. 92 shows rings for detachable tires, A being the rim attached to the felloe G, B C the slip rings, and D the contracting locking ring. The ring C of both sets is fitted with two pins which fit into holes .E of locking ring D. The ring D is locked by drawing together the two ends by a special tool with pins engaging with F, until the pins on C (referred to above) slip into the holes E, these pins being in register with the holes when the two ends of ring D are drawn together. By the use of a lug or spreader on the valve stem the\tire is forced against the slip rings, which in turn prevent the ring D from jumping off from the pins. The locking ring is then secured. To remove, the spreader on the valve stem is released, which permits ring C being pressed inwards until the pins release the two ends of ring D. The ring is 'then easily removed, releasing C, and the shoe is then readily taken off. To replace, the two ends of ring D must be at the valve stem. Ring C is replaced and D sprung into place and drawn together, as explained above. The lug on the valve stem is then drawn up and D secured. FISK SEPARABLE RIM. This rim has been manufactured by the Fisk Rubber Company for a number of years. A (Fig. 93) is a steel band secured to the felloe of the wheel, and B C are rings that slip over the beads of the tire and are held in place by clip bolts. D is the head of one of these bolts and is shaped to grip the ring C and rim A. The bolt passes through a channel made in the bead and is threaded at the other end to receive a nut. This nut holds in place another clip, which likewise grips the other slip ring and rim. The number of these bolts used depends on the size of the tire, a 30 inch tire being fitted with ten bolts. To remove a shoe from this rim the nuts E are removed, freeing the clip F, which in turn allows the ring B to be removed. The tire can then be removed. To replace, the rings are slipped in place and the clips inserted and drawn up tight by the nuts E. Creeping is said to be practically impossible with this rim, as the beads are firmly gripped between the two rings. 158 FIG. 94. MICH ELI N. DEMOUNTABLE RIMS. Another step in advance in the endeavor to reduce the trouble and delay consequent upon a tire puncture on the road was the introduction of the demountable rim. This consists of a complete rim, carrying a tire and tube fully inflated, which is always carried on the car as a reserve. If one of the tires on the car is damaged so as to make it inadvisable to continue running on it, this tire with its rim is removed bodily, and the reserve tire and rim are substituted for it. The demountable rim was first exploited (so far as our knowledge of the matter goes) by a French- man of the name of Vinet. It was first brought forcibly to public atten- tion during the Grand Prix race in 1906, when a number of the com- peting cars were fitted with such rims by the Michelin tire firm, and it was claimed that the winner owed his victory to the fact that his car was so fitted. Since that time there has been great development in both sepa- rable and demountable rims, and the principal types now upon the Ameri- can market are described in the following: MICHELIN DEMOUNTABLE RIM. The Michelin Tire Company manufactures the demountable rim con- struction shown in Fig. 94. To the felloe A is secured the band B with a flange on its inner edge to receive that edge of the clincher rim C. This rim is clamped in place by D, there being eight of these clamps spaced around the felloe and held in place by the nut F on bolt E, which passes through and is secured to the inner side of the felloe. To remove the rim, the eight nuts F are re- moved and the clamps D slipped off, which releases the rim C, which is removed by tak- ing off the side opposite the valve stem and then lifting up. To replace, the valve stem is the rest of the rim, and the clamps are slipped on and tightened. DIAMOND DEMOUNTABLE RIM. A steel band B (Fig. 95) is secured to the felloe A. This band has a small flange, as shown in the cut, which is the only part of the band that the rim C touches, except the lugs. The rim C is formed with six lugs, one of which is shown in section at E, spaced at regular intervals around the wheel, and which fit into slots cut in the band B and felloe A. Drawing up on the nut F draws the lug E securely against A. By means of these six lugs the rim C is held firmly to the wheel. There seems to be little chance of the rim sticking to the band B because of rust, as the only points where the two touch are the lugs and the small flange A feature of this rim is the valve construction em- ployed. By this construction FIG. 95. DIAMOND. inserted first, followed by FIG. 96. DIAMOND VALVE. 159 the valve stem is brought flush, like the lugs, with the inside of the rim C, and there is no chance of the valve stem being injured by careless handling of the rim, and it also allows the rim to be more easily removed. The principle of this valve is the same as that of the regular type, the only difference being in the length. This valve, a cross sectional view of which is shown in Fig. 96, is i^ inches' in length, which brings the valve cap just below the surface of the rim. To inflate the tire, the cap is removed and an extension tube is screwed in. The tube has a nipple at its outer end, threaded to receive the standard pump connection. . To remove the rim the six nuts are removed and the rim is easily slipped off. The inflated unit is now slipped on, the nuts are screwed on and tightened, and the tire is ready for use. THE FISK DEMOUNTABLE RIM. The Fisk Rubber Company has lately brought out a demountable rim based on the same general principle as its separable rim, which has been on the market for some years. To the felloe A (Fig. 97) is fastened the hollow beveled ring B, which has a raised flange at the right for the support of the rim C. The clamping de- vice is a beveled expanding ring D, held in place by five lock nuts, one of which, F, is shown, spaced equally around the ring B. The tire is fastened to the rim C by the regular Fisk method, the only change being the valve stem construction. This valve stem is in the form of an L, the valve cap projecting through the bead of the tire, as shown at G. This con- struction allows the rim to be removed with- out chance of injury to the valve. To remove the rim, the five nuts are re- moved, which allows the clamping ring D to be removed. The rim C is now slipped off and the spare inflated unit is put in its place, the ring D slipped over the bolts E, and the nuts F replaced. Drawing up on the nuts F expands the ring D, and the rim C is held in the channel formed by the two flanges. FIRESTONE DEMOUNTABLE RIM. In Fig. 98 C is a standard clincher rim, to which block B is attached. This block, of which there are six, spaced equally around the rim, fits into a channel cut in the steel band, which is attached to the felloe A. This band has a small flange at each edge on which the rim sets, thus giving a comparatively small area of contact for rust- ing and sticking. By means of the clips D E the rim is pre- vented from slipping off side- ways, and creeping cannot oc- cur because of the block B in the channel in the band. THE HORSELESS AE FIG. 97. FISK. FIGS. 98 AND 99. FIRESTONE. To remove the rim, nut G is loosened, freeing the eccentrically mounted clip D, which is turned in the opposite direction (Fig. 99), and the nut 160 THE HORSELESS >G( FIG. loo. CONTINENTAL. G is lightly drawn up to hold it in position. All six clips are treated in this manner, and the rim is easily slipped off, as the lugs and valve stem are flush with the inside of the rim. This valve is of the same type as the one illustrated in Fig. 96. The inflated unit is now slipped on, the clips are reversed and the nuts tightened. CONTINENTAL READY-FLATED TIRE RIM. To the felloe A (Fig. 100) is secured the band B, which has a flange on its inner edge to receive rim C, which is made slightly larger than the band B, to allow of the insertion of the wedgelike clamp D, which holds the rim C in place. There are eight of these clamps, spaced at equal distances around the felloe. These clamps are held in place by nuts F, on bolts E, which pass through and are secured to the felloe. To remove this rim, the nut F is taken off, freeing wedge D, which is also removed. All eight clamps are removed in this manner, and the rim is re- moved by pulling off first the side opposite the valve stem, and then by lifting the valve stem out. To replace it is simply the reverse operation, the clamps being replaced and the nuts drawn up until all is firm. Replacement is facili- tated by the use of a brace wrench, which is supplied. CRESCENT DEMOUNTABLE RIM. B (Fig. 101) is a beveled steel band secured to the felloe A. The clincher rim C is beveled on its inner side to fit on B, and is clamped into position by six hinged clips spaced at equal distances around the felloe. One of these clips is shown at D. These clips are drawn up by nuts E on bolts which pass through the felloe B. The rim is removed by burying the valve stem, preferably at the top, and removing nut E, which releases D, allowing it to be swung out and down, away from the rim. All the clips are thus opened and the rim is removed by pulling the lower part of the rim away first and releasing the valve stern by lifting up on it. The inflated unit is slipped on by inserting the valve stem first and then the other half on the wheel. The clips are turned up and the nuts tightened. Bands B and C are galvanized, clips D are nickeled, and bronze nuts are used, which is claimed to prevent any sticking due to rust. H HOUSELESS ICI FIG. 101. CRESCENT. Demountable Rims in Practice. (H. H. BROWN.) The demountable rim proper weighs substantially the same as the ordinary clincher rim, which is permanently attached to the wheel, the 161 additional weight involved being simply that of the inner rim attached to the wheel and that of the clamps and bolts. This amounts to about 9 to 12 pounds per wheel, according to size, making a total of, let us say, 45 pounds for the four wheels. The spare demountable rims weigh on an average 15 pounds, and as two of these are generally carried, the total added weight is increased by 30 pounds, making a total of 70 pounds for the complete additional equipment. The weight of the spare shoes and tubes has not been included, as these are now carried in almost every case. It hardly seems as if a matter of 75 pounds is of much moment on a car weighing from 2,000 to 3,000 pounds, especially as more than half of this goes toward strengthening the wheel and puts no additional weight on frame or axles. In order to be sure of having the spares ready for immediate use they should be examined about once a week to see that they are properly inflated. In case a power air pump and tank are at hand, in which latter a known constant pressure is maintained, it would only be necessary to connect the spares to this from time to time. How- ever, as there may be slow leaks, valve troubles, etc., and as one may not have a power pump available at all times, it is best to have a tire pres- sure gauge with which the pressure in the spares may be measured from time to time. This gives one a line on the tightness of the valve, etc. Two HANDY TOOLS. Placing of a tire on the detached rim is easier than placing one on a wheel, if it is gone about in the right way. Two simple tools are of great assistance in this. The first is some form of plug to place through the valve hole in the rim and the valve notch in the shoe. A tapered wooden plug will serve for this purpose, or even a discarded valve stem. The other is known as a "lug hook." It consists of a piece of three- eighths inch round iron, bent at its centre to an angle of about 30 degrees, the ends of these arms being turned up at an acute angle in a plane per- pendicular to that of the main angle. The arms are about 6 inches long and the turned up ends about I inch long. This is used in conjunction with some form of lever about five-eighths inch in diameter and 18 inches long. This tool forms part of two standard kits, but may be easily made by any blacksmith. METHOD OF REPLACING. The rim is first laid on the ground, the shoe laid over it, the lower part of the bead at the valve hole being put in its place on the rim and the "plug" inserted in the valve notch and hole. The remainder of the lower bead may now be put into position. Now stand the rim upright, the detached edge of the tire away from the body, and the lug hole next the valve hole uppermost. Catch the edge of the tire on either side of the lug hole with the lug hook, pass the round lever through the angle of the hook, and, with the near edge of the rim as a fulcrum, bend back the tire. By slightly canting the rim away from the body it will be found that the end of the lever can be caught in the crook of the knee, and then both hands can be used to place the lug in position. The use of this device not only enables one to pull back the cover from over the lug hole, but actually pulls the bead of the tire into position in the clinch of the rim. It is best to work round pro- gressively in placing the lugs, as in case of the use of a "protector strip" 162 this will then not be moved out of position. When all the lugs are in position the valve stem of the tube may be put into position by means of the lug hook, the "plug" being first removed. The rim is now laid on the ground and the remainder of the tube placed in position in the shoe. It is now as well to slightly inflate the tube, seeing to it that it is not twisted and that the lugs do not nip it. The outer edge of the tire may now be placed in position and the lugs tested by the stems to see lhat they are all right. After this is done the tire may be fully inflated, in place. If the lugs are new ones the ends of the stems should be filed During the inflation the lug stems may be removed and the nuts screwed or sawed off flush with the nuts. This may, however, be done before they are placed on the rim, if an old lug is available as a guide. By following this method it is possible for one man to place a new tire complete on a rim in between fourteen and seventeen minutes, this including inflation by power pump. In case of a simple puncture the rim is placed on the ground, the nuts are removed from the lugs, and the edge of the tire is removed from the rim. The stems are then attached to the lugs without the aid of the lug hook, while the rim is on the ground. The lug hook is only used to remove and replace the valve stem of the old and new tubes. It would appear that the use of the same size tire all around, while desirable even on the ordinary type of rim, is even more so in the case of demountable rims. For carrying the rims some form of carrier requir- ing less straps and buckles than the ordinary form of tire bracket would be a great convenience, and would probably greatly shorten the total time of making the change. As a matter of fact none of the arguments used against the demount- able rim have proven valid, with the possible exception of that to the effect that a second puncture takes more time. This total extra time would not amount to more than five minutes over that required to replace a tube in the ordinary clincher rim, as the only additional work would be the unscrewing and replacement of the clamps and the changing of the rims. The wheel would have to be jacked up and the inner tubes removed and replaced in both cases. On the other hand, apart from the time saved by shortening roadside delays, it is probable that the money saved by preventing pinching of inner tubes and ruining of shoes by being run deflated goes far toward defraying the cost of the outfit. 163 THE INSPECTION, CARE AND USE OF MOTOR CARS. The Inspection and Supplying of a Car. (ALBERT L. CLOUGH.) Constant inspection is the price of successful and safe motor car operation, as indeed it is with any other piece of mechanism which is complicated and harshly used. Inspection not only reduces the liability of those derangements which may cause imperfect operation and stoppages on the road, but, what is far more important, it in a measure forestalls those imperfections which may result in accident to the occupants of the machine or damage to the car itself. Inspection for the latter class of derangements is far more imperative than for the former, and it may be well to mention a few of the matters which should be looked to particularly with an idea of pro- tecting the passengers and the machine from danger. THE STEERING GEAR, from the hand wheel to the wheels themselves, must be scrutinized with the most minute attention. Every nut must be demonstrated to be in place and its cotter pin, if it have one, properly secured. The ball joints in the steering linkage should be in correct and firm adjustment. If there is much lost motion between the hand wheel and the steering axles, it should be located and, if possible, removed. Sometimes an adjustment is provided to take up wear in the worm gear, or whatever irreversible mechanism is provided in the steering column. The column should also be demonstrated to be perfectly fast to the frame. Tightness in all parts of the mechanism, but still a perfect freedom of motion of the gear, should be the desideratum. If the gear springs badly when it is operated with the vehicle at rest, it should be viewed with suspicion, and if there is a large amount of incurable backlash the worn parts had best be replaced. The irreversible mechanism at the foot of the column is gen- erally intended to be kept packed in lubricant, and every joint and pivot should be lubricated with grease or oil. In connection with the steering gear one should try both front wheels to make sure that they are fast on their axles and that there is no possibility of their working off. THE BRAKES. Upon the integrity of the brakes depends the lives and limbs of the occupants of the car, and no pains should be spared to make sure that they are effective. The pull rods or cables which transmit the braking power from pedal or lever should be securely attached to the mechanism' which they operate, and entirely free from interference with other parts. Adjustment must be so made that the brake is fully applied before the operating pedal or lever reaches the limit of its motion. In the case of 164 hub brakes one should see that the brake band on one wheel acts just as strongly as that on the other. If fabric bands are used they should be kept free from oil, but if the braking surfaces are metal, oil is gen- erally expected to be used upon them. There is no excuse for anyone who operates with his brakes in bad order, as their condition may be tested at any moment on the road by any operator, no matter how untech- nical he may be. Do not neglect one brake because you employ it but little, but see that it is in as good condition as the other. LUBRICATION. The chief causes of damage to the mechanism which may be removed by inspection are the failure of the lubrication of some part, the loosen- ing of some part from the fastenings which normally hold it in place, and the failure of the water circulation. Upon the lubrication of each moving part of the mechanism depends its wearing quality, and even its operability, and too great care cannot possibly be taken in regard to it. It will be spoken of in connection with the several parts of the mechanism. No matter how much care is taken to prevent the working loose of NUTS, BOLTS AND SCREWS (and the greatest pains are taken to obviate it in the best modern machines), the constant vibration of the car occasionally causes the slack- ening of these important fastenings and sometimes their complete work- ing out and their loss, with very serious consequences. Nothing but a trial with a wrench or screwdriver of these bolts and screws, covering all parts of the machine, can assure one that everything is as it should be ; and right here it may be well to make a few remarks as to some of the conveniences which make inspection easy and conduce to its thor- oughness. The machine should preferably be capable of being readily stripped so that its every part is easily reached, and engine and change speed gear should be provided with liberal hand holes. If possible a pit should be built in the floor of the stable, over which the machine may be placed and in which one may stand at full height and secure a "worm's-eye" view of the whole mechanism. An incandescent lamp with wire guard and a long, flexible cable is almost a necessity of a thorough inspection, as are wrenches and screwdrivers of all shapes and sizes. One should constantly be on the lookout for nuts that have dropped off or lost their check nuts or cotter pins. WATER CIRCULATION. The maintenance of a plentiful supply of cooling water circulating energetically through the engine jacket is necessary if injuries to pistons and cylinder walls are to be avoided. It is a part of the work of inspec- tion to see that the water tank is full, that no leaks have developed and that the circulating pump is doing its full duty and is properly lubricated. If it is driven by gears they should be carefully greased, and the belt which operates the air fan of the radiator should be kept well dressed and at the proper tightness, and its fastenings should be secure. In the general inspection of the car one may well begin with THE RUNNING GEAR. The tires should be examined for nails or other puncture producing objects and the sides for evidences of rim cutting. If any parts of the 165 tread are cut it is sometimes possible to stick down the chipped portions with a rubber cement manufactured for this purpose. The front wheels may be jacked up and demonstrated to run perfectly free, but without any serious side play. The ball or roller bearings used must occasionally be packed in grease, and should be adjusted to that degree of tightness which secures freedom from wobble, but without the least tendency toward binding. If the car has a live rear axle, care should be taken that its bearings, usually four in number, and of balls or rollers, are fully lubricated. The large nuts securing the wheels to the axle tips should be shown to be per- fectly tight. In case the axle is chain driven one should see that the chain is neither too tight nor too loose, and that it is clean and well lubricated. Occasionally it should be examined, link by link, to make sure that none of the parts have worn excessively and are in danger of giving 'way. The link which fastens together the two ends of the chain should be closely examined to see that it is secure. The two distance rods which adjust the chain should be set up tight, and at equal length, so as to keep the axles parallel, and be lubricated at their bearings, and the differential case should be supplied with the proper amount of heavy oil to secure constant lubrication. If the car has a shaft drive the lubrication of the bevel gears, if attended to, will probably insure the oiling of the differential. In case of the solid axle and double chain drive the bearings of the wheels on the axle must be attended to, but the lubrication of the differential will probably be taken care of when the change speed gear case is supplied with oil. The springs should be inspected to see that no leaves are broken, and every nut on the clips, which secure the springs to the frame and to the axles, should be left in a tight condition, as otherwise a broken leaf may be the result. The paint will usually hold these nuts from loosening. THE ENGINE. The engine should be turned over by the crank, and the compression in each cylinder should be proved to be satisfactorily maintained. If it is not, an attempt should be made to locate the escape of the gas, which, if not being lost by the piston rings, may escape past a spark plug that does not fit tightly or through an inlet or exhaust valve which does not seat properly. Sometimes one can determine where the loss of gas is by the sound when the engine is slowly cranked. The bottom of the crank case should be removed or the hand hole cover taken off, as the case may be, and the moving parts inspected. No perceptible looseness should be allowed in the bearings of the connecting rods on the crank pins or at the wrist pins, and shims are sometimes provided to allow of the neces- sary adjustment of the former bearings. It is of the greatest importance that the bolts holding the caps on these bearings should be tight and prop- erly locked, and the caps on the crank shaft bearings in the engine base should be left in a perfectly secure condition. If any of the valves have- proved to be leaky they should be removed, together with their seats (if these are separable), and ground in. The bearings of the secondary shaft should be in proper adjustment, and if any part of the engine appears to have lacked oil one should ascertain the reason. If splash lubrication is employed the case, after being put together, should be filled with the 166 proper amount of high test cylinder oil, and any undue escape of the lubricant through joints or otherwise should be corrected; and if the oil is fed to the cylinders and other parts through oil pipes it is well to occasionally disconnect these and see that oil is actually delivered when the lubricator is working. SPARK PLUGS. Spark plugs should be removed and seen to be clean and uncracked, and their terminals adjusted at the right distance. The timer may be uncovered, the contacts cleaned and the connections of the wires to it demonstrated to be tight and not liable to breakage. It is well to take a look at all the wiring to see that it is not oil soaked or that it does not pass too near any conducting part of the car. If storage batteries are employed it is a good idea to make a volt- meter test of each cell, examine the contacts for tightness and signs of corrosion, and to see that no slopping of electrolyte is taking place. In case dry cells are used it is well to TEST EACH CELL of the battery by means of a gauge. The cells should be packed in such a way that they cannot shift from the motion of the car, and the connec- tions between them should be of flexible cable, provided with proper ter- minals. Where a magneto is used it should receive the lubrication which the makers intend, and its contacts and binding screws should be in good electrical condition. If driven by gears they should be kept well lubricated. Coil vibrators must be adjusted propefly, and the adjustments set very securely. The platinum points should be carefully brightened with emery cloth. If the contact spark is used the igniters should occasionally be removed from the cylinders to see that the points are in proper condi- tion to give a good contact, and the mechanism should work perfectly freely, and not at all sluggishly, in order that the break may be quick and "snappy." CHANGE SPEED GEAR. The change speed gear, if of the sliding pinion system, should have its case provided with a sufficient but not excessive quantity of heavy oil or grease and oil mixture, and the old oil should be drawn off and the parts thoroughly washed with kerosene before new lubricant is put in. The shifting mechanism should be thoroughly oiled at its joints, and seen to be in such adjustment that the gears fully mesh when the lever is locked in its several positions. In case a planetary gear is used the straps must be adjusted so as to secure freedom from .slipping on each speed and so as not to drag when released, and the case should contain plenty of lubri- cant. The pivots of the operating mechanism which tightens the straps should be lubricated, as well as the operating parts of the high speed locking clutch. These gears frequently have a number of oil holes, vary- ing with different makes, and none of them should be neglected. It may he remarked in passing that the operation of lubrication, if intelligently performed, will often bring to light, without special effort on the part of the attendant, many cases of looseness of parts, excessive wear and other defects. One cannot completely inspect the lubrication system without viewing and perhaps handling most parts of the machine, and in so doing 167 one is likely to notice anything which is out of order. One should not take for granted that a force feed lubricator, operated either by the ex- haust pressure or mechanically driven by the engine, is infallible in its workings. Oil pipes will sometimes clog, and the small pumps used in the latter type sometimes fail to draw their charge of oil. One must be sure that oil actually reaches the part intended, and to this end oil magazines and their pipes should occasionally be flushed out with gasoline. Oil ways and holes must be free so as to carry the lubricant to the very point at which it is needed. One should have a variety of oil cans of proper sizes and lengths of spout, so that there may be no temptation to slight any parts of the mechanism. If a cone clutch is employed there seldom will be any need of adjust- ment, but the operating mechanism which throws the clutch out must be oiled. Castor oil is sometimes used on the leather lining to keep it soft and to make it "take hold" properly, and neatsfoot oil is also recommended. All operating levers and their connections, including the gear shifting handles, the spark advance and the throttle or accelerator pedal or lever, should be proved to be perfect in their workings. Gasoline piping should be inspected for leaks, and the tank as well. The carburetor float chamber should occasionally be drawn off and flushed with gasoline, in order to remove any water or sediment, and the spraying nozzle and chamber should be kept free of all foreign substances. It is impossible to give any directions for inspection which will cover all makes of machine, but a short acquaintance with any particular car is sure to bring out special points which need examination frequently. If, however, all parts are carefully examined in the stable at frequent inter- vals, there will be very few troubles met with on the road, and it should be the aim of every conscientious automobilist to secure, by his own fore- sight, a clean road record. Tire troubles and rare instances of the break- age of parts, neither of which classes of troubles can be avoided by inspec- tion, are about all the difficulties which a good operator ought to expect while the machine is in service. An ounce of prevention applied in the stable is better than many pounds of cure applied under the disadvan- tageous circumstances which the road generally imposes. Tire repairs being treated in a separate chapter, nothing will here be said regarding them. SPARE PARTS. After all the precautions in the way of inspection have been taken, it is well to be prepared to meet all ordinary emergencies of the road, and in order to do so the tool box should be liberally and judiciously supplied with the proper tools and supplies. Although modern cars are almost proof against serious breakages, if a long tour is contemplated through" a district where repair shops are few, quite an extensive list of spare parts and supplies had best be taken. As to what spare parts should be chosen nothing but experience can determine. But it may be said that whatever part or parts of a particular machine have shown weakness should be the parts carried in duplicate. An extra inlet valve and an extra exhaust valve, with their springs, should be included in the kit, together with a good supply of spark plugs, if the jump spark is used, and a complete 168 extra igniter if the low tension system is employed. A spare make and break mechanism for tlie magneto may not be amiss. Some people carry an extra set of springs, or an extra front spring at least, but these are not likely to be needed unless the machine is over- driven, and they are rather cumbersome and heavy. A good country blacksmith is ordinarily able to make new springs, at least for temporary use in case of breakage on the road. Extra links for the driving chain and ah extra master link should, of course, be included, and an extra belt for the air fan, if one is used, may well be kept on hand. One should have on hand a stock of spare nuts and bolts of the sizes used in the machine. Ordinarily the supply necessary to fit all parts of the machine will not prove burdensome. The small springs, such as used on contact igniters and governors and flexible pump connections, sometimes break, and duplicates should be at hand. Gaskets and packings, although not much employed in modern machines, should, in cases where they are used, be carried ready cut for use. Spare tires are a necessary part of the touring equipment of all automobiles, and both extra shoes and inner tubes should be carried, together with patches, cement, graphite, sandpaper, extra lugs and valves, a pump and one of the folding jacks which are now on the market. In addition to whatever special wrenches or spanners are required to fit special parts of the mechanism, and the tool equipment outlined in a later chapter of this work, a pocket battery gauge will not come amiss. One can add to the equipment a pair of overalls and a jumper and a piece of oil cloth to kneel or lie upon when making repairs, but these "insignia of the trade" are not nearly so often needed as they were formerly. SUPPLIES. Among the supplies which should be carried, a good quantity of the best high test gas engine cylinder oil is the most important. Oil of this quality cannot always be obtained in the rural districts, and without it operation is impossible. It can be used for the lubrication of every part of the mackine, and there are few places where it is not equal, if not superior, to anything else. Ordinary steam engine cylinder oil will not do for gasoline engine cylinders, and care should be taken that it is not "palmed off" as suitable for gas engine use. It will, however, suffice for gear box lubrication and may be used if desired. Grease of the proper quality for use in cups and in packing hearings and graphite for chain lubrication should be included in the outfit. A plentiful supply of cotton waste and a cake of tar soap should not be forgotten. A supply of annealed iron wire of medium size, compactly coiled, and a little rubber covered electric cable of about No. 16 may prove of value, the former in making temporary mechanical repairs and the latter in renewing a defective portion of the sparking circuits. A little emery or quartz powder of rather fine grade should be provided, in case valves require grinding. Every machine should be supplied with a funnel fitted with a chamois leather strainer, for use when the gasoline tank is to be filled. The three supplies most necessary to the running of an automobile (excluding the cooling water) are gasoline, lubricating oil and plenty of ignition energy. As long as these are at hand and no part of the machine is 169 actually broken, anyone worthy of the name of an automobilist ought to be able to keep the road. It is rather a commentary on human responsibility that there are so many stops made from lack of gasoline and so many "foolish virgins." Fresh batteries are not obtainable at every cross roads, and one set at least ought to be brand new when one is starting on a long tour in "truly rural" districts, and if storage batteries are used they should be freshly charged, as charging facilities are very limited in the country districts. In genuine touring, when long distances are made each day, inspection and lubrication, as previously outlined, should be carried out punctiliously at the beginning of each stage. Common Engine Derangements and Their Diagnosis. (ALBERT L. CLOUGH.) The most common trouble likely to be experienced on the road is a failure of the engine to develop its power. This may be total or partial, and it is necessary to locate the trouble and remove it. When an engine stops or becomes weak the chances are at least ten to one that the cause is defective ignition rather than anything else (see chapter on "Ignition"). With a single cylinder or a double cylinder motor explosions which are actually missed can be readily detected at low speeds by the sound and by the unsteadiness of the motion, but when at high rates of revolution it is less easy to be sure that missing is going on, while with a four or six cylinder engine it is very difficult to detect the occa- sional missing of one cylinder, especially when the speed is at all high, unless the muffler cut-out be opened. An engine may ignite perfectly when tested running light, with nearly closed throttle, at a very moderate speed, but will miss very badly when the throttle is opened widely, the spark advanced and the speed high. There are several reasons for this. When the throttle is nearly closed a very small charge of gas is taken, the compression is quite low, and even a weak electric tension will cause a spark at the plug through the not very dense charge ; but when the throttle is opened wide and the spark advanced so as to take place at the maximum point of the now greatly increased compression, a strong electrical tension is required to force the spark through the dense gas. If battery ignition is used, when the engine is running slowly the contact device makes a longer electrical connection than when it is speeded up, and a weak battery is then more likely to build the current up to the sparking point than when the connec- tion is so brief as it is at very high speed. Sometimes, too, when the con- tact surfaces of the timer are worn, the contact brush, when revolving at very high speed, may pass over the contact surface without touching it sufficiently to establish a connection. When a magneto is used the chances of the failure of the make and break device are greater at high speed, and the possibility of a short circuit at the" distributor or at the plugs making itself felt are greater at the high voltage which is then generated. One should not reason that because an engine ignites properly at low speeds, on light throttle opening, it will fire its charge regularly under heavy 170 duty. The chances are very large that the engine which suddenly fails to develop its wonted power under these conditions is either missing charges or igniting them feebly. The carburetor is very likely to be blamed for giving a bad mixture in such cases, but it is generally inno- cent. When the engine is shut down after giving weak power attention should be paid to whether it stops promptly after the throwing off of the current. If it does not, the chances are that it is hot and has been igniting prematurely. Such a condition is generally preluded by "knock- ing" or some signs of labor. Overheating may be caused by a failure of the cooling water to circulate properly or by lack of cylinder lubrication, and if the engine is found unduly heated the circulating pump should be inspected to see that it is operating properly and the water tank examined to see that it is full. If the radiators are comparatively cool while the engine is excessively hot, it is pretty certain that the circulation is defective, and the cause of its stoppage must be sought. Some of the best machines are equipped with a gauge which shows at a glance whether the pump is developing pressure, but this does not necessarily prove that the circu- lating system is not clogged at some point. In case the cooling water is doing its work properly, and yet the engine overheats, investigation of its cylinder lubrication must be undertaken, and one must be satisfied that sufficient oil is actually delivered to all the bearing surfaces. Lubrication may have failed so completely that the pistons stick when the engine is stopped, and it cranks with difficulty. In this case, cylinder oil should be injected freely through oil holes, priming cocks or spark plug holes until the engine is "limbered up" sufficiently to operate upon its regular oil supply which has been restored. Another common cause of loss of power, which, however, does not come on suddenly, is the carbonization of the piston heads, the combustion spaces and the valves. This condition is usually manifested by metallic clanking sounds, which are especially noticeable when the throttle is widely opened and the motor is slowed down under load. These clanking sounds are the result of the premature ignition of the charges by incan- descent carbon particles within the combustion space, and the loss of power is mainly due to the fact that the explosion takes place while the piston is still ascending in the cylinder, the result being that part of the energy of the fuel is expended in "back work." Self ignition, arising from carbonization, will sometimes cause an engine to run after the switch has been thrown off, and if such a tendency