L« * s • • » ^ O w o ' V-^ °o y ^ *' O N o ^ O.V s • • . -^^^ ^ (V " c '^ ^^ «. ♦ • '^o A ^0,* j^ ^^ WW<' / \ '.% •5> .° K^ Farm Implements AND FARM MACHINERY, AND THE Principles of their Construction and Use : WITH EXPLANATIONS OF THE Laws of Motion and Force as Applied on the Farm. WITH OVER THREE HUNDRED ILLUSTRATIONS BY. JOHN J . ^^H03 MAS. NEW EDITION, REVISED AND ENLARGED. 1 fJ^ 'J «,'OFCo/vg;p; , :;,50 " One 2000 " 5000 " One and a quarter 3000 " 7500 " Oi'« and a half 4500 " 12,500 *• STRENGTH OF MATERIALS. 31 TIio38 results will vary about one-fourth with the qual- ity of common hemp. Manilla is about one-half as strong as the best hemp. The latter stietches one-iifth to one- seventh before breaking. Wood is about seven to twenty times stronger when taken lengthwise with the fibres than when a side force is exerted, so as to split it. The splitting of timber or wood for fuel is, however, accomplished with a comparatively small power by the use of wedges, tlie force of heavy blows, and the leverage of the two parts. The attraction of cohesion is very weak in liquids ; it is sufficient, however, to give a round or spherical shape to very small portions or single drops, and to furnish a beautiful illustration, on a minute scale, of the same prin- ciple which gives a rounded form to the surface of the sea. In one case, cohesion, by drawing toward a common centre, forms the minute globule of dew upon the blade of grass ; in the other, gravitation, acting in like manner, but at vast distances, gives the mighty rotundity to the rollinor waters of the ocean. CAPILLARY ATTRACTION. Capillary attraction is a species of cohesion ; it takes place only between solids and liquids. It is this which holds the moisture on the surface of a wet body, and which prevents the water from running instantly out of a wet cloth or sponge. By touching the lower extremity of a lump of sugar to the surface of water in a vessel, capillary attraction will cause the water to rise among its grarmles and moisten the whole lump. It may be very distinctly shown by placing the end of a fine glass tube into water; the water will rise in it above the level of the surrounding surface. If the bore of the tube be the twelfth of an inch 82 MECHANICS. in diameter {a, fig. 15,) it will rise a quarter of an inch; if but the twenty-fifth of nn inch in bore, as b, it will rise half an inch; but if only a fiftieth of an inch, the water will rise an inch. This ascent of the liquid is caused by the attra,ction of the inner surface of the tube, until the weight of the column becomes equal to the force of the attraction. Capillary attraction may be also exhibited by Fig. 16 Capillary attractioyi in Uibes. Capillarij attraction hrtireen tiro panes of two small plates of glass, ])laced with their edges in wai ter, in contact on one side, and a little open at the other side, as in fig. 16. As the faces of the } dates apr proach eacli other, the water rises higher, forming the curve, a. Capillary attraction performs many important offices in nature. The moisture of the soil depends greatly upon its action. If the soil is composed of coarse sand or grav- el, the interstices are large, and, like the larger glass tube, will not retain the rain which falls upon it. Such soils are, therefore, easily worked in Avet weather, but become too dry in seasons of drought ; but when the texture is finer, and especially if a due proportion of clay be mixed with the sand, the interstices become exceedingly small, and retain a full sufficiency of moisture. If, how^ever, there is too much clay, the soil is apt to become close and compact, and the water can not enter until it is broken up EARTH A DESERT AVITIIOUT CAPILLARY ATTRACTIOX. 33 or pulverized. It is for tliis reason that subsoil plowing becomes so eminently beneficial, by deepening the mellow portion, and thus affordmg a larger reservoir, which acts like a sponge in hokling the excess of f ilUng rains, until wanted in the dry season. For the same reason, a well- cultivated soil is found to preserve its moisture much bet- ter during the heat of summer than a hardened and neg- lected surface. If capillary attraction should cease to exist, the earth would soon become a barren and uninhabitable waste. The moisture of rains could not be retained by the parti- cles of the soil, but would immediately sink far down into the earth, leaving the surface at all times as dry and unproductive as a desert; vegetation would cease; brooks and rivers would lose the gradual supplies Avhich the earth affords them through this influence, and become dried up ; and all plants and all animals die for want of drink and nourish- ment. Thus the. very existence of the whole human race evidently depends on a law, ap- parently insignificant to the unthinking, but pointing the observing mind to a striking proof of the creative design m hich planned all the works of nature, and fitted them with the utmost exactness for the life and comfort of man. Ap]iiir/ifas ex- plaining the risitig of sap. ASCENT OF SAP. The following interesting experiments serve to explain the cause of the ascent of sap in plants and trees : Take a small bladder, or bag made of any similar sub- stance, and fasten it tightly on a tube open at both ends (fig. 17) ; then fill them with alcohol up to the point C, and immerse the bladder into a vessel of water. The al- cohol will immediately rise slowly in the tube, and if not 2* 34 MECHANICS. more than two or three feet high, will run over the top. This is owing to tlie capillary attraction in the minute pores of the bladder, drawing the water within it faster than the same attraction draws the alcohol outward. One liquid will thus intrude itself into another with great force. A bladder filled with alcohol, with its neck tightly- tied, will soon burst if plunged under water. If a blad- der is filled with gum-water, and then immersed as before, the water will find its way vv^ithin against a very heavy pressuie. In this manner sap ascends through the minute tubes in the body of trees. The sap is thickened like gum-water wlien it reaches the leaves, and a fresh supply, therefore, enters through the pores in the spongelets of the roots by capillary attraction, and, rising through the stem, keeps up a constant supply for the wants of the growing tree. CENTRE OF GRAVITY. The centre of gravity is that point in every hard sub- stance or body, on every side of which the different parts exactly balance each other. If the body be a globe or Fig. la round ball, the centre of /' \^ gravity will be exactly at the g'^ J^.,^"""'^'^ centre of the globe; if it be a rod of equal size, it will be at the middle of the rod. If a stone or any other sub- stance rest on a point directly under the centre of gravity, it will remain balanced on this point ; but if the point be not under the centre of gravity, the stone will f:ill toward the heaviest side. Some curious experiments are perforaaed by an ingenious management of the centre of gra^vity. A light cylinder of cork or pasteboard contains a concealed piece of lead, g (fig. 18). The lead, being heavier than the rest, will CENTRE OF GRAVITY. EXPVERTMENTS. 35 cause the cylinder to roll up an inclined plane, when placed as shown by the lower figure on tlie preceding en- graving, until it makes half a revolu- ^ jg tion and reaches the place of the up- per figure, when it will remain sta- tionary. If a curved body, as shown in fig. 19, be loaded heavily at its ends, it wall rest on the stand, and present a singular appearance by not falling, the centre of gravity lying between the two heavy portions on the end of the stand. A light stick of some length may be made to stand on the end of the finger, by sticking in two penknives, so as to bring tlie centre of gravity as low as tlie finger-end (fig. 20), If any body, of whatever shape, be suspended by a hook or loop at its top, it will necessarily hang so that the centre of gravity shall be di- rectly under the hook. In this way the centre in any substance, no matter how irregular its shape may be, is ascertained. Sup- pose, for instance, we have the irregular plate or board shown in the annexed Fig. 21. figure (fig. 21) : ' ^"^ Body singularly hntnnced by lead kiwhs. Fig. 20. first hang it by the hook a, andcff^ / — the centre of Centre of gravity maintained by tu^o penknives. gravity Avill be somewhere in the dotted line a b. Then hang it by the hook e, and it will be somewhere in the line c d. Now the point e, where they cross each other, is the only point in both, conse- 36 MECHANICS. quently this