to run with the spark off is manifested when the cylinder jackets are not unduly hot, while the radia- tor is properly warm, there is a strong probability that the engine is car- bonized. Instructions for dealing with this condition will be given in a later chapter. If the engine is found to stop promptly upon the withdrawal of the sparking current it is not a case of overheating. It is a good plan to crank the engine over and note carefully whether the compression in each cylinder is of the usual strength, and whether the inlet and exhaust valves of the respective cylinders open properly at the correct times. If com- pression is lacking in any cylinder it may be that its exhaust or inlet valve is stuck open, a valve or its spring may have broken, or some foreign object may have lodged on the seat of the valve. Everything appearing 171 right in this quarter, and the engine still unable to develop its full power, the ignition is almost certainly at fault. In case two entirely separate systems of ignition are fitted to the ear, the obvious course is to change over from the one which has been in use to the reserve system, and if this latter is known to be in condition, and there is still a lack of power, it is not likely that the difficulty is one of ignition. The only exception to this is that the plugs of both systems have become fouled with gaso- line or oil soot. If no spark gap is provided it is sometimes possible to discriminate the defective cylinder by successively cutting out the spark plugs. This may readily be done by means of a screwdriver having a wood handle, the blade of which is made to simultaneously touch the engine and the head of the spark plug, which it is desired to short circuit. The engine should be speeded up somewhat by means of the throttle, and the successive short circuiting of the plugs performed. When the igni- tion of a cylinder, which is working properly, is thus cut off, the engine will slow down considerably, and will probably work somewhat irregularly, as the defective cylinder or cylinders are still in action; but when a cylinder, which is missing badly, is thus cut out the speed will be very slightly reduced, and the action of the engine will become more regular. After a little practice it is easy to determine which cylinders are doing full work and which are not. If the missing is confined to a single cylinder the trouble is generally easy to locate and does not usually denote a general failure of the ignition system or lack of current. The spark plug of the defective cylinder should be removed, carefully cleaned with waste dipped in gasoline, and tried again, unless it is obviously broken, in which case it should be replaced by a plug known to be perfect. The length of the spark gap should be examined, and adjusted if found incorrect. If the ignition trouble is being experienced in connection with a mag- neto, it should be carefully inspected in accordance with the directions given in the chapter on "Ignition." In case a special battery system is being used the instruction book which usually accompanies this apparatus should be consulted. If ignition equipment be of the vibrating coil type the coil belonging to the defective cylinder should be examined and the car placed close to the vibrator to see that it buzzes at perfectly regular intervals and with a sound of uniform pitch. If it does not, or if there is an excessive or irregular spark between the vibrator points, the trouble may be there. The points should then be carefully cleaned with emery cloth and the adjustments manipulated until the best possible action of the buzzer is obtained, and the adjusting screws made tight. In case the buzzer still fails to respond properly, it may be that the primary wire between the coil and the contact device is broken or short circuited, or that the timer makes a poor contact for that particular coil, although this is unlikely, as some other cylinders would then probably be affected. If, on the other hand, the buzzer of the defective cylinder is working regularly and energetically, the trouble is likely to be in the secondary, and the secondary wiring should be examined to see that it is not broken and that the discharge is not taking place through some poorly insulated portion of the circuit to some metallic portion of the machine, thus cutting out the spark plug. The inspection of the secondary circuit is equally 172 necessary whatever system of jump spark ignition is employed. There is, too, a remote possibility that the secondary of the coil may have broken down, but this hardly need be considered. It is pretty certain that the trouble in the defective cylinder will be located at one or the other of the points mentioned. If, instead of a single defective cylinder, there is a general failure of battery and coil ignition, resulting in the stoppage of the car or very erratic operation of the engine, the natural thing to do is to change to the other battery. Both batteries of a well kept machine are always assumed to be in perfect condition at the start of a long run, and so when the second set is thrown in it is reasonable to assume that it is of full power. If only the battery was at fault perfect ignition will be restored, but one should remember to inspect the defective battery, test it with the battery gauge, tighten all battery contacts, and replace any wires which may be found broken as soon as opportunity is afforded. In case the change of battery does not remedy the difficulty it is highly probable that one of the "common" wires may have been broken, i. e., one of the wires upon which all cylinders depend. These are the wires from the switch, and the wire or wires which connect to the engine frame and ground the system. These should be inspected to see that they are perfect, and if broken should be replaced. A general failure of magneto ignition is likely to be due to a broken common wire, a failure of the make and break device, or a failure of the magneto drive (see chapter on "Magnetos"). In the rare instances in which the stoppage of the engine is not found to be due to faulty ignition, and not until all parts of the ignition mech- anism have been clearly demonstrated to be in good order, the carburetor should be inspected. The spraying nozzle should be demonstrated to be clear by depressing the float so as to force gasoline through it. If it is not clear, a very fine wire may be used to make it so. The float should be shown to be free in its motions and free from leak, and it should be proved that it operates its needle valve properly. All adjustments should be examined to make sure that they have not worked loose and altered. The air intake may have been clogged by something sucked into it from the road, and it should be examined with this possibility in view. It seems superfluous to add that the tank should be examined to see if there is gaso- line, and that the gasoline valve should be open, but many long stoppages have been occasioned on these two accounts. The Care of Clutches. (JULIAN C. CHASE.) It is impossible to emphasize too strongly the fact that the breakage of parts, the wear and tear of the car as a whole, and its consequent general depreciation, are due in a much larger measure to the sudden shocks to which the vital parts are subjected than to the natural wear resulting from the constant transmission of driving power from the engine to the tires. The shocks of sudden braking severely tax the running gear construction, but the shocks of improper clutching affect also the 173 power mechanism and are, therefore, of even more serious consequence. Defects or disarrangements in clutches reveal themselves in two dif- ferent ways either by gripping or seizing of the clutch, or by what may be called "spinning." Clutch defects may be classed accordingly, as the two phenomena are due to entirely different causes and affect the trans- mission gear differently. When the clutch "grips," it is impossible to engage it gradually, the power is therefore applied suddenly, and a blow delivered to all parts along the line of transmission. In the majority of cases, poorly designed controlling mechanism is responsible for this condition of affairs. It should be possible to permit the clutch to engage very gradually, so that it slips at first, and grips tighter as the car accelerates. To do this, it is necessary that there be a liberal amount of movement of the foot pedal or operating lever, so that a considerable amount of time, comparatively speaking, is occupied in making the engagement, and at the same time a sufficient leverage secured to make the physical effort required small and therefore more steadily applied. There should be no looseness in the joints, nor any "give" or springing, either in the levers or at the fulcrums, for as the amount of movement between the engaging surfaces is neces- sarily small, it is essential that the means of obtaining it be absolutely positive. With a perfectly operating mechanism it is possible to engage a clutch easily and without gripping, no matter what the tension on the spring may be, within, of course, certain reasonable limits. However, not all controlling devices are perfect, and it may, therefore, happen that ex- cessive spring tension causes a clutch to grip, while a tension just suffi- cient to meet the normal demands of driving could be easily controlled and would permit gradual engagement of the frictional surfaces. In this connection it may be said that the proper tension on the clutch spring should be made the subject of careful study. Too great a tension may not only lead to the trouble indicated above, but will also cause excessive wear on the thrust bearings and on all parts of the controlling mechanism. The clutch should set as a safety device, to an extent. It should, of course, be capable of transmitting sufficient torque to drive the car up the steepest hill which the power of the engine will enable it to climb, yet it should slip when a heavier shock is delivered to it, and thereby prevent this shock from reaching the breakable parts of the transmission. Generally speaking, a sufficient spring tension is that which will just permit the clutch to slip very slightly when the car is climbing a grade which taxes the engine to its limit when the highest speed is in use. Gripping may also be caused by an improper condition of the engaging surfaces. If both engaged and engaging surfaces are of metal, the lack of sufficient oil between them may prevent the slipping necessary to effect an easy start. It would also tend to aggravate the gripping by roughing up the surfaces. If leather and metal are employed^ the cause of the trouble usually is that the leather has become dry and rough through' lack of care. Water and gasoline should not be allowed to reach it, as they help to dry out the oil held in its pores. Gasoline will accomplish this very quickly, while water may have just as bad an effect in the end, although it does not act so rapidly. The heat generated as one surface 174 slips over the other also tends to dry out the oil, and if a car has been operated for some time with a slipping clutch, a careful inspection of the surface of the leather should be made to ascertain whether the heating has dried it up to any extent. If this is not done the clutch may grip when the spring is tightened. There are a number of different recipes for clutch leather dressing which are recommended by motorists of experience, but castor oil is most generally used, sometimes mixed with equal parts of glycerine. In either case it should be applied in limited quantities. Neatsfoot oil is also extensively used. Machine oil should never be used, as it is not so readily taken up by the leather, and will allow slipping under a higher spring pressure than is necessary if the surfaces are in perfect condition. In applying the dressing, it is better to use a small brush or swab, as if it is poured on it is not likely that it will distribute evenly, and as a result some portions of the leather will receive too much and others not enough. The driving effort should be distributed evenly around the periphery of the clutch, which can only be the case if the engaging sur- faces are uniform at all points. Spinning, as we have called it, is the continued revolution of the driven member after it has been disengaged. It results in a series of sharp, hammerlike blows to the gears (if of the sliding type) as they are brought into engagement, which tends to chip and burr the teeth, and, what is a less serious matter, to create considerable noise. Spinning may be caused by faulty design, defects in construction, or by improper adjustment. In some cone clutches the rim of the driven member is very heavy and of considerable inertia, and when disengaged continues to revolve much longer than is desirable. In this case the part of the operating mechanism which bears directly against it should be so designed that it acts as a brake and retards the revolving part when the latter is disconnected. Another cause of "spinning" is failure to cut the driving power off entirely, either through lack of sufficient movement between the surfaces to permit them to clear each other, lack of proper lubrication, too tight a bearing or bending of the clutch shaft, which causes binding between the two members. It is well to note carefully the action of the driven member when suddenly withdrawn from the driving member while the engine is running at a fair rate of speed and no gears are in mesh- If it is in perfect condition it will stop almost instantly. If it does not stop, a careful investigation should be made to learn the reason. Upon the free action of the clutch, more than upon any other thing, depends the successful operation of a good slide gear transmission. Slipping of the clutch may result from either of two common causes. The first is insufficient spring tension, and the second greasy surfaces. The remedy for the first is obvious. The second is only possible with leather clutches, and the remedy lies in getting rid of the superfluous oil. To do this it is best to use French chalk or talc. It can be blown into the space between the two clutch members by means of a glass tube, and will absorb the oil rapidly. Gasoline or resin should never be used, as the former dries up the leather, and the latter embeds itself into the surface and may ruin it. 175 Before concluding that a clutch spring needs tightening or that some of the oil should be removed from the leather it is well to ascertain whether the slipping is not due to the fact that some part of the trans- mission is binding, as this might be the real cause of the trouble and the slipping of the clutch merely one of the results. The action of a multiple disc clutch depends very largely upon the quality of lubricant used in its enclosing case. If the oil is of too thin body, engagement is likely to take place too fiercely and the plates may become cut or otherwise damaged. If the oil is too heavy and viscous, engagement may be slow and uncertain, and there is likely to be serious spinning set up which makes gear changing difficult and noisy. When there is sufficient reason to believe that the oil is too thick (as may especially happen in cold weather), a slight admixture of kerosene some- times remedies the difficulty. If the clutch is too sudden in its action the use of a heavier grade of oil may allow of more gradual engagement. Most car manufacturers give explicit directions for the lubrication and care of their multiple disc clutches, and these instructions should be carefully followed. The Care of Chains and Sprockets. In a high grade automobile driving chain are to be found as nice fits as in any other part of the car, yet the chains are required to perform their functions under more adverse circumstances than any other part of automobile mechanism. Most chains are exposed to the grinding action of mud and grit, and conditions are such that proper lubrication is a difficult matter. If a large amount of lubricant is applied, it serves only to collect dust and grit, and soon becomes a destructive agent rather than a preventive of wear. On the other hand, lack of lubrication is nearly as bad, for rusting may then set in, and the resulting wear would be nearly as great. It is interesting to consider the effect of a small amount of wear on every wearing portion of a chain. In the ordinary block chain there are four wearing surfaces for each block and link, viz., two between the pin and block and two between the pin and link. If we assume that there is .01 inch of wear between each of these pairs .of surfaces, in a chain of sixty links the total wear would amount to 1.2 inches, and the chain would consequently be just so much longer than when new. This lengthening due to wear is commonly known as "stretching." To prevent wear as much as possible chains should be frequently removed and cleaned thoroughly, by first placing them for a time in gasoline and then going over them carefully with a brush, until all traces of grit are removed. When perfectly clean, it is well to allow them to stand for an hour or so in melted tallow mixed with half its weight of graphite. Heat must be applied to the bath while the chains are in it, to prevent it from hardening, but care should be taken that it does not boil. Afterward the chains should be removed and all surplus tallow wiped off with a doth. This operation impregnates all the small bearings with a good lubricant which stays in place and prevents mud from working in between the wearing surfaces. Instead of making the tallow-graphite 176 mixture himself, the motorist can buy such chain lubricants already compounded. Another matter of importance in the care of chains is to keep them at the proper tension. Too great a tension not only increases wear between the various parts of the chain itself, and between the chain and sprockets, but also causes a greater loss in the transmission of power and greater wear in the sprocket bearings. A slack chain is, of course, more likely to climb the sprocket or to jump off under sudden shocks. The proper tension is that which will hold the chain in two straight lines between the tops and bottoms of the sprockets when idle, and not bring a greater strain upon the sprocket bearings than is necessary to accomplish this. It should be kept in mind that as a chain wears, its "pitch" varies, and in time a tendency to "ride" the teeth of the sprocket wheels develops. This increase of "pitch" increases the amount of wear on the sprocket teeth, and, as a result, when replacement becomes necessary, a new chain will not fit perfectly, and it will be more difficult to make it run quietly. It will be necessary also to use it under greater tension to prevent its jumping off, and this in turn will result detrimentally, as described above. It is expedient, therefore, to replace chains before they have seriously damaged the sprockets. Another cause for unnecessary wear in chains, which is perhaps of less serious consequence than the others mentioned herein, is failure to keep the sprockets in proper alignment. In cars fitted with side driving chains this condition may arise through the shifting of the axle sidewise under the springs, or the unequal length of the distance rods. Care should be taken in adjusting the chains to see that these rods are taken up or let out equally, so that each pair of sprockets revolves in the same plane. A set of substantial master links is essential if chains are to be handled with any degree of comfort. If there is sufficient clearance space, it is advisable to use the kind which is fitted with two bolts and nuts which are locked in place by cotter pins. The nuts can be loosened with a small wrench, and the parts are usually of sufficient size to make handling easy. Much time and energy has been wasted in the past in working with small, delicate master links, which are a heritage of the bicycle trade. Chain cases are beginning to come into quite extensive use. Their employment permits the chain to run in a dust-free bath of lubricant, but more atten- tion must be given to this matter if chains are to survive as a means of transmitting the driving power of automobiles. The chain drive is com- paratively efficient when all parts are clean and well lubricated, but a large part of this efficiency is lost when they are bespattered with mud and grit, to say nothing of the accompanying wear and uncleanliness. (C. L. LAMPKIN.) A very convenient and efficient way of cleaning a chain is to have a tank made of galvanized iron, as shown in Fig. 102, with two wood strips on the top edges to bolt or screw bearings to. At one end put a dolly box (or bearing) with a shaft running crosswise of the tank, on which fasten sprockets of different pitches to accommodate the chains mostly used. On the other end use dolly boxes with a shaft running 177 FIG. 102. SHEET IRON PAN FOR CLEANING AND LUBRICATING CHAIN. cross wise and parallel with the sprocket shaft and hav- ing a flanged roller on it. These dolly boxes can be made of wood, if desired, and slotted for bolt holes to allow for adjustment of the chain to suit the various lengths, or, better still, the wood strip can be made with deep slots and accommo- date a greater difference in lengths. A pulley or crank can be used on the sprocket shaft to apply power by. Adjust the chain so the slack side will just clear the bottom of the tank, place a common sink brush on a crossbar so it will rub the chain lightly, put gasoline (some use lye, but it is hard on the hands) enough in the tank so it will cover the lower chain, and start the pulley in motion. A very few minutes will suffice to clean it thoroughly. Then wipe dry and oil with good lubricating oil, wiping off the surplus oil, and then apply a mixture of oil and graphite mixed to the consistency of paste, or graphitoleo will answer as well. In replacing the chain on the car the method of procedure depends upon whether the rear axle has spiders of open construction, or whether it has the differential encased. In the former case the chain can be put on the small sprocket first, and then connected on the rear sprocket, the same as a bicycle chain, without tools; but where the rear sprocket is encased it is more difficult to connect the chain without special tools or FIG. 103. CHAIN TIGHTENING TOOL. FIG. 104. CHAIN PLIERS. without loosening the adjustment of the strut rod. Sometimes baling wire is resorted to, and it is not to be despised, for it has helped many an autoist out of trouble. A handy device for connecting chains, and one which should be in every chain user's kit, is shown in Fig. 103. The tongs as shown in Fig. 104 are very quick and handy, but the tool shown has an advantage in holding the chain at any place and allowing free use of both hands to connect the link. After the chain is connected 178 THE HORSELESS In passing from a lower to a higher gear it is, of course, necessary to speed the engine quite a little by means of the accelerator or ordinary throttle, in order to store enough energy in the increased speed of rota- tion of the flywheel to furnish the work necessary to accelerate the car up to its new speed. In most cases it is desirable to change gears as quickly and deftly as possible, but never nervously. When climbing a severe hill it is desira- ble to ascend as far as possible on a high gear by the judicious use of throttle and spark, but never to "hang on" so long that the engine labors seriously or is in danger of stopping. When it finally becomes necessary to change to a lower gear, advantage should be taken of the momentum possessed by the vehicle, and in order to do so the change should be made with as little delay as possible and before the vehicle has time to slow down. The gasoline engine having no reserve of power to draw upon, as does the steamer or electric, its momentum must be carefully conserved. When approaching hills the power should be increased in ample time to give good speed when the grade is reached, and full power should be applied on the ascent, to prevent the vehicle's slowing down to a point where a gear change will become necessary. Steep hills, if short, may be rushed successfully, if attacked in time and a high speed average maintained over hard roads, without indulging in dangerous speeds on the level or on descents. With large motors of four or six cylinders there is, of course, less necessity for this "rushing" than with one and two cylinder engines. These are by no means all the "tricks of the trade" which enable one to operate speedily and comfortably and with due regard for the car. The use of the spark timer is something which not everyone under- stands. The great majority of cars have a lever mounted upon the steer- 199 ing wheel for this purpose. It is useful in retarding the ignition at starting, and for slowing down the engine when standing below the point obtained by throttling alone, both of which results are secured by delaying the spark. A position of the spark lever may be found which gives good average results on varying throttle openings and through quite a range of speed, and may not require change for long distances. Experi- ence will teach one where this position is to be found. When it is desired to secure a high rate of speed the spark should be advanced made earlier, but not too suddenly, as then severe strains are imposed on the moving parts. If a grade is to be attacked the spark may be advanced, with full throttle, to give the car a high momentum, but as the engine slows down to a low rate of speed on the steep slope it may begin to "knock," when the ignition must be retarded enough to cause this symptom to disappear. If a magneto is used very little change of spark time is required. When the engine is slowed down nearly to the limit, under open throttle, a slight retard may be necessary and a slight advance from the usual running position may be required during "speeding." CONTROL OF CAR SPEED by means of the engine may be made so perfect that the use of brakes and the attendant throwing in and out of clutches may be minimized. When approaching water bars or other rough places in the road the car may be brought to a safe speed by the engine alone and without brake application, unless the conditions are very bad or appear suddenly, and when approaching any portion of the road which looks slippery and where skidding might occur the engine speed may well be reduced to a mini- mum as well as when a stop is to be made. There is no object in rushing up to the stopping place and applying the brakes when at high speed, as the tires are caused to slip, are severely worn and badly strained, and other portions of the mechanism suffer as well. It is more essential, from considerations of safety, to be able to stop a car promptly than it is to be able to start it, and the cautious operator, like the careful locomotive engineer, will try his brakes to see that they are dependable. When a steep descent is about to be reached the brakes should be tested to see that they are working well and to give time if this is not the case to control the car otherwise. It should always be remembered that the vehicle may also be controlled in event of brake failure by engaging the lowest gear and slowing down the engine by throttle and spark for the purpose of holding back the car. If this is not sufficient the spark may be cut off, and no car can show any speed on the lowest gear even on the steepest grade when this has been done. If slippery places are encountered in the road and a tendency to skid is manifested, one should apply the brakes with caution. As soon as possible get the car under engine control on its lowest speed. Safety in operation rather than speed should be the prime considera- tion in automobile driving, and every operator can assist in placing the reputation of the motor car in this respect upon a firm foundation. As all gasoline cars create a certain amount of noise, as long as the engine is running, whether or not the vehicle is in motion, the operator is deprived, in a degree, of the sense of hearing, so far as its value in warning him of danger is concerned. He has to rely almost exclusively upon his sense of sight. This fact demands an especial amount of visual alertness on his part. When approaching an intersecting street, the view of which is cut off by buildings or otherwise, he must have his car under perfect control, as he will not be warned by the noise of intersecting traffic so effectually, at least, as is the horse driver. In crossing a street car track, at an angle, the only safe course is to take a backward as well as a forward look for approaching cars. Unguarded steam railroad cross- ings are a menace to the public at large, and especially so to the auto- mobilist, as the sound of an approaching train will not generally be audible above the hum of the motor. Unless the track is visible for a considerable distance in both directions, great care should be exercised in crossing. In fact, almost all dangers which in other situations appeal to one through the ear must, in motor driving, be avoided by the watchfulness of the eye. When driving in districts where the automobile is not yet in common use the problem of meeting and passing horses becomes a serious matter, and results in the unpleasurable consumption of much nervous tissue on . the part of all concerned. One rule bearing upon this phase of auto- mobiling which may always be profitably observed is this : Never allow yourself to infringe the rules of the road or the prevailing law or ordi- nance in regard to stopping on request or as to speed. It is of the greatest advantage in case of trouble to feel that you were well within your rights. It appears to be not so much the noise of the motor car that frightens the horse as its "horselessness." In the dim equine intellect the motor car doubtless savors of the supernatural, and the horse's fear is corre- spondingly unreasonable and uncontrollable. When passing a restive animal the voice is very effective as a quieting agency. Such expressions as "Whoa boy," "Easy, now," "It won't hurt you," said in a reassuring tone, seem to have great influence, and evidently relieve the situation of its supernatural element, as judged from the equine standpoint. Experience has shown that ordinarily the best manner in which to pass a standing horse, headed in the same direction as the car, is to throw in the quietest gear, cross to the extreme further side of the road, and drive by about as quickly as the law allows, but never faster. The machine is soon past the animal and he will seldom start to follow the cause of his fright and rarely will back, because the machine and its terrors are rapidly drawing away from him. Passing a standing horse headed in the opposite direction, the animal has a full opportunity to see the car approach and work up his nervous tension, and some more care is necessary. The quietest gear should be retained, if possible, and the car should be slowed down to its minimum in every instance below the legal limit, and one should approach on the extreme opposite side of the road, ready to throw out the clutch and cut off the spark at the least exhibition of dangerous disquietude. In meeting a horse being driven by a capable driver, it is perfectly legiti- mate to pursue your regular legal pace, until some sign of fright is noted, when the speed should be decreased and the car stopped if necessary. The engine may be shut down if it seems needful, but if it is possible to get by without taking too great chances, it is almost always advantageous. When the car is past the horse, it may be speeded up in order to get out of hear- ing as soon as possible. Any signal to stop on the part of the driver should be obeyed as quickly as the brakes permit. When horses are met driven by ladies or children, and there are the slightest indications of freight, the machine had best be brought to a full stop, and one should wait, with hand on the ignition switch, ready to slop the engine instantly, unless the animal is under full control. Under all circumstances the automobile operator should speak to any horse which appears frightened. Such action on his part, in conjunction with the efforts of the driver, generally proves effectual. Sometimes, even when the machine is stopped and the engine motionless, a horse cannot be induced to pass the car. There is only one thing to do in this case, and that is for the automobilist to lead him by. This gives one an opportunity to say a few pleasant words to the occupants of the horse carriage and perhaps relieve the situation. Jt is very unpleasant to meet or pass teams on a bridge or on parts of the road having a precipitous declivity on one side, guarded perhaps only by a few frail fence rails. The possibilities of a runaway, under these circum- stances, should be sufficient to demand extra care on the part of the oper- ator. Such meetings should be avoided, whenever possible, even if a slight delay is incurred. Covered bridges, within which the state of the traffic is not visible, should be approached very circumspectly. Country roads are often very narrow, densely wooded on both sides and have very sharp curves. These curves should be rounded with the machine under perfect control and the horn should be sounded well in advance. Night driving over roads of this description is more picturesque and exciting than safe and restful. One interesting fact is that horses will hardly ever start to run away when confronted by the acetylene search- light of a motor car. The horse is evidently completely dazed and some- what stupefied and ordinarily will not move. How dazzling the huge acety- lene projectors of modern cars are to the occupants of horse-drawn vehicles one of the "automobile fraternity" can probably but dimly imagine. There is such a thing as carrying too much light on a machine so far as the comfort of traffic in general is concerned. The automobile horn, too, may be perverted from a valuable instrument of warning to an agency of offense. It is intended to notify the drivers of other vehicles of the machine's approach, and not as an advertisement to the community at large that one has a motor car. The excessive use of the horn has done more to create a feeling adverse to automobiles than almost any other feature of the movement. The horn must, of course, be used in accordance with the law, but it is entirely unnecessary to go "tooting" through the open country to the useless annoyance of everyone within earshot. The horn's legitimate use is to notify traffic of the car's approach wh'en otherwise it would be unaware of the fact. When about to pass a team going "in the same direction it becomes really necessary to warn the driver of the other vehicle by sound that one is approaching, as the sense of sight will not advise him. In fact, the horn is only intended to notify people of the vehicle's approach who would not be likely to learn of it through the sense of sight. When meeting or passing street cars when they are either moving or stopped, the automobilist should use especial care, for at any instant a passenger may jump from the running board of a moving car directly in front of the motor vehicle. The noise of the car drowns the sound of the approaching auto, and people do not always "look before they leap." When a street car is stopped passengers will frequently step around the end of the car directly in front of the motor vehicle, the car having cut off the view of the approaching auto. Sometimes a person will make a frantic rush for a trolley car which is stopped and place himself suddenly in the path of the machine. The use of the horn is very advisable in passing trolleys, and they should be given as wide a berth as possible. When crossing streets the view of which is obstructed by signboards or street or building operations, great care should be exercised, as pedes- trians may suddenly place themselves in the path of the car. The operator of a motor car who always occupies the driving position and has the support of the steering columns seldom realizes, until he tries it, the discomfort which he imposes upon the occupants of the harder riding tonneau seats, in passing over crossings and "thank-you-ma'ams" at a high rate of speed. A few rides in the tonneau, behind a speedy operator, will be likely to make him more considerate in this feature of his driving. In turning corners, too, the tonneau passengers have the full benefit of the slue which accompanies high speed, under these conditions. The governor or the throttle and spark control of every car ought to be so adjusted as to admit of low speed being instantly realized when passing over "bumps" or turning corners, so that they may be traversed without unnecessary discomfort, and usually without throwing out the clutch or applying the brake except on down grades. Very few people fully realize how large a part of the breakages and general wear and tear of motor cars result from running too fast over city crossings and over the water bars and "thank-you-ma'ams" of country thoroughfares. Not only so, but the greatest element of discomfort to the passengers arises from the severe bumps originating from this cause. When a bad irregularity in the road is encountered, the whole weight of the car and its occupants comes down with great force and sudden- ness upon the running gear, and then rebounds with extreme violence. Terrific stresses are thus imposed upon tires, springs, axles and steering pivots, as well as upon the supports of the engine and change speed gear. There is hardly a part of the machine which does not participate in the general distress, and its intensity increases very rapidly with the speed at which the obstruction is met. ENGINE CONTROL VERSUS GEAR CONTROL. The life of a car may be greatly extended and its derangements mini- mized by avoiding these stresses through careful and moderate driving over road inequalities. To effect this constant watchfulness on the part of the driver is required, and such adjustment of the throttle and spark should be attained as to enable the machine to be slowed down to a very low speed by the control of the motor, without the necessity of throwing out the clutch, and generally without an application of the brake being necessary. There is no objection whatever to a mild applica- tion of the brake when the engine is clutched in and it is desired to slow down the speed of the machine more than it can be done with the throttle and spark. Putting on the brake under these conditions amounts simply 203 to loading the engine somewhat more, and may result in less wear and tear than that occasioned by unclutching and clutching. One soon gets to know just how bad a road inequality can be traversed at a certain speed with merely a gentle undulation of the springs result- ing, instead of a violent "throw" being the consequence. Of course, the engine must be speeded down and unclutched, and the brakes applied, when very bad places are encountered, and if these operations are per- formed expertly it is surprising how little the average speed is reduced and how well one is recompensed for the sacrifice in increased comfort and decreased liability to breakage. Quite a considerable amount of fuel may be saved by taking advan- tage of the ability of the car to coast on down grades. The vehicle may thus be allowed to run free on all slopes upon which it will coast at a speed greater than it would be propelled by the engine running at its minimum speed. It is of no advantage to allow it to coast at a lower speed than this, as there would obviously be no saving in fuel and the wear and tear thus imposed upon the clutch would not be warranted. How TO COAST. When about to coast the engine should be unclutched, the lever left in the neutral position, and the engine slowed down by throttle and spark to the lowest speed at which it will keep running. If the change speed gear is of the sliding type, the gears may be thrown entirely out of mesh, or in the neutral position, or at least placed in mesh for the highest speed, so that the velocity of the gears and the consequent loss of power may be a minimum. In coasting one should, of course, have the car under complete brake control. When a very long coast is at hand one may stop the engine entirely, thus stopping the gasoline con- sumption and the motor's wear and tear, and giving it a chance to cool off. At the top of the down grade the switch may be thrown off after the engine is unclutched, but before the end of the coast is reached, and while the machine still possesses good headway, the switch should be closed and the clutch gently thrown in, when the engine will be started by the energy of the vehicle's motion. In starting an engine by means of the clutch, the highest speed must be used and never one of the lower gears, as the stresses imposed upon the mechanism in the latter case would be too severe. A BRAKE FAILURE KINK. One of the commonest causes of accidents to motor vehicles has been the failure of the brakes to hold the car from running down a severe .hill upon which the engine has stalled. When this occurs while climb- ing a bad grade, the tendency is for- the car to run down the slope back- ward, and this is a very embarrassing if not a dangerous accident. The brakes of modern vehicles are now very generally double acting, in fact as well as in name, and this accident is becoming rather rare. Even now some misadjustment might conceivably deprive the driver of the use of one or the other of his brakes and the remaining one might not hold the car under extreme conditions. One should always remember that if the brakes fail to hold, the engine, if clutched in, -on the lowest speed, with the spark cut off, will almost invariably hold the car motion- less if the compression is good and the clutch is working properly. The 204 backward tendency of the car will almost always be insufficient to over- come the compression of the engine at least at a rate sufficient to give the car more than the very slowest motion. In such a case as this, the rear wheels will have to be blocked with stones to hold the car when a fresh start is to be made. Using the Car as a Winch for Extricating It. (J. S. CORBIN.) With a hundred feet of three-quarter inch (diameter) .rope, and a hand axe, it ought to be possible to extract a pretty heavy auto from mud hole, side ditch or bridgeless culvert, without the intervention of a "hay motor" and the sacrifice of three dollar bills. Select some stable object, as a sapling, a stone, or a fence corner foun- dation, or sharpen and drive a stake into the side bank so that the rope when attached will draw over some rounded surface of ground. Take from the fence the straightest rail obtainable. Gather sticks and stones to block up one end of the rail when inserted under the rear axle, close to one driving wheel. With the jack one should always have set up the rear end of the rail so the wheel is suspended, or at least much of the weight of the machine taken off. The wheel will now "skid" freely. Now, "snub" the rope around the projecting hub of the wheel, holding the loose end of it snugly so it will bind on the hub and let your assist- ant turn on the power carefully. The rope if properly arranged will wind on and off and pull the car with a tremendous force in whatever direction you may have planted your stake, the axle sliding along the rail. Repeat if this does not take you out of your difficulty. The other driver will be helping to move the machine as it is resting on the ground and through the differential is dividing the pull with the rope, though taking much the smaller share of it, of course. This reads lengthily, but one will have reached the turnpike if he tries it, long before the farmer with rattling rack and jingling trace chains comes hurrying over the hill to render assistance. The crafty builder of motor cars should prepare his rear wheel hubs to suit the idea here given, and should form them of the proper taper to allow the rope to "side step" as fresh portions are wound on and off. Anyone who has watched the warping of a vessel by rope and capstan will catch the idea readily. A piece of gaspipe 2 feet long, one end welded down to a point and the other upset and welded into a knob or head, will make a good "stake" to carry along. The whole outfit need not weigh over a dozen pounds, not counting the jack which everybody touring has already. Care and Maintenance of Electric Vehicles. (ALBERT L. CLOUGH.) The care required by an electric vehicle, exclusive of that demanded by its battery, is very slight as compared with that which must be bestowed 205 upon a gasoline or steam vehicle. Nevertheless, it, like every other mech- anism, requires a certain amount of well directed attention in order that it may be maintained in perfect condition. The time and attention called for by a vehicle battery, however, in charging it and keeping the cells in proper working order, is by no means small, and represents the greater portion of the total labor which the maintenance of an electric automobile involves. A few points relative to the care of the vehicle itself will first be enumerated, and then the matter of looking after the battery will be spoken of. Lubrication of moving parts, their proper adjustment and the security of all holding devices are matters which require attention in the electric vehicle in common with those of other motive powers. LUBRICATION OF BEARINGS. The bearings of the motor armature should be most carefully providec' with lubrication, as their undue wear may cause the armature, which runs very close to its pole pieces, to strike the latter and cause injury to the armature winding. These bearings may be oiled by chain or ring oilers, operating in oil reservoirs surrounding the bearings, by lubricant absorbed in waste or wicking, held in oil boxes surrounding the bearings, or by other means. If the former method be employed the reservoirs should be kept properly filled with good dynamo oil, which must not be allowed to become dirty or spent through long use. In case the latter mode of lubrication is used the absorbent material should always be saturated with good, rather light, oil. Whatever system of oiling is provided, it should be frequently replenished with the grade of lubricant intended to be supplied to it. CARE OF COMMUTATOR. As the voltage used is very low, vehicle motor commutators require but very infrequent attention. The brush tension should be firm and fairly strong, as otherwise there may be a jumping of the brushes at high motor speed, with sparking effects destructive to the commutator surface. If the commutator has a polished, bronze colored surface, and is free from black- ening, nothing need be done to it unless the brushes squeak, when the finger wet in oil may be rubbed over the commutator bars. There is no harm, however, in wiping off the commutator occasionally with a piece of fabric which is free from loose threads, using a firm pressure upon the bars and turning the motor meanwhile by pushing the vehicle by hand. If the commutator be found black and rough, the car may be jacked up and the motor started. A piece of medium grade sandpaper may then be used to polish the commutator surface, which should be finished with a piece of dry fabric to remove the abrasive particles, after which a minute quan- tity of oil may be supplied as described above. After very extensive use the commutator may become so unevenly worn as to require to be trued up in a lathe. The cable connections to the motor should always be kept tight and the insulation of the cables should not be allowed to become abraded. If the motor is of such construction that dust may gather within it there is no objection to the occasional use of a bellows or the compressed air supply of a garage to blow out copper and carbon particles which may be worn off in commutation and dust particles from the road. 206 CLEANING CONTROLLER CONTACTS. The cable connections to the controller should always be kept tight, and it is essential that the controller fingers should make firm connection with the contacts corresponding to the different speeds, as otherwise there may be arcing, which will roughen their surfaces and cause the lever to work hard. If the contacts become burnt they may be smoothed with a file, when the current is cut off by the safety plug, and a minute amount of vaseline rubbed dver them to lessen friction. All copper particles or other dust should be blown or wiped off from the controller and its connections, as it might cause a short circuit. The acid fumes produced by the battery, and the slopping of the elec- trolyte which sometimes takes place, are likely to cause a destructive corro- sion of all metal parts subjected to their influence. Wherever it can be used asphaltum or tar paint will be found a good preservative, and parts which cannot be so treated should be frequently wiped off. RUNNING GEAR LUBRICATION. Lubrication of the front wheel and rear axle bearings and those of the rear wheels should be attended to from time to time. Non-fluid oil is the lubricant generally used for wheel bearings and fluid oil for the axle bearings. Such an adjustment of the wheel bearings should be secured as will allow of perfect freedom of rotation without any tendency to wobble. Manufacturers' instructions as to adjustment and lubrication should be carefully followed. In the case of gear driven electrics which have the gears completely housed an occasional replenishment of the gear case with grease of medium stiffness, with which has been mixed a quantity of flake graphite, will be found effective. If the filling hole in the gear case is small the grease may well be melted and poured in. Where gears are not fully housed more fre- quent lubrication is required and a mixture of non-fluid oil and graphite should be frequently "slushed" over the gear teeth. The same mixture is effective upon the chains of electrics which employ them. The degree of tightness of chains is important. They should not be so tight as to run hard nor so loose as to be in danger of running off or climbing the sprockets and thus being broken. In adjusting a chain care should be taken that the rear axle is not thrown out of parallelism with the front axle. Sometimes means are provided for adjusting the pitch of gears, and if a gear seems to drive its mate with unnecessary noise the pair may be found so closely pitched that the teeth nearly or quite "bottom." This involves unnecessary wear and a waste of power. The enclosed "silent chains," now so largely used in the transmission gear of electrics, require but little attention. The oil baths in which they operate should, however, be occasionally replenished with fresh lubricant after the old oil has been thoroughly washed out. STEERING GEAR AND BRAKES. The steering gear deserves most careful attention, as its mechanical integrity is a life and death matter. All joints must be frequently lubri- cated, and all nuts must be kept tight. The gear, at the same time, should operate with perfect freedom. The front wheels should be adjusted to true parallelism or undue tire wear will take place. Brake band linings should never be allowed to become worn out, and brake 207 adjustments should be frequently proved correct. The only proper test of a brake is to drive the car partly up a steep pitch in the road where there is plenty of backing room, in case it is needed, and then to see whether each brake is able to hold the car from running backward. If not, a better brake adjustment is required. A brake which will hold a car from backing may almost always be depended upon to stop its for- ward motion under at least as severe conditions. It is not well to depend upon using the reverse for forward braking or the application of a forward speed to prevent the car's running backward, as there is grave danger of stripping the motor pinion, twisting off the armature shaft or doing other serious damage if these expedients are resorted to except in a most cautious manner. SIGNS OF DISTRESS. An electric vehicle is normally so quiet in operation that any unusual rattle or other sound is quickly recognized. Such sounds should be traced and their causes removed. Sometimes the squeaking of the spring leaves rubbing one upon the other becomes quite annoying. It may be obviated by the insertion of graphite grease between the ends of the leaves, the latter being slightly separated by forcing a screwdriver point between them. There is quite a perceptible difference between the power required to drive an electric vehicle with fully inflated and with partly deflated tires the advantage resting with the hard tires. Electric vehicle tires should thus be kept sufficiently inflated so that the weight of the car flattens them but very little at the points of contact. AMMETER READINGS. The driver of an electric carriage has one advantage over the steam or gasoline car operator, in that he has constantly before him a means for determining the mechanical running condition of his vehicle. The ammeter indications, if studiously observed, will furnish an indication of undue friction in any part of the mechanism. If the operator finds that the ammeter reads higher than usual, when the car is traveling a certain road under certain conditions, he may feel that there is some faulty adjustment or lack of lubrication which requires attention. CHARGING OUTFIT. It is here assumed that the charging and other care of the vehicle battery is to be performed by the owner, or under his direction, and that charging facilities are available. The charging switchboard should be provided with an ammeter, and, unless the supply is at a constant voltage, with a voltmeter. In addition to the main switch, rheostat and charging cords, there may well be included an overload and reverse current circuit breaker, the former to limit the current strength sent into the battery and the latter to prevent a discharge of the battery through the charging circuit, in case of low voltage in the latter. If a mercury rectifier is the source of current, these possibilities will be found to be provided for in the regular equipment. If someone is to be at hand during the whole charging period the circuit breakers may be dispensed with. DETERMINING POLARITY. In case a vehicle battery is ever charged on the road, at stations which do not make a business of such service, it is well for the operator .208 to know how to distinguish the polarity of the charging leads. If the two wires of the charging circuit are held a slight distance apart in a glass vessel of water and a few drops of acid or a small pinch of salt added to the liquid, bubbles will begin to rise from the two immersed conductors. One will give off gas much more freely than the other. This is the negative and should be attached to the negative charging terminal of the car. The immersed wire,' which gives off little gas and blackens rapidly, is, of course, the positive. WHEN TO RECHARGE. It is time that the battery received a full charge when its running voltage drops to 1.75 volts per cell. It should on no account be exhausted to a lower voltage than this, and the car voltmeter should be frequently consulted, while one is on the road, so that one may not be "stranded" at a distance from a charging station, with the battery fully exhausted. By "running voltage" is meant the voltage shown by the voltmeter when the car is being driven at full speed over a good level road. It should be remembered that voltage indications derived from the battery when on open circuit are meaningless, so far as its condition as to charge is concerned. A twenty-four cell lead battery is in need of charging when its "running voltage" falls to 42 volts, and the same may be said of a thirty cell battery at 52 volts and a forty cell battery at 70 volts. These figures are necessarily a general average, and if the manufacturers of a particular car or battery quote others particularly applicable to their product they should be followed in preference to the abdve. MILEAGE. In determining when a battery requires recharging the mileage which the car has made since its last charge should be taken into considera- tion, and a trip odometer, set at zero each time the car is charged, is convenient for this purpose. The condition of the roads traveled should, of course, be considered in estimating the work which has been taken out of the battery. As a rule it is not advisable to recharge a battery unless its charge is at least one-half expended, and the length of charge given it, if only partially exhausted, should be proportioned to the frac- tion of the charge which is estimated to have been utilized. Unnecessarily frequent charging is found to be disadvantageous. The charge in ampere hours to be given a partially discharged battery is often taken as the estimated ampere hours of discharge, plus 15 or 20 per cent. If one carries an odometer or recording ampere hour meter, or has some other means of estimating the mileage covered, any noticeable reduction in the distance which the car can travel on a single charge, as time goes on, will become apparent. When such diminution in discharge capacity becomes obvious it is evident that the battery is out of condition, assuming that the car is running at its usual rate of current consumption. RATE OF CHARGE. The rate at which a particular battery should be charged is best obtained from the manufacturer's published figures. As a rule, a cer- tain number of amperes (regulated by the charging rheostat or by the voltage control of the rectifier) is prescribed for each type of cell. This rate is maintained until the voltmeter shows that a certain voltage rise ,209 has taken place a voltage of about 2.55 volts per cell (current flowing) is frequently the figure named. The current is then reduced to a value about one-half of that previously supplied, which, of course, causes the voltage to drop considerably. This reduced amperage is then maintained until the voltage rises again to, say, 2.55 volts per cell, when the charge is regarded as complete. Some manufacturers prescribe a fixed amperage for the first part of the charge, which is continued until the voltage reaches about 2.55 volts per cell (current flowing), and a diminishing current during the latter part of the charge sufficient to maintain this voltage the current being cut off when the amperage required to maintain this voltage falls below a prescribed figure. ACID FUMES AND HEAT. It is very desirable that the battery compartment of the car should be fully opened during charge, in order that the acid spray and explosive gases generated, particularly during the latter part of the charge, may readily escape. There should be good ventilation in the stable where charging is conducted, as otherwise the air may become too irritating to be breathed with comfort, very corrosive to all metal surfaces, and possibly highly explosive. The temperature of the cells should be carefully watched during the charge, and if they become very hot to the touch the current may well be reduced or the charge may be discontinued long enough to allow the cells to resume a safe temperature. ' PRECAUTIONS IN CHARGING. It is a safe plan never at any time to exceed the charging rate advised by the manufacturers, but if, owing to lack of time, it is very important that the charge be hastened, the excess of charging current should be applied during the first part of the process only, and never at or near the finish of the charge, which should always be conducted according to direc- tions. When charging, always keep in mind the extent to which the previous charge has been exhausted, and plan the recharge accordingly. While the car is in operation under ordinary conditions of level road the running voltage will be found to be about 2.2 volts per cell until the charge shows signs of exhaustion. SPILLING OF ELECTROLYTE. It is of importance that the electrolyte in all the cells be maintained at the proper height. There is frequently some loss of liquid by slopping, and some through evaporation and spraying. Sometimes through accident a cell may break, its solution be lost, and wet the battery compartment, as well as dripping upon the running gear and corroding it. Solution spilt into the battery compartment deteriorates the woodwork, and may cause serious leakage of current. The elements of the broken cell are likely to be considerably injured, and the capacity of the battery as a whole is reduced. If there is evidence of spilt acid around the cells the source should be determined and the defect remedied. It is customary to keep the liquid within the cells at such a height as fully to cover the elements. If the level is reduced by slopping or spraying fresh electrolyte of the proper gravity should be added to replace the loss. In case the loss' has been occasioned by evaporation the proper quantity of distilled water should be added. SYRINGE AND HYDROMETER. Every user of an electric vehicle should be provided with a battery syringe and a hydrometer for determining the specific gravity of the elec- trolyte, and the condition of the liquid in each cell should be occasionally tested. The use of this instrument has been fully discussed in an earlier part of this work. The proper density of the liquid, when the cells are fully charged, is usually considered to be about 1.300, or 34 Baume, although some authorities give 1:250 s. g., or 28 B. If, in testing the charged individual cells, certain ones are found the liquid of which shows a smaller density, it is to be presumed that they are out of condition for some reason. Low gravity of the solution will often be found coincident with low cell voltage and a white appearance of the plates, which indicates a sulphated condition. TESTING CELLS. A low reading voltmeter should be periodically employed to ascertain the voltage of the separate cells. The battery should be put on discharge through a rheostat, and the cell voltages then taken. Any cells which show a voltage noticeably below the average should be noted for future treat- ment. Sometimes, however, these "low" cells may be brought up by com- pletely discharging the whole battery through a rheostat or otherwise, and then immediately subjecting it to a moderate overcharge at a reasonable amperage. In fact, a slight periodical overcharge of a battery is regarded as beneficial rather than otherwise, but, as before stated, habitual over- charging is to be carefully avoided. If, however, any cells which are found to be "low" are short circuited or otherwise seriously deranged the above treatment will afford no permanent cure the defective cells immediately degenerating into their previous "sick" condition, which is recognizable by low voltage, low gravity of the electrolyte or an abnormal appearance of the plates. CLEANING CELLS. Active material is likely to scale off the plates from the effects of hard service, jarring or an excessive rate of charge, and sometimes may collect as sediment in the bottom of the jars. If it collects in sufficient quantity, it may bridge the positive and negative groups of plates and short circuit the cell, destructively discharging it. Sometimes the separators of the opposing groups of plates of a cell become bridged by sediment and a short circuit results. A short circuited cell is prone to heat badly, and lose its voltage and charge rapidly. It is essential that sediment be removed from the jars and the jars thoroughly washed out before much falling of active material has taken place. The elements should be exposed to the air as short a time as possible. The connections between cells should be seen to be intact. In case a cell appears to be internally short circuited or otherwise defec- tive so that it cannot be brought up to a normal capacity, it is better for the average user to call upon the manufacturer for assistance in rectifying the trouble. Of course, if one wishes, the "low" cells may be removed from the trays and given special, repeated, low rate charges and discharges in order to try to bring up their capacity. A detailed treatment of the derangements common to storage cells and the means for their correc- tion will be found in the first chapter of this book. To PREVENT SULPHATING. One thing which should carefully be avoided is allowing a battery to remain fully discharged for any length of time, as serious sulphating of the plates will be the result. The battery of any car which is out of regular service should, at intervals of three or four. weeks, be discharged through a rheostat, or otherwise, and then given a full fresh charge. Of course, the battery of a car which is out of commission may be disassembled, but this process involves considerable labor and the adoption of special pre- cautions in order to avoid injury to the plates. Periodical discharging and charging is not very expensive or troublesome. It tends to reduce the effects of local action, the result of which is lessened capacity. SUMMARIZED INSTRUCTIONS. Instructions covering the main points in the care of a vehicle battery may be briefly summarized as follows: Do not discharge the battery too far and do not let it long remain discharged. Do not habitually overcharge it or charge too frequently, but let the charge be proportioned to the extent to which energy has been taken from it. Follow instructions as to charging rates. Note the mileage obtainable from a charge, and if it diminishes obviously, ascertain the cause at once. Watch the condition of the individual cells in respect to voltage, heating, retention of the charge and state of the electrolyte in point of density and quantity. Keep the jars reasonably free from sediment, the battery compartment dry and the cell connections tight. When a cell seems incurably "sick" let the manufacturer deal with it. GARAGES, WASHING AND SHIPPING CARS. Private Garages. The building shown in the accompanying plans makes an ideal garage for the man with one or two cars and a chauffeur. It is of two story construction, but can be built only one story high, if there is no chauffeur and the owner is of a mechanical turn of mind, and can make his own repairs. Every- thing has been designed with the idea of econo- mizing space, reducing fire risks and minimizing all chances of accidents. The building is made as nearly fireproof as possi- ble, ventilation, heating, lighting and plumbing all being taken into con- sideration. The con- struction is of cement pressed into blocks, in imitation of cut stone, with a roof of terra cotta tile. This is an ideal construction for such a building. The cement blocks are made by a very simple and cheap machine, by which any design or style of stone can be imitated in ce- ment, at a cost cheaper than either stone or brick. The face of these blocks can be made of two parts cement and one part sand; the body, one part cement and five parts gravel and sand. These blocks are made with a core through them to provide for air circulation through them. The face of the blocks is impervious to water, resists all climatic changes, and will not crumble or disintegrate. The building shown is 22 feet wide and 35 feet long, and the car room on the first floor will comfortably hold two large touring cars, with ample space for turning. The car room is 20 feet wide and 25 feet long. FIG. 107. FIRST FLOOR PLAN. 213 with an entrance of large double doors, 10 feet wide, which swing in and back against the front walls, taking up no space when open. These doors may be made after the fashion of Dutch doors, and when desired the upper half can be swung open while the lower half is kept closed. The floor is of cement, one corner being so constructed as to provide space for washing the cars. This space has a drain in the centre, which is about 2 inches lower than the sides, which are on a level with the floor. This confines all water to this space, so that the entire floor is not slopped up when washing. Directly overhead on the ceiling is placed a washing machine, of which there are several on the market. These machines consist of a ceiling plate, a ball bearing joint, and a hose arm of iron pipe about 5 feet long, which swings horizontally near the ceiling, and to which a rubber hose is attached that is just long enough to reach the floor. This is very handy, as a man can walk all around the car and swing the hose around with him. Nozzles for washing can be purchased which give intermit- tent jets of water, which are very effective in removing caked mud. A gasoline pump is located in this room, with the tank sunk under- ground outside of the building. The pump shown is of well known make, and is very convenient and economical. This pump can be regu- lated so that any desired amount of gasoline can be drawn from the tank. This prevents running over of tanks while filling, and results in a great saving. Four large windows are provided in this room, and they are so arranged that by lifting the lower sash the upper sash is lowered at the same time, which furnishes a draught, removing immediately all smoke and odors. All the windows on the first floor are protected by orna- mental iron guards on the outside. Heating has been arranged for by providing coils of pipe run around the walls, about 2 or 3 feet from the floor, in order to be out of the way. In this room should be placed a sandbox and a few chemical extinguishers for fire use in case of emergency. Sprinklers should be arranged on the ceiling, about 3 feet apart. A track for a chain hoist should run from the car room back into the repair shop, in order to enable one to remove the engine, transmission or any other heavy part from the car and run it into the repair shop for repairs. This hoist can also be used for removing or changing car bodies. The repair shop is located in the rear, and has three windows and a rear entrance. This room may well contain a workbench, a lathe, a drill press, and an emery wheel. Power for these machines may be furnished by an electric motor, which may also be utilized for operating a power air pump for inflating tires and cleaning by compressed air. Electric light wires for lighting purposes should be run in iron pipe and be connected to incandescent lamps through ceiling brackets, which are bolted to the ceiling with a ball joint, and have adjustable arms, so that the light may be thrown in any desired position. An oil tank, with force pump for lubricating oils, may be conveniently kept under an ornamental iron stairway which leads to the second floor. On this floor are three rooms, a front room 12 feet wide by 20 feet long, intended for the chauffeur, and a bathroom, 8x13 feet, containing a bathtub, stationary 214 washstand and a toilet. The third room is a store- room, which may be used for storing extra tires, batteries, lamps, touring baskets, trunks and other supplies. Across the hall i's provided a large closet for winter coats, furs, waterproofs, linen dusters and all necessary clothing needed on touring trips. These rooms may be changed to suit individual ideas, or the en- tire second floor may be turned into one large room and used for storing cars in winter if not in use. A lift could be installed, operated by electric, power, to run from the first to the second floor for hoisting cars. A building laid out and constructed along these lines will be both ornamental as well as serviceable, and will well repay its cost. FIG. 108. SECOND FLOOR PLAN. In case fireproof qualities are not considered essential, and the cost is to be kept down to a minimum, the following brief specifica- tions may prove of value: (WALTER C SCOTT.) In building a garage the first thing to be thought of is the site. The owner should choose a high one with plenty of sunlight if he would avoid dampness. Next comes the floor, which should be of cement, slop- ing toward the front. If the owner wishes, he may have a pit in the centre, but this is by no means necessary, especially if the engine of his car be under the hood and not under the body. A well built frame building is good enough for all practical pur- poses. Its size will depend on that of the owner's pocketbook, but it should hardly be less than 10x20 feet. There should be a window at each side, and a skylight is highly desirable, not only for assisting the owner to see the inside of his car but for ventilation. Some men prefer to have doors at both front and back of the garage, thus doing away with the annoyance of backing in or out. A workbench may be erected at one side, and a tool chest is handy. There is, of course, an element of danger in connection with the heat- ing, lighting and draining that should not be neglected. Steam heat is best, but where it is not to be had a room should be built at the side 215 of the garage for a stove or a small furnace. The only artificial light to be used in the building should be produced by electricity. If the current cannot be obtained from a power house a pocket flashlight can be used when needed, but all repairs are best made in the daytime. The water from the washstand should be led through a drain to a cesspool outside the building, thus avoiding the danger of gasoline explosions. If the owner cannot afford to buy one of the gasoline storage outfits he should place a galvanized tank at a safe distance from the garage, and under no conditions should gasoline be kept in the building in an open vessel. If city water be installed a hose can be used to fill the radiator and to wash the car. Care should be taken to loosen the mud with the water before a sponge is applied. Tires should not be washed, as water injures the rubber. It is sometimes found convenient to have the auto stable" attached to the owner's dwelling, and in such cases the motor room should be sepa- rated by sound and fireproof partitions from the main house, and have an inside entrance by a double door, as well as its outside portal. The floor should be of cement, and slope gradually, not to the centre but to the most convenient side, where water will be caught in a shallow and wide gutter and carried to a coarse strainer, thence to a large water trap, and so to the sewer. Everything about this drainage system should be large, for it will have much mud to contend with. This floor should be but little above the ground level, and the ap- proach should be very easy. Half the broken lamps and damaged radia- tors are due to steep entrances. The heating system and illumination should be the same as those of the main house. Probably hot water and certainly electricity. Natural illumination should be as great as the circumstances will allow. STORING CAPACITY. The floor space should be able to accommodate, at a pinch, three cars. A man who uses his cars for business needs two, and a possible visitor must be provided for. There should be room also for a workbench along the lighted side, and the ceiling should be n or 12 feet high at least. Electric light plugs should be many, but it is not essential that all should have bulbs. One or two on opposite sides of the room should be near the base of the wall. These are for the portable lights. It leaves the wires on the floor when in use, and not in a position so liable to trip one or to need stepping over. The portable lights themselves should be provided with a large copper wire hook, preferably with a swivel in its base. With such a hook one can hang the light to almost anything. One light should be capable of being switched on from outside the outer entrance and another from outside the inner door. This will save many barked shins, both entering and leaving the room. The writer does not recommend a pit, as the average pit is a sink that should be suppressed by the board of health. It is a dirty, dark, damp, dis- agreeable hole, sure to be oily, smelly and, however beautifully provided with steps, hard to get into or out of when covered by a car. When one 216 does get in one is sure to find that one has left just the tool most needed on the bench, and when one has finished in the pit and taken the work to the bench, lo and behold ! the whole tool kit is in the pit. A substitute for the pit may be constructed in the form of an elevated platform of strong construction, on to which the car is run or hauled over an inclined plane approach. Through an outer wall of this room, in some convenient, out of the way spot, an iron pipe should be let. A flexible hose connection, with a slip joint big enough to slide over the exhaust pipe of the muffler, should be provided. Adapters to fit various sizes of exhaust pipes are easy to arrange. This simple contrivance the writer knows from experience to be exceedingly convenient, as it allows running the motor indefinitely in a closed and heated room without vitiating its atmosphere. At times this is a very important point, as the exhaust gases are by no means harmless. The contrivance costs little in money or trouble, and it seems queer that it is not more common. WASHING FACILITIES. An overhead swivelled connection for the washing hose should be pro- vided, with the plumbing so arranged that the hose can deliver water of any temperature. Also the working end of the hose should be provided with means for holding a sponge. Such an attachment is now on the market. A washstand, suitably equipped, will prevent much disorder in the family bathroom. A long distance gasoline outfit, and a few chemical extinguishers, with the regular washing hose, should be ample fire protection. A fusible plug with sprinkler in the overhead plumbing should render this system perfect. Drip pans filled with sand, to be emptied into the ash cans when foul, should be provided, and waste gasoline or kerosene should be burnt outdoors. Heating and Ventilating Garages. (N. B. POPE.) The problem of heating and ventilating the garage is one which demands the serious consideration of every owner, and, as a great many cars are at present kept in small, unwarmed buildings, the following sug- gestions may be helpful in enabling users to overcome this difficulty: A certain amount of heat must be supplied during cold weather to keep the working parts of the car limber and to render less arduous the neces- sary labor of starting, washing and oiling. That ventilation is needed wherever gasoline is in use is axiomatic. Herein, however, it is intended merely to enunciate certain principles, and to suggest a simple method or two by which the desired results may be obtained. The conditions involved in the case of a large station comprising shops, offices, and several floors are too numerous and complicated to be taken up in detail here, but in the small stable and private motor house they are 217 less complex and are, perhaps, of more vital interest to the average motorist. Considering first the matter of heating, the problem is to keep the storage place at a reasonably uniform temperature throughout all weather changes, and this without danger of igniting the vapors which are so much to be dreaded. The temperature which is to be maintained, with which the choice of method to a large extent varies, depends chiefly on the fancy of the owner. The only absolute requirement is that the temperature shall never get low" enough to freeze the water in tanks and pipes. This is essential, not simply because of the dangers attendant upon freezing the cooling water of gasoline machines or the boilers of steamers, but also on account of the unpleasantness of working about cold machinery, and the difficulty of filling grease cups and lubricators when the oil is congealed. Besides, if kept in a cold stable, the bearings of a car become so stiff as to use up considerable extra power when run again, while if they are kept reason- ably warm when the car is standing they will not stiffen up while on the road, except in extreme weather. Moreover, certain types of carburetors give trouble when cold. Its inflammable character and the fact that gasoline vapor is heavier than air make it imperative that the heater be one which contains no open fire at least within the walls of the building. As it is necessary that gaso- line be handled in the garage, the precautionary measures must consist essentially of placing the fire where the vapor cannot come in contact with it. This may be done by locating the source of heat in another building or in a compartment of the same building which is partitioned off by fireproof walls, and having its entrance from the outside only. Basement, boiler and furnace rooms, as used in other buildings, are out of the question. And in this connection it may be noted that the use of basement floors in a garage is always unsafe, unless special ventilation is provided for removing the heavy gases which accumulate there. The not uncommon practice of locating shops and battery rooms in ill lighted, unventilated sub-floors is extremely dangerous, both on account of the fire risk and because of the unhealthy conditions which are to be found there. The heating of any building may be accomplished by either direct or indirect radiation. It may have its own heating system or it may be one of a system of several deriving their heat from a central plant, just as the" several floors may be heated by a single furnace. As to the method of distributing the heat to the air in the various rooms this may be done by placing the radiating surface directly in the room and heat- ing it by circulating through it some conductor, like hot water or steam, or the radiating surface may be outside the room and the air heated by being passed over it and then to the room by pressure or induction. The latter method introduces a combined heating and ventilating system. Evidently this method is particularly applicable to automobile houses, as it eradicates not only all fire but all heated surfaces which might cause the charring of dry wood or waste, and the ignition of the gaso- line vapors in an indirect way. But this method, involving as it does the installation of fans and heating stacks, is too expensive for use except in elaborate establishments. It is a comparatively simple matter, 218 in many cases, to use steam or hot water heat, piping the supply from a neighboring building. This is applicable to many of the very small private garages. Where it is necessary to heat the building independently there are several satisfactory methods which may be employed. One, an English arrangement, consists of a small heater, using oil, or preferably gas, placed in a metal sheathed compartment on the outside of the building, to which access is obtained from the outside. Within, on the adjacent wall, there is placed a combined radiator and expansion tank of simple construction. On the same principle any small heater, as is used for greenhouses, for instance, may be employed, the coils being laid upon the more exposed walls and under the windows. A simplification of this is to build the compartment sufficiently large to enclose a stove, and to place a sheet iron bell over it leading to a register in the wall, as in Fig. 109. The inside of this "lean-to" must be lined with sheet metal, and a considerable air space allowed between the lining and the sheathing to prevent undue leakage of heat. The efficiency of such a method would depend largely on the construction of the building and the amount of leakage of heated air through roof and walls, which could easily be reduced to a practical mimi- mum, and the system thereby made very effective. Turning to the subject of ventilation, it will be seen that the capacity of the ven- tilators must be sufficient to remove any excess of vapor which may be caused by un- locked for conditions in the machine, or may be due t6 evaporation while filling or using the gasoline for clean- ing purposes. Heated air rises. This fact must be the basis of all considerations of the ventilating problem, and in many systems it is used to induce a circulation of air from all parts of the room to one at the top. But, as already stated, gasoline vapor is heavier than air, and .must always tend to stay near the floor, except when stirred by a draught. Therefore the air outlet in a garage must be at the bottom of the room instead of at the top. Many garages, especially the small ones, are so flimsily built and have so much free ventilation unavoidably that no special provision is FIG. 109. ARRANGEMENT FOR HEATING SMALL GARAGES. 