is the centre sought. If the mass or body, instead of being ilat like a board, be shapeless like a stone or lump of chalk, holes bored from different suspending points directly downward will all cross each other exactly at the centre of gravity. LINE OF DIRECTION. Fig. 22. Centre of gravity on level aiid inclined roads. An imaginary line from the centre of gravity perpendic- ularly downward to where the body rests is called the line of direction. Now in any solid body whatever, whether it be a wall, a stack of grain, or a loaded Avagon, the line of direction must fall within the base or part resting upon the ground, or it will immediately be thrown over by its own weight. A heavily and even- ly loaded wagon on a level road will be perfectly safe, be- cause the line of direction falls equally between the wheels, as shown in fig. 22, by the dotted line, c, being the centre. But if it pass a steep side- hill road, throwing tiiis line outside the wheels, as in fig. 23, it must be instantly overturned. If, however, instead of the higti load represented in the figure, it be some very heavy material, as brick or sand, so as not to be higher than the square box, the centre will be much lower down, or at 5, and thus, the line falling within the wheels, the load will be safe from upsetting, unless the upper wheel pass over a stone, or the lower wheel sink into a rut. The centre of gravity of a large load may be nearly ascer- tained by measuring with a rod ; and it may sometimes happen that by measuring the sideling slope of a road, all of which may be done in a few minutes, a teamster may save himself from a comfortless upsetting, and perhaps CENTRE OF GRAVITY. LOADING WAGONS. 37 heavy loss. Again, a load may be temporarily placed so much toward one side, while passing a sideling road, as to throw the line of direction considerably more np hill than nsual, and save the load, which may be adjusted again as soon as the dangerous point is passed. This princijjle also shows the reason why it is safer to place only light bundles of merchandise on the top of a stage-coach, while all heavier articles are to be down near the wheels ; and why a sleigh will be less likely to npset in a snow- drift, if all the passengers will sit or lie on the bottom. When it becomes necessary to build very large loads of hay, straw, wool, or other light substances, the " reach," or the long con- necting-bar of the wngon, must be made longer, so as to increase the length of the load Fig. 24. Fig. 25. Centre of gravity of an even and one-sided load. ; for, by doubling the length, two tons may be piled upon the wagon with as much security ffom upsetting as one ton only on a short wagon. Where, however, a high loaiiiiiiii»iiiiii«ii^^ thin wedsje, on which the balance turns almost without friction. Small balances have been so skillfully constructed as to turn with one-thousandth part of a grain. 2. Levers of the second kind are less numerous, but not uncommon. A handspike used for rolling a log is an ex- ample. A wheel-barrow is a leverof the second kind, the fulcrum being the point where the wheel rests on the ground, and the weight the centre of gravity of the load. Hence, less exertion of strength is required in the arm when the load is placed near the wheel, except where the ground is soft or muddy, when it is found advantageous to place the load so that the arm shall sustain a consider- able portion, to prevent the wheel sinking into the soil. A two-wheeled cart is a similar example ; nnd, for the same reason, when the ground is soft, the load should be placed forward toward the horse or oxen ; on the other hand, on a smooth and hard, or on a plank road, the load should be 48 MECHANICS. more nearly balanced. An observance of this rule would often save a great deal of needless waste of strength. A sack-barrow, used in barns and mills for conveying heavy bags of grain from one part of the floor to another, Fig. 45. and in warehouses for boxes, is a lever nearly intermediate between the first and second kind, the weight usually rest- ing very nearly over the fulcrum or wheels. When the bag of grain is thrown forward of the wheels, it be- comes a lever of the first kind ; Avhen back of the wheels, it is a lever of the second kind. As it is used only on hard and smooth floors, and not, like the wheel-barrow, on soft earth, the more nearly the load is placed directly over the wheels, the more easily they will run. 3. In a lever of the third kind, the weight being further from the fulcrum than the power, it is only used where great power is of secondary importance when com- pared with rapidity and dispatch. A hand-hoe is of this class, the left hand acting as the fulcrum, the right hand as the power, and the resistance overcome by the blade of the hoe as the weight. Ahand-raks is similar, as well as a fork used for pitching hay. Tongs are double levers of this kind, as also the shears used in shearing sheep. The limbs of animals, generally, are levers of the third Suck-barroiv. ESTIMATIXG THE POWEK OF LEYEKS. 49 kind. The joint of the bone is the fulcrum; the strong muscle or tendon attached to the bone near the joint is the power; and the weight of the limb, with whatever re- sistance it overcomes, is the weight. A great advantage Jesuits from this contrivance, because a slight contraction of the muscle gives a swift motion to the limb, so import- ant in walking and running, and in the use of the arms. ESTIMATING THE POWER OF LEVERS. The power of any lever is easily calculated by measuring the length of its two arms, that is, the two parts into Fig. 46. which it is divided by ,.'^'^'" the weioht, fulcrum, --- ' ^--'""ir ' ^" Tr and power. In a 'f- ,:-,--'"' "^ leverof the first kind, ."'' if the weight and uter of m first kind. power be equally dis- tant from the fulcrum, they will move through equal dis- tances, and nothing will be gained ; that is, a power of 100 pounds will lift a weight of 100 pounds only. If the power be twice as far as the weight, its force will be doubled; if three times, it will be tripled; and so forth. In a lever of the second kind, if the weight be equidistant between the fulcrum Fig. 47. and power, the power ';"^--r,-;:.-_ Avill move through ;' ; "^'^^'----c-^,,^ twice the distance of ' I ;^* ^ , the weight, and the ^^ p\ power of the instru- Lever of the second kind. meiit will therefore be doubled ; if twice as far, it will be tripled, and so on, as shown in the annexed figures. The same mode of reasoning will explain precisely to what extent the force is diminished in levers of the third kind. These rules will show in what manner a load borne on a polo is to be placed between two persons carrying it. 3 50 MECHANICS. lono^er. For the same leason Fis;. 48, If equidistant between them, each will sustain a like por- tion. If the load be twice as near to one as to the other, the shorter end will receive doubJe the weight of the when three horses are worked abreast, the two horses placed together should have only half the length of arm of the main whiffle-tree as the single horse, fig. 48. The farmer who has a team of two horses un- like in strength, may thus easily know how to adjust the arms of the whiffle-tree so as to correspond with the strength of each. If, for instance, one of the horses possesses a strength as much greater than the other as four is to three, then tlie weaker horse should be attached to the arm of the whiffle- tree made as much longer than the other arm as four is to three. In all tlie preceding estimates, the influence of the weight of the lever has not been taken into consideration. In a lever of the first kind, if the thickness of the two arms be so adjusted that it will remain balanced on the fulcrum, its weight will have no other effect than to in- crease the pressure on the fulcrum ; but if it be of equal size throughout, its longer arm, being the heavier, will add to its power. The amount thus added w^ill be equal to the excess in the weight of this arm, applied so far along as the centre of gravity of this excess. If, for ex- ample, a piece of scantling twelve feet long, a b, fig. 49, Fiff. 49, COMBINATION OF LEVERS. 