219 considered necessary. But as a safeguard against emergencies, par- ticularly at night, when a flooding carburetor or a leaky pipe joint may be the means of distributing several quarts of gasoline over the floor, absolutely certain ventilation must be secured. For the small stable a very simple method, which should be effective in clearing the danger zone within a few inches of the floor, is illustrated in Fig. no. An ordinary stovepipe is run up one of the walls of the building and, projecting through the roof, is topped with a ventilator cap. At the bottom it is left open a few inches above the level of the floor. Part way up the wall it is heated by close con- tact with the radiator. Or it may be jacketed and heated by the burning gases from the stove; but this -is not to be recommended on account of the danger from sparks in the smoke passage. The air within it, thus heated considerably above the mean temperature of the room, will rise, and form an appreciable draught, thus drawing from the floor by displacement. It will be seen that the effectiveness of this depends on the amount of heat which can be concentrated about the pipe at one point. The other radiating surface must be so disposed as to aid a circulation of air about the room and produce a swirling current toward the outlet. The diagrams, Fig. in, il- lustrate the principles of ventilation. Were the outlet to be made simply a register in the outer wall of the building, instead of serving as a ventilator, it would act as a cold air inlet, the heated air within drawing in more and more by displacement, and as a result there would be no real ventilation. If the natural tendency of the air be used, and the FIG. no. GARAGE VENTILATING ARRANGEMENT. FIG. in. VENTILATION DIAGRAMS. 220 outlet be at the top of the room, as in many of the older systems in present use, a current of heated air will be set up in an upwardly curving line from the radiator to the outlet; the heat will largely go to waste, and eddies of stagnant air will accumulate along the 'floor. This is what must be particularly avoided in garage work, as it is the floor line which must be cleared first. By reversing the natural tendency, wholly or in part, and placing the source of heat upon the walls, or at the top of the room, and drawing away the spent air and gas from the bottom, uniform heat distribution is secured and the necessary ventilation effected. Handy Garage Contrivances. About as unhandy a job as a man can "tackle*" alone is to try to remove an automobile body without suitable appliances. For the man with a small garage holding only one or two machines, and even for larger establishments, an appara- tus as illustrated in Fig. 112 will be found extremely convenient. This consists merely of suitable rollers suspended in bearings from the roof on floor above and having a rope wound around it, long enough to come down below the vehicle body. The roller at one end has four suit- able handles to turn it by, and the supporting timber has a hole through it through which to pass a stop pin to hold it wher- ever wanted. The different parts are clear- ly shown in the illustration (Fig. 112) and the construction will be readily understood. The roller is made of any suitable stick of timber, a good, straight piece of 4x4 making a good roller by rounding off the corners. The short pieces S S at each end, forming the journals, can be of one-half inch or five-eighth inch cold rolled steel shafting, or other suit- able material, and can just as well run in a couple of holes bored in the 2 inch plank or scantling T T forming the supporting framework. The handles H H should be of one-half inch gaspipe and about 12 inches to 14 inches long each side of the roller. The holding pin P should be of three-eighth inch or one-half inch gaspipe. The rope R R should be one-half inch to three-fourth inch, according to the weight of the body to be handled. Two of these rollers will be required, one for the back and one for the forward end of the body. With these, by raising one end a little at 221 THE HORSELESS AGE FIG. 112. A HOME MADE BODY HOIST. a time, one man can easily remove the heaviest automobile body with very little trouble. A very handy short jack screw to use in cramped places can be made by taking a hexagon threaded nut and a square or hexagon headed cap screw of suitable length. By using a thin wrench, such as. a bicycle or automobile wrench, to hold each one, it is possible to exert a very great lifting power in quite a cramped place. For handling engines and other quite heavy parts of an automobile, a self locking rope tackle block is a very handy contrivance. It can be fastened to a hook in the ceiling, or a better way is to put up a jib or Y FIG. 113. WALL CRANE FOR HANDLING ENGINES, ETC. wall crane with a traveler and thus make it available over quite a large space. Fig. 113 illustrates a cheaply made contrivance of this sort which, while it will have to be somewhat heavier than the factory made kind for the same capacity, still can be made to serve a very useful purpose at comparatively little expense. As shown in the drawing, the mast or upright is made of a suitable piece of gaspipe (about .3 inches would be a good average size). At the bottom a reducing tee is screwed on and a piece of 2 inch or 2^/2 inch pipe is screwed in for the boom. A hole is drilled near the outer end of the boom and the upper end of the mast for the guy, which may be a piece of one-half inch mild steel rod with a thread on each end on which is screwed a nut to hold it in position. At the upper end of the mast is screwed on a reducing coupling with a I inch nipple screwed into it for a pivot. The bottom pivot is made in the same manner, as shown, by screwing a nipple into the tee and then putting on a reducing coupling and a i inch nipple. The upper bearing is formed of a piece of three-eighths inch by 3 inch flat steel, bent as shown, and belted to the wall or post and with a hole in the projecting end to receive the piv.ot. The lower bearing is made in the same manner and is stiffened by the addition of a bracket brace bolted on as shown. The sides of the traveler are made of H x2 ulcn ^ a t steel, bent and welded as shown, two pieces like this being required. Two grooved rollers are mounted on short shafts, as shown in the upper part of the traveler. The two sides of the traveler are held together with bolts or rivets, there being pieces of gaspipe cut to a suitable length and placed between the sides, the bolts or rivets passing through the pieces of pipe. At the bottom of the traveler is provided a ring to hook the tackle block into. A self-locking rope tackle is all right, or a light chain block of the Weston differential type may be used anything which will lift and hold the load wherever required is all right. With this device it is possible to take the engine out of the rig, swing it around and place it on a workbench or elsewhere without any very great amount of labor, and by making the boom of suitable length it will serve several machines at once. This device is as well or better adapted to a regular garage man's use than to the use of a private owner, although it is applicable wherever it is desired to handle machine parts. Hints on Washing Cars. Any means of reducing the depreciation in value of a motor car is worthy of the consideration of the motorist. In attempting to sell a used car, the owner soon finds that appearance has a distinct value, measurable in dollars and cents, and for this reason, and also because of the great personal satisfaction derived from the ownership of a well kept car, it is desirable to preserve, as far as possible, the original high finish of the varnish and of the polished metal parts. To do this, the car must be washed carefully, as careless and improper washing may do as much to ruin the appearance of a car as neglect. Before attempting to rub any dust or mud off the varnish, it should be gone over thoroughly with a stream of water from a hose without nozzle. If too much pressure is applied there is danger of bespattering certain parts of the mechanism which should be kept dry, and also of scratching the varnish by driving small particles of sand over it too rapidly. When it is impossible to remove any more dirt in this way, a sponge may be used, which should be kept constantly soaked with water, by directing the stream upon it as it is moved over the paint. If there is a consider- able accumulation of mud, as, for instance, after operating the car over dirt roads on a rainy day, the sponge should be carefully rinsed after each few strokes, so that there can be no danger of grit clinging to it. Every particle of dirt should be removed before the chamois is applied to wipe off the water which remains clinging to the varnish. The chamois should be carefully rinsed and wrung dry before it is applied, and should also be rinsed before the water which it absorbs in wiping the car is wrung out, in order to prevent accumulation of grit. 223 It is not considered the best practice to use any sort of soap or hot water, as both tend to dull the finish of the varnish, but their use may occasionally be permissible. In the case of some automobiles, oil is likely to reach certain parts of the body or running gear. This should be removed with gasoline (if the water will not carry it away) before the sponge is applied. Great care should be taken that no oil or grease is touched by the sponge or chamois, as in that event it may be transferred to some other part of the car, thus still further injuring the general appearance. Furthermore, with a greasy chamois it is not possible to wipe the surface dry. For certain cars, parts of which cannot be reached with a sponge, a long, narrow back brush with soft hair filling is often found to be a handy instrument for removing accumulations of dirt. The brush should be used in the same manner as the sponge. There are now a number of handy washing appliances on the market. It is very bad practice to rub over the varnish with kerosene or any other oil, to make it shine, as in a short time the finish will be ruined, both because of the action of the oil on the varnish and because of the extra accumulation of dust upon the varnished parts, which is held by the oil and is not easily removed in washing. The beautiful finish of expensive cars is frequently ruined by the use of soap and sponges in which there are tiny bits of coral or shells. With the proper care the finish of an auto- mobile should retain its lustre, like that of a piano, for several seasons, unless it is marred by some unavoidable accident, but many cars look dull and dead after a few months' use, owing, in many instances, to the needless use of strong alkali soaps. It is a question whether it is not wiser to use less soap and more of some sort of oil or varnish food, treating the varnish by some such method as employed by piano and fur- niture dealers to enliven the finish of pianos or furniture. As a matter of fact, it is unnecessary to use soap on the body, except at places that have become greasy, and then only in limited quantities. When soap is used every trace of it must be rinsed off and the surface thoroughly dried by rubbing with a soft, dry chamois. Under no conditions should a car be washed or soap used on any varnished surface which is hot, as on the hood or parts adjacent to the motor immediately after use, as the varnish is softened by the heat and is easily ruined when in this condition. Cars should never be allowed to stand in a muddy condition until the mud becomes thoroughly dried on, for its removal then becomes very difficult and permanent damage ft> the finish may even result. Cleaning Automobile Tops. Since genuine leather is not used for automobile tops, except on small electrics, the following instructions apply to Pantasote tops and to tops of similar materials. For cleaning genuine Pantasote tops proceed as follows : (A) Unless the outside has been subjected to some foreign stains, the ordinary collection of dust and dirt should be removed with a sponge and pure water. Impure water containing a large percentage of salts is 224 apt to leave a white deposit on the material, which will have to be removed with a second application of pure water. In most locations the city water is satisfactory. This treatment can be applied occasionally while the car is being washed by turning a hose on the deck of the top and rubbing with a sponge. (B) If the soil is from grease or other stains which treatment "A" will not remove, go over the top once with a sponge and the suds of some pure soap, and a second time with only water to remove all traces of the soap. (C) This is a treatment of the outside to bring out the lustre and need not be resorted to until the top is very old. It involves the application of a resurfacing liquid to be used as a last resort. Give the outside of the top treatment "B," and when thoroughly dry apply a very thin coat- ing of a renovating liquid in same color as the top, allowing same to dry thoroughly before the top is used. For this renovator it is best to use an article made especially for Pantasote, as some of the liquids offered as dressing for leather carriage tops contain ingredients which improve the appearance when applied, yet shorten the life. Preparations of this kind are to be obtained from carriage supply dealers. (D) To clean the inside of a Pantasote top, where the accumulation of dust and dirt cannot be removed with a stiff brush, remove the top and place it on the ground inverted. Apply a fairly stiff brush and the suds of some pure soap, and go over a second time with water only to remove traces of the soap. Gasoline or other similar cleaning liquids, while not permanently injuri- ous to the interlining gum, should be avoided, as they only force the stain further into the cloth, where it cannot be removed. By way of explaining this it might be said that gasoline and other cleaning liquids clean cloth- ing, etc., by driving the stain completely through the fabric, but in top goods the interlining gum will not permit of a complete penetration. To clean the outside of leather substitutes other than Pantasote use treatments "A," "B" or "C," mentioned above, and for the inside treat- ment "D" ; but under no circumstances use gasoline or other hydrocarbon liquids, as they rot the interlining gum, deprive the material of its water- proof qualities and cause the fabrics to separate. Materials with rubber on the outside are as a rule grained to imitate leather. For the outside use treatments "A" or "B." Treatment "C" is not recommended on this class of material. For the inside use treatment "D." Avoid the use of gasoline and oils on either side, as both are injurious. Mackintosh materials have fabrics exposed on both sides, and include materials known as "mohairs," etc. The ways of cleaning them are unfor- tunately very limited. Gasoline and other cleaning liquids cannot be used, as they ruin the interlining gum, causing the fabrics to separate, and only serve to drive the stain in. If the application of a stiff brush does not produce the desired results use treatment "D" on both inside and outside. A surface application of dye to bring back the color of fabrics does not seem to produce a result which is proof against the fading actions of sunlight and water. 225 Keeping Wind Shields Clean. The clouding of the glass of a wind shield when a car is being used in misty or rainy weather is not only very annoying but may involve grave danger, as it seriously interferes with the control of the car. Some adjust- able shields are so arranged that the upper section may be raised away from the lower section, and an unobstructed vision space be left between them, through which, however, the rain cannot drive on account of the protection afforded by the position of the upper section. Frequent wiping off with a cloth of the portion of the glass imme- diately in front of the operator is the obvious remedy for this condition, and an attachment applicable to wind shields has been devised whereby by the moving of a handle a wiper is drawn over the surface of the glass, thus cleaning it. The clouding effect of moisture which destroys the transparency of the shield is due to the presence upon its surface of minute drops of water, which act as convex lenses and by their irregular refractive effect prevent clear vision. An application to the front surface of a thin coating of some transparent material which will prevent the adhesion of the moisture, or will cause it to spread in an even film rather than collecting in drops, will preserve the transparent qualities of the glass. Preparations designed to accomplish this result are upon the market. in the form of paste, sticks or liquids, the usual method of use being to apply the compound and then wipe the glass surface, leaving a very thin film of the material over the glass. Such compounds are also used to prevent the misting or frosting of store windows, eyeglasses, etc., and may be used advantageously upon wind shields. Common bar soap, rubbed over the front of the glass and then rubbed to a very thin film with a cloth, is sometimes found effective for a limited length of time, and preparations containing glycerine are also somewhat used. All these remedies are but temporary in their effects, requiring periodical reapplication. For cleaning and brightening the glass of the shield from the film of dust which accumulates upon it, alcohol applied with a soft cloth is very good. Water containing a small quantity of aqua ammonia is also used, and, indeed, any window cleaning substance which will not scratch the glass may be employed. The celluloid lights in the storm front and side curtains, which are often kept rolled up, should be protected from becoming scratched by so rolling a piece of soft fabric with the celluloid that the latter may be kept from contact with buttons, fasteners and other sharp parts of the curtains. Fire Precautions. The following suggestions may be of assistance: Don't allow smoking about the garage. Use nothing but electric lights protected against accidental breakage of the bulbs. Where electric lighting service is not obtainable use a pocket electric flash-lamp when entering the garage at night. 226 Keep no unprotected supplies of gasoline about the building. Be careful in lighting the lamps, and be sure to extinguish them when leaving the car at night. Allow no gasoline to be spilled either from a leaking fuel system or through carelessness in filling the tank. It is best to shut off the carburetor supply at night. Do not permit oil or oily waste to accumulate on the garage floor or in the under pan of the car. Be careful in the storing of carbide and in the disposition of the waste from gas generators. See that no wood or other combustible substances are in contact with the exhaust piping or muffler of the car. Keep an abundant supply of dry sand in pails about the building for fire purposes, and use this in preference to water on a gasoline fire. Install one or more chemical extinguishers in an accessible place, and see that they, are kept freshly charged. If the garage is not heated, use extinguishers which are not affected by low temperatures. Preparing Automobiles for Shipment. (F. E. WATTS.) The material for this article was gathered from the shipping depart- ments of about a dozen automobile factories, including some of the largest American makers. It represents the experience obtained from shipping thousands of machines to all parts of the world by the men who had charge of the packing and shipping and shouldered the blame if anything went wrong. The various methods employed are largely natural outgrowths from those first tried, and in only a few cases have efforts been made to cut the cost. A large touring car is a very bulky article to ship, and when finished as usual at present requires very careful packing to prevent any scratching. While primarily intended for private owners, it is hoped that this article will be of some use to more experienced shippers, as it will give them a glimpse of methods different from their own. For convenience in treating, shipments will be divided into three groups : Domestic shipments not crated, crated domestic shipments, and foreign or boxed shipments. DOMESTIC SHIPMENTS NOT CRATED. If there is any one point upon which shippers agree it is that crating should be avoided wherever possible. The actual factory cost of a crate is in the neighborhood of $25, and a private owner would ordinarily have to pay considerably more to get one made. The saving in freight rates between points in the United States of crated over uncrated automobiles is not sufficient to cover this cost, except in a few special instances, which will be mentioned under the next heading. It is the ordinary practice in most factories to ship machines uncrated whether a single machine or a lot is being sent to any point where they can go without transfer. From large cities it is comparatively easy to get through cars or half cars to most parts of the country, but in the smaller places this is more difficult. Wherever the auto must be transferred from 227 car to car it should invariably be crated, for it will seldom be properly handled while changing, or properly secured in its new quarters. I have seen finely painted show jobs come back to the factory looking more as if they had gone through a railroad wreck than a mere transfer from car to car. Of course, the railroad is responsible for this damage, but payment is usually delayed for eight or nine months, and even when received is poor solace for delay and annoyance while on a tour. In preparing a machine for shipment, the gasoline tank and carburetor are carefully drained. Then, if the car is water cooled and the weather is cold, or likely to become so, the cooling system must be emptied, par- ticular care being taken to get all the water out of the engine jackets. This last caution cannot be too strongly emphasized, for instances have become known of several manufacturers who have suffered from the cracking of water jackets by neglecting this precaution. The machine .should now be pushed to its proper place in the car, and the emergency brakes firmly set. All four wheels should then be secured to the floor of the car. Fig. 114 shows the method which seems to provide the most secure fastening with the least work. Pieces A, B, D and E are 2 by 6 inch planks, long enough to have about the relation to the wheel shown. FIG. 114. METHOD OF BLOCKING. They are fastened to each other and to the floor with twenty-penny nails. The construction A, B is of course placed at the front of the front wheels, and to the rear of the rear wheels. To secure the wheels from jumping upward, take four pieces of burlap about 2 feet by 15 inches, and fold them lengthwise to form straps about 2}/2 inches wide, as shown at F (Fig. 114). These should now be placed over the rim of the wheel and fastened by pieces C, which are nailed to the floor, special care being taken to get pieces C as close to the tire as possible, and to get burlap F very light. This last object may be accomplished by securing the end of the burlap toward the middle of the machine, taking the outer piece C, driving the nails through it so as to project about one-half inch, and fastening the burlap to two of these nails so that it rests against C, and is fairly tight when the points of the nails just touch the floor of the car. Driving the nails home will stretch the burlap very tightly. Rope is sometimes used in place of burlap. It is fastened to .the floor by staples, and one turn is taken around a spoke, the spoke and rim 228 being covered with burlap. In a number of cases triangular blocks like D E are used at both front and rear of the wheels with perfect satisfaction. Fig. 115 shows a very satisfactory though somewhat elaborate arrange- ment for blocking wheels. H, I and J are sawed to fit the tire, I being sawed at right angles to the side of the board, and J and H on a 45 degree angle. Block C, which is composed of boards E, F, G fastened together, is separate, while block D is secured to side boards K. In fastening wheels with this arrangement, a strap of burlap is first secured as in Fig. 114, except that blocks C are placed farther from the tire, and the burlap is left slightly loose. Block C is now placed in posi- tion, and block D with side boards K forced in place. K and C are then nailed together, and the boards K draw the burlap tight. Lastly the entire construction is nailed to the floor. Having secured the wheels, it is well to look the car over carefully and see that there are no parts, such as tonneau doors, which may work loose and swing or shake. It is common practice to leave lamps on their K E / \ H F | 1 ' G \ / J K THE HORSELESS *3E A FIG. 115. TROUGH FOR HOLDING WHEELS. brackets, although they are sometimes packed in boxes, and these nailed to the floor of the car. If it is desired to protect the machine from dirt, a cloth cover may be thrown over it and tied in place, or if one has no cover, heavy wrap- ping paper may be used, which is even better but more troublesome to apply. If only a single machine is being sent, the part of the car containing it should be separated from the remainder by boarding across with i inch boards. A machine packed this way is about as secure from injury as is possible in freight shipments. The manner of crating varies with the kind of machine; a heavy tour- ing car requires a much stronger crate than a runabout, not only because of its greater weight, but also on account of its larger bulk. For a touring car a crate such as is shown in Figs. 116, 117 and 118 should prove satisfactory. It is constructed as follows : A top and bottom are made as in Fig. 116; the frame is of 2 by 4 joists, covered with I inch boards about 12 inches wide. These project I inch beyond the frame all the way around, so that the side boards will come flush. These frames 229 should be made at least 6 inches longer and wider than the automobile to be shipped. The bottom should now be fitted with two beams like C in Fig. 117, the inner edges of which must be the proper distance apart to fit tightly against the shoulders on the wheel spindles. The car may now be wheeled into position on this bottom, blocked up, and all four wheels removed, then gradually lowered until the spindles rest upon beams C. The spindles are covered with burlap and fastened to C by clamps E made of i^x^ inch wrought iron, and secured to the beams by six 3^x4 inch lag screws. The eight vertical corner boards may now be nailed to the bottom, also the adjoining boards on the sides. The springs should be compressed and 2x4 pieces cut the proper length to go across the crate inside, fastened to hold them in compression. FIG. 1 16. BOARD CRATE FOR DOMES- TIC SHIPMENT. E_HOfiSELES3 AOF FIG. 117. ONE CORNER OF BOTTOM FOR CRATE SHOWN IN FIG. 116. A cover or wrapping paper should now be placed over the car after tying tonneau doors, etc. For fastening the wheels eight straps like that shown in Fig. 114 should be provided, also four three-eighth inch bolts long enough to pass through the hubs, and two of the straps with a couple of inches to spare. The wheels may be secured to boards at the middle of the sides and ends of the crate, as shown in Fig. 118, or they may be fastened underneath the car, which is probably the better position. The remaining side and end boards can now be nailed to the bottom, and the top dropped in, and the sides and ends nailed to it, which com- pletes the crate, excepting the diagonal braces of 1x6 inch boards, and skids F F made of 2x6 inch planks. These skids can perhaps be best secured by nailing to the beams on which the car rests, after the position of these beams has been determined. One manufacturer of runabouts uses a crate similar to that shown in Fig. 123. Pieces A, B, F are 2x4 inches; corner posts E are 4x4 inches, notched at the lower end so that the space between C and G is 2 inches. Beams C are 4x4 inches, and go the entire length of the crate. Blocks D are also 4x4, and have holes for the axle spindles. They are secured to C by one-half inch lag screws. The wheels are secured to the sides as in the crate just described. The bottom has only one diagonal and one cross brace. It will be noted that the steering column has been removed, and the upper part of the seat reversed. By doing this from 9 inches to a foot may be saved in the height of the case. In shipping between certain points there is an advantage in crating a runabout in this manner, even though it is possible to get through cars. For example, from Detroit west the freight charge for uncrated cars is for 5,000 pounds at first class rate, no matter what the weight of the machine, while for a runabout crated as in Fig. 123 the charge is for 4,000 pounds from Detroit to Chicago and for THE HORSELESS CE FIG. 118. ADDITIONAL DETAIL OF BOARD CRATE. the actual weight west from Chicago. A crated car usually weighs about one and a half times as much as the uncrated machine. Some very light runabouts, weighing about 900 pounds, are shipped in crates made by covering a 2x4 inch frame with I inch boards for the floor, and fastening four small horses to this floor for the axles to rest on. The remainder of the crate is built of about 1x6 inch boards. For all this work a fair grade of white pine is good wood. Good white spruce, or even the best quality of white fir, is also serviceable, but beware of the grade of wood ordinarily used in rough boarding buildings, as it splits at the ends too easily to make good crates. FOREIGN SHIPMENTS. For shipping by steamer machines must be tightly boxed, and this box should be strong enough to withstand being lifted by a crane from a chain wrapped around the middle. Also it must be strong enough to hold freight of all kinds piled on top. Manufacturers shipping to foreign countries usually make a box sim- ilar to the crate shown in Fig. 118, except that there are no spaces between the boards, and that 2x4 inch pieces are put across from side to side wherever possible. One and one-quarter inch band iron nearly one-six- 231 \ FIG. 119. STRAP FOR WHEEL. teenth inch thick is wrapped around the box in several places. One shipper advises the use of not less than i% inch boards in any ocean shipment. A prominent Eastern firm in shipping electric carriages to Europe makes its boxes of two layers of I inch boards with sheathing paper between them. One maker of run- abouts with side springs removes wheels and axles, and fastens the machine to the box by these springs. The wheels and axles are packed in a separate box, so the total space taken is less than if all were in one box; as steamer shipments go by bulk and not by weight, this pays. In some instances it is cheaper to remove the body and steering posts, and to pack the body in a separate box. This is almost always so with limousine bodies. In shipping private machines various methods have been tried, includ- ing solid boxes and boxes with hinged sides or ends, but the method which is most commonly used at present is to make a knock-down box which may be laid flat when packed away, and so cost little for storage, and can be reassembled for the return trip. Details of such a box are shown in Figs. 120, 121 and 122. Fig. 122 also shows the construction of an end, which is exactly similar FIG. 120. BOTTOM FOR EXPORT Box. to a side. The bottom, Fig. 120, is made of 2 inch matched planks nailed to the frame, which is of 2x8 inch planks, with thirty-penny nails. The top, shown in Fig. 121, is of i inch matched boards with a framework of 2x4 inches. Sides and ends, Fig. 122, are also of I inch matched boards with 1x6 inch cleats and 1x8 inch diagonal braces. These parts are fastened together by heavy screws to form the complete box. Large blocks inside the bottom frame- work serve to hold the wheel spindles. The bottom is of course fitted with skids, as in Fig. 118. These boxes are being successfully used without band iron, but it seems FIG. i2i. TOP FOR EXPORT Box. FIG. 122. SIDE FOR EXPORT Box. 232 they would be safer with band iron, and with 2x4 inch uprights in each corner bolted to the sides and ends. The cost of building such a box is not far from $50, counting materials and labor. As to freight rates, they vary from day to day, and quotations will have to be got for the exact time of shipment. All quotations are made on a bulk of 40 cubic feet. A crate for a touring car having 106 inch wheel base and good sized FIG. 123. CRATE FOR RUNABOUT. tonneau body, which was recently measured, was 6 feet by 6 feet by 12 feet 7 inches, or 453 cubic feet. It would seem that if one were to ship his machine often, either at home or abroad, it would pay to have a box similar to that just described made, and have it sent by freight, knocked down, to the place from which the machine was to be shipped whenever it was desired to ship it home from a tour. In sending cars to Mexico manufacturers often take them almost com- pletely apart, as the duty is very much less on parts than on complete machines. 233 REPAIR SUGGESTIONS. There is a considerable' class of motor car users who become per- sonally interested in their cars, from a mechanical standpoint, and take a certain pleasure in making simple repairs upon them, in their own stables. Even those who do not care for this sort of thing will find it for their interest at least to know, in a general way, how certain repairs should be executed, in order properly to instruct the mechanics who are to do the work, as time and money may frequently be saved by so doing. It is impossible fully to cover the subject of repairs, as the breakages and derangements which may befall a car are multifarious in the extreme, but there are certain common ills to' which automobiles are subject, through accident or the effects of long and hard usage, the remedies for which every motorist ought to know. In this chapter certain of the fre- quently required repair operations are explained in language which is intended to be clear and concise. Tool Box Equipment of a Car. The tools which the motorist must carry in his car may be divided into two classes, viz., those which are used for ordinary adjustments and those which are used for extraordinary repairs. By "ordinary adjust- ments" is meant the tightening of the various screws and nuts, as they work loose through the jar of driving; taking up wear in bearings, etc. The motorist sometimes also finds it necessary to repair on the road some break which may either seriously interfere with the successful operation of the car or prevent its running at all, and to resort to "makeshift" measures in order to reach his destination. When this occurs, he who is the better equipped with carefully selected tools and repair supplies is, of course, the better able to cope with the situation. With the idea of reducing the number of individual implements in the repair outfit, a considerable number of so called combination tools have been put upon the market. These usually take the form of a combined screwdriver and bicycle wrench, a combined pipe and nut wrench, etc. This type of tool is usually not satisfactory, being, for instance, neither a very good screwdriver nor a very good wrench, and is likely to become useless prematurely through the breaking or wearing away of some vital part. It is also true that it is very often necessary to use two tools at the same time, as, for instance, when a lock nut is run down a set screw. In this case a combination tool is useless, and the necessity for carrying both screwdriver and monkey wrench for such cases as this makes it superfluous. It is, however, only fair to state that there are certain com- bination tools which, for the lighter kinds of work, are exceedingly handy. 234 The awl with a hollow handle for holding a number of variously shaped points which can be fitted to it is one of these. Another is the screw- driver with a number of interchangeable blades. If strongly made, it may obviate the necessity of carrying two or more of these implements to fit the different size screws. There arc, too, wrenches which serve equally well for tightening nuts as for holding round rods or pipe, but, as practice has shown, there is nothing better suited to accomplish the first of these than a monkey wrench with parallel jaws, and no better pipe wrench than one specially made for the purpose. A tool which, with the same jaws, will either hold a pipe or turn a nut, provided it does the first satis- factorily, is more likely to cut off the corners of a nut, thereby injuring it to a degree, than is a wrench with smooth parallel jaws. To the first of the two classes of tools herein discussed (those for ordinary adjustments) belong the monkey wrench, screwdriver, special spanners, etc., and possibly the pliers. Certain manufacturers equip their cars with telescoping socket wrenches. These are nothing but short lengths of steel tubes formed on each end to fit the various nuts and one within another. Two or three holes are drilled through each of these tubes, into which is fitted a round rod which provides the necessary leverage for handling the nuts. This rod when not in use is slipped within the inside tube. This form of wrench has been found very useful; the objection that it requires the picking up of another tool if a different sized nut is to be worked on being more than offset by its many advantages over the monkey wrench in any case where its use is possible. The socket wrench need not be removed from the nut at the end of each stroke, and as it fits on all sides of the nut, there is no danger of injuring the corners. It is especially useful in removing spark plugs from an engine, as they are held by it when out and can be cleaned and adjusted the more readily. A development of this type of wrench is that which is supplied with a universal joint and a set of interchangeable sockets. With this attach- ment the complete outfit is not so compact, but its use is made possible in many places in which the straight tube could not be worked. It can also be fitted with an extension member which will possibly enable the user to work in a less cramped position, and secure a larger sweep for the lever rod by bringing it clear of obstructions. There are a number of monkey wrenches on the market which vary much in quality and price. It is usually desirable to carry two, one a well made bicycle wrench and the other of similar design but larger. With these it is ordinarily possible to get at and handle successfully any screw or nut on the car. Something has already been said on the subject of screwdrivers. To make the labor of turning screws as light as possible, and to prevent injury to the screw and to the blade of the driver, it is necessary that the blade fit to the bottom of the slot and tightly against its edges. The sides of the blade should be nearly parallel, as the more they taper the greater is the amount of endwise pressure necessary to keep the driver in the slot, and the greater the likelihood of doing damage to the screw. A good sized handle is a necessity, as the amount of leverage obtain- able is dependent upon its diameter. 235 What special spanners should be carried depends upon the design of the car. The makers usually supply them as part of the regular equip- ment. For pliers, the automobilist will do well to select those which provide for a parallel jaw movement and are also fitted with a wire cutting attach- ment. This type is superior to the ordinary pivoted variety in many ways. They can be used for turning small nuts without danger of wearing off the corners, and because of the fact that they grip for the entire length of the jaws it is possible to hold more tightly with them and there is little likelihood of slipping off and pinching fingers. We come now to the tools for extraordinary repairs. They consist mainly of the more common bench tools of the machinist the hammer, cold chisel, drifts, files, pipe wrench, etc. The hammer should be of the machinist's type and of medium weight. Two cold chisels will usually be enough, one for light and the other for heavy work. It pays to have good chisels and to keep them sharp. Those which can be had at a relatively small price are ordinarily made from inferior steel improperly hardened, and if they do not break easily they will most likely dent on a bit of metal which a good chisel would cut through. Care should be taken that hardened steel pieces be not attacked with a chisel. If there is any doubt as to whether the piece is "hard" or "soft" it is best to test it first with a file. A set of drifts so selected that any taper pin or key on the car can be driven out should find a place on every car. It is a common sight to see motorists endeavor to drive out a pin with a wire nail or a bit of wire. If a pin is fitted properly, it will be practically impossible to do this. Before it starts, the nail or wire will bend, and the chances are that metal around the hole will be considerably dented. With a drift, a vigorous blow can be delivered without danger of its bending, and the pin will therefore start more readily. As it is not to be expected that road repairs will be "finished jobs," as the machinist would say, a great variety of files is not necessary. Three is usually a sufficient number one a coarse bastard with which a considerable amount of material can be removed in a short time; another a finer "float," which can be used for finishing off the roughness left by its larger companion, and for lighter work; the third, a fine finger nail file, to be used for dressing electrical contact points. There are on the market small strips of emery paper designed for use on the finger nails. They are light, compact and inexpensive, and are very satis- factory for cleaning platinum points. For handling small rods and pipe nothing is more satisfactory than a small Stilson wrench, although there are several other wrenches on the market which may serve the purpose equally well. A pair of gaspipe pliers, so called, will also meet the requirements and have the advan- tage of quick adjustment. They are also useful in turning small nuts the corners of which have become worn off. There is also on the market a flat wrench with an adjustable saw edge jaw which can in many instances be used to advantage. Besides the extra parts bolts, nuts, screws, etc. which should be carried, the kind and number depending upon the construction of the car, there are a few general supplies which should be included in -the outfit. It is surprising to find how many purposes a piece of bare copper wire of about No. 12 gauge will serve. It is so nearly a "cure all" in minor cases of troubles that the motorist who has had experience in its use considers it a necessity. A considerable amount can be rolled into a small coil, and a length of 12 feet or so should be always on the car. Rubber tape is also a necessity. Its tensile strength and adhesive quali- ties make possible its advantageous use on many occasions. Two pieces of soft sheet brass should also be included one of about one-eighth inch thickness and the other not over one sixty-fourth inch. Brass works easily, and can be bent to almost any desired shape. From the thicker piece can be cut, by means of a hammer and cold chisel, locking nuts, washers and irregular pieces which may be used to hold broken parts together temporarily. In conclusion it may be said that in selecting tools for an automobile equipment the purchaser should be governed more by quality than by price. A well made, substantial tool more than pays for itself in length of life, the results accomplished and the satisfaction derived from its use. Adjustment and Renewal of Bearings. Although most of the recent vehicle engines are fitted with babbitt bearings, duplicates of which can generally be obtained from the factory when wear has progressed too far to make adjustment possible, there are a great many motors in service fitted with- bronze bearings, and the follow- ing suggestions by Mr. Frank S. Hanchett apply primarily to such : All bearings demand constant attention, but most especially do those of the crank shaft and connecting rod want watching, as they are most subject to strains, wear faster than the others and require more frequent readiustment and renewals. With the crank shaft bearings there is a constant tendency to acquire end motion from the thrust of the clutch, which not only causes a pound or knock, which will be most evident when the motor is running free, but will, if not looked after, cause heating of crank and wrist pin bearings by straining the connecting rods out of line. The amount of this end motion may be ascertained by prying on opposite side of the flywheel with a bar so as to cause the crank shaft to move laterally in the boxes or bearings. TAKING UP END MOTION. Where there is room a collar composed of two semicircular pieces of brass or iron, bolted together through lugs at the ends and held in place by set screws, may be used between the flywheel and nearest crank shaft bearing. This will take part of the thrust and may be reset to take up the wear as it occurs. If no room is found for such an attachment, the bearing must be renewed whenever the end motion gets bad. Looseness in these bearings comes from natural wear, which can be kept down to the minimum by careful and conscientious lubrication. Whenever this looseness becomes great enough to require taking up, either new bearings must be fitted or the old ones bored out and babbitted, which last is a cheap and good method of repair, but one requiring that the 237 lubrication be constant, as any lack of oil and consequent dryness of the surface will cause the babbitt to become heated, and to melt and run out of the bearing, which makes necessary the removal and smoothing up of the journal and rebabbitting of the bearing. Connecting rod bearings or brasses, though they wear faster at the crank pin ends and demand more adjusting than any other about the motor, generally get the least attention of any, because they are covered up, hard to get at and dirty to handle. The piston pin brasses are gen- erally solid bushings and require renewing when worn, but as the motion at this end is slight and the wear small these renewals do not have to be made frequently. At the other end of the rod the bearings, as has been stated, wear quite rapidly, and require to have the ensuing lost motion taken up frequently. To facilitate this, these bearings, or brasses (as they are frequently called), are made in two halves and clamped to the rod and around the pin by what is termed a cap. These caps and brasses, with their adjusting means, take various forms, each of which has its own peculiarities. CRANK PIN BEARINGS. A good form is made with a semicircular cap bolted direct to the end of the rod, as shown in Fig. 124, with the brasses between. In this form the brasses are held apart at the edges by liners A, which are kept in place by the cap bolts running through them. To take the lost motion out of this design of brass, the liners must be removed and filed down the requisite amount or else replaced by thinner ones. While this forms a fairly strong construction, it has the fault of being unhandy to ad- just, and of causing the opening for the pin to assume an oval form when the liners are filed and having light and short- lived brasses. About the poorest form in use is that which uses only one bolt for keying purposes and has the other side of the strap arranged with a hinge (Fig. 125). This uses the same style of liner that Fig. 124 does, but only on one side. It has a greater tendency to cause the brasses to be- come oval and is hard to adjust cor- rectly. The brasses must be fitted very carefully or they will pinch the pin, and the key bolt pulled up solid for any slackness will let the brasses be loose in the strap, making a nasty, rattling pound, and adding to the FlG - '^.-CONNECTING ROD WITH danger of breakage. It is also prac- tically impossible to get a liner to Stay between the brass and strap for lining out, so that after the keying HORSEXC33 AGE FIG. 124. CONNECTING ROD HEAD, HALF BUSHINGS AND SHIMS. THE HCrtSCLTSS AGE has been done often enough to eliminate the liner and bring the edges of the brasses together they will have to be replaced by a new set. A pin run in this form of brass seems very hard to oil, and is almost always to be found rough or cut after a few days' usage. Filing and fitting brasses requires careful work, but can be done by a person possessing some mechanical ability and capable of handling a file. For good work the tools needed are a vise, inside and outside calipers, a medium coarse file, either flat or half round, and a scraper made of tem- pered steel about one-quarter inch thick, i inch wide and 10 or 12 inches long, cut off square at one end and rounded at the other, and carefully ground so that the edges of the ends are sharp. EXAMINING BEARINGS. When the brass is taken down for filing the strap and rod should be examined closely for possible cracks, and the pin looked over to see how badly it is worn. This is done by trying its diameter from different posi- tions with the outside calipers (Fig. 126). If not badly out of round, it will run all right, but if much worn it will be advisable to have it turned up. SMOOTHING THE CRANK PIN. If the pin is cut or rough, but not bad, it can be smoothed up without removing the crank shaft, as follows : Take a piece of hard rope (clothes line will do) of suitable length, and to each end fasten a handle made of a piece of broom stick or similar round wood. Into the centre of the rope for about a foot work a good dose of emery and oil, now give the rope a turn around the crank pin so that the emery part will come in contact with it, and taking a handle in each hand and pulling first with one and then with the other, cause the emery part of the rope to rub on the pin; at the same time keep the rope moving back and forth along the length of the pin by pulling at a slight angle with the work in the direction that it is desired to have the rope go. If this is patiently and conscientiously followed out, applying more emery as needed, the pin can be brought into very good shape without disassembling the engine and putting the crank shaft in a lathe. FITTING THE BRASSES. When the pin has been got in satisfactory shape the next step is filing and fitting the brasses to it. First fasten one of the brasses into the vise and set the other one on top of it in the position which they would occupy when in the strap. Now, with the out- side calipers take the diam- eter of the pin, being careful to do' this at its largest point if out of round. Then adjust FIG. 127. TRANSFERRING CALIPER the inside calipers to fit be- MEASUREMENTS. tween the points of the out- HORSELESS AGE FIG. 126. TESTING CRANK PIN FOR ROUNDNESS. 239 side calipers, as shown in Fig. 127. Now with the inside calipers try the inside diameter of the brasses to ascertain how much they will have to be reduced, and remember that in filing equal amounts must be removed from both brasses, otherwise they will not be of the same shape. Next remove the upper half of the brass and file the lower half along the edges. From time to time as the filing proceeds the top brass should be again set on the bottom, both to see whether the lower one has had its share of filing, which is found by using the calipers (Fig. 128) and comparing the diameter with what it was originally, and to find out if the filing is being done true and square with the brass. If 'poor work is being done and the edges are not square with the body, the top half of the brass can be "teetered" on the bottom in the same way that a chair with one short leg will act in relation with the floor. When the half in the vise has re- ceived its share of filing, take it out and fasten the other in, proceeding as at first and apply- ing the test mentioned for squareness from .. . , . it. time to time, until the diameter has been re- duced to fit the calipers. Of course, if the FIG. 128. CALIPERING brasses being filed are of the variety shown in BEARING BUSHINGS. Figs. 124 and 125, the test for diameter, both before and during filing, must be made with new liners of the original thickness between the edges of the brasses on one or both sides, as the case may be. After the filing comes the fitting to bring the bearing in the proper place. In going about this the pin is smeared with a mixture of lamp- black and oil or red lead and oil stirred into a fairly stiff paste. Then the brass is keyed on as in service, and the engine turned over a few times, or the brass turned on the pin, whichever is most convenient. Now remove the brasses from the strap and note any marks left on their surface by the lampblack or lead. Then with the scraper cut down these projections, erase all cuts and relieve the brasses around the sides and edges until the .mark left by the lampblack assumes an oval form on the face of the brass. Always be careful after the first test to return the brasses to the strap in the same position each time, and not to get them mixed. If the oil hole or holes in the edge of the brasses have been filed out, make new ones, and if the brasses are arranged with babbitt bars in them make sure that the babbitt is in tight ; if not, peen it down with the ball end of the hammer before scraping. You may now put up your rods and key the brasses up solid, and if the work is well done the brass can just be nicely moved laterally on the pin at any point of the stroke, and by running your engine slowly under light load for a few miles and using plenty of oil, your pins should give you no trouble till they again need filing. Should babbitt be melted out of a bearing of the connecting rod, it can be temporarily replaced by leather or fibre soaked in oil. 240 Rebabbitting Shaft Bearings. (JOHN P. CONKLING.) First make sure that you obtain a supply of the same class of lining metal, or babbitt, as that originally used in the boxes. A better grade, if procurable, will do no harm; a poorer grade will prove very expensive and unsatisfactory, as these bearings are generally worked up to their limit. Remove the brass boxes with the babbitt lining and place them, with a couple of bars of babbitt, in a melting ladle or pot over the fire. If the pot or ladle is not large enough to re- ceive all the boxes at once, place therein one or more at a time, according to that receptacle's capacity. Heat the ladle, the babbitt and the boxes slowly until the babbitt is melted and flows in th'e ladle. When the babbitt is melted out of the boxes, remove the brass boxes and let them cool off slowly. Repeat this operation until all of the brass boxes have been relieved of their babbitt lining. Never allow your bab- bitt to become red hot. Keep it so that it will look like fluid silver. The tem- perature is about right when it Is just at a point which will slightly scorch a dry white pine stick placed in the molten metal and left there ten or fifteen sec- FITTED UP WITH LINER FOR onds - Put the brass boxes back in their BABBITTING places. At each end of each box place a little strip of leather, from one-eighth A, showing leather strips in place to & quarter Q f an j nch wide and long to centre shaft; B, showing end -11 / /T-- plates in place and strips removed, enough to encircle the shaft (Fig. I2p). ready for babbitting. Each of these pieces should be thick enough to fill the space allotted to the babbitt metal between the brass box and the strip, and support the shaft just a trifle above its proper position. Now place the strap in position. By this means the cavity is formed into which the molten babbitt is poured. In most of these boxes the babbitt extends from end to end of the box. To extend the babbitt space, take six pieces of medium heavy cardboard or thin sheet metal, each piece equal in length to twice the diameter of the shaft, and equal in width to one-half the diam- eter of the shaft. About the centre of one of the long edges of these pieces cut a semicircle equal in diameter to the shaft. Against each end of each of these boxes TME-HORSCUS3 ACE FIG. 129. BEARING BOXES FIG. 130. CRANK CASE LOWER HALF WITH BRASS BOXES. 241 place one of these pieces of sheet metal, so fitted as to close up the ends of these babbitt spaces; clamp these sheet metal pieces in place, then remove the strips of leather and the cavities are ready for pouring. Before pouring, be sure your boxes and shaft are dry, otherwise the steam created by the hot metal will blow the babbitt out and scatter it all over the operator, which is dangerous. Now if your molten babbitt is at the right temperature, scrape oft from its surface the oxidized portion with a stick or metal spoon, and then pour the molten bab- bitt into the cavities pre- pared for it, filling each box brimming full. The babbitt solidifies in a few seconds, when the shaft can be removed to inspect the work. If the work is im- perfect, repeat it until prop- erly done. Many expert babbitters heat their boxes and shafts to a temperature of about 180 before pouring, which insures them against cold FIG. 131-BABBiTT LADLE AND SCRAPER. sheets> and generally pro . duces a much finer bear- ing surface and a more perfect casting. I recommend this method when putty is not used to form dams or to stop up the ends of the spaces in the boxes which are to be babbitted. Babbitt shrinks when cooling after pouring, and needs expanding by some method to cause it to fit tightly into the recesses formed in the box for the purpose of holding the babbitt in place, increases the density of the metal, and generally pro- duces a better bearing sur- face. To do this in small half boxes of this type, leave the box in its seat and use a swage with a convex face of practically the same form and size as the ball peen of a three-quarter FIG. 132. END PIECE. round hammer. Place the ball against the babbitt and by hammering the swage with a one pound hammer, striking lightly each time the swage is moved, go over and indent the entire surface of the babbitt with this, swage, thus expanding the metal into place and at the same time hardening its surface by compressing it. Endeavor to perform this work uniformly, both as regards the strength of the blows delivered and the spaces between the indentations, which should apparently run one into the other, like hammered brass work. Expanding also After each of the boxes has been treated in this manner the shaft should be put back in place and the scraping process previously described should be followed until the bearings are perfectly fitted to the shaft throughout its length. Repairing a Broken Bearing Cap. A piece of steel is bent over the cap, and holes drilled in it to corre- spond to the holes in the cap. The strap thus formed is placed as in the cut, and the same nuts used to hold the whole in place. This should enable the driver to run about carefully until a new cap can be pro- FlG I33 cured. In the cut (Fig. 133) A is the upper half of the crank case, B the bushing and D the cap. The steel strap is shown at C, and the shaft at S. Renewal of Worn Connecting Rod Bearings. (C. L. LAMPKIN.) If the rod is one that cannot be babbitted while it is in position, one should bush the worn piston end of the connecting rod and ream the hole again after the bushing is pressed in, as pressing a thin bushing in usually closes it in considerably, and as now nearly all piston pins are standard sizes, a reamer may be run through, but, if none is at hand, scrape carefully with a half round or three cornered scraper. Put a piece of cold rolled shafting through the piston pin hole, already reamed, leaving it to project an inch or two on each end. Place the cold rolled steel on two parallel strips (Fig. 134), with the connecting rod between, then take another piece of cold rolled the size of the crank pin, or turn a /^T\ ^...--^ piece to thai size, put it /(( ))^ ) \ ((^ J) through the rod and ^ --' -^"J'V | block up the rod till the ' ^t noRse^ ct crank pin is central, leaving the cold rolled in FIG. 134. REBABBITTING CONNECTING ROD place as a mandrel. Use BEARING. a piece of cardboard on each side, with a hole to slip over the shaft, put putty or clay around and pour one-half at a time, assuming that the rod is one with a hinged cap. Using the parallels will keep the pins in line with each other. It is better to bore holes for the cold rolled, but it takes more time. Before pouring, make sure that both ends of the cold rolled are an equal distance apart, or that they are parallel with each other. After babbitting the next thing to do will be to scrape or file the 243 fillets out, as a bearing should never touch in the fillet. Scrape to a nice fit, clamp together and revolve it on the crank pin. The cap should be screwed on solidly, so there can be no movement, or it will work and cause trouble. Removing a Flywheel. (C. L. LAMPKIN.) If no hydraulic or screw press is at hand, it is better to make a pulling clamp, as it is dangerous to try- driving the wheel off with a sledge. Fig. 135 shows a simple device for pulling flywheels that is safe and sure, and costs but little to make. First bend two clamps of I inch FIG. 135. YOKE FOR PULL RODS. FIG. 136. square steel, as shown in Fig. 136, drill a hole in each end and put a bolt through; then put this back of the hub of the wheel (never pull on the spokes or the rim of a wheel to 'any great extent). If there' are holes through the shaft be sure and put pins in them or the pressure FIG. 137. PULLING OFF FLYWHEEL. will upset the shaft and probably ruin it. Fig. 137 will make clear the use of the clamp and screw. The object in using one central screw is to get a straight pull. If the wheel has an even number of spokes, the bolts, as shown in Fig. 137, will be all right, but if the number of spokes 244 is odd, then two bolts should be used on one side and the spoke straddled. With this outfit one can remove a flywheel very expedi- tiously. Of course, a screw press is much quicker, but this clamp is cheap, easily made and does the work. Resetting a Loose Flywheel. (JOHN P. CONKLING.) Flywheels occasionally become loose upon their shafts. A type of wheel mounting in common use is that in which the wheel is held against the crank shaft flange by bolts, and the twisting effect is resisted by radial steel keys (Figs. 138 and 139). Long usage and frequent adjustment may so wear the bolts and bolt holes in the discs, and the threads on the bolts and nuts, that, as in this construction there is no locking device on the nuts, it may be impossible to keep the two discs tightly together long after the engine is put in operation. This condition of the bolts may permit the discs to become slightly separated, and open a trifling space in the beds of the radial keys, which increases the flywheel's leverage on the bolts. Under such slight leverage the continuous changes in the speed of the engine soon hammer these parts, so that there may be considerable vacant space around the keys and bolts in time. The hammering continues when- ever the engine is in use until the owner may become alarmed at the noise and thumping produced. While the vacancies surrounding the keys, bolts, hubs, and disc may not be sufficient to appear at all alarming when examined while not in motion, Ihe^ effect produced upon the occupants of the car at 900 revolutions of a 75 pound unbalanced flywheel is far from pleasant. The wear may not be sufficient at any one point to permit of inserting a bushing or shim which will last any length of time. Peining carefully with a one-pound ball pein hammer (Fig. 140) at about 6 inch drop; all around the edge of the centre hole, about one-eighth inch to three-eighths inch back from its edge on both sides of the flywheel, and performing the same operation on the outer edge of the ring on the rear face of the flywheel becomes advisable. To do this satisfactorily it is necessary to place the flywheel on a heavy anvil (Fig. 141), or smooth heavy piece of metal, to secure the resistance necessary to expand the metal equally throughout the thickness of the disc. A 35/2 inch disc of steel may be used between the anvil and the wheel to lift the rim and ring clear of the anvil. After peining carefully several HORSELESS ACE FIG. 138. FLYWHEEL FLANGE. 245 times around the centre hole on both faces of the flywheel disc, and several times around the outer edge of the ring on the rear face of the flywheel, these diameters may be so reduced that they are made to fit perfectly onto the forged steel disc and hub of the engine shaft. A swage with a convex face of nearly the same form and size as the radial keys may be used to expand the keys. They should be placed upon the anvil and treated in FlG - I39- KEYS AND BOLT FOR FLYWHEEL. the same manner as the wheel, with the exception that the convex face of the swage and not the ball of the hammer should come in contact with the face of the keys. The broad face of the hammer being used to hit the swage, these keys should be, each in its turn, so swaged out, by swaging first one side and then the other, until they are evenly expanded so as to fit tightly into their places. This work of expanding by swaging and peining may be done so evenly as to present finished bearing surfaces, showing no inequalities and no unsightly bruises on the surfaces where the peining is done. The peining and swaging may be completed in about three hours. By the addition of six new bolts, which should be tightly fitted into the bolt holes, and supplied with tightly fitting nuts and extra or lock nuts on each bolt, the work may be completed. In performing this operation, the ball pein end of the hammer should be used. The progress of the hammer around the circle should be very slow, striking lightly many times almost in the same place, but gradually and continuously working onward around and around the circle, until the desired reduction in the diameter of the central hole is secured. FIG. 140. PEIN HAMMER. FIG. 141. ANVIL. This can be determined by the use of calipers, with which the diameter should be frequently tested during the operation. Great care should be exercised to prevent the hammer from striking too close to the edge of the hole, as this would produce lumpy work. When doing such work the hammer should make about 200 strokes per minute. 246 Reboring Hole for Piston Pin. (D. A. HAMPSON.) It frequently happens that the piston pin of an auto engine wears (he piston so that the hole has to be rebored and a new pin or bushing inserted. To true up the piston in a lathe so that the hole when finished will be concentric with the original one in both "sides" is an arduous and difficult task. A method which is quick, simple and always dependable, is shown in Fig. 142. First an arbor is turned so that it is a nice running fit in the seg- ments of the old hole, and the piston is slipped on it. A four jaw ^ THE HORSELESS AGE FIG. 142. REBORING HOLE FOR PISTON PIN. chuck is put on the lathe and piston caught as shown, with the arbor resting on both centres. Now it is a short matter to tighten the jaws so that the arbor turns as freely as it did out of the lathe. The arbor can now be removed and the piston bored with the certainty that it will be concentric with the old hole. In the drawing a -four jaw chuck is shown, though a two jaw one answers as well; likewise the method is applicable to pistons with the hole either in the centre or one end. Restoring a Broken Valve Guide. (OLIVER LIGHT.) In event of the breakage of the portion of a cylinder casting which forms. the guide for one of the valves (Fig. 143), the following procedure may be resorted to : The motorist took the writer into consultation, to see if the cylinder, otherwise in perfect shape, need be replaced. There was too little of the guide left in the interior of the valve chamber to insure accurate seating of the valve, and the engine operated very unsatisfactorily at any- thing but low speeds. The writer applied a new bushing or guide to replace that broken, and while there can be no claim for the exercise of any great ingenuity or originality in this method of making a repair, it is believed that the manner in which it was accomplished may be of 247 FIG. 143. some interest to those not specially skilled in "patchwork" repairs. The first operation is facing off the irregular metal on the bottom of the valve chamber, which is done by a simple facing tool as shown at Fig. 144. This is forged from a piece of tool steel. The lower portion should be turned 7-16 inch in diameter, and the upper part so that it will go into the chuck of a back geared drill press. If the guide hole for the stem is worn con- siderably, the hole should be cleaned out with a 7-16 inch drill, to form a guide for the lower portion of the facing tool. The cylinder E is firmly clamped to the drill press face plate by means of two long through bolts D and the strip of steel bar C, which extends across the mouth of the cylinder, and is held in position on the parallel blocks H by the nuts B. After the metal has been removed from the bottom of the valve chamber, which is faced flush, the cylinder is reversed, and again clamped in position. Then the facing tool is used till all of the projection H has been removed. An 11-16 inch drill is then placed in the chuck G and a large hole drilled through the metal at the base of the valve chamber, following the 7-16 inch hole as a guide. The cylinder is again clamped in the position shown in Fig. 144, and, using a centre in the chuck bearing against the depres- sion in the top end of a 54 inch, 32 thread tap to in- sure a straight thread, the hole is tapped out, turning the tap with a spanner placed on the squared por- tion, the chuck being fed down as the tap progresses FlG- I44 ' in the hole. The next operation is turning up a suitable guide, which is done in a lathe, using a piece of bronze bar stock. On this is left a substantial shoulder, and a greater length of threads than has been tapped into the valve chamber metal is cut oh the bushing, in order that a check nut may be employed to make a sound job. The bushing is shown at B, Fig. 145, and the check nut at C. The threads on the bushing B should be cut a little larger than those in the hole A, and the bushing screwed in place by the use of a large spanner, the check nut being applied with a socket wrench from the top. 248 FIG. 145. To prevent backing out, the metal protruding above this is upset with a centre punch, this mak- ing a very strong construction; in fact, of greater resistance to both wear and shock than the original cast iron bushing which it replaces. This bushing is shown in position in Fig. 146. The method employed to insure that the hole through the guide shall be in the proper rela- tion to the valve seating is as follows: A spare valve being at hand, the head is cut from this, after it has been thoroughly ground in to a correct seating, and a portion of the stem, where it flares out to join the head and obviate an abrupt head, is left on. The valve head is accurately centred in the lathe chuck, and the centre mark, which had 'acted as a support for it when it was first machined from the forging, forms an accurate guide by which a ^ inch hole is drilled exactly through the centre of the head. The head is then held in position on the bevel seating by means of a piece of tube, accurately faced off at both ends, which is in turn retained by the valve cap. If the valve cap E is tapped for a spark plug, and as the tube D holds the valve head A positively in place, a guide may thus be obtained for the twist drill F, and the y^ inch hole for the valve stem bearing drilled so accurately that the new valve shall have a perfect bearing at all points on the seating. FIG. 146. Seating a Driven=in Valve Guide. In replacing a damaged valve guide which is retained by driving it into a coned seat in the cylinder casting, it is generally found next to impossi- ble to drive it in from below without dismounting the push rod guide, since there is no room between the crank case and the end of the guide to swing a soft hammer to give sufficient blow for the purpose. The diffi- culty may be overcome in the f ollowing "manner : A rod of slightly smaller diameter than the valve stem should be cut with a screw thread running its entire length. Two nuts are then provided to fit the rod, and a plate of steel, three-eighths of an inch thick, cut so as to rest over the valve chamber opening, a hole of slightly larger diameter than the threaded rod being drilled through the plate. The apparatus is rigged as in Fig. 147, B being the threaded rod and G the valve guide placed upon it, the nut C holding the same in position. The guide is placed in position by hand, 249 and the rod B passed through it, and through the hole in plate E, nuts A and C being then put on. Upon screwing down A the guide is forced home, when by removing nut C the apparatus is re- moved by lifting it out. D is the push rod guide, F the valve seat and H the chamber to the manifold. Repairing Cracked Water Jackets. (W. O. ANTHONY.) Many schemes have been devised to do away with cast iron water jackets, upon which freezing of the water there- in usually produces such disastrous re- sults. Most of the substituted construc- tions are eminently successful, being much lighter and even withstanding an occa- sional "freeze up," the only result of this being a stretching of the metal, usually copper or brass. For some time to come there will, however, be many cast iron water jackets, and as "to err is human" and once in a while one gets caught by an unexpected cold spell, a description of the method to be employed in the repair of breaks from this cause may enable the owner or repair man to avoid the usually heavy expense of a new cylinder or head, or the still heavier expense if these two are integral, as is becoming the standard method of making these cylinders. If it is decided not to have the crack brazed the following methods may be adopted : Should the break in the jacket wall be very slight, a strong rusting solution, consisting of a saturated solution of sal ammoniac or ammonium chloride in water, is poured into the water space, making certain that the cracked portion is covered by the solution. If this is used, care should be exercised to avoid getting any of the solution inside the cylinder, and the cylinder should be set in a warm place and allowed to stand for a day or two. It is seldom, however, that this method will be successful, as the cracks are generally too wide to be filled solidly with the rust resulting from the action of the solution. By the following method it is possible successfully to repair a badly cracked jacket, even though the crack extends the whole length of the cylinder jacket and up nearly half the diameter of the head, and besides the main crack there are a number of small ones radiating from a point E HOUSELESS IE FIG. 147. 