51 be used as a lever to lift the corner of a building, then the two portions, a c, c c?, will mutually balance each other. If these be 'each a foot in length, the weight of ten feet will be left to bear down the lever. The centre ^of gravity of this portion will be at e, six feet from the fulcrum, and it will consequently exert a force under the building equal to six times its own weight. If the scant- ling weigh five pounds to the foot, or fifty pounds for the excess, this force will be equal to three hundred pounds. In the lever of the second kind, its weight operates against the moving power. If it be of equal size through- out, this will be equal to just one-half the weight of the lever, the other half being supported by the fulcrum. With the lever of the third kind, the rule applied to the first must be exactly reversed. COMBINATION OF LEVERS. A great power may be attained without the inconven- ience of resorting to a very long lever, by means of a cowz- j,j„ 5Q hinatlon of levers. In fig. : . -y/ 50, the small weight P, act- fe-. ; /K ^ ' lA© ijig ^s a moving power, ex- ^ ^ erts a three-fold force on the next lever ; this, in its turn, acts in the same degree on the third, which again increases the power three times. Con- sequently, the moving })ower, P, acts upon the weight, W, in a twenty-seven-fold degree, the former passing through a space twenty- seven times as great as the latter. A combination of levers like this is employed in self- regulating stoves. It is in this case, however, used to multiply instead of to diminish motion. The expansion of a metallic rod by heat the hundredth part of an inch acts on a set of iron levers, and the motion is increased, by the time it reaches the draught-valve, to about one hundred times. 52 MECHANICS. Fisx. 51. A more compact arrangement of compound levers is shown in fig. 51, where the power, P, acts on the lever A, exerting a force on the lever B five times as great as the power. B acts on the lever C with a force increased three times, and this, again, on the weight, W, with a four-fold force. Multiplying 5, 3, and 4 together, the prod- uct is 60 ; hence a force of one pound at P will support 60 pounds at W. By gradu- ating (or marking into 1^ \ notches) the lever C, so that Compound levers. the distance is measured as the weight is moved along it, a compact and powerful steelyard for weighing is formed. WEIGHING MACHINE. A vahiable combination of levers is made in the con- struction of tlie weighing machine, used for weighing cat- tle, wagons loaded with hay, and other heavy articles. Fijr. 52. Weighing Machine. The wagon rests on the platform A (fig. 52,) and this platform rests on two levers at W, W, which presses their other ends both on a central point, and this again bears on THE WEIGHING MACHINE. 53 Fi*?. 53. the lever D, the other end of which is connected by means of an upriglit rod with the steelyard at F. There are two important points gained in this combina- tion. In the first place, the levers multiply the power so much that a few pounds' weight will balance a heavy load of hay weighing a ton or more ; and, in the next, the load resting on both the levers, communicates the same force of weight to the central point, from whatever part of the platform it hap- pens to stand on : for if it presses hardest on one lever. Portable Platform Scale. it bears lighter, at a cor- responding rate, on the other. In practice, there are Fig. 54. Large Platform Scale. always two pairs^or four levers, which proceed from each 54 MECHANICS. Fig. 55. corner of the platform, and rest on one point at tlie centre. We have taken the two only, to simplify the explanation. A powerful stump-extracting machine, allowing a suc- cession of efforts in the use of the lever, is exhibited by fig. 55. The lever, a, should be a strong stick of timber, furnished with three massive iron hooks, secured by bolts passing through, as represented in the figure. Small or truck wheels are placed at each end of the lever, merely for the purpose of moving it easily over the ground. The stump, h, used as a fulcrum, has the chain passing round near its base, while another ch.iin passes over tlie top of the stump, c, to be torn out. A horse is at- tached to tlie lever Lever Stump Machine. at wer. Where a cord is passed over a single fixed wheel, as in fig. 66, or over two or more wheels, no power is gained, Ftg. 66. the moving force being the same in 17 velocity as the w^eight. Such pulleys are sometimes, however, of use by altering the direction of the force. The latter is applied with advantage to unloading or j) itching hay by means of a horse-power, saving much time and labor, as explained on a future page. Among the many applications of the pulley, one is shown in the ac- companying figure (fig. 67) rep- resenting Packer's Stone Lifter^ for raising large boulders from the soil, w^eighing from one to four and five tons, and afterwards placing them in walls. It is also employed for tearing out small or partly decayed stumps. The usefulness of the pulley depends mainly upon its lightness and port- Fig. 67. able form, and the facility with which it may be made to operate in al- most any situation. Hence it is much Used in building, and is extensively applied in the rig- ging of ships. In Packer's Stone Lifter. the computation of its power there is a large drawback, not taken into account in the preceding calculation, which mateiially lessens its advantage; this is the friction of the wheels and blocks and the stiffness of the cordage, THE INCLIXED PLANE. 63 which are often so great that two-tliirds of the power is lost. THE INCLINED PLANE. The mclmed plane or slope possesses a power which is estimated by the proportion which its length bears to the height. If, for example, the plane be twice as long as the perpendicular height, then in rolling the body a up the inclined plane (fig. 68), it will move tiirough twice the distance required to lift it directly from h to c. Therefore only one-half the strength else inquired need be exerted for this purpose. The same reasoning Fig. 68. will apply to any other proporti(m q between the height and length ; that is, the more gradual or less steep the slope becomes, the greater 1) will be the advantage gained. A familiar example occurs 'in liftinjr a loaded barrel into a wac^on : the lono-er the plank used in rolling it, the less is the exertion needed. A body, in rolling freely down an inclined plane, acquires the same velocity that it Avould attain if dropped perpen- dicularly from a height equal to the pei*pendicular height of t4ie plane. Thus, if an inclined plane on a plank road be 100 yards long and 16 feet high, a freely rimning wagon, left to descend of its own accord, will move 32 feet per second by the time it reaches the bottom, that being the velocity of a stone falling 16 feet. Or, a rail- car on an inclined plane 145 feet high will attain a speed of 96 feet per second, or more than 65 miles an hour, at^ the foot of the plane, which is equal to the velocity of a stone falling three seconds, or 145 feet. ASCENT IN KOADS. All roads not perfectly level maybe regarded as inclined planes. By the application of the preceding rule, we 64 MECHAXICS. may discover precisely how much strength is lost In draw- ing heavy wagons up hill. If the load and wagon weigh a ton, and the road rise one foot in height to every five feet of distance, then the increased strength required to draw the load will be one-fifth of its weight, or equal to 400 pounds. If it rise only one foot in twenty, then the increase in power needed to ascend this plane will be only 100 pounds. The great importance of preserving, as nearly as practicable, a perfect level is obvious. There nre many roads made in this country, rising over and descending hills, which might be made nearly level by deviating a little to the right or to the left. Suppose, for example, that a road be required to connect the two points Fie:. 69. Bnules b tl__ W-'-xk^-^^' 3rr a and h (fig. 69), three miles apart, but separated by a lofty hill midway between them, and one mile in diameter. Passing half a mile on either side would entirely avoid the hill, and the road thus curved would be only one hundred and forty-eight yards, or one-twelfth of a mile longer. The same steep hill is ascended perhaps fifty to five hundred times a year by a hundred different farmers, expending an amount of strength, in the aggregate, sufficient to elevate ten thousand tons annually to this height, as a calculation will at once show — more than enough for all the increased expense of making the road level. It is interesting and important to examine how much further it is expedient to carry a road through a circuitous level course than over a hill. To ascertain this point, we must take into view the resistance occasioned by the rough surface or soft material of the road. Roads vary greatly THE RESISTANCE OF ROADS. 