250 at the bottom and much resembling in appearance the spokes of a wheel. Two small cold chisels should be obtained, one like Fig. 148, the other like Fig. 149. Removing the cylinders from the machine, a groove as narrow as the widest part of the break should be cut with the chisel first mentioned, of THE HORSELESS ACE. FIG. 148. COLD CHISELS. FIG. 149. about one-eighth inch in depth, and following the crack and bringing it about in the centre of the groove all the way. Should there be much variation in the width of the original crack, it may be well to have made several widths of both styles of chisel, using the narrower wherever possible, for the groove should be made no wider than necessary to cover the crack. It will require some care in cutting these grooves, because some of these cast iron jackets are quite thin, and too hard blows might break through. The chisel must be kept sharp. After cutting a groove with the chisel shown in Fig. 148 and, by the way, it should be stated that both these chisels are a little wider at the edge than just above it, to avoid binding the chisel FIG. 150. DOVETAIL GROOVE IN CYLINDER JACKET. shown by Fig. 149 should be run over the grooves with the side A at the bottom, and it should be held with the edge B about parallel with the surface of the jacket. The object of this latter chisel is to dovetail the groove, making it slightly wider at the bottom than at the top as shown in Fig. 150. This form will effectually secure the metal to be caulked in against coming out. 251 Regarding the metal most suitable for caulking the groove, it is slightly easier to solder it, afterward caulking with a tool to be described; but this metal has been found of too low a melting point in certain motors, running at high rates of speed, and where the jacket water sometimes attains so high a temperature as to form superheated steam. This condition is gen- erally attributable to defective circulation, due to partial or complete stop- page of the circulating pump. Where the crack to be mended is at the bottom of the jacket wall, solder may be quite safely employed. Soldering coppers, weighing 2 or 3 pounds each, should be employed for this work, as an iron of much less weight will not hold the heat a sufficient length of time, and in any event the whole cylinder and its jacket must be heated quite hot by a blow torch or by being placed in a hot oven for an hour or so. There are many solutions used as fluxes for different metals. A good flux to use in this case is known as "cutter" acid. This is prepared by adding one part by bulk _of commercial hydrochloric or muriatic acid to two parts of water and dissolving scrap zinc in this solution until the acid is neutralized. This solu- tion becomes more efficient with age, and should be allowed to stand for several days, tightly corked, before being used. With a flat brush, made by fastening bristles from an old dust brush into the end of a flat tin tube, as in Fig. 151, squeezing the end to- gether in a vise, after insert- FIG. 151. FIG. 152. ing the bristles, coat the in- side of the groove, an inch or two -at a time, with the acid solution, and then allow the solder to drop into the groove where thus treated by holding the hot soldering iron against it and following it along. It is a good plan to follow the iron with a blow torch, directing the flame against it and the work. In this way the groove may be completely filled with solder; but unless the work is watched very carefully air bubbles will .form underneath and only a film of solder form across the top of the groove. This condition of affairs will be found when the job is finally caulked; but it may be overcome by running a piece of fine steel piano wire into the molten solder in the groove, and work- ing it back and forth, when the air is quite sure to follow the opening made by the wire, and escape. After going over the whole job in this way, the soldered joint should be caulked with a tool like that shown in Fig. 152, having a concave groove in its edge of about the width of the caulked groove, or perhaps a little less. This caulking compresses the solder in the groove, thereby helping rnaterially to make a tight joint. After caulking, the joint should be 252 resoldered on the outside, more for the sake of appearance than anything else, and after filing off any surplus solder and repainting it would take a sharp eye to detect any evidence of a break. As before stated, in many machines the solder is almost sure to melt and run out at points high up in a horizontal motor where the heat is most intense and the natural circulation not always of the best. In such places the groove may be caulked with soft copper, and a job of this kind prop- erly done almost defies detection, and of course cannot melt and run out under extreme conditions. For this the purest obtainable copper rod, about three-sixteenths inch diameter, should be secured. This may be softened by heating to a red and dipping quickly into cold water, and this should be done by all means, as it renders the metal much easier to caulk, and the blows, incurring always more or less risk, are lessened in proportion. Unless flat copper rod can be secured, the round rod should be flattened to a thickness which will just enter into the outer part of the groove, and the aim should be to have as few joints as possible, selecting the longest part of the break and cutting off a few inches more than enough for it, to facilitate handling. One end of the piece of copper is to be placed at one end of the groove, and with the face of an ordinary machinist's hammer, weighing about I pound, it should be firmly driven down into the groove for an inch or so in length and hammered until it has spread down in the groove and filled every crevice. Having secured one end in this manner, the rest of the piece should be driven down into the groove, but not finally spread, the idea being to spread it, as nearly as possible, all at once, and avoid the rather sharp kinks which would otherwise be formed. By hammering until the cop- per begins to spread materially at the top we may be reasonably sure that it has filled all the crevices in the groove. When filed off even with the surface of the jacket the job is, or should be if carefully done, extremely satisfactory. It sometimes happens that the expansion in freezing will force out part of the metal of the jacket, so that neither of these methods can be employed as a repair, or if they can be the result is not at all sure to be lasting, and in such cases a method now to be described will work very nicely, but has the disadvantage that it disfigures the cylinder, which thereafter bears mute evidence of disaster which sometimes inter- feres with a subsequent sale of the machine. Chalk over the surface upon and for an inch around the break with blue chalk, or smear it over with a thin mixture of lampblack and oil. Now cut a piece of soft, clear pine the shape of the outside of the mark- ing, and holding the piece against the broken place in its relative posi- tion the high parts will be shown by markings upon the wood. These should be worked down with a chisel and gouge until the piece bears quite uniformly over the broken part. Now trim off the top, as nearly as possible making top and bottom parallel with one another, and have cast in copper or soft brass. Drill for No. 12 machine screws around the edge about one-half inch apart, and drill and tap into the jacket through these holes. 253 Mix up a small quantity of "Smooth-On," as it is called, and smear it over the broken part for a depth of about three-sixteenths inch, and tighten up the machine screws until the preparation oozes out around the edges. This sets in a few hours and forms a hard, strong cement, unaffected by either heat or moisture. As many may not be aware of the place of manufacture of this preparation it may be well to state that it is made by the "Smooth-On" Manufacturing Company, Jersey City, N. J. The amount of work necessary in fitting the wooden pattern for the copper casting may be reduced very greatly by securing a sheet of paraffine wax about three-sixteenths inch thick, and by holding for a few seconds in a dish of warm water this will soften and become pliable, so it may be bent to the exact shape required, and the cast made from this as a pattern. Another method of repairing a bad break which cannot be caulked, which may at this point suggest itself, consists in making a number of strong iron bands to go around the outside of the jacket at points close enough together to enable them to draw the joint tightly together, if it has not been too badly distorted, when a rust solution may complete the repair. This method makes a very bungling job, however, and it is very doubtful if it possesses any advantages over the first described methods. It not infrequently happens that the cracks in the jacket assume a very irregular and broken outline, as in Fig. 153. Such a break leaves two very weak points at A and B, and an attempt to caulk the break with copper in parts adjacent to these points would almost surely result in breaking out these corners. To guard against this a couple of one-quarter inch studs should be threaded into both the jacket wall and the cylinder wall, thus reinforcing the former. If these studs come inside the cylinder in the clearance space, they should be run through one- thirty-second inch and riv- eted over solidly, but if they come into that portion of the bore swept by the pis- ton this would be inadvisa- ble, and the hole for the stud should be drilled and tapped only part way into p IG I5 ^ the cylinder wall. In tap- ping these holes, it must be done simultaneously in both cylinder and jacket walls, otherwise the latter will be apt to spring, as the tap will not take hold at once in the hole in the cylinder wall. If a clamp is brought to bear firmly over a point as close to the hole being tapped as possible, this springing will be overcome. THE HORSELESS ACS. 254 Care of Poppet Valves and Piston Rings. (FRANK S. HANCHETT.) In order to grind in a caged valve first remove it and the bushing or ring in which it works, and which contains the seat, from the cylinder, take the spring and its retaining washer from the stem, and then turn the bushing and valve upside down, fastening the bushing in a vise or clamp of some kind, which will hold it stationary. Then, between the valve and its seat, place a small amount of oil of any kind, and on it sprinkle evenly a light layer of very fine emery powder. Now place a screwdriver in the slot which will be found cut for the purpose in the centre of the bottom of the valve, and give the valve twenty or thirty one-eighth to one-quarter turns on the seat back and forth, then give the valve a half turn or less, and proceed with the back and forth motion as before, keeping this up, with occasional additions of more emery and oil, until the faces of the bevels of the valve and seat appear to be bright for their full width all around the circle; then carefully wash with gaso- line, and, making sure that no particles of emery are left between the valve and seat, turn the work right side up, replace the spring and pour gasoline into the bushing on the top of the valve. If there is no leakage by the valve it will be a fair presumption that the work is well done, but if the gasoline escapes, continue grinding as before until the gasoline will not leak through. Strict attention must be paid to the back and forth grinding, never using a continuous rotary motion, as this will cause the emery to collect in a ball and cut a groove in either the valve or the seat, thereby defeating the purpose of the operation. For good results very light pressure should be applied and the work done slowly. Should the stem fit loosely in its guide care must be taken not to allow the valve to wobble on its seat while being ground, or the surfaces produced will be more or less convex instead of flat. WHEN RENEWAL is NECESSARY. When a valve has been ground a sufficient number of times to allow the face of the valve to get much below the edge of the seat, it is time to renew, as under these conditions there is a tendency on the part of the valve to stick in its seat and fail -to open on the suction stroke of the engine. Of course this applies more to suction operated valves than to those mechanically operated. In testing and overhauling the exhaust valves it is not customary to remove the seat, even where it can be done. The test for tightness js made by removing the valve from its seat and with a soft lead pencil make a series of marks across the level of the valve at intervals of one-quarter inch around the circle, insert a screw- driver point in the grinding slot and revolve the valve on the seat, at the same time applying pressure on the screwdriver. If the seat be true the pencil marks will be entirely wiped out, if not the marks will be left either at the centre or edges of the level, as the seat may be either concave or convex. The grinding is done in the same manner as in the case of the intake valves, and continued until the lead pencil test shows out O. K. A distance of one-thirty-second of an inch must be maintained between the lower end of the exhaust valve stem and its actuating trip rod for 255 the purpose of preventing -any rebound of the valve from its seat when closing. When this clearance commences to disappear through the valve and seat wearing away from frequent grinding, this should be corrected by adjustment. Pocketed valves are necessarily ground while in place in the cylinders and great care should be exercised that none of the abrasive enters the cylinder. The same instructions for grinding are here applicable as in the case of caged valves. Cylinder packing rings or the cast iron rings which surround the piston in the grooves provided for that purpose, should fit in their grooves loosely enough to move freely in any direction, so that the tight joint between the cylinder walls and piston may be maintained, even though the piston does not travel perfectly in the centre of the cylinder. This necessary looseness is apt to bring about a condition which must be guarded against, and which consists of the cuts or openings in the rings which allow them to have the necessary spring effect working into line and causing a loss of compression through the gas leaking by at this point. When rings are to be renewed it will be found necessary, as a rule, to fit them by hand. Remembering that these rings are compara- tively light, and made of cast iron, consequently more or less brittle, it will be readily understood that the less they are bent or opened, the better; therefore, the fits should be made when possible before the rings are adjusted in the grooves. This can be done, where the only fitting necessary is in the width of the ring, by filing the edges off until the outside of the ring can be placed in the groove and the ring "walked" or revolved around the circumference of the piston and rotated on its own axis at the same time without binding at any point. Should it be necessary to remove and replace the ring several times during the fit- ting, because of the ring being too thick, great care must be used not to spring the ring too much, or it will be broken. In cold weather, warming the ring through with a torch at the side opposite to the open- ing will be found to reduce the chance of breakage to some extent. If rings are worn thin or have lost their spring through overheating, a temporary repair may be made by removing the ring and making a series of light centre punch .marks along the inside of the ring for two inches or more on the side opposite to the cut. Valve Setting. (FRANK S. HANCHETT.) Mechanically operated valves, either intake or exhaust, are actuated by what are known as cams, the simplest definition of which term is a wheel with a hump on one side of it. These cams for each valve are mounted on a shaft which runs through or alongside of the crank case, or, in some cases, on top of the cylinders parallel to the crank shaft, from which it receives its motion, either through a worm or train of gears, usually the latter. This shaft is called either the cam shaft or two to one shaft, the last name being derived from the fact that the actuating and receiving 256 gears on the two shafts bear that proportion to each other, a matter which the following explanation may make more clear: Each power impulse of the engine requires four strokes of the piston to produce it: one to get the gas into the cylinder, one to compress it, one to transmit the power of the explosion to the crank, and one to clean out the remains of the exploded gas from the cylinder. Now, each one of these strokes or movements of the piston in one direction in the cylinder will give a half revolution to the crank shaft, which makes two complete revolutions for the four strokes. Taking the case of the exhaust valve, it can readily be seen that it is necessary that the valve be opened on the exhaust, or fourth stroke, but on no other, and, as the cam has its projection or "hump" extending only over one-fourth its circumference, the shaft on which it is mounted must revolve only once to each four pis- ton strokes to bring this about; but as the shaft from which it receives its motion revolves twice to every four piston strokes, the cam shaft gear wheel must contain twice as many teeth as the one driving it in order that it may turn once to the latter's twice, making a two to one gear train, hence the name. Sometimes the cams for both intake and exhaust valves, where both are mechanical, are on the same shaft, and in other cases there is a sepa- rate shaft provided for each set of valves, one cam shaft being placed on each side of the crank shaft, the cams generally being forged on the shaft or keyed solidly and case hardened to prevent wear. Setting valves or regulating their opening and closing, in accordance with the position that the piston should occupy when these events occur, is one of the most important adjustments about the machine, as a mistake of one tooth in the position of the gears toward one another will make a poor working engine out of a good one. The proper setting of the exhaust valves is very essential, for the reason that if they open too early part of the power of the explosion will escape without doing any work, while if they open too late the rising pistons will have commenced to recompress the expanded gas, thereby absorbing some of the power gener- ated, to do an entirely useless work, that of overcoming the back pressure due to the recompression of the gases. It is therefore necessary that the valve shall commence to open at precisely the proper moment, which must be just long enough before the ending of the explosion stroke to allow sufficient opening for the exploded gas to escape of its own accord at the beginning of the exhaust stroke, which it will do through its ten- dency to continue to expand down to atmospheric pressure. The rule followed is to adjust the gears to one another in such a manner that the valve will commence to lift at one-tenth the length of stroke before the completion of the explosion stroke, this preopening of the valve being called "lead" because the rising motion of the valve precedes or leads the rising motion of the piston. Of course, if all the cams are forged on the cam shaft or fastened with keys, the setting of one valve will set them all, if the man who laid out the cam shaft has done his work properly; but if the intake valve cams are on a shaft of their own it is necessary to make an adjustment of- that shaft also. In doing this lead is also allowed, for the purpose of having the valve partially open at the commencement of the suction stroke, but 257 in this case the lead allowed is only one-twentieth of the length of the piston stroke or only one-half of what the exhaust lead is. This work Is best done by an expert, but should it happen, as it sometimes does with makes of opposed cylinder engines, that the pin through the collar on the outer end of the cam shaft which holds the shaft in place breaks, allowing the valve gear to become disengaged, then the resetting of the valves will have to be done at the roadside. The operator proceeds as follows: First remove the crank case cover so that the cranks can be seen; then, selecting one to work with, turn the crank shaft round by means of the starting crank until the crank selected is within an inch of the bottom of what would be its explosion stroke. Now turn the cam shaft around in the direction in which it runs when in operation until the cam is just against the valve stem; slip the gears into each other and turn the crank shaft until the exhaust is finished, carefully watching the motion of the valve stem while this is being done. If the lift commences with the crank at a little more than an inch from the bottom of its throw, and continues until the outer end of the crank has moved about 2 inches, and then all motion of the valve stem ceases until the crank has arrived within about 2 inches of the end of its revolution, the valve commencing to close at this point, but not being completely closed until the crank reaches its centre, your engine will run all right, and you can replace the collar and fasten it in place with a wire nail or piece of wire in lieu of the broken pin. If, however, the valve closes, which will be shown by the cessation of motion on the part of the valve stem, before the crank completes its revolution, disengage the gears and turn the larger one one or two teeth ahead, which will usually accomplish the result desired. In doing this adjusting it must be kept in mind that the thing most desirable, even if lead must be sacrificed, is to hold the valve open until the completion of the exhaust stroke, for if it closes before that time the effect will be to cut down the speed and power of the motor through the generation of back pressure. In setting intake valves the same process can be followed, remembering the fact that less lead is allowed in this case than in the other. The intake cams on some engines are of such length that they hold their valves open for a considerable period after the bottom .centre is reached. As the piston is nearly stationary at this point, for a moment, and commences to rise very slowly, the intake valve may be held open for at least 20 degrees of crank angle beyond the bottom centre without danger of any of the charge being pushed out. In fact, the increased length of valve opening allows the cylinder to more completely fill with charge than would be the case with a shorter period of opening. This is especially true when the engine is at high speed. It is of importance that there be the proper amount of clearance al- lowed between the push rod and the end of the valve stem. If there is not, the valve stem should be shortened by filing, grinding or facing in a lathe. The latter is the better way. Care should be taken to have just enough clearness ; one-thirty-second of an inch is about right in ordinary cases. If more is given the valve may not get the required amount of lift, and if less is given, when the engine is cold, the valve stem may expand enough when the engine warms to prevent the valve from seating 258 properly. Should a valve stem prove too short it can be easily and quickly made longer by drilling a hole in the e*nd of the stem and turning a piece to fit into it, with a head of a thickness equal to the additional length required, and brazing them together. The end may be case hard- ened at the same time if necessary. The above rules, while of quite general application, are not intended to supersede definite instructions furnished by the builders of a particular car as to the periods of opening and closing of the two sets of valves. Most motors are now provided with markings inscribed upon the face of the flywheel which indicate when these actions should take place a stationary pointer or index being furnished, under which the mark- ings upon the flywheel pass as the engine is turned over. The inscrip- tions are usually somewhat as follows : "Exhaust opens," "Inlet closes," etc., and in inserting a cam shaft after its removal for repairs or other- wise the gears should be so meshed that these operations take place at the periods specified. Ordinarily, too, the cam shaft gears are marked one gear having a tooth prick-punched and its mate having the tooth space in which this tooth should be set also designated by prick-punch marks. The flywheel markings are also useful in determining the mistiming effect of wear in the valve mechanism and in facilitating the correction of the same. Valve Gear Suggestions. OVERCOMING VALVE STEM WEAR. Quite a large number of motors are made without means of lengthen- ing the valve stem or shortening it if necessary. Usually the user of such a motor is compelled to purchase a new tappet rod, or even a new valve (and stem) in some cases. For actual, continuous service this is the best way in the end, but an emergency repair can be made as follows: A thimble, one of the ordinary brass kind, can be used to fill up the gap, the thimble being filed and hammered into place. The benefits derived FIG. 154. FIG. 155. the motor is restored to its former efficiency and runs very quietly. Though the expedient is only for temporary use, a double opposed motor fitted as above has run some 700 miles without appreciable loss of effi- ciency due to small lift of valves and consequent incomplete exhaustion. NOISELESS VALVE TAPPETS. While on the subject of noiseless valve action, mention may be made of the use of fibre tappets, which are fitted on some American built mo- tors. The idea is all right, but as fibre is soon "stamped out" or dis- 259 FIG. 156. torted and worn the valves lose their proper timing and replacement is necessary. Follow- ing current practice in the spinning industry, cither of the following arrangements of "built up" fibre tappets can be used: The first (Fig. 154) consists of a metal piece of the shape of a pump leather, the portion inside being thor- oughly filled with fibre. The diameter of the metal piece should be slightly less than that of the valve stem. This arrangement will be nearly noiseless, and will cushion the blow given to the valve stem. A more noiseless arrangement is shown in Fig. 155. Here the metal piece is cross shaped, and the fibre which sur- rounds it is prevented from splaying by a cup. This is more expensive to construct than the first, and consequently will not be had on the moderate priced stock models of automobiles. , QUIETING TIMING GEARS. Some very thin sheet copper should be se- cured and cut to the same width as the idler gear face. This is fitted carefully over the teeth and fastened in several places, as at A in Fig. 156. A little depression should be filed at the root of a tooth B, Fig. 157, the two ends (or single thicknesses) pressed into place in the depression, and a soft iron wire passed over the ends and fastened completes the repair. The thickness of copper used is determined by the amount of back lash and clearance in the gears. FIG. 157. Applying a Magneto to an Opposed Motor. Where the opposed motor in question is located under a curved hood at the front of the motor, there is usually only sufficicent space above the crank casing and the valve chambers for the placing of a magneto. The crank case cover affords a good place, but when this is removed the magneto would have to be removed also, thus breaking the setting. The arrangement shown (Fig. 158) obviates this. A stand P is built up and fastened to the top of the crank case flanges, a supporting leg being placed as shown. The magneto is bolted to this stand with the operating end toward the crank case. Upon the projecting . end of the half time shaft (which formerly held the timer) a bevel pinion is keyed ; in mesh with this bevel pinion is another, their ratio being i :2, as the magneto is designed to drive at motor speed. These bevel gears are contained in a casing bolted to the crank casing, the shaft of the driven bevel gear being prolonged and terminating in a ball. The drive shaft of the magneto has keyed to it the socket, which, together with the ball, forms a universal joint. An adjusting device is fitted in this case, being shown in section in the illustration. F is the magneto drive 260 shaft fitted with the key K. The interior of the socket collar is pro- vided with a series of slots G G, by the use of which adjustment for wear, etc., may be made. The key is shown in one of these slots. The socket is held 'upon the shaft by .means of a set screw S. This method of mounting has no other objection than that it renders the valve spring of the left cylinder a trifle difficult to remove, due to HE NMUIUI OE FIG. 158. MAGNETO FITTED TO OPPOSED MOTOR. the proximity of the magneto and its stand. The magneto is discon- nected by the withdrawal of the drive pins R R. It would undoubtedly be better if the drive were in a straight line, but this would place the magneto so that it would interfere with the closing of the hood or rest against the manifold, and it was also for these reasons that the above mounting was adopted. AN ADAPTER FOR DUAL IGNITION. This is the day of double systems of ignition, and cars adapted therefor have either two sets of spark plugs (when the ignition is high tension) or make and break mechanisms and spark plugs. But for cars having only one spark plug aperture an adapter may be used. This may be of pipe fit- tings or of a special casting. The idea is to enable the use of either of two spark plugs in one aperture. Fig. 159 shows several forms of adapter. A is PIG. 159. made of pipe fittings, B and C are castings. The branches of the adapters are tapped to take the spark plug, while the shank is threaded to fit in the spark plug aperture. It will, 261 of course, be necessary to have the spark plug the same distance from the interior of the combustion chamber in all adapters in use on a multi- cylinder motor, to equalize the time of ignition as much as possible. Overhauling a Motor. (PIERRE MAILLARD IN "OMNIA.") When it becomes necessary to overhaul a motor the latter will usu- ally give notice of the fact itself by giving out a very characteristic metallic sound, well known to every experienced driver under the name "knocking." The knocking is especially pronounced if the ignition is advanced slightly too much. This metallic sound is the result of shocks between the connecting rod and the piston pin ori the one hand, and the connecting rod and the crank pin on the other, due to play in the bushings of the rod. As soon as this knocking becomes at all pro- nounced it is advisable to discontinue driving the car. The writer has seen connecting rod heads worn to such an extent as to split apart. This entailed the immediate bending of the crank shaft, and the connect- ing rod, being no longer maintained in place, broke at one stroke through the bottom of the crank case. The first precaution to take in case a motor knocks is to demount the cylinders, after having first removed the inlet, exhaust and water pipes. This demounting process in general does not involve any difficul- ties. However, in some of the older types of motors the cyl- inder heads are separate, and these separate heads must not be taken off, as it is very diffi- FIG. 160. cult to make a good joint again. On the contrary, the cylinder and head should be removed together, as though they were made in one piece. After this has been done one may easily ascertain by means of the hands if there is any play at either end of /the connecting rod ; if there is the crank shaft, the connecting rods and the piston pins must be taken apart. In certain motors this latter disassembling process is quite diffi- cult. These are the motors in which the crank shaft is introduced from the ends, the bearings being supported by end plates bolted to the casing. It is often a very difficult job in the case of such motors to ^remove the connecting rod caps inside the crank case, which must be done' before the crank shaft can be withdrawn. At the same time as the crank shaft the cam shaft and its gearings must be taken out. Before disassembling the cam gearing it is neces- sary to mark the gears by means of prick punch marks in order to avoid laborious trials in putting the gearing together again. After the motor has thus been disassembled, and all pieces have been duly cleaned by means of gasoline, the separate parts are taken in hand successively. 262 FIG. 161. CRANK SHAFT. The main journals and the crank pin journals must be carefully examined. As the crank shaft is the most expensive part of the motor it must be saved as much as possible. In most cases all of these journals will be found to have worn more or less oval, but as in general the crank shaft is not hardened, it is easy to true them up in the lathe. For truing up the main journal the crank shaft is placed in the lathe between centres, but for truing up the crank pin journal the crank shaft must be placed in special brackets, which bring the crank pins in line with the lathe centres. If there are no suitable brackets available a lead lapping fixture is made use of (Fig. 160). This consists of two strips of wood, A and B, into which are sunk two half bushings of lead, C and B. The crank shaft being centred at F in the lathe, the workman presses the lead bushings, which have previously been covered with a paste of emery and oil, tightly against the pin. The lathe is then started up by the workman, who holds the "lapper" in his hand, the latter working exactly as a connecting rod. In this manner a good journal is obtained in short time. No attempt should be made, however, to remove much material from the crank shaft, as, notwithstanding the fact that the sections are very liberally proportioned, there is danger of breaking the shaft, or, at least, of bending it. A reduction in diameter of one sixty-fourth inch may be considered quite appreciable. It is relatively rare that a crank shaft is found to be bent. This may occur if the flywheel of the motor strikes some obstacle in the road. A bent crank shaft is nearly always discarded, and only the factory which produced it can tell whether it can be righted again. CYLINDERS, PISTONS AND PISTON RINGS. The cylinders in the majority of cases are slightly ovalized. They may be made round again by reboring them, provided only very little stock needs to be removed, for if considerable material must be re- moved it is necessary to make new pistons of a larger size, which would be more expensive than to make new cylinders. If the compression rings are worn, they must be replaced, and care must be taken to nicely fit and grind the rings into the cylinders. In this connection it should be remarked that a worn cylinder always has more or less the section shown in Fig. 161. The portion A of a slightly increased diameter is that where the piston moves up and down. The compression rings must, therefore, be forced through the section B and then expand in A. It is this latter diameter to which they should be adjusted. It is, moreover, a good plan to take out a light cat at C and D in order to remove the lower and upper shoulders of the "counterbore" A. If this is not done, after the slack on the connecting rod heads has been taken up the piston may hammer against the offset or shoulder and cause a mysterious noise. Where this precaution is 263 neglected the motor, after being overhauled, often knocks as much or more as before, and much time may be lost in looking for the cause of this knocking. With regard to the pistons there is little to be said, except that frequently the compression rings have too much play in their grooves, which take on a section similar to that shown at A, Fig. 162. The piston should then be put into the lathe and the grooves turned out to the normal section B, and special compression rings C must be made to fit these grooves without play. If the cylinders are fitted with hand hole plates or cover plates for inspecting the interior of the water jackets these covers should always be taken off and the jacket space cleaned of the deposits of lime, as FIG. 162. the cylinder walls will be nearly always found heavily incrusted. The valves are then ground into their seats, after the latter have first been trued up with a valve seat cutter, if that is necessary. The cylinders are then in working condition again. BEARINGS AND BUSHINGS. The bearings (we are not referring here to ball bearings, which are as yet very little used in automobile motors) are of two different kinds, according to whether the bushings .are entirely of bronze, or whether they are of babbitt. If babbitt bearings are used the babbitt is melted up and new bushings are cast, which requires a somewhat special equip- ment. In the case of bronze bushings, on the other hand, if the bushings are badly worn there is no other course open than to replace them en- tirely. If they show only slight wear it may be sufficient to repolish them by means of a scraping tool. If they are slightly more worn they may be counterbored and lined with babbitt. In every case the bushings and journals should be fitted by means of a scraping tool and red lead on the shaft until the bearing is perfect. This attention must be given to the main bearings of the crank shaft, the crank pin bearings and the cam shaft bearings. After the bushings have thus been thoroughly adjusted one must not forget to place oil holes in the proper positions, nor to cut oil grooves in the bushings. The connecting rods and the cam shaft generally wear but very slightly. and all that is necessary to do is to examine them as to their straight- ness, as well as with respect to the keying of the cams, if the latter are not made in a single piece with the shaft. ASSEMBLING. This is the most delicate part of the entire process. The operation is the easiest in the case of a four cylinder motor having only three crank shaft bearings, especially if the bearing caps are independent of the crank casing. In that case the lower half of the crank case serves only as a dust guard and an oil well, and it is put in place only after all the bearings have been completely adjusted, which can be done in full view^of the operator. Every part can then be thoroughly examined from underneath. Special care should be taken to see that everything turns 264 nicely, that the connecting rods have plenty of play and do not cram any of the pistons in the cylinders. That the connecting rod heads are properly fitted on the crank pins is shown by the fact that they turn on the pins with some slight friction without oil. In the case of other motors the process of reassembling is sometimes quite difficult. The operator must not be in haste, and the process must be recommenced, if necessary, a number of times until perfect results are obtained. After everything has been put back in place the cam gearing is taken in hand, which is put in place easily if the gears have been properly marked; then the lift of the valves is adjusted, either by filing off the valve stems or by adjusting the adjustable push rod heads, if these are provided. The flywheel is then put back in place and the motor is connected to the shop line shafting by means of a belt running over the flywheel, after having first flooded the crank case and cylinders with oil. The pistons are thus allowed to run themselves in for a couple of hours. The motor is then cleaned, and is ready to be placed on the testing stand, if one is available; if not, it is put back into the car, which, after all, is an excellent testing stand as well. It will be seen from this that the over- hauling of a motor is a tedious and delicate operation, and it is there- fore not advisable to confide it to inexperienced hands. Faulty Compression: Its Causes and Remedies. (ALBERT L. CLOUGH.) Upon the perfection of the compression attained within the cylinders of a gasoline engine depends in a very remarkable degree the character of its performance. Its fuel efficiency depends directly upon the compression, and some idea of the relation between the two may be conveyed by the following values cited from a competent authority. The fuel efficiency represents the fraction of the energy inherent in the explosive mixture which the engine turns into useful work, and hence, as the rate of using fuel per cycle is fixed by the dimensions of the engine, the fuel efficiency is a measure of the work which it can do. With a compres- sion pressure of 38 pounds the ideal efficiency figures out as 33 per cent., with 66 pounds compression 40 per cent, and with 88 pounds 43 per cent. Actual efficiencies are closely proportional to these ideal values, hence the importance of keeping the engine compression near its original value. EFFECTS OF FAULTY COMPRESSION. A failure to attain and to hold the expected compression pressure is always due to a lack of tightness of those elements which are supposed to confine the gases during this portion of the cycle, namely, the valves, the cylinder walls, head and passages, and the piston and its packing rings. Faulty compression acts in three ways to reduce the useful work devel- oped in each cycle. After the full charge has been drawn into the cylinder and the compression stroke commenced, a portion of the fuel leaks out either into the crank case or muffler, or is pushed back into the suction pipe, and by the time ignition takes place there is a considerably reduced amount of fuel within the cylinder. The condition is, in effect, as if a 265 partly throttled charge instead of a full charge had been admitted, although in point of fact a nearly full charge of fuel has been expended. When such leaky conditions obtain, not only is the initial pressure upon explosion abnormally low, but a certain proportion of the expanded gases escapes prematurely through the leaks and reduces the working pressure at an excessive rate, especially rendering the useful pressure upon the piston during the later portion of the stroke much lower than it should be. When gas is compressed behind a tight piston it acts as a rather perfect spring, and is ready, when released, to return to the engine a portion of the energy which was absorbed in its compression. When, however, a portion of this gas escapes through leaks, it expands uselessly outside the cylinder, and its energy content is lost irrevocably. Imperfect com- pression results in reduced output and in decreased fuel efficiency. AGGRAVATED AT Low SPEEDS. A cylinder which is leaky may serve fairly well at high speeds, as the duration of the compression period is so brief that not a very large part of the charge is able to escape, but when the motor is slowed down almost to the laboring point, as when climbing a steep hill on the high gear, the effects of imperfectly maintained compression make themselves especially manifest. Under such conditions a longer time elapses between the commencement of the compression stroke and the time of firing, and also btween ignition and release, and a greater proportion of the expanded gases is thus able to escape uselessly during the power stroke. In other words, just when the maximum pulling power of the motor is desired it is falling off quite rapidly. VERIFYING FAULTY COMPRESSION. In a single or even a double cylinder engine it is very easy to deter- mine whether there is a freedom from leaks and whether the expected pressure is attained, by the "feel" of the starting crank when the motor is turned over with the spark shut off and the throttle partly open. If, when the engine is cranked and the compression stroke begun upon, there is a constantly increasing resistance transmitted to the hand through the 'starting crank up to the time that the inward dead centre is passed, no matter how slowly the starting handle is turned, one may feel confi- dent that the compression is good. If, on the contrary, there is no such springy^ resistance, unless the engine is cranked very suddenly and ener- getically, and if the compression stroke may be completed with very little effort when passed slowly and gradually, the compression is faulty. If the compression were absolutely perfect the starting handle would spring back when released at any portion of the compression stroke, and the same amount of force would be required to turn the handle to a certain point in the stroke, no matter how many trials were made. The ideal condition is seldom if ever realized in practice, and after a certain number of trials enough gas usually leaks out to enable the stroke to be completed with much lessened effort. METHOD FOR MULTI-CYLINDER ENGINES. The compression strokes of a four cylinder engine immediately succeed one another, so that one cylinder is always under compression, and in a six cylinder motor successive compression strokes overlap. With such 266 motors it is not very easy to determine whether there is any lack of com- pression, and which cylinder or cylinders are defective in this regard, unless some precautions are taken. The best method of procedure, then, is to remove all the spark plugs but one, and crank the engine. This will give a test of the compression of the cylinder, which is closed by the plug, all the others turning freely. After the compression of this cylinder has been noted the plug may be removed and placed in one of the other cylinders, the compression of which may then be tested. All four or six cylinders may successively be tested, by noting the manner in which their respective compressions may be overcome by cranking, and those which are unsatisfactory may be noted. If pet cocks are provided, the spark plugs need not be removed but all cocks except that on the cylinder being tested should be kept open. AUDIBLE INDICATIONS OF COMPRESSION FAULTS. Sometimes attention may be called to faulty compression conditions in one cylinder of a double engine by the difference in sound of the exhaust puffs of the two cylinders the one with low compression giving a relatively weak exhaust and when the motor is slowed down extremely there may even be a noticeable difference in the vibration of the engine, due to the difference of the actions of the two cylinders. A cylinder with faulty compression sometimes detracts noticeably from the even smoothness of the exhaust "purr" which a good four cylinder motor emits. This is especially noticeable at low engine speed. LOCATING THE LEAK. If it be decided that the compression in one or more cylinders of a motor is sufficiently unsatisfactory to warrant investigation it becomes necessary to locate the exact cause of the leak. The first inspection to be made will naturally cover the inlet and exhaust valves, to determine if their actions are perfect. First the cap over the valve is removed, when the valve is exposed to view, and may be removed through it. A cursory examination may immediately show the valve under inspection to be broken, and in this case it is of the utmost importance that the frag- ments shall all be recovered, as otherwise they may enter the cylinder and lead to serious damage. In this event a new valve must be supplied. Occasionally, though very seldom, it happens that some object is drawn through the carburetor, and is caught between an inlet valve and its seat, thus preventing its seating properly. A broken valve spring will most likely be apparent as soon as the valve is operated by the ringers, but a weakened spring may only be detected when its strength is compared with its mates. The valve should work with perfect freedom from sticking or friction between the valve stem and its guide, as otherwise it may be caught open. Unless the valve stem is bent, a little lubrication of the guide ought to render the valve action perfectly free. A broken or weakened spring in a modern engine may readily be replaced. APPLYING THE SENSE OF TOUCH. If no obvious valve trouble is apparent, and still the cylinder is weak in compression, it becomes necessary to determine whether either of its valves is leaky. The only sure way to determine this requires the removal of the 267 intake and exhaust pipes. This may involve considerable labor, but it is often well worth while. When the pipes have been removed it is usually easy to insert one's finger into the inlet and exhaust port and find their respective valves. When the engine is set at the beginning of the compres sion stroke of the cylinder in question, and strongly cranked, in case of a leak of any consequence the air can be felt escaping. If the inlet and exhaust valves are on opposite sides of the head, so as not to be too close together, placing the ear at the port openings will serve to detect leaks, as the escaping air will be heard hissing past the valve. If the charge cannot be felt or heard escaping from either valve, and if a flame held close to each port opening is not blown outward during the compression stroke (the gasoline having been drawn from the carburetor), the valves are tight and the lack of compression must be sought for elsewhere. If one of the valves is seen to leak during the compression stroke it should be replaced, or it may be ground to its seat by the use of quartz powder or emery. The cap over each valve should, of course, be demonstrated to be tight. If these closing caps are of the ground joint type, the abutting surfaces should be seen to be free from any foreign particles before they are put together. The same precaution should be taken when replacing the pipes, if ground flanges are used, and if gaskets are employed they should be in perfect condition. LEAKS AROUND PISTON. If after the valves are in perfect condition there is still a lack of com- pression, the crank case should be opened and the engine cranked over compression with the plugs out of all cylinders, except the one under test A hiss of escaping gas may be heard when the ear is placed at the crank case opening, and this indicates that there is a lack of tightness between the cylinder wall and the piston. Before taking the trouble of removing the cylinder and piston, it may be worth while to make an attempt to remedy the difficulty. Sometimes, after long use and long periods of dis- use, especially if a considerable amount of poor cylinder oil has been fed, and too rich mixtures used, the piston packing rings rrfay become fouled with carbon and burnt oil, and thus fail to spring out and perform their function. A large quantity of kerosene fed to the cylinder while the engine is being turned over will tend to remove these deposits and free the rings, and may improve their fit. This is hardly likely, however, and the piston will in all probability have to be removed. This will mean the removal of the cap screws, which are usually employed to hold the cylinder base to the crank case, or, in case two cylinders are cast together, the removal of the pair which includes the defective one. All pipe connections must, of course, be freed, and the cylinder or cylinders lifted off. The connecting rod tips, when freed from thefr crank pins, allow the pistons to be taken off. INSPECTION OF PISTON RINGS. An inspection of the piston should first be made. One or more rings may be found broken, in which case new ones should be procured from the manufacturers. Good rings can, of course, be made and fitted in any first class machine shop, but unless one is in a very great hurry and willing to pay for a special job of this kind, it is better to get them from the factory, 268 unless the cylinder itself is badly worn, in which case the regular rings will not fill properly. Sometimes, when rings are not pinned to prevent their turning in their grooves, they may turn so that the cut in each one is in the same line, in which case the escape of gas is facilitated. This very rarely happens, how- ever. The rings should be inspected, and each one should be found to have worn bright over its entire outside surface. If any portion of a ring is dull and covered with burned oil, it is a sure sign that it was not cor- rectly fitted or that it has lost its spring or worn out so that its remaining resiliency is insufficient to expand it enough to cause it to touch the cyl- inder walls. If any one of the rings is bright over its whole length, it indicates that it is possible to pack the cylinder by the use of rings; that is, the cylinder is probably not so much out of shape as to be entirely unfit for use. Although a ring may appear to touch the cylinder wall throughout its length, it may be so worn and reduced in outside diameter that its ends do not nearly abut and leave a considerable space for the escape of gases. If at least one pinned ring seems to have made a perfect contact with the cylinder wall, a complete new set of rings will probably restore the com- pression after they have worn into place. If all the rings show a perfect bearing upon the cylinder wall, the cylinder may well be inspected before they are disturbed. In putting in new rings from the factory the greatest care should be taken not to strain them unnecessarily, and if they do not fit their grooves perfectly they should not be used. Extra ones should be ordered in case some are broken when being sprung in. SCORED PISTON AND CYLINDER. WALLS. The inspection of the cylinder should include running the hand over its bore to see that its surface is perfectly smooth. It may be found that it is badly scratched in lines along its length. Sometimes the piston pin becomes loosened from its fastenings and moves laterally, bringing one end into forcible contact with the cylinder wall and wearing a groove in it. If a cylinder has been allowed to run for a long time without oil, it may become badly scratched, and if a ring breaks there is a chance that its broken ends may score the wall, especially if the accident was due to lack of lubrication and the consequent sticking and breakage of the ring. REBORING CYLINDERS. Cylinder bores after long usage tend to wear from the true circular section to a more or less elliptical form, the longer axis being in the plane of the connecting rod movement. After a time a distinct "shoulder" can be felt in the cylinder wall at the inward limit of piston travel. The "shoulder" is especially noticeable in the plane -"of the connecting rod movement. If measurement of the bore diameter with a pair of inside micrometer calipers shows that the diameter of the cylinder in this plane differs more than a few thousandths from its diameter in the opposite plane, or if the bore diameter near the limit of inward travel varies much from its diameter at or near the outer limit of piston travel, it is not unlikely that the cylinder has worn into such shape that no packing rings can make it perfectly tight. A competent machinist can advise one as to 269. whether the cylinder is usable in its present condition or whether it must be rebored and a new piston fitted. While inspecting the cylinder bore one may well examine its walls for CRACKS, SAND HOLES OR POROUS PLACES. Sometimes these allow the leakage of the compressed charge and also the slow entrance of water from the jacket. Such defects are not very common, but are occasionally met with. A solution of copper sulphate forced into them will precipitate metallic copper and perhaps stop the leak. Sometimes, by the use of a solution of sal ammoniac, the iron oxide which is formed will plug fine cracks or small sand holes. If reboring of the cylinder has to be resorted to the job should be entrusted only to a well equipped machine shop, known for accuracy of workmanship. Not every shop which possesses a lathe large enough to swing the cylinder can do the work properly. The best, most accurate boring mill, with the most rigid tool and most competent machinist, is none too good for the work. In the case of a single cylinder engine or an engine in which all the cylinders are worn out, advantage may possibly be taken of the fact to have the cylinder bore slightly increased, in order to increase the power, but this should not be attempted except after taking competent advice. Increasing the bore of one cylinder of a multiple engine is not to be recommended. REPLACING DAMAGED CYLINDERS. Of course, if one prefers, a new cylinder may be ordered from the factory to replace the defective one if the other cylinders are all right, instead of reboring the defective cylinder. Probably the old piston with new rings will work properly in the new cylinder, as the piston itself wears slowly compared with its rings. In extreme cases a new piston will have to be ordered with the new cylinder. When cylinders are rebored new pistons, of course, have to be made. Often the old piston, with slight modifications, may be used for a pattern for casting the new ones. Just how tight a piston should fit its bore is still somewhat a matter of dispute, but the best practice seems to be to machine it to a very easy fit and to a slightly less diameter at the head end than at the crank end in order to allow for the differential expansion between piston and cylinder. Fortunately for the motorist's finances it is only after a num- ber of seasons' use (barring accidents) that a cylinder which originally was true should become unfit for use. As a rule the fit of the rings is the matter which most often determines whether compression shall be satisfactory or defective. - MISCELLANEOUS CAUSES. A few other occasional causes of loss of compression remain to be mentioned. A very obvious one is that of a broken spark plug. If the plug is loose or the porcelain has given way there may be an escape of gas through it. A priming or compression cock may, in the course of time, become loose or leaky. Some of the older automobile engine cylinders are cast with a separate head, and a gasket of asbestos or copper is used between the head and the cylinder in order to secure tightness. The gasket may blow out or 270 become loose, and this will admit gas from the cylinder to the water jacket, thus preventing perfect compression. It will also admit water from the jacket to the cylinder, which is, in practice, far more serious. A replacement of the gasket is the natural remedy for this condition. Some air cooled motors employ separate cylinder heads usually packed to the cylinder with a copper gasket. If the bolts, which normally secure the heads, loosen up through any cause there will be an escape of gas. Almost everyone has noticed that certain engines give more power after they have been run for a few miles. This is often due to an increased tightness of the piston, due to its expansion and the expansion of the rings at a greater rate than the water cooled walls of the cylinders. The use of a cylinder oil which does not become too thin when heated tends to secure tightness between the piston and cylinder walls. Air Leaks in Gasoline Engines. (ALBERT L. CLOUGH.) Air leaks are a most prolific cause of irregularities in the operation of vehicle engines of more than one cylinder. In fact, it is not too much to say that a very considerable portion of the obscure troubles manifest- ing themselves by the erratic action of one or more cylinders is traceable to this cause. Oftentimes carburetor action and ignition are wrongly blamed for the skipping or weak running of a particular cylinder or cylinders. Since the proportion of air to fuel is correctly fixed by the carburetor adjustments, or is at least supposed to be, the entrance of additional air into the charge results in a weak mixture. A leak may be so located as to affect one cylinder or all cylinders to a variable extent. The weakened mixture, resulting from the leak, is slow burning and, for a given degree of spark advance, the cylinder in which it exists suffers from late ignition, which may be so much delayed that combustion is not over before the next charging stroke, in which event a "pop back" through the carburetor is likely to occur. The explosion is a weak one under these circumstances and noticeably different from those in the unaffected cylinders. The air leak may be sufficient to reduce the quality of the mixture below the explosive point, in which event the cylinder or cylinders affected will miss. WORST AT SMALL THROTTLES. The effect of an air leak is serious mainly at low throttles, for several reasons. When the throttle is wide open there is but a slight degree of vacuum existing in the cylinder during the suction stroke, as the incoming gas is unobstructed and flows in readily to fill the piston displacement. With the throttle completely closed, and assuming a tight condition of piston and valves, there is nearly the full atmospheric pressure acting be- tween the inside and outside of the cylinder. At very small throttle openings, such as are used when the engine is idling or running slowly on the level, the gas inside the cylinder is at a pressure very considerably below atmosphere and the ingress of air through any leak is at its maxi- mum, while with wide open throttle it is at its minimum. Not only is 271 the actual amount of air leaking in very large when the throttle is closed, but it bears a much larger proportion to the whole weight of the small throttled charge then sucked in than it does to a full charge taken at open throttle. Furthermore, when an engine is run very closely throttled the propor- tion of dead clearance gases to the small fresh charge admitted is very large, and the resulting mixture is often very near the limit as to com- bustibility. The addition of accidentally admitted air to this very imperfect gaseous mixture is often sufficient to prevent regular ignition, although the cylinder may "eight cycle" that is, fire on every other power stroke, the burned gases having been scavenged during the inactive portion of the cycle. As the compression realized when running on low throttle is very slight, the ignitibility of the charge is reduced and only a slight reduction of its richness, due to an air leak, is required to cause a "skip." At full open throttle the effect of an air leak, unless it be a very bad one, is usually not obvious, or at least not serious. ' In the case of any motor showing faulty running of a certain cylinder,- a leak of this kind should be searched for as soon as the spark and valve action has been shown to be faultless. RENDERS STARTING DIFFICULT. As a rule, the presence of an air leak renders an engine difficult to start without excessive priming of the carburetor, as most carburetors tend to deliver a rather weak mixture when the motor is turned over by hand. The admission of accidental air will often weaken this below the point of inflammability. An air leak may occur either on the cylinder side of the inlet valve, in which case the particular cylinder will be affected, or it may be outside the inlet valves, in which event the action of all the cylinders may be interfered with more or less. It is this former kind of leak that is most apt to produce missing or weak explosions in a certain cylinder, and it is the latter which makes an engine hard to start or renders its action generally erratic, especially at low throttle openings. WHERE LEAKS OCCUR. The following are some of the points at which leaks of the first descrip- tion may develop. After considerable service, especially if, as is often the case, good lubrication is not provided, the inlet valve stem may become quite loose in its guide. A considerable space is thus created through which air may enter the inlet valve chamber and dilute the charge. In such a case as this the leak is so near one particular cylinder that the diluting effect is mainly felt therein, although the leak is into a space which has connection with the other cylinders. If the valve sterns are bushed and the wear is found to be mainly confined to the bushing itself, a new bushing is the obvious remedy; but if the stem is guided in the metal oT the housing, the hole requires to be bored out and a special bushing made and fitted. Many instances of weak and irregular action in a par- ticular cylinder are due to this cause, and this is especially true now that engines are required to be able to turn over so slowly when idling. Unless the caps which screw in over the inlet and exhaust valves are perfectly tight there is a chance for the outside air to be sucked in at these points. Occasionally, when a cap has been screwed in and out several times, the copper gasket which . is used for packing becomes roughed up or broken, and a leak takes place past it and the thread. Graphite should be applied to the thread and a new gasket supplied. There is also a possible chance for a leak around the cage containing the valve in case a "caged" construction is used. The ground joint between the cage and the cylinder may not seat perfectly or, if a gasket is used at this point, it may not be tight. Not infrequently a spark plug will be found which has an imperfect thread, which cannot be made tight in the plug hole. A very small leak at the plug or around the inlet valve cap is especially bad, as the diluting air is admitted so close to the spark points that the mixture is diluted at the very point where it should be most easily ignitible. Another derange- ment, which, while not strictly an air leak, may yet be spoken of here is the imperfect seating of the exhaust valve. This allows of exhaust gas being drawn into the cylinder, during the suction stroke, not only diluting but fouling the charge. Under the same head may be mentioned leaks around the piston rings. This is less serious, as regards the regular running of an engine (unless of very large amount), than most other kinds of leak, as the foul gas or air drawn in during the suction stroke enters the lower end of the cylinder space and does not so directly inter- fere with ignition. Leaks around the plugs, cages, valve caps, exhaust valve and piston rings, are manifested by reduced ability to maintain compression in the cylinder affected, but a leak around a valve stem is not. Oil or soap suds flowed around the valve caps will show bubbles during the compression stroke if a leak exists. Especially in the case of air cooled cylinders there is the possibility of a crack having developed in the cylinder head or in the passages thereto. With a watef cooled cylinder such a defect will manifest itself by the entrance of water into the combustion space, and usually by steam in the exhaust. SYMPTOMS OF LEAKS. Any lack of tightness between a branch of the inlet manifold and its port flange on the cylinder allows excess air to be sucked in therethrough. If the leak is very slight only the cylinder supplied from the branch in question is usually affected, but if it is at all large a weakened mixture may be supplied to all the cylinders, and it may be next to impossible to start the motor unless the carburetor is adjusted for a very rich mix- tureso rich, indeed, that satisfactory running on full throttle will become impossible on account of a gross excess of gasoline in the mixture. Such a defect as this is not evidenced by any lack of compression, as the trouble is outside the valves. If the suspected joint can be gotten at, oil or soap suds flowed around it will be seen to be sucked in during the charging stroke. Sometimes, too, the faulty joint, when taken down, may show blackening, due to the slow combustion of the overrich charge, sometimes taken, allowing it to still be burning at the beginning of the succeeding suction stroke. These joints are now usually ground in or made with 273 copper gaskets, some form of clamp holding device being employed. Formerly they were often made with bolted flanges. Inlet- manifolds being very thin castings and rather difficult to produce without imperfections, sometimes contain foundry defects which have to be plugged before the manifold can be successfully installed upon an engine. Occasionally these defective points open up in service, allowing of an air leak. If there are joints of any kind in the main mixture pipe between the carburetor and the branched portion of the manifold a leak may develop, due to the loosening up of these connections. There is always a joint where the carburetor is attached to the piping, and it has sometimes happened that when the carburetor has been taken off the gasket used in the replacement has not insured a tight joint. A gas leak at this point tends to make it difficult or impossible to start the motor, and causes spasmodic running at any but quite large throttle openings, poppings in the carburetor being frequently heard. Prevention and Removal of Carbon Deposits. (ALBERT L. CLOUGH.) The use of kerosene in the cylinders tends to prevent deposits from adhering to and hardening upon the piston heads and cylinder heads. It also tends to keep the valves and rings clean and free in operation. After each two or three hundred miles of driving it is a good idea to inject into each cylinder through the spark plug hole or pet cock two or three tablespoonfuls of kerosene, while the motor is fully warmed up. This should be allowed to remain over night, when it is cleaned out of the cylinders during the next day's running. Account should be taken of the fact that the kerosene works down into the crank case and tends to thin the oil therein, and the supply of fresh oil may be advisable after the above treatment has been applied. Kerosene may also be introduced in such a manner as to clean the valves by injecting it gradually into the carburetor air valve when the motor is running, using a squirt can to feed the fluid, and applying per- haps half a pint in all. Despite the use of kerosene, carbon deposits will in time collect within the engine combustion space and finally require removal. They may be removed mechanically or by the use of one of the solvent preparations known as decarbonizers. Mechanical removal implies the scraping of the piston heads, valve seats and other parts, small special scrapers being used, which can either be bought outright or forged out by a tool maker. In some few engines the piston heads may be pretty well cleaned by insert- ing the scraper through overhead valve ports. In some other construc- tions the cylinder heads are removable, and when so removed the piston heads are fully exposed and may be cleaned with an ordinary machinist's scraper. In some other engines a large plug is screwed into the cylinder head which, when removed, allows the scraper to be used. However, most engines having pocketed valves must needs be disassembled to allow of scraping. Under these conditions the cylinders are removed from the crank case and cleaned very handily, the greater part of the work being 274 that of taking the motor down and assembling it. Occasionally an engine will be found so designed that the pistons and Tods may be removed through the hand holes of the crank case, thus obviating the necessity of disassembling. As a rule the valves will require regrinding after de- carbonization has been performed. In order to mechanically decarbonize a motor without disassembling it, it has been proposed to insert into the combustion space some metallic object, the striking of which against the piston and cylinder heads, when the engine is run, tends to clean off the deposits. Good sized steel balls or one of the common metal wash-rags made up of interlaced rings have been proposed for this purpose. It is of the utmost importance that what- ever be used should be free from the danger of catching under the valves, wedging between the piston and head, or otherwise causing injury to the motor. This method should be used, if at all, with caution. Fluid decarbonizers are liquids which have the power of softening the binding material which holds the carbon particles in the form of a hard crust or scale upon piston heads and other parts. When so softened, the accumulations are blown out through the exhaust when the engine is run. The usual practice is to supply a certain amount of the "decar- bonizer" to one cylinder at a time, allow it to stand for a prescribed length of time and then run the engine. After all cylinders have been treated, fresh oil is supplied to the motor and the valves are reground. as particles of the deposits are frequently found under the valve seats. The occasional use of a "decarbonizer" is claimed to keep down the deposits to a harmless point. When used, the directions furnished should be carefully followed. Fitting a New Leather to a Cone Clutch. When a new leather is to be fitted the clutch should be removed from the car and taken apart and the worn out leather removed. The rivets can usually be punched out with a piece of round stock after the burr or "upset" has been cut away with a chisel. The old leather should be used as a pattern, the new piece being considerably thicker and with a uniform surface, or as nearly uniform a one as can be obtained. With stiff leather an oil dressing should be given and the treated leather hung up for some time, say a day or two. The trick is to get the leather stretched tight and true on the cone. One end is cut square and secured by a rivet, the other is then brought around to meet it. The leather must be only two-thirds on the cone at this stage. All that is left now is to draw up the leather on the cone, drill the holes and countersink them, and then "in with the rivets." This is much better than cutting the holes in the new leather beforehand, as when it is applied the holes do not usually square up. The cone should be chucked in a lathe and the leather trued up, or a file used for the same purpose if no lathe is at hand. Any high spots will show up after the clutch has been running in the car for some little time, and these can be smoothed down afterward. It usually takes some time before the new leather has a good working surface. Asbestos fabric such as used for brake bands may also -be applied to cone clutches. 275 Truing Up a Brake Drum. (A. P. PRESS.) If a brake drum is "out of true" no brake will operate properly, and the object of the present article is to show how the drum can be made to run true. If the drum is made integral with the hub casting, as it is in some of the smaller cars, it can only be trued in the lathe, which is a machine shop job, but if it is bolted to the spokes it can be made to run as well again as when it left the wheel maker's, and perhaps better. Jack up the car at the side where the drum is out, so the wheel can be taken off and the drum removed. Put the wheel back and put the wheel nuts on. Take the wheel and true off the seat where the drum goes. This can be done by using a rest and a sharp chisel. It will take two persons to do this, one to turn the wheel and the other to hold and use the chisel, the same as in wood turning. The spokes being faced off, take off the wheel and put on the drum with two small bolts. That is, if the wheel bolts are three-eighth inch vise a five-sixteenth inch bolt and tighten as hard as possible, and still move the drum with a smart blow with a wood mallet. Put the wheel back on the axle and turn it the same as in truing off the spokes, holding a piece of chalk on the outside of the drum, if the brakes are of the contracting type, or inside if they are of the expanding type. Strike on the high side with the mallet to knock the drum true, and try with the chalk again. Continue in this manner until the drum runs perfectly true, and tighten the two bolts very tight. Now, take a twist drill or a reamer the size of the wheel bolt (don't try to use a carpenter's bit) and ream out each hole true with the hole in the drum. The drum being of metal, it will guide the reamer to cut the hole in the spoke true with itself. Now take the wheel bolts and put them in, taking care to put them in opposite to each other, and to tighten them equally hard. Put in four bolts in this manner, and then ream and put in the other eight bolts. If the bolts are all too large to fit the holes dip them in white lead. This will make them hold and also stop them from rusting. A drum can be THE HORSELESS AGF FIG. 163. CLUTCH BRAKE. 276 trued in this manner to within i-ioo of an inch, which is near enough for all practical purposes. Clutch Retarders. The ordinary cone clutch, unless made with an aluminum spider or frame, is usually quite heavy, consequently it "spins" more or less when drawn, making gear-changing less easy than with a lighter clutch. A damper or brake can be constructed to check the spinning when the clutch is fully drawn ; this may be simply a small block of metal, leather or fibre faced, fastened to the cross-member or clutch actuating tube, or the pivoted lever which acts as the clutch is drawn by means of the pedal. Fig. 163 shows two methods by which this "damping" is accom- plished. As the clutch is drawn it meets the brake and its momentum is overcome. -In the second sketch the brake arm falls to the dotted posi- tion to act. Bushing a Gear Shifting Rod. (F. E. WATTS.) In a certain rather old style car the rod for shifting the gears slid through holes drilled in the gear case. The case was of cast iron, and since the walls were only about a quarter of an inch thick, and there were no bosses where the holes for the shifting rod were drilled, these holes soon wore oval, being nearly ... x one-quarter of an inch larger than '. -. ._"i i) the rod on their longest dimension This not only made the gears shift THE HORSELESS AGE badly, but allowed a good deal of oil to escape. The trouble was remedied by FIG. 164. BEARING FOR GEAR SHIFT- making two bushings from hard ING ROD brass rod. The holes in the case were filed round, so as to be a snug fit over the small diameter of the bushing. The bushings were secured by riveting, as shown in Fig. 164. The dotted lines show the original shape ' of the small end of the bushing, which was countersunk to make riveting easier. The holes for the rod were originally a little loose, and the parts ' went together with very little scraping. The fits were found to be good enough, so that the leakage of oil was not objectionable. "Gate" for the Reverse Slot. The majority of American cars with selective type of change gear have only three forward speeds. This means that the quadrant in which the change gear lever works has but two slots, one usually having the low and the reverse gear positions at the two ends, respectively, and consequently a false movement may mesh the reverse when the low. for- ward is intended. In several instances when this has occurred the bot- tom of the gear box was sprinkled with broken teeth or the drive shaft converted to a crude corkscrew. 277 To prevent any possibility of such misfortunes a gate can be fitted. This need not extend com- pletely across the slot, but just sufficiently to cause a check to the lever. Two such gates are shown, (Fig. 165) one for quadrants sepa- rated from the body and the other for those sunk in the floor boards. The pedal A is so arranged in both cases that by depressing it the gate C is removed from the slot, allow- For 5vnkQu ^ X X^ \ - N X X , \ X i s x X t > x r* -6p -TO x, X \ s x S 10 46 SO JU 1 20 iO 00 SO 60 7 ** FREEZING POINTS OF SALT SOLUTION. Percentage of Alcohol. 30 ONS. 30 ==c == = =^ ^J . =t= =^= =^j =L= . ^-> ^^ X to -10 ^ V - s^ \ 1 \ x X, |. y^ \ \ \ ! s s K \ FR 1 1 EEZIN 00 1 J c TE r 1 HPEV a ^= 1 TUREI ^ | i OF 1 1 CALO .0*0 ^=] i -an. ( I a pi^ 2 ,RLd M XM. H iS OLUTK ^^ FR ^ EEZING TEMPERATURES OF WOOD ALCOHOL SOLUTI 1 ; 20 10 ^ \ s> ^- ^^ N \ "^v V j" s X x \ X I \ t \ s \ ft -10 -is \ \ \ .. ^S 10 is 20 as jot, ~"o 10 20 30 4 50% HALF AND HALF. WOOD ALCOHOL-GLYCERINE MIXTURE Percentage of Glycerine. SOLUTION IN WATER. FREEZING POINTS or GLYCERINE AKD WATER. FIG. 171. and any acidity is taken out by a neutralizing solution of milk of lime, the dissolving action on the metals is negligible. The freezing tempera- tures of calcium chloride are given in the accompanying curve. In the latitude of New York a solution of 1.22 specific gravity, which has a freezing point of about minus 15 Fahr., meets all requirements. This solution is best prepared by first making a saturated solution of calcium chloride. To make i gallon of this saturated solution requires about a half gallon of water and 8 pounds of commercial calcium chloride. The solution is shown to be saturated when a few crystals of the calcium chloride remain at the bottom of the vessel, undissolved. This saturated solution is then diluted with an equal amount of water, and a handful of lime is added to render it slightly alkaline. If you want to be sure of having added enough lime you can get some red litmus papers from a drug store and insert one of them in the solution, and if it turns blue it is proof that the solution is alkaline. Such a solution boils only at 220 to 225 Fahr., and it is^ therefore, not likely to evaporate rapidly. In the case of cars which are much used it is advisable to test the strength of the solution once in a while with a hydrometer, ,and to add water if the density is found too high, or saturated solution if it is found too low. A solution of wood alcohol has been much used in recent years. Such a solution when made of the proper strength will withstand any tempera- ture to which a car is likely to be exposed, and the only disadvantage of the alcohol solution is that it boils at a low temperature, and, there- fore, evaporates rather rapidly. Furthermore the alcohol boils away somewhat faster than the water, instead of only the cheaply re- placeable water being lost, as in the case of the calcium chloride solution. Denatured alcohol having essentially the same properties as wood alcohol, and being cheaper than the latter, is now generally used in preference. One advantage of the denatured over the wood alcohol is that it does not boil at so low a temperature and its loss by evaporation is therefore smaller. For instance, a 30 per cent, solution of wood alcohol boils at 168 Fahr., while a 30 per cent, solution of denatured alcohol boils only at 184 Fahr. For 40 per cent, solutions the corresponding boiling temperatures are 150 and 182. There is, there- fore, quite an advantage in favor of denatured alcohol from this viewpoint. There has recently been a considerable decline in the price of wood alcohol, and at present it is practically the same as that of dena- tured alcohol, so that it is very doubtful whether there is any advan- tage in the use of denatured alcohol over wood alcohol for a non-freezing fluid. It will be seen from the curves herewith that for the same freezing point the denatured alcohol solution must be of considerably greater strength than the wood alcohol. Of course the boiling point of the denatured alcohol solution of given strength is considerably less than that of a wood alcohol solution of the same strength, which compensates for the difference in freezing points. In making use of the accompanying curve showing the freezing temperature of denatured alcohol solutions of different strengths, the percentages refer to the proportion of absolute alcohol in water, and if the ordinary 90 per cent, alcohol is used for making the solution, about 12 per cent, more alcohol by volume must be used, to -allow for the 10 per cent, water in the alcohol. The alcohol solution is not very suitable for cars which are subject to hard usage and which have a rather inadequate cooling system, in which the water is kept constantly at or near the boiling point. It will be seen from the curve that a 30 per cent, solution of wood alcohol has a freezing temperature of minus 9 and would serve practically all requirements, except during a spell of extreme cold. To overcome this defect of rapid loss of the alcohol by evaporation the glycerine-alcohol solution has been devised. Alcohol and glycerine are generally mixed in equal quantities, and a solution of this mixture of given strength has about the same freez- ing point as an alcohol solution of the same percentage. Now, the glycerine does not depress the boiling point of water, and as there is only half the amount of alcohol present the boiling point is much higher than for an alcohol solution of the same freezing point. A number of manufacturers recommend a solution of 30 per cent, half alcohol and half glycerine, which has a freezing point of minus 5 Fahr. It has been found that there is no loss of glycerine from such a solution by evapora- tion, and only alcohol needs to be added from time to time. The addition of more alcohol is also fecommended in case lower temperatures must be guarded against than the solution as originally prepared will stand. The solution of glycerine and potassium carbonate was recommended as a substitute for the calcium chloride solution, on account of its lesser corrosive effect, and has been used with satisfaction by a number of motorists. The potassium carbonate is used on account of its anti-rust properties, but a simple solution of this salt, even near the point of saturation, has not a low enough freezing point to "meet the requirements of automobile work. It is with the object of further reducing the freez- ing point that the glycerine is added. A solution of 75 parts, by weight, of carbonate of potassium, in 100 parts, by weight, of water, to which 50 parts, by weight, of glycerine had been added, was found to remain perfectly liquid at minus 22 Fahr. Common salt solutions have also been used with satisfactory results by a number of motorists, and are recommended by some manufacturers. It is well known that brine has a corrosive effect on iron and steel, but this can be almost entirely neutralized by adding a little sal soda or sodium carbonate to the solution to render it alkaline. The defect of the salt solution is that it does not withstand low enough temperatures to be serviceable for all winter use in every part of the country. It will be seen from the accompanying curve that a solution of 20 per cent., by weight, will stand temperatures down to about 8 Fahr. Where no lower temperature than this needs to be provided against, this is undoubtedly the cheapest of all non-freezing solutions. Where a lower freezing point is required it seems that the addition of glycerine to such a solution might serve the desired end. Light mineral oil has been used as a cooling fluid for winter use by a number of motorists, but the opinions regarding its suitability for the purpose have been widely divergent. It can only be recommended for cars having a pump which circulates the cooling fluid energetically. For thermo-siphon cooling systems its use would be out of the question, as the engine would overheat when working for any length of time under full load, and would probably pound. Oil has a much lower specific heat U}i" 289 than water; that is, much less heat is required to raise a certain volume of oil through a certain temperature range than the same volume of water. The fire danger involved has also been referred to, but is negligible if proper caution is exercised. Oil might be recommended where extremely low temperatures have to be guarded against and where energetic circu- lation is assured by the construction of the car. No scientific accuracy is claimed for the curves shown herewith, but they are sufficiently accurate to serve all practical purposes. The specific gravities indicated in the diagrams are for 60 Fahr. For the testing of the freezing points of denatured alcohol solutions a special hydrometer is made, which, when floated in a sample of the mixture drawn from the radiator, indicates directly the temperature at which the solution under test will freeze. Traction in Snow and Mud. In order to prevent the slipping of the smooth surfaces of pneumatic tires under these unfavorable conditions and either a failure to move the car or the development of a tendency toward side slip, such tires are provided with surface pro- jections of various kinds, which tend to enable the wheel to secure a foothold. These projections may either be formed upon the tread of the tire itself or may be applied in a separable form. To the former class belong the spe- cial treads with molded rubber knobs, such as the Morgan & Wright tread (Fig. 172) and the treads containing embedded wires, such as the Midgley (Fig. 174). These treads are intended more for ordinary use and the pre- vention of skidding than for over- coming extreme conditions of dif- ficult traction. In the second class belong the steel rivet studded applied bands, which may either be readily re- movable from the tire tread, as is the Woodworth (Fig. 173), or FIG. 172. made as an integral part of the tread, as the Michelin (Fig. 175). To meet extreme conditions of ice, snow and mud, the tire chain is generally employed and is found in various forms. Figs. 176 and 177 show such chains applied to wheels. They are readily removable and occupy but little space when carried in the car. The traction chains are hardened and wear very well and are, moreover, very readily and cheaply replaceable 290 when worn out. Fig. 176 shows the tractive portion in the form of ordinary sections of chain disposed in a zig-zag manner, while in Fig. FIG. 173. THE WOODWORTH TREAD. 177 the tractive portion is composed of flat links which are claimed to be easier on the rubber of the tire tread and to hold more effectively. Of the various means of securing traction in mud or snow which may be extemporized, or made at short notice, probably the best is to take short lengths of old hose pipe, preferably steam or heavy pneumatic hose, cut to just go around tire and rim. Through these rope of a FIG. 174. diameter about an eighth of an inch less than that of the inside of the hose is passed, and these are tied over the tire and to the spokes (see Fig. 291 178). These secure a very good grip for the wheel and at the same time are elastic enough so that they can do no harm to the tire. Another good idea is to take an old outer cover and cut it into sections about 6 to 8 inches long. Leather straps are riveted or sewed to the ends of these, as shown in Fig. 179. Several of these sections may be put over the shoe, and strapped firmly to rim and spokes. In use, the drag of the road on the tire bends the sec- tion backward against the shoe, and the snow, packing up against it, also helps in the gripping effect. Probably the commonest and simplest way, particu- larly in case of an emergency, is to wrap the wheel with heavy rope. This is very effective, especially in deep snow, does not injure the tires, and if carefully used is not particularly dangerous. But it must be watched very closely, otherwise the rope, which wears quite rapidly, FIG 175 w ''l break and become entangled in some part of the MICHELIN mechanism of the car. Hence, in using rope, it must be ANTI-SKID discarded when it begins to show considerable wear. TIRE I* should be applied as shown in. Fig. 180, using not more than five turns, and putting the ends on the outside of the wheel. The same rope may be used for several successive days by repeatedly shifting it to distribute the wear. In regard to the use of such gripping devices, it may be said in general that since they always detract somewhat from the smooth running and speed of the machine, and since a car may often be driven for days at a time without any great in- convenience from slipping, it is just about as well to run without anything of the sort except when it is actually needed. A car should always be provided with some sort of "creepers," however, to be put on in case of an un- looked for stall. Very often a single grip on one wheel is sufficient to get the car started, for by reversing till the grip is next the ground on the back side, and then driving forward, the wheel acquires considerable velocity in slipping almost an entire revolution, and consequently the grip strikes the road surface with an energetic kick which seldom fails to start the car. Sometimes, in case of a stoppage where rope is not at hand, the car may be rescued by winding a leather strap about the tire, or even by using several turns of insulated wire such as is often carried in the tool box. FIG. 176. ZIG-ZAG CHAIN. 292 How to Avoid Skidding. (H. H. BROWN.) The general rule in case of a skid is to steer slightly in the opposite direction from which the skid tends to head the car. As to the use of 177. Fox CROSS CHAINS AND SIDE CHAINS. brakes, the general rule is to use them sparingly, if at all, where skidding occurs or is likely to occur, but rather to allow plenty of time and let the car speed die down gradually and to use a brake which acts on the rear wheels direct and not on the differ- ential or propeller shaft. Supposing a case where the rear skids toward the right curb, the machine will be headed toward the left. Therefore, following the rule, the wheel should be turned to the right. The only exception to this would be in the case of a tendency for the car to move bodily to the right owing to excessive crowning of the road. In this latter case it might possibly be advisable to steer to the left to regain the crown, although even in this -instance the skid will probably have altered the direction sufficiently for this purpose. As to the use of the brake, it is questionable whether in this instance FIG, 178. USE OF RUBBER HOSE AS TIRE GRIPS. FIG. 179. SECTIONS OF OLD TIRE COVERS AS TIRE GRIPS. FIG. 1 80. USE OF ROPE TO SECURE TRACTION. 293 it is wise to even throw out the clutch or slacken the speed of the motor, for it is necessary to get the machine moving in the direction of its length before it can be steered to the right to be straightened out. As soon as the car is moving in the direction of its length and properly answering the wheel, then, of course, the clutch may be thrown out and the brake applied with judgment, if necessary. The three rules to be observed on slippery streets are: Steer small, use brakes sparingly, if at all, and either keep far enough away from the curb, so that in case of a skid the machine will not strike it, or keep as close as possible, so that in case it does strike the momentum of the car toward the curb will be small and the blow glancing. 294 USEFUL CHARTS AND TABLES. Vehicle Speed Charts. The following chart or diagram permits of instantly determining the vehicle speed in miles per hour when the engine speed in revolutions per minute, the ratio of reduction from the engine to the road wheels, and the wheel diameter are known. The use of the chart may be illus- trated by an example. Suppose it is required to find the speed a car will run at when the engine turns at 900 r. p. m., the gear reduction is 3 and FIG. 181. GEAR RATIO AND VEHICLE SPEED CHART. 295 the road wheels are 30 inches in diameter. The ordinary method of calculation is as follows: The circumference is 30X3.1416 = 94.248 inches, The speed of revolution of the road wheels is 95? =300 r. p. m. The distance covered by the road wheels in one minute is therefore 300X7.854 = 2,356.2 feet, and in one hour 60X2,356.2=141,372 feet, which is equal to I iI > ^I^ ^26^ miles (approx.). 5,280 By means of the chart this result may be arrived at by locating the point on the lower horizontal scale denoting the engine revolutions, then passing vertically upward until intersecting the inclined line representing the gear ratio, then horizontally to the right (or the left, as the case may be), until intersecting the inclined line representing the wheel diameter, then vertically upward to the upper horizontal scale, where the miles per hour at which the vehicle will run under these conditions may be read off. The method of use is indicated by the sketch in the lower right hand corner of the chart. A Gear Ratio Table. (F. E. WATTS.) Accompanying is a table which has proven very useful in transmission calculations. The method of using is almost self evident, still a few words of explanation may not be out of place. The values in columns 5, 6, 7, 8 and 9 make no allowance for tire slip or compression; doubtless some of the speedometer makers could supply data on these points if they were needed for exact calculations. In order to secure the gear ratio required between the engine and rear wheels under any given conditions, the usual method of procedure is to assume a normal piston speed in feet per minute, obtain from this the number of revolutions per minute of the engine, and select from the table the value for the particular wheel diameter and the desired car speed. The ratio of this value to the engine revolutions will be the gearing ratio to be divided among chain, gears, etc. For instance : Assume 28 inch wheels, 5 miles per hour on first speed, and 800 revolutions per minute with 5 inch stroke, the piston speed being 666 feet per minute. Value from table (column 5) is 60.025. Gear ratio is 800-^-60.025 = 13.3; or the engine revolves 13.3 times for each revolution of the wheels on first speed. Column 10 gives the tangential pull in pounds at the tires due to I horse power, the full wheel diameter being assumed and no compression on tires considered; from these figures can be obtained the pull acting on the chain or bevel gears by multiplying by the wheel diameter and dividing by the pitch diameter of the sprocket or gear. 256 30MI>COO( SSSSSSSSS ioeo 10 inJ- Is s So" w *u g iBiilsisSssi gs o _v o i : i ? ki a -I s. I 297 Column ii gives the energy in foot pounds which I pound will possess due to motion at the given speeds; these values would be decreased by friction and by air resistance. Multiplying them by the weight of the car in pounds will give a measure of the energy which must be absorbed by the brakes or in order to- stop the car. Dividing this last quantity by 778 will give the heat in British thermal units which the brakes must get rid of, and show why so many brakes "burn up." For example: At 20 m. p. h. to stop a car weighing 2,500 pounds loaded would require 2,500X13.36 = 33,400 foot pounds, and 33,400-^-779 = 43 British thermal units must be absorbed by the brakes, bearings and wind resistance. The values in column 4 are exact, and the others are near enough for most practical work. The values for i mile per hour form a compact table for a pocket notebook, since from them any value in the table may easily be found. The Measurement of Grades. There is considerable misunderstanding current as to the method of measuring road grades and a general tendency to overestimate the incline of hills. The matter, however, is a very simple one. Grades are usually measured on a percentage basis, and this percentage is the ratio of the vertical distance climbed to the length of the horizontal distance traveled. A horizontal base line is assumed originating at the commencement of the incline, and all grades are referred to this. If a perpendicular is erected to this horizontal line, the distance along it from its base to the point where it intersects the grade itself is the rise. The ratio of this vertical rise to the length of the base line from its beginning to the foot of the perpendicular is the measure of the grade. Of course, the ratio of the difference in height between two neighboring perpendicu- lars, to the horizontal distance between them, is the measure of the grade. Tf two perpendiculars be chosen 100 feet apart and one of them be 20 feet and the other 30 feet in height, the rise in the 100 feet of horizontal distance is 10 feet and the grade is one of 10-100 or 10 per cent. Horse Power Formulae. The following considerations enable one to form some idea of the maximum horse power which may be expected to be obtainable from any four cycle gasoline vehicle engine. Let n be the number of cylinders (working on the Otto or four cycle principle) ; d, the piston diameter in inches ; /, the length of piston stroke in inches; N, the number of crank revolutions per minute; P, the mean effective pressure in pounds per square inch in- the cylinder during the power stroke, and e the efficiency factor. Then the horse power developed will be: 7854 ^ ^2 v 2.X 12 X 33,000 The values of P and e are not known without experiment. P, the mean effective pressure during the explosion stroke, varies with the com- pression used, but 70 pounds per square inch is a conservative figure. The value of e, the mechanical efficiency, depends upon the quality of the workmanship on the engine and should be about .75. Substituting these two values in the above equation and reducing we have rl. d'X/X N X M r. - 19,200 This formula, of course, applies only when the motor is running at about its most advantageous speed. Usually this speed is such that /xN = about 4,800 (that is, 800 revolutions per minute for a motor of 6 inches stroke, or 1,200 revolutions per minute for a motor of 4 inches stroke). The formula then reduces to H. P. =s!l_S' 4 As some manufacturers use as high as 80 or 90 pounds compression and others only 50 to 60, it is evident that there must be quite wide variations in the power obtained by the different makers. 500 600 700 800 FIG. 182. ENGINE HORSE POWER CHART. Piston Speed in Feet Per Minute. To determine the horse power per cylin- der of a gasoline engine, locate the point on the left-hand scale corresponding to the stroke; proceed to the right until inter- secting speed line; proceed up or down until intersecting the "bore" line; then con- tinue to the right and read off the horse power on the vertical scale at the right. 299 In order to estimate the horse power of a motor, the diameter of a piston in inches should be squared and the product multiplied by the number of cylinders. This result, when divided by 4, gives an estimate of the horse power of any four cycle gasoline motor when running with a piston speed of 800 feet per minute and a mean effective pressure of 70 pounds per square inch. The accompanying diagram, Fig. 182, is calcu- lated on the basis of a mean pressure of 70 pounds per square inch. A. L. A. M. Formula. This formula was adopted by the mechanical branch of the Association of Licensed Automobile Manufacturers, and is believed to represent very closely the output of a good average engine at a piston speed of 1,000 feet per minute. By running at a considerably higher piston speed it is 'possi- ble to get more power from an engine of given cylinder dimensions, but the high speed is a disadvantage in itself. The formula is as follows : Horse power per cylinder = bore in inches squared, divided by 2^. Thus a cylinder of 5 inch bore will develop 5x5 + 2*4 = 10 horse power. Assuming a four cylinder motor, its total output should thus be 40 pounds. The length of stroke does not enter as long as the piston speed remains the same. Piston speed in feet per minute is obtained by multiplying the length of the stroke in inches by the number of revolutions per minute made by the motor and dividing the product by 6. Thus an engine having a 5 inch stroke running at 1,200 revolutions per minute.possesses a piston speed of 5 x 1,200 H- 6 = 1,000 feet per minute. It will be observed that the A. L. A. M. rating gives very much higher results than does the formula just developed above. This is partly on account of the higher piston speed assumed in the former formula, and partly due to other assumptions upon the part of its framers. The A. L. A. M. formula, while conventional in its nature, rather than rational or directly empirical, possesses the advantages of simplicity and of having been very widely adopted. As a matter of fact, there is no formula as yet developed which is capable of accurately evaluating the horse power of any individual motor taken at random. 300 INDEX A * * Bearing Cap, Repairing a Broken 243 PAGE Bearing Oils 125 Accumulator, The 34 Blocking Up a Car 134 Accumulators, Care of 43, 190 Body Hoist, How to Make a 221 Accumulators, Derangements of 40 Brake Drum, Truing Up a 276 Accumulators, Ignition 45 Brake Failure, What to Do in Case of. Accumulators, Laying Up of 181 200, 204 Adapters for Double Ignition Systems. 261 Brakes, Adjustment of 186 Adjusting the Carburetor 108 Brakes, Care of Electric Vehicle 207 Adjusting Valves 255 Brakes, Dragging 134 Air Leaks and Their Effects 271 Brakes, Inspection of 165 Air Leaks, Symptoms of 273 Brakes, Intelligent Use of 200 Air Valve, Floating Ball . 101 Brakes, Testing the 195, 200 A. L. A. M. Rating 300 Brakes, Effect on Tires 140 Alcohol Anti-Freeze Solutions 288 Brasses, Fitting 239 Alternating Current Magnetos 60 Brass Parts, Dull Finish for 283 Ammeter, The 65 Bright Parts, Treatment of 182 Ammeter, Use of Electric Vehicle.... 208 Bushings, Refitting 264 Ampere, The 6 Anti-Freeze Solutions 285, 286 ^^ Anti-Skid Devices for Tires 290 ^^ Asbestos Fabric, Use of 275 Calcium Chloride Anti-Freeze Solution. 280 Assembling a Motor 264 Capacity, Electrical 4 Atwater Kent SparR Generator 62 Carbon Deposits, Removal of 274 Automatic Air Valve, The 99 Carbonization, Loss of Power from... 171 Automatic Carburetors 98 Carbonization, Preventing 274 Axle, Straightening a Bent 280 Carbonization of Oils 120, 125 Axle Bearings, Inspection of 184 Carburation 91 Axles, Adjustment of 185 Carburation Difficulties in Winter 284 Axles, Inspection of 166 Carburetor, The 97 Carburetor, Action of the 99 Carburetor, The Automatic 98 Carburetors, Derangements of 105, 173 Babbitt, Expanding 242 Carburetor, Freezing of 108 Babbitting Shaft Bearings 241 Carburetor, The Mechanically Con- Backfiring, Cause of 113 trolled 102 Ball Bearings, Lubricant for 127 Carburetor, The Multiple Jet 104 Battery, The Storage 34 Carburetor, The Vaporizing Tube 102 Battery Auxiliary for Magneto 74 Carburetors, Artificial Heating of 101 Battery Ignition Systems, Special 62 Carburetor Adjustment 108 Battery Ignition Systems, Locating De- Carburetor Floats, Defects of 106, 111 fects in 80 Cars, Hints on Washing 223 Battery Switches, Defects in 83 Caulking 257 Batteries 7 Cell, Electric 7 Batteries, Electric Vehicle 208 Chains, Cleaning and Lubricating 177 Batteries, Use With Magnetos 50 Chains, Inspection of 185 Batteries, Paralleling 81 Chains, Lubrication of 126 Batteries, Reserve 80 Chains, Tire 290 Batteries, Testing of 66 Chains and Sprockets, Care of 176 Bearings, Adjustment and Renewal of. 237 Chains and Sprockets, Repairing Old.. 179 Bearings, Adjustment of Engine 187 Chain Tools 178 Bearings, Rebabbitting 241 Charging Connections 48 Bearings, Seizing of 119 Charging Accumulators from Primary Bearings, Testing for Play in 262 Cells 48 I INDEX Continued. PAGE Charging Storage Cells 38 Charging Vehicle Batteries, When Re- quired 209 Cleaning Tops, Instructions for 224 Clincher Tires, Attaching and Detach- ing 136 Clouding of Windshields, Prevention of 226 Clutch, How to Engage the 198 Clutches, Adjustment of 196 Clutches, Care of 173, 192 Clutches, Gripping of 174 Clutches, Multiple Disc 176 Clutches, Slipping of 175 Clutches, Spinning of 175 Clutch Brake, How to Make a 277 Clutch Leathers, Treatment of 168 Coasting, Gear Setting for 134 Coasting, Instructions for 204 Coasting, Saving Fuel by 204 Coils, Current Consumption of 68 Cold Chisels 236 Cold Test of Lubricants 124 Cold Weather, Effects on Gasoline 112 Common Salt Anti-Freeze Solution 289 Commutators, Care of Electric Vehicle. 206 Compressed Air for Drawing Gasoline. 95 Compression, Its Influence on Fuel Economy 115 Compression, Loss of 265 Compression, Testing the 186, 266 Compression Leaks, Locating 267 Condenser, Electrical 5, 15 Conductors 3 Cone Clutch, Fitting a Leather to a.. 275 Cone Clutches, Care of 173 Connecting Rod Bearings, Refitting. 238, 243 Connections of Jump Spark Apparatus. 68 Contact, Time of 27 Contacts, Defective 82 Contact Spark System, The 75 Controllers, Care of Electric Vehicle.. 207 Cooling System, Cleaning out 188 Cooling System, Defects in 171 Cooling System, Draining the 180 Cooling System, Inspection of 165 Cracked Water Jackets, Repairing 250 Crane, How to Make a 222 Crank Pins, Smoothing Up 239 Crank Pin Bearings, Refitting 238 Crank Shaft, Truing Up a 263 Crating of Cars for Shipment 227 Current, Electric 4 Current Tap, The 47 Cut Shafts, Repairing 278 Cylinder Heads, Leaks in 271 Cylinder Oil, Selection of 123 Cylinders, Order of Firing 75 Cylinders, Reboring 263, 269 Cylinders, Replacing Damaged 270 Cylinders, Scored 269 PAGE Decarbonizer, Use of 275 Defects in Ignition Systems, Location of 80 Denatured Alcohol Anti-Freeze Solu- tion ...288 Demountable Rims 159 Demountable Rims, Replacing Tires on 163 Demountable Rims, Tools for 162 Demountable Rims in Practice 161 Depolarizers 8 Derangements of Magnetos 57 Differential Case, Inspection of 184 Direct Current Magnetos 59 Disassembling a Motor 262 Distance Rods, Overhauling 185 Distance Rods, Adjustment of 166 Distributor, The 28 Distributor, Magneto 53 Distributor System, Connections of... 69 Double Ignition Systems 75 Double Ignition Systems, Adapters for. 261 Drifts 236 Driving Instructions 197 Driving Gears, Adjustment of 185 Driving Pinion, Repairing a Broken.. 279 Dry Cell, The 29 Dry Cells, Ammeter Tests of 66 Dry Cells, Deterioration of 68 Dry Cells, Methods of Connecting 32 Dry Cells, Purchasing 190 Dry Cells, Short Circuits in 31 Dual System of Ignition, The 56 Dual System of Ignition, Connections for 74 Dynamo Ignition Generators 61 Dynamos, Self Regulating Ignition... 62 Dynamos, Use in Vehicle Lighting 62 Electric Current, Chemical Effects of. 5 Electric Vehicles, Care and Mainten- ance of 205 Electric Vehicles, Lubrication of 206 Electric Vehicle Batteries, Charging and Care of 208 Electric Vulcanizers 154 Electrical Generators, Chemical 7 Electrical Measuring Instruments 65 Electrical Principles 3 Electricity, Properties of 3 Electro-chemical Equivalent 6 Electrolyte, Spilling of 210 Electrolyte for Storage Cells 36 Electrolytes 5 Electromagnetic Induction 10 Electromotive Force 4 Emergency Tire Sleeves 150 Engine, Assembling an 264 INDEX Continued. PAGE Engine, Inspection of 166 Engine, Overhauling an 262 Engine, Running in an 166 Engine, Significance of Stalling 195 Engine, Starting the 197 Engine Bearings, Adjustment of 187 Engine Derangements 170 Engine Lubrication, Inspection of 166 Engine Lubrication, Methods of 128 Engine Speeds, Car Speeds With Vari- ous 295 Fierce Clutches 174 Filtering Gasoline 96 Fires, Extinguishing Gasoline 93 Fire Precautions 226 Firing of Cylinders, Order of 75 Flash Test of Oils 124 Flywheel, Removing a. 244 Flywheel, Resetting a Loose 245 Force Feed Lubricators 129 Foreign Shipment, Crating Cars for... 231 Frame, Trussing a Weak 280 Friction, Excessive Engine 135 Friction, How to Locate Abnormal... 133 Friction, Rolling and Sliding 119 Fuel Economy and Its Significance... 113 Funnel for Gasoline 97 Garages, Heating and Ventilating 217 Garages, Plans for Private 213 Garage Contrivances 221 Gasoline, Composition and Properties of 92 Gasoline, Density of 92 Gasoline, Density Scale 88 Gasoline, Effects of Cold on 112 Gasoline, Explosive Mixtures of. 93 Gasoline, Filtering of 96 Gasoline, Foreign Matter in 107 Gasoline, Precautions in Handling. .94, 95 Gasoline, Safety Cans for 93 Gasoline, Source of 91 Gasoline, Storage and Handling of 93 Gasoline, Taking on 197 Gasoline, Underground Storage of.... 94 Gasoline Fires, Extinguishing 93 Gasoline Funnel and Filter 97 Gasoline Leaks 105, 196 Gasoline System, Draining the 181 Gasoline System, Flushing Out 189 Gasoline System, Inspection of 168 Gasoline Separator 97 Gasoline Storage and Dispensing Sys- tems 95 Gasoline Supply, Automatic Variation of 103 Gear Box, Care of 191 Gear Box, Lubricant for 126 Gear Changing, Instructions for Gear Ratio Table Gear Ratios, Speeds With Various Gears, When to Change Gear Shifter, Bushing a Gear Teeth, Repairing Broken Glycerine Anti-Freeze Solution Glycerine and Potassium Carbonate So- lution Governor Driven Magnetos Grades, Measurement of Gradometer, Use of Graphite, Used on Inner Tubes Graphite as a Lubricant Grating Sounds, Significance of Gravity Feed Oiling Grinding Valves 186, Grease Grease Cups, Use of Grounds in Wiring H Hammers Heat, Electrical Heating Garages Heating of Moving Parts Heating of Tires Heat Supply for Carburetors High Speed, Destructive Effects of... High Tension Ignition High Tension Magnetos High Tension Magneto Connections... "Homo" Fuel Mixer Horn, Intelligent Use of the. '. Horse Power Chart Horse Power Formulae Horses, How to Meet Restive Hydrometer, The Hydrometer, Use on Vehicle Batteries. Hydrometer Scales Hydrometer Syringe Hydrometer Tables PAGE 199 296 295 199 277 279 106 152 127 194 181 255 125 127 SI 6 217 134 145 101 203 13 53 72 101 202 299 211 87 Igniters, Care of 167 Igniters, Contact Spark 25 Ignition 3 Ignition Accumulators, Care of 45 Ignition Accumulators, Charging of.. 46 Ignition Connections 68 Ignition, Defects in 170 Ignition, Double Systems of 75 Ignition Dynamos 61 Ignition, High Tension 13 Ignition, Low Tension 13, 75 Ignition, Synchronized 71 Induced Currents, Curves of 15 Induction Coil 12, 13 Induction, Electromagnetic 10 IIT INDEX Continued. Induction, Mutual 12 Induction, Self 11 nductor Type Magnetos.. 51 nflation Pressure of Tire on 145, 146 nlet Manifolds, Defective 274 nner Tubes, Care of Spare 142 nspection of Cars 164 nspection During Stops 196 nspection Lamp 132 nsulators 3 Jump Spark System, Simple 18 Jump Spark System, The 13 K Kerosene, Use in Cylinders ..181, 186 Kerosene, Its Use as a Decarbonizer. . 274 Knocking, Causes of 193 Knocking Due to Spark Position 200 Lamp, Inspection 132 Laying Up a Car for the Winter 179 Leakage of Gasoline 115 Leaks of Air into Intake 271 Leaks in the Gasoline System 105 Leaks, Gasoline 196 Leaky Pistons 187 Lines of Force, Magnetic 9 Lining a Cone Clutch 275 Low-High Tension Magnetos 53 Low-High Tension Magneto Connec- tions 73 Low Tension Ignition 13, 75 Low Tension Magnetos 59 Lubricants, Automobile 121 Lubricants, Effect of Heat on 120 Lubricants, Testing of 120 Lubrication, Cold Weather Precautions Regarding 285 Lubrication of Electric Vehicles 206 Lubrication of Engines 128 Lubrication, General Instructions on.. 127 Lubrication, Importance of 131 Lubrication of Minor Parts 133 Lubrication, Theory of 118 Lubrication System, Inspection of 167 Lubricators, Care of 191 Lubricators, Force Feed 129 Lubricators, Pressure Feed 131 M Magnetic Plug System 78 Magnetic Vibrator 18 Magnetism 8 Magnetization, Electric. . .' 9 Magnets, Permanent 9 PAGE Magnets, Properties of 8 Magneto, The 49 Magneto, Circuit Connections for High Tension 72 Magneto, Circuit Connections for Low- High 73 Magneto, Fitting a, to Opposed Motor. 260 Magneto, The High Tension 53 Magneto, Inductor Type 51 Magneto, The Low-High Tension 53 Magneto, Rotating Armature Type 51 Magneto, The Synchronous 50 Magneto Make and Break, The 52 Magnetos, Alternating Current 60 Magnetos, Care of 191 Magnetos, Derangements of 57 Magnetos, Direct Current 59 Magnetos, Governor Driven 61 Magnetos, Low Tension 59 Magnetos, Non-Synchronous 59 Magnetos, Timing of 55 Make and Break Devices 52 Make and Break Ignition 75 Master Vibrator Ignition System 71 Mats, Preserving Rubber 283 Measuring Pump for Gasoline 95 Mechanical Controlled Carburetors 102 Mechanical Homogenizing Devices.... 101 Mechanical Ignition Generators 49 Missed Explosions, Detecting 193 Missing, How to Locate and Correct.. 172 Mixture, Causes of Badly Proportioned. 110 Mixture, Causes of Too Lean Ill Mixture, Its Dependence upon Suction. 100 Mixture, Preheating the 101 Motor, The (See Engine) Motor Generators 46 Mud Guards, Injury to Tires by.. 140 Muffler, Choking of 116 Multiple Coil Ignition Connections 69 Multiple Jet Carburetor, The 104 Multiple Series Connections 33 Mutual Induction 12 N Non-Freezing Solutions 285, 286 Non-Synchronous Magnetos 59 Nuts, Methods of Fastening 281 Nuts, Removing Refractory 282 Nuts, Tightening of 183 Nuts, Working Loose of 165 Ohm Ohm's Law 6 Oil as an Anti-Freeze Solution 289 Oil, Cylinder 123 Oil, Detrimental Effect on Tires * 141 Oil Feeds, Adjusting 13 Oiling Systems, Care of 191 IV INDEX Continued. PAGE Oiling Systems, Engine 128 Oils for Bearing Lubrication 125 Oils, Carbonization of 120, 125 Oils, Desirable Properties of 120, 122 Oils, Flash and Cold Tests of 124 Oils for Gear Boxes 126 Oils, Storing and Handling of 132 Overhauling a Motor 262 Overhauling Cars 183 Overheating, Causes of 194 Overheating a Cause of Knocking. . . . 193 Overrich Mixtures, Causes of 110 Oxidizing Brass Parts 282 Pantasote Tops, Cleaning 224 Paralleling Batteries 81 Peining 246 Piston Pin, Reboring Hole for 247 Piston Rings, Inspection of 268 Piston Rings, Renewing 256,264 Piston Speed, Computation of 300 Pistons, Leaks Past 187, 268 Polarity, Test for 47, 208 Polarization 7 Popping in Carburetor, Significance of. 113 Potential, Difference of 4 Precautions Against Fire 226 Pressure Feed Lubricators 131 Pressure Feed Systems, Defects in 112 Pressure, Mean Effective 300 Primary Circuit Connections 26 Pumps, Tire 146, 152 Punctures, Patching 148 Q Quick Detachable Tires 155 R Radiators, Washing Out 188 Railroad Crossings, Looking Out for.. 201 Rate of Charge of Vehicle Batteries. . 209 Rating Engines, Methods of 298 Rectifier, The Mercury 49 Refitting Bearings 237 Repair Suggestions 234 Reserve Batteries 80 Resistance 3 Reverse Latch, How to Make a 277 Rim Cutting 148 Rims, Demountable 159 Rough Roads, Comfort on 203 Rules of the Road, Observance of 201 Running Gear, Inspection of 165 Running in a Motor 265 Rust, Effect on Tires 144 PAGE Safety Cans for Gasoline 93 .Scales, Hydrometer 87 Screwdrivers 235 Secondary Commutators 28 Seizing of Bearings 119 Self Contained Oiling System, The 128 Self Induction 11 Shaft, Repairing a Cut 278 Shipment of Cars, Instructions on 227 Short Circuits in Wiring 84 Single Coil and Distributor System... 69 Skidding, How to Avoid 200, 293 Slipping of Clutches 175 Smooth-On, Repairing Cracks with 254 Soap, Danger of Using Too Much 224 Soldering 252 Sounds, Significance of Various 194 Spare Parts 168 Spark Advance Cause of Knocking... 193 Spark Coil 13 Spark Generator, The Atwater Kent . . 62 Spark Plug, The 17 Spark Plug, Construction of 21 Spark Plugs, Inspection of 167 Spark Plugs, Low Tension 78 Spark Plugs, Non-Sooting 23 Spark Plugs, Repairing 86 Spark Plugs, Sooting of 22 Spark Plugs, Testing 85 Spark Regulation, Instructions on 199 Spark Regulation, Principle of 26 Spinning of Clutches 175 Splash System of Lubrication 128 Springs, Inspection of 166 Spring Leaves, Lubrication of 183 Sprockets, Reversal of 185 Squeaking Noises, Significance of .... 194 Stalled Car, How to Extricate a 205 Starting the Motor 197 Starting a Motor in Cold Weather.. 284 Steering Gears, Care of Electric Vehicle 207 Steering Gears, Inspection of 164 Steering Gears, Overhauling of 183 Stones, Effect on Tires 141 Stops, Inspection During 196 Storage Battery, The 34 Storage Battery, Floated on the Line.. 61 Storage Batteries, Cleaning Vehicle... 211 Storage Batteries, Ignition 45 Storage Batteries, Summarized Instruc- tions on 212 Storage Batteries, Testing Vehicle 211 Storage Cells, Care and Repair of 43 Storage Cells, Charging 38 Storage Cells, Derangements of 40 Storage Cells, Durability of 38 Storage Cells, Testing with Voltmeter. 67 Storage Cells, Voltage of 35 Storage and Handling of Gasoline 93 INDEX Continued. Street Cars, Avoiding Collisions with. 202 Sulphatation, Prevention of 212 Supplies to Be Carried 169 Switches, Defects in Battery 83 Synchronized Ignition 71 Testing Dry Cells 66 Throttle, Control of Car by.. 198, 200, 203 Timer, The 21 Timer, Care of the 28, 190 Timer, Magneto Type 16 Timer, Roller Contact 27 Timers, Defects in 81 Timing Gears, Quieting Worn 260 Timing of Magnetos 55 Timing of Valves 256 Tire Chains 290 Tire Pumps 146, 152 Tire Repair Outfit, The 150 Tire Sleeves, Emergency 150 Tire Tools 151 Tire Treads, Non-Slipping 290 Tire Valves, Defects in 146 Tires 136 Tires, Affected by Oil 141 Tires, Affected by Rust 144 Tires, Anti-Skid Devices for 290 Tires, Attaching and Detaching Clincher 136 Tires, Care of Electric Vehicle 208 Tires, Care of Spare 143 Tires, Causes of Wear 138 Tires, Detecting Deflated 195 Tires, Effects of Improper Attachment. 143 Tires, Heating of 145 Tires, Jacking Up 147 Tires, Inflation Pressure for 145, 146 Tires, Injured by Abrupt Starting 141 Tires, Injured by Bad Wheel Align- ment 139 Tires, Injured by Brakes 140 Tires, Injured by Mud Guards 140 Tires, Inspection of 165 Tires, Quick Detachable 155 Tires, Rim Cutting of 143 Tires, Road Repairs of 148 Tires, Should Not Be Run Deflated 142 Tires, Slow Leaks in 146 Tires, Steel Studded 290 Tires, Tractive Effort of 297 Tires, Treatment of Cuts in 149 Tires, Vulcanizing 148, 153 Tires, Winter Storage of 182 Tops, Methods of Cleaning 224 Tool Box Equipment 234 Traction, Emergency Methods for In- creasing 291 Traction Increasing Devices Transmission, Inspection of. PAGE . 290 . 167 u Unisparker, The 62 Universal Joint, Temporary Repair of. 279 V Valve Actions, Clearance in 258 Valve Adjustments 255 Valve Caps, Effect of Leaky 273 Valve Derangement, Its Influence on Fuel Economy 115 Valve Guide, Restoring a Broken 247 Valve Guide, Seating a 249 Valve Guides, Effect of Worn 272 Valve Mechanism, Adjusting the 188 Valve Stem Wear, Overcoming 259 Valve Tappets, Noiseless 259 Valves, Care of 255 Valves, Detecting Leaks in 267 Valves, Grinding of 186, 255 Valves, Setting 256 Vaporizing Tube Carburetor 102 Vehicle Batteries, Running Voltage of. 210 Vehicle Speed Chart 295 Ventilating Garages 217 Venturi Tube, Use of 101 Vibrator, The Magnetic 18 Vibrators, Adjustment of 20, 82, 190 Vibrators, Care of 167 Vibrators, Defects in 82 Volt 6 Voltage of Vehicle Batteries 210 Voltammeter, The 66 Voltmeter, The 65 Vulcanizer, How to Make a Steam 153 Vulcanizers, Electric 154 Vulcanizing Tires 148 W Washing Car Before Laying It Up.. 182 Washing Cars, Hints on 223 Waste of Fuel, Causes of 114 Watching a Car on the Road 192 Water Jacket, Patching a Broken 253 Water Jackets, Repairing Cracked 250 Weak Mixture, Causes of Ill Wheel, Emergency Repair of a Broken. 281 Wheels, Improper Alignment of 139 Wheels, Speeds with Various Sizes of. 295 Wind Shields, How to Clean 226 Winter Use of Cars 180, 284 Wiring, Defects in 83 Wood Alcohol Anti-Freeze Solution 288 Working Loose of Nuts 165 Wrenches, Special 235 VI A Trial Subscription for The Horseless Age will con- vince you that it is worth every cent of the two dollars we receive for it. Every week it gives, be= side the news of the week, reli= able descriptions of new cars and parts ; many valuable technical articles ; also a resume of legis= lation affecting motorists. It gives the automobile owner and the engineer just the infor- mation they need it is absolutely independent and unprejudiced, and states nothing but facts. Subscription price, six months (trial), $1.00; one year, $2.00. Single copies, 10 cents. THE HORSELESS AGE MOTOR HALL,' 250 WEST 54th ST. NEW YORK " The Bosch Magneto is the make that others try to equal in quality." Springfield Republican. More than 150 makers of Ameri- can cars equip with Bosch Mag- neto. More than 87 per cent, of high grade American cars are so ' equipped, and a proportionate number of motorcycles, motor boats and aeroplanes. Inform yourself, and when buying you'll always specify " Bosch Ignition." A copy of " The Bosch News," an illustrated magazine, will be sent on request. Bosch Magneto Co. 223-225 W. 46th St., New York Chicago Branch : San Francisco Branch : 1253 Michigan Ave. 357 Van Ness Ave. Detroit Branch : 870 Woodward Ave. TL THE LIBRARY UNIVERSITY OF CALIFORNIA Santa Barbara THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW. If your dealer hasn't MONOGRAM OIL, write COLUMBIA LUBRICANTS CO. OF NEW YORK 116 BROAD STREET NEW YORK CITY I ; SOUTHERN REGIONAL LIBRARY FACIl A 000 587 567 9 HOMO More Power Less Gasoline Steady Pull More Speed Less Vibration Less Heat , Makes a four cylinder run like a six cylinder on the gasoline consumed by a two cylinder A MEANS OF PERFECT CARBURATION Everyone who has driven an Automobile, a M9tor Boat or a Motorcycle, has I observed that the power and smooth running qualities of gasoline engines dimin- ish at a rate out of all proportion to the diminished speed. This is partly due l to the difficulty of so constructing a carburetor as to maintain the proper pro- portion of gasoline spray to air under varying conditions. But there are two other elements which enter into this problem of the hydro- carbon engine, namely; EVAPORATION and HOMOGENEITY The more thorough the evaporation ration of the gasoline spray, the more easily is re even the distribution of the gasoline in the \ i the air carbureted;" and th f carbureted air, the greater the efficiency of the explosion. The HOMO is a demonstrable solution of the difficulties presented in the case of these two important factors. The HOMO consists of a housing or casing so constructed as to be inserted between the carburetor and the intake manifold of the engine. Inside of this housing is a mesh wheel which revolves upon annular ball bearings. This wheel is composed of fan blades and wire mesh of a given degree of coarseness. The mixture of gasoline spray and air in the carburetor is drawn by the engine through this mesh-fan-wheel. The fan blades cause the wheel to revolve at high speed, and the mixture must pass through the flying mesh, which, by violent impact, breaks up the particles of gasoline and enforces evaporation. In the consequent agitation, the air be- comes evenly carbureted with this evaporated gasoline. THE INCREASED POWER 25 to 40 PER LESS GASOLINE AND LESS HEAT RESULT IS PER CENT. 25 to 40 PER CENT. 2 o 40 . Ihe excess of gasoline required, where the carbureting is not thoroughly and own the power and causes heat because of homogeneously accomplished, T^?f expansion due to slower combustion. This is eliminated. INCREASED SPEED Because of quicker expansion due to more rapid com- bustion. LESS GEAR CHANGING Because you can "stay on the high," with the in- creased power, at low speeds LESS VIBRATION Because of the even explosions. LESS VALVE GRINDING Because of reduced heat and impossibility of getting raw gasoline on the valves. GET DESCRIPTIVE MATTER, INOW ! GASOLINE MOTOR EFFICIENCY COMPANY ] 3 EXCHANGE PLACE, JERSEY CITY, N. J., U. S. A.