65 in this particular, but the following may be considered as about a fair average. In drawing a ton weight (including wagon) on freely running wheels, on a perfect level, the strength exerted will be found about equal to the follow- ing : On a hard, smooth plank road 40 pounds. On a good Macadam road 60 " On a common good bard road 100 " On a soft road about 200 " Now let US compare this resistance to the resistance of drawing up hill. First, for the plank road — forty pounds is one-fiftieth of a ton ; therefore a rise of one foot in fifty of length will increase the draught equal to the resistance of the road. Hence the road might be increased fifty feet in length to avoid an ascent of one foot ; or, at the same rate, it might be increased a mile in length to avoid an ascent of one hundred and five feet. But in this estimate the increase in cost of making the longer road is not taken into account. If making and keeping in repair be equal to three hundred dollars yearly per mile, and one hundred teams pass over it daily, at a cost for traveling of four cents each per mile, being four dollars daily, or twelve hundred dollars per annum, then the cost of making and repair would be one quarter of the expense of traveling over it. Therefore the mile should be diminished one quarter in length to make these two sources of expense counterbalance each other. Hence a road with this amount of travel should, with a reference to public accommodation, be made three-fourths of a mile longer to avoid a hill of one hundred and five feet. This estimate applies to loaded teams only. For light car- riaores the advantasres of the level road would not be so great. One-half to five-eighths of a mile would, there- fore, be a f lir estimate for all kinds of traveling taken together 66 MECHANICS. The following table shows the rise in a mile of road for different ascents : For a rise of 1 foot in 10, the load ascends 528 feet per mile. do. do. 13, do. 406 do. do do. 15, do. 352 do. do. do. 20, do. 204 do. do. do. 25, do. 211 do. do. do. 30, do. 176 do. do. do. 35, do. 151 do. do. do. 40, do. 133 do. do. do. 45, do. 117 do. do. do. 50, do. 106 do. do. do. 100, do. 53 do. do. do. 125, do. 42 do. The same kind of reasoning applied to a common good road will show that it will be profitable for the public to travel about half that distance to avoid a hill of one hundred and five feet. In this case the whole yearly- cost of the road, including interest on the land, and the cost of repairs, would not usually be more than a tenth part of the same cost for plank, or would not exceed thirty dollars. On rail-roads, where the resistance is only about one- fifth part of the resistance of plank roads, the dispropor- tion between the draught on a level and up an ascent be- comes many times greater. Thus, if a single engine move three hundred and fifty tons on a level, then two engines will be required for an ascent of only twenty feet pei mile, four engines for fifty feet per mile, and six engines for eighty feet per mile. Such estimates as these merit the attention of the farmer in laying out his own private farm roads. It may ^ be worthy of considerable effort to avoid a hill of ten or twenty feet, which mu>^t be passed over a hundred times yearly with loads of manure, grain, hny, and wood. The greatly increased resistance of soft materials, also, is too rarely taken into account. A few loads of gravel, well applied, would often prevent ten times the labor in plow- form: and materials for roads. 67 ing through deep ruts, to say nothing of the breaking of harness and wagons by the excessive exertions of the team. FORM AXD MATERIALS FOR ROADS. The depth of the mud in common roads is often un- necessarily great, in consequence of heaping together with the plow and scraper the soft top-soil for the raised Ficr. TO. / / '// /W/ //'//// Section of badly frnmied road. carriage-way. When heavy rains fall, this forms a deep bed of mud, into which the wheels work their way, and cause extreme labor to the team. A much better way is to scrape oft* and cart away into the fields adjoining all the soft, rich, upper surface, and then to form the harder subsoil into a slightly rounded carriage-way, with a ditch on each side. Such roads as this have a very hard and firm foundation, and they have been found not to cut up Ficr. 71. Section of wellfm'tiied road. into ruts, nor to form much mud, even in the wettest sea- sons. On this hard foundation six inches of gravel will endure longer and form a better surface than twelve inches on a raised "turnpike" of soft soil and mud. It frequently happens that the form of the surface in- creases the quantity of mud in a road, by not allowing the water to flow off freely. The earth is heaped up in a high ridge, but having little slope on the top (fig. 70), where the water lodges, and ruts are formed, the only dry portions being on the brink of the ditches, where the water can escape. Instead of this form, there should be a gradual inclination from the centre to the ditches, as shown in fior. 71. This inclination should not exceed 1 68 MECHANICS. foot in 20. On liill-sides the slope should all be toward the higher ground, as in fig. 72. Hard and durable roads are made on the plan of Telford. Their foundation is rounded stones, placed upright, with the ^smaller or sharper ends upward. The smaller stones ' \ Fig. 72. Section of ivad for hillsides. are placed near the sides, and the larger at the centre, thus giving to the road a convex form. The spaces are tlien filled in with small broken stone, and the whole covered with the same material or with gravel. The pressure of wagons crowds it compactly between the stones, and forms a very hard mass. IMPORTANCE OF GOOD ROADS. The principles of road-making should bs better under- stood by the commuidty nt large. Farmers are deeply interested in good roads. Nearness to market, and facili- ties for all other kinds of communication, are worth a great deal, often materially afiecting the price of land and its products. The difference between traveling ten miles through deep mud, at two miles per hour, with half ^1 load, and traveling ten miles over a fine road, at five miles per hour, with a full load, should not be forgotten. " In the absence of such facilities," says Gillespie, " the richest productions of nature waste on the spot of their growth. The luxuriant crops of our western prairies are sometimes left to decay on the ground, because there are no rapid and easy means of conveying them to market. The rich mines in the northern part of the State of New GOOD AND BAD ROADS. 69 York are comparatively valueless, because the roads among the mountains are so few and so bad, that the expense of the transportation of the metal would exceed its value. So, too, in Spain it has been known, after a succession of abundant harvests, that the wheat has actually been allowed to rot, because it would not repay the cost of carriage." Again, " When the Spanish government re- ' quired a supply of grain to be transferred from Old Castile to Madrid, 30,000 horses and mules wei'e necessary for the transportation of four hundred and eighty tons of wheat. Upon a broken-stone road of the best sort, one-hundredth of that number could easily have done the work." He further adds, in speaking of the improvements in roads made by Marshal Wade, in the Scottish Highlands, *' His military road is said to have done more for the civilization of the Highlands than th6 preceding efforts of all the British monarchs. But the later roads, under the more scientific direction of Telford, produced a change in the state of the people which is probably unparalleled in the history of any country for the same space of time. Large crops of wheat now cover former wastes ; farmers' houses and herds of cattle are now seen where was previously a desert ; estates have increased seven-fold in value and annual returns ; and the country has been advanced at least one hundred years." THE WEDGE, The wedge is a double inclined plane, the power being hpplied at the back to urge it forward. It becomes more and more powerful as it is made more acute ; but, on ac- count of the enormous amount of friction, its exact power can not be very accurately estimated. It is nearly always urged by successive blows of a heavy body, the momentum of which imparts to it great force. All cutting and piercing instruments, as knives, scissors, 70 mecha:mcs. cliisels, pins, needles, and awls, are wedges. The degree of acuteness must be varied according to circumstances ; knives, for instance, which act merely by pressure, may be made with a much sharper angle than axes, which strike a severe blow. For cutting very hard substanttes, ns iron, the edge must be formed with a still more obtuse angle. The utility of the wedge depends on the friction of its surfaces. In driving an iron wedge into a frozen or icy stick of wood, as every chopper has observed, the want of sufficient friction causes it immediately to recoil, unless it be previously heated in the fire. The efficacy of nails depends entirely on the friction against their wedge-like faces. THE SCREW The screw may be regarded as nothing more than an Fig. 74 inclined plane winding round the surface of a cylinder (fig. 74). This may be easily under- stood by cutting a piece of paper in such a form that its edge, a h (fig. 75), may represent the inclined plane ; then, beginning at the wider end, and wrapping it about the cylindrical piece of wood, c, the iipper edge of the paper will represent the thread of the screw. Althousrh the friction attendincr the use of the screw is considerable, and without it it would not retain its place, yet the slope of its in- pi^ -5 clined thread being so gradual, it possesses It great power. This power is multiplied to a still greater degree by the lever which is usually employed to drive it, a (fig. 76). If, for example, a screw be ten inches in circumference, and its thread half an inch apart, it exerts a force twenty THE SOllEW. 71 times as great as tlie moving power. If it be moved by a lever twenty times as long as the diameter of the Fig. 76. screw, here is another increase of twenty times in force. Multiplying 20 by 20 gives 400, the whole amount gained by this combination, and by which a man applying one hundred pounds in force could exert a pressure equal to twenty rii'^ngi^^MnnniE?! tons. About one-third or one-fourth of ^MimiiMTiiTiii ihii ii i' i iiii^Niihh i this shoidd, however, be deducted for friction. When the screw is combined with the wheel and nxlc (fig. 77), it is capable of exerting great power, which may be readily calculated by multiplying the power of the screw and its lever into the power of the wheel and axle. Hcrtw and lever combined. THE KNEE-JOIISTT POWER. Fig. 77. The hnee-joint or toggle-joint is usually regarded as a com- pound lever, and consists of two rods connected by a turn- ing joint, as represented in fig. 78. The outer end of one of the levers is fixed to a solid beam, and the other connected with a movable block. When the joint a is forced in the direc- tion indicated by the arrow, it produces a powerful pressure upon the movable block, which in- creases as the lever approaches a straight line. This is easily understood by the rule of virtual velocities, for the force moves with a velocity many times greater than the Sci'ew, lever ^ and wheel combined: Knee-joint power. 72 MBCHA]S1CS. power given to tlie block, and this relative difference in- creases as the joint is made straighter. This power is made use of in the lever printing-press, wheie the greatest force is given just as the pressure is completed. Another example occurs in the Lever Wash- ing-machine (fig. 79), which is worked by the alternating motion of the handle, A, pressing a swinging board, per- Fi<'. 79. Lever Washing-machine. forated with holes, with great force against the clothes next to one side of the water-box. Like the printing- press, this machine exerts the greatest power just as the motion of the lever is completed, and at the time it is most needed. The same principle is exhibited in KendaWs Cheese-press (fig. 80), where the lever and the wheel and axle are combined with the two knee-joints, one on each side of the press, drawing down a cross-beam upon the cheese with a greatly multiplied power. D tele's Cheese-press (fig. 83), operates on a similar piinciple. Figs. 81-2 show the structure of its working LEVE i: '\\-AS II IXG-MACIIIXE. Fi"-. 80. 73 Fig. 82. KendaWs Cheese-press. part, the dotted lines indicating tlic position of the lever, "Nvhich is inserted into a roller or axle, and, by turning, drives the movable iron blocks asunder, and raises tlie cheese against the broad screw-head above, as shown in fig. 82. In fig. 81, the raised lever shows that the blocks rjo-. 81. ^1'® ^t first near together, but are crowded asunder as the lever is press- ed downward. This cheese-press is male of cast-iron, and has great power; to try it, weights were in- creased upon the lever, until the ironi frame broke with a force equal to six- teen tons. The power exerted by a rolling' tnill, where bars of iron are flattened in their passage between two strong rollers, is precisely like that of the knee-joint. The only 4 74 MECHANlCSo FiK- 83. Dick's cast-iron Cheese-press. difference is, that the rollers, whicli may be considered as 3 constant succession of levers coming into play as they re- volve, are both fixed, and consequently the bar has to yield between them (fig. 84). The Fig. 84. greatest power is exerted just as the bar receives the last pressure from the rollers. The most powerful and rapidly- vrorking straw-cutters are those wliich draw the straw pr hay between two rollers, one of which is furnished with knives set around it parallel with its axis, and cutting on the other, which is covered with un- tanned ox-hide (fig. 65), (See page 292. J Principle of the knee-joint in the rolling-milL STRAW CUTTERS. Pig. 85. 75 Hide Holler Straw Cvtter, CHAPTER V. APPLICATION OF MECHANICAL PRINCIPLES IN THE STRUCTURE OF SIMPLE IMPLEMENTS AND PARTS OF MACHINES. In contriving the more difficult and complex macliines, the principles of mechanics must be closely studied, to give every i)art just that degree of strength required, and to render their operation as perfect as possible. But in making tlie more common and simple implements of the farmer, mere guess-work too often becomes the only guide. Yet it is highly useful to apply scientific knowledge even in the shaping of a hoe handle or a plow-beam. The simplest tool, if constantly used, should be formed with a view to the best application of strength. The laborer who makes with a common hoe two thousand 76 MECHANICS. strokes an hour, should not wield a needless ounce. If any part is heavier than necessary, even to the amount of half an ounce only, he must repeatedly and continually lift this half ounce, so that the whole strength thus spent would be equal, in a day, to twelve hundred and fifty pounds, which ought to be exerted in stirring the soil and destroying weeds. Or, take another instance : A farm wagon usually weighs nearly half a ton ; many might be Fi^. 8«. ^^_____ (t I .. Iladly-fcnned/o -a- handle. reduced fifty pounds in weight by proportioning every part exactly to the strength required. How much, then, should we gain here? Every farmer who drives a wagon with its needless fifty pounds, on an average of only five miles a day, draws an unnecessary weight every year equal to the conveyance of a heavy wngon-load to a dis- tance of forty miles. Now a knowledge of mechanical science will often ena- ble the farmer, when he selects nnd buys his implements, to judge correctly whether every pait is properly adapted to the required strength. We shall suppose, for instance, that he intends to purchase a common pitchfork. He finds them differently formed, although all are made of the Fig. 87. Badly-formed fork handle. best materials. The handles of some are of equal size throughout. Some are smaller near the fork, as in fig. 86, and others are largei- at the same place, as in fig. 87. Now, if he understands the principle of the lever, he knows that both of these are wrongly made, for the right hand placed at a is the fulcrum, where the greatest strength is needed, and therefore the one represented by fig. 88 is both stronger and lighter than the others. PRINCIPLES IX THE STRUCTURE OF IMPLEMENTS. 77 Again, hoe handles^ not needing much strength, chiefly require lightness and convenience for graspino-. Hence in selecting from two such as are represented in the annex- ed figures, the one should be chosen which is lightest near Fig. 88. Well-formed fork handle. the blade, nearly all the motion being in that direction, because the upper end is the centre of motion. The right hand, at a, acting partly as the fulcrum, the hoe handle should be slightly enlarged at that place. Fig. 89 rep- resents a well-formed handle ; fig. 90, a clumsy one. Rake handles should be made largest at the middle, or where the right hand ])resses. Rake-heads should be much larger at tlie centre, and tapering to the ends, where the stress is least, the two parts operating as two distinct lev- Fij,'. 89. 0= Well-formed hoe handle. ers, acting from the middle. Wood horse-rakes might be made considerably lighter than they usually are by ob- serving the same principles. The greatest strength requir- ed iov plow-beams is at the junction with the mould-board, and the least near the forward end, or furthest from the fulcrum or centre of motion. Now it may be that the fiirmer who has had much ex- perience may be able to judge of all these things without Fig. 90. ^ p^ _ ■ , ^ Badly-formed lice handle. a knowledge of the science. But this scientific knowledgre would serve to strengthen his experience, and enable him to judge more accurately and understandingly by showing him the reasons ; and in many cases, where new imple- ments were introduced, he might be enabled to form a 78 MECHAXICS. good judgment before he had incurred all the expense and losses of unsuccessful trials. Even so simple a form as that of an ox-yoke is often made unnecessarily heavy. Fig. 91 represents one that is faulty in this respect, by having been cut from a piece of Fifj. 91. timber as wide as tlie dotted lines a c / and being thus weakened, it requires to be correspondingly large. Fig. 9:2 is equally strong, much lighter, and is easily made from a stick of timber only as wide as a b in the former figure. In the heavier machines, it is necessary to know the de- gree of taper in the different pnrts with accuracy. A thorough knowledge of science is needed to calculate this Fis:. 92. with precision, but a superficial idea may be given by cuts. If a bar of wood, formed as in a (fig. 93), be fixed in a wall of masonry, it will possess as nnich strength to sup- port a weight hung on tlie end as if it were the same size throughout, as b. The first is equally strong with the second, and much lighter.* The same form doubled must * The simple style of tliis work precluck'S an explanution of the mode of calculation for determininu; tlie exact form. Where the stick tapers only on one side, it is a common purabola; if on all sides, a cubic parabola. VARIOUS EXAMPLES. 79 be given if the bar is supported at the middle, with a weight at each end, or with the weight at the middle, supported at each end, as c. This form, therefore, is a proi>er one for many parts of implements, as the bars of whiffle-trees, the rounds of ladders, string pieces of bridges, and any cross-beams for supporting weights. The proper form for rake-teeth and fence-posts, the pressure being nearly alike on all parts, is nearly that of a long wedge, or with a straight and uniform taper. Therefore a fence- post of equal size throughout contains nearly twice as much timber as is needed for strength only. The form of these parts must, however, be modified to suit circumstances; as whiflie-trees must be large enough \ '■■" at the ends to receive the iron hooks, wagon-tongues for ironing at the end, and spade handles for the easy grasp of the hand. The axle-trees of wagons must be made not only strong in the middle, or at centre of pressure, but also at the en- trance of the bub ; because the wheels, when thrown side- wise in a rut, or on a sideling road, operate as levers at that point, a and b (fig. 94), show the manner in which the axles of carts may be rendered lighter without lessen- ing the strength, a being the common form, and b the im- proved one. 80 MECIIAISTCS. Sometimes several forces act at once on different parts. For example, the spokes of wngon-wheels require strength at the hub for stiffening the wheel ; they must be strong in the middle to prevent bending, and large enough at Fiff. 94. hub '^^^=^ ^ the outer ends, where they are soonest weakened by de- cay. Hence there should be nearly a uniform taper, slightly larger at the middle, and with an enlargement at the outer end, as c (fig. 94). A very useful rule in practice, in giving strength to structures, is this: The strength of every square beam or stick to support a weight increases exactly as the width increases, and also exactly as the square of the depth in- creases. For example, a stick of timber eight inches wide and four inches deep (that is, four inches thick), is exactly twice as strong as another only four inches wide, and with the same depth. It is twice as wide, and consequently twice as strong ; that is, its strength increases just as the width increases, according to the rule given. But where one stick of timber is twice as deep^ the width being the same, it is four times stronger ; if three times as deep, it is nine times stronger, and so on. Its strength increases as the square of the depth, as already stated. The same rule will show that a board an inch thick and twelve inch- es wide will be twelve times as strong when edgewise as when lying flat. Hence the increase in strength given to whiffie-trees, fence-posts, joists, rafters, and string-pieces to farm-bridges, by making them narrow and deep. CALCULATING THE STRENGTH OF PARTS. 81 Again, the strength of a round stick increases as the cube of the diameter increases ; that is, a round piece of wood three inches in diameter is eisiht times as strong: as one an inch and a \\2\.i in diameter, and twenty-seven times as strong as one an inch in diameter. This rule shows that a fork handle an incli and a half in diameter at the middle is as much stronger than one an inch and a quarter in diameter, as seven is greater than four. Now this rule would enable the farmer to ascertain this without break- ing half a dozen fork handles in trying the experiment, and it would enable the manufacturer to know, without Fi<'. 95. the labor of trying many experiments, that if he makes a fork handle an inch and a linlf at the middle, tapering a quarter of an inch toward the ends, it will enable the workman to lift with it nearly twice as much hay as with one an inch and a quarter only through its whole length. A mode of adding strength to light bars of wood, by means of braces, is shown in fig. 95, representing light whiffle-trees, stiffened by iron rods in a simple manner. The same method is sometimes adopted to advantage in making light fruit ladders, and for other purposes. CHAPTER YI. FRICTION. The subject of fiiction has been postponed, or merely alluded to, to prevent the confusion of considering too many tilings at once. As it has an important influence on the action of machines, it is worthy of careful investigation. 4* 82 MECHANICS. It is familiar to most persons, that when two surfaces slide over each other while pressing together, the minute unevenness or roughness of their surfaces causes some ob- struction, and more or less force is required. This resist- ance is known as friction, ROLLING FKICTION. The term is also applied to the resistance of one body Tolling over another, Tliis may be observed in various degrees by rolling an ivory ball successively over a carpet, a smooth floor, and a sheet of ice; the same force which would imj^el it only a few feet on the carpet would cause it to move as many yards on a bare floor, and a still greater distance on the ice. Tiie two extremes may be seen by the force required to draw a carriage on a deep sandy or loose-gravel road, and on a rail-road. NATURE OF FRICTION. If two Stiff" bristle brushes be pressed with their faces together, they become mutually interlocked, so that it will be quite difficult to give them a sliding motion. This may be considered as an extreme case of fiiction, and serves to show its nature. In two pieces of coarse, rough sandstone, or of roughly-sawed wood, asperities interlock in the same way, but less in degree ; a diminished force is consequently required in moving the two surfaces against each other. On smoothly planed wood the friction is still less; and on polished glass, where the unevenness can not be detected without the aid of a powerful magnifying glass, it is leduced still further in degree. ESTIMATING THE AMOUNT OF FRICTION, In order to determine the exact amount of friction be- tween different substances, the following simple and in* TO ASCERTAIN THE AMOUNT OF FRICTION. 83 genious contrivance is adopted: An inclined plane, a h (fig. 96), is so formed that it may be raised to any desired height by means of the arc of a circle and a screw. Lay a flat surface of the substance we wish to examine upon this inclined plane, and another smaller piece or block of the same substance upon this surface ; then raise the plane until it becomes just steep enough for the block to slide down by its weight. Now, by measuring the degree of slope, we know at once the amount of friction. Suppose, for example, the two surfaces be smoothly-planed wood : it will be found that the plane must be elevated about half as high as its length ; therefore we know, by the Fig. 90. properties of the inclined plane, heretofore explained, that it requires a force equal to one-half the weight of the wooden block to slide it over a smooth wooden surface. Some kinds of wood have more friction than others, but this is about the average.* From the result of this experiment we may learn that to slide any object of wood across a floor requires an amount of strength equal to one-half the weight of the object. A heavy box, for instance, weighing two hundred pounds, can not be moved without a force equal to one hundred pounds. It also shows the impropriety of placing * These experiments may be made with tolerable accuracy, by hook- ing a spring-balance into any object of known weight, and then observ- ii)g the comparative force as measured by the balance, to draw it over a perfectly level surface. 84 MECHANICS. a heavy load upon a sled in winter for crossing a bare wooden bridge or a dry barn floor, the friction between cast-iron sleigh-shoes and rough sanded plank being nearly equal to one-third of the whole weight.* Hence a load of one ton (including the sled) would require a draught equal to more than six hundred pounds, which is too much for an ordinary single team. On bare unfrozen ground the friction would be still greater. On a plank bridge, with runners wholly of wood, it would be equal to half the load. All these facts may be readily proved by actually placing the sled on slopes of plank and of earth, and by observing the degree of steepness required for sliding down by its own weight. In a similar way, we are enabled easily to ascertain the force required to draw a wagon upon any kind of level sui-fice. Suppose, for example, that we wish to determine the precise amount of force for a wagon weighing, with its load, one ton, on a plank road. Select some slight de- scent, where the wagon will barely run with its own weight. Ascertain by a level just what the degree of de- scent is ; then divide the weight of the wagon by the de- gree of the slope, and we shall have the force sought for. To make this rule plainer by an example : It will be found that a good, newly-laid plank track, if it possess a de- scent of only one foot in fifty feet distance, will be suflS- cient to give motion to an easy-rimning wagon ; therefore we know that the strength required to draw it on a level will be only one-fiftieth part of a ton, or forty pounds. The resistance offered to the motion of a wagon by a Macadam road, by a common dry road, and by one with six inches of mud, may be readily determined in the same way by selecting proper slopes for the experiment. If by such trials as these the farmer ascertains the fact that a * On clean hard wood, with polished metallic shoes, the friction irould be much IcaS, or a fourth or tifth. BESTJLTS WITH THE DTNAMOMETEK. 85 few inches of mud are sufficient to retard his wagon so much that it wiJl not run of its own weight down a slope of one foot in four (and few common roads are ever steeper), then he may know that a force equal to one-fourth the whole weight of his wagon and load will be required to draw it on a level over a similar road — that is, the enormous force of five hundred pounds will be needed for one ton, of which many wagons will coTistitute nearly one- half Hence he can not fail to see the great importance, for the sake of economy, and humanity to his team, of providing roads, whether public or pnvate, of the hardest and best materials. RESULTS WITH THE DYNAMOMETER. Another mode of determining the resistance of roads is by means of the Dynamometer.^ It resembles a spring- balance^ and one end is fastened to the wagon and the other end connected with the horses. The force applied is measured on a graduated scale, in the same way that the weight of any substance is measured wiih the spring- balance. ' A more particular description of this instrument will be given hereafter. Careful experiments have been made with the dynamom- eter to ascertain accurately the resistance of various kinds of roads. The following are some of the results : On a new gravel road, a horse will draw eight times as much as the force applied ; that is, if he exerts a force equal to one hundred and twenty-five pounds, he will draw half a ton on such a road, including the weight of the wagon, the road being perfectly level. On a common road of sand and gravel, sixteen times as much, or one ton. On the best hard-earth road, twenty-five times as much, or one and a half tons. • From two Greek words, dunamis, power, and nutreo, to meaiure. 86 MECHANICS. On a common broken-stone road, twenty-five to thirty- six times as much, or one and a half to two and a quarter tons. On the best broken-stone road, fifty to sixty-seven times as much, or three to four tons. On a common plank-road, clean, fifty times as much, or three tons. On a common plank-road, covered thinly with sand or earth, thirty to thirty-five times as much, or about two tons. On the smoothest oak plank-road, seventy to one hund- red times as much, or four and a half to six tons. On a highly-finished stone track-way, one hundred and seventy times as much, or ten and a half tons. On the best rail-road, two hundred and eighty times as mucli, or seventeen and a half tons. The firmness of surface given to a broken-stone road by • a paved foundation was found to lessen the resistance about one-third. On a broken-stone road it was found that a horse could draw only about two-thirds as much when it was moist or dusty as when it was dry and smooth; and when muddy, not one-half as much. When the mud was thick, only about one quarter as much. The character of the vehicle has an influence on the draught. Thus, a cart, a part of the load of which is sup- ported by the horse, usually requires only about two-thirds the force of horizontal draught needed for wagons and carriages. On rough roads the resistance is slightly diminished by springs. On soft roads, as earth, sand, or gravel, the number of pounds draught is but little affected by the speed; that is, the resistance is no greater in driving on a trot than on a walk ; but on hard roads it becomes greater as the velocity increases. Thus a carriage on a dry pavement requires one-half greater force when the horses are on a trot than WIDTH 07 WHEELS. 87 on a walk ; but on a muddy road tlie difference between the two rates of speed is only about one-sixth. On a rail- road, where a draught of ten pounds will draw a ton ten miles an hour, the resistance increases so much at a higli degree of speed as to require a force of fifty pounds per ton at sixty miles an hour — that is, it would require five times as much actual |)Ower to draw a train one hundred miles at the latter rate as at the former; but as the speed is six times as great, the actual force during a given time would be five times six, or thirty times as great. WIDTH OF WHEELS. Wheels with wide tire run more easily than narrow tire, on soft roads ; on bard, smooth roads, there is no sensible difference. Wide tire is most advantageous on gravel and new broken-stone roads, both by causing the vehicles to run more easily, and by improving the surface. For the latter reason, the New York turnpike law allows six-inch wheels to pass at half price, and twelve-inch wheels to pass free of toll. Wheels with broad tire on a fai-m would pass over clods, and not sink between them ; or would only press the surface of new meadows, without cutting the turf But where the ground becomes muddy, the mud closes on botli sides of the rim, and loads the wheels. On clayey soils, narrow tire unfits the roads for broad wheels. For these reasons, broad wheels are decidedly objection- able for clayey or soft soils, and they are chiefly to be recommended for broken-stone roads, and gravelly, or dry, sandy localities. They are also much better for the wheels- of sowing or drilling machines, which only pass over mellowed surfaces. The larger the wheels are made, the more easily they run ; thus a wheel six feet in diameter meets with only half the resistance of a wheel three feet in diameter. A flat piece of wood, sliding on one of its broad sur- 88 MECHANICS. faces, is subject to the same amount of friction as when sliding u])on its edge. Hence the friction is the same, provided tlie pressure be the same, whether the surface be small or large.* Or, in other words, if the surfaces are the same, a double pressure produces a double amount of friction ; a triple pressure, a triple amount, and so on. A narrow sleigh-shoe usually runs m ith least force, for two reasons : first, its forward part cuts wath less resist- ance tlirough the snow ; and, secondly, less force is re- quired to pack the narrow track of snow beneath it. The only instance in which a wide sleigh-shoe w^ould be best, is where a crust exists that would bear it up, and through which a narrow one would cut and tsink down. VELOCITY. Friction is entirely independent of velocity ; that is, if a force of ten pounds is required to turn a carriage wheel, this force \\\\\ be ten pounds, whether the carriage is driven one or five miles per hour. Of course, it will re- quire five times as much force to draw five miles per hour, because five times the distance is gone over ; but, measured by a dynamometer or spring-balance, the pressure would be the same. In precisely the same way, the weight of a stone remains the same, whether lifted slowly or quickly. If the friction of the wheels of a wagon on their axles be equal to ten pounds, driving the horse fast or slowly will not increase or diminish it. But fast driving will require more strength, for the same reason that a man would need more strength to carry a bag of wheat up two flights of stairs than one, in one minute of time. FRICTION AT THE AXLE. A carriage wheel, or any other wheel revolving on an * Generally speaking, this is very nearly correct ; but when the pres Bure is intense, the friction is slightly less on the smaller surface. SIZE OF WHEELS GN ROADS. 89 Fig. 97. axle, will run more easily as the axle is made smaller. This is not owinsc to the rubbing: surfaces beins: less in size, as some mistakenly suppose, for it hns just been shown that tliis makes very little or no difference, pro- ■vided the pressure is the same; but it is owing to tho leverage of the wheel on the friction at the axis ; and the smaller the axle, the greater is this leverage ; for, if the axle, a (fig. 97), be six inches in circumference, and the wheel, b c, be ten feet in circumference, then tlie outer part of the wheel will move twenty times further than tlic part next the axle. Therefore, accord- ing to the rule of Adrtual velocities (already ex- plained,) one ounce of force at the rim of the wheel will overcome twenty o:mces of friction at the axle ; or if the axle were twice as large, then, according to the same rule, it would require two ounces to over- come the same friction acting between larger surfaces. For this reason, l.irge Avheeb in wheel-work for multi- plying motion, if not made too heavy, run with less force than smaller ones, the power acting upon a larger lever. Horse-powers for thrashing-machines, consisting chiefly of a large, light crown-wheel, well stiffened by brace-work, have been found to run v»'ith remarkable ease ; a good example of whicli exists in what is known as Tcdpi?i's horse-power, when made in the best manner. FRICTIOX-WnEELS. On the preceding principle, //•^c^/07^-^^Aee^5 or friction- roUers are constructed, for lessening as much as possible 90 MECHANICS. the friction of axles in certain cases. By this contrivance, the axle, a (fig. 98), instead of revolving in a simple hole Friction-ivheels. Yls. 99. Fig. 98. or cavity, rests on or between the edges of two other wheels. As the axle re- volves, the edges turn with it, and the rubbing of surfaces is only at the axles of these two wheels. If, therefore, these axles be twenty times smaller than the wheels, the friction will be only one-twentieth the amount without them. This contrivance has been strongly recom- mended and con- siderably used for the cranks of grind- stones (fig. 99), but it was not found to answer the intended purpose so well as was expected, for the very plain reason "- that, in using a grindstone, nearly all the friction is at the circumference, or between the stone and the tool, which friction-wheels could not, of course, remove. Grindstone on Friction-wkecls LUBRICATING SUB3TAN0ES. Lubricating substances, as oil, lard, and tallow, applied to rubbing surfaces, greatly lessen the amount of friction, partly by filling the minute cavities, and partly by sepa-" rating the surfaces. In ordinary cases, or where the machinery is simple, those substances are best for this purpose which keep their places best. Finely-powdered black-lead, mixed with lard, is for this reason better for greasing carriage wheels than some other applications. Drying oils, as linseed, soon become stiff by drying, and LC7BRICATING SUBSTANCES. 91 arc of little service. Olive oil, on the contrary, and some animal oils, which scarcely dry at all, are generally pre- ferred. To obtain the full benefit of oil, the application must be frequent. According to the experiments made with great care by Moriii,at Paris, the fiiction of wooden surfaces on wooden surfaces is from one quarter to one-half the force applied; and the friction of metals on metals, one-fifth to one- seventh — varying in both cases with the kinds used. Wood on wood was diminished by lard to about one-fifth to one-seventh of what it was before ; and the friction of metal on metal was diminished to about half what it was before ; that is, the friction became about the same in both cases after the lard was applied. To lessen the friction of wooden surfaces, lard is better than tallow by about one-eighth or one-seventh ; and tal low is better than dry soap about as two is to one. For iron on wood, tallow is better than dry soap about as five is to two. For cast-iron on cast-iron, polished, the friction "with the different lubricating substances is as follows : Water 31 So:ip 20 Tallow 10 Lard 7 Olive oil 6 Lard and black-lead 5 When bronze rubs on wrought iron, the friction with lard and black-lead is rather more than with tallow, and about one-fifth more than with olive oil. With steel on bronze, the friction with tallow and with olive oil is about one-seventh less than with lard and black-lead. As a general rule, there is least friction with lard when hard wood rubs on hard wood ; witli oil, when metal rubs on wood, or metal on metal — being about tlie same in Well-constructed machines for saving human labor by means of horse-labor, when encumbered with little fric- tion, will be found to do about five times as much work for each horse as where the same work is performed by an equal number of men. For example : an active man will saw twice each stick of a cord of wood in a day. 112 MECHANICS. Six horses, with a circular saw, driven by means of a good hors^e-power, will saw five times six, or thirty cords, work- ing the same length of time. In this case the loss by friction is about equal to the additional force required for attendance on the machine. Again : a man will cut with a cradle two acres of wheat in a day. A two-horse reaper should therefore cut, at the same rate, ten times two, or twenty acres. This has not yet been accomplished. We may hence infer that the machinery for reaping has been less perfected than for sawing wood. It should, however, be remembered, that great force is exerted, and for many hours in a day, in cutting wheat with a cradle, and therefore less than twenty acres a day may be regarded as the medium attainment of good reaping-machines when they shall become perfected. Applying the same mode of estimate, a horse-cultivator will do the work of five men with hoes, and a two-horse plow the work of ten men with spades. A horse-rake accomplishes more than five men, because human force ia not strongly exerted with the hand-rake. In using different tools, the degree of force or pres>tfure applied to them varies greatly with the mode in wliich the muscles are exerted. The following table gives the results of experiments with human strength, variously applied, for a short period : Force of the hands Forte of the tool on the tool. on the object. With a drawing-knife 100 1 b». 100 lbs. " a large auger, both hands 100 " about 800 ♦» *' a Bcrew-drivcr, one band 84 '♦ 250 ". " a bench-vice liandle 73 " about 1000 " ** a windlass, with one hand 60 " 180 to 700 " " a hand-saw 36 " 36 ** " a brace-bit, revolvin;; 16 " 150 to 700 " Twisting with thumb and fingers, but- ton-screw, or small screw-driver 14 " 14 to 70 " The force given in the last column will, of course, vai"y BEST WAT TO APPLY STRENGTH. 113 with the degree of leverage applied; for example, the arms of an auger, when of a given length, act with a greater increase of power with a small size than with a large one. This degree of power may be calculated for an auger of any size, by con side ling the arms as a lever, the centre screw the fulcrum, and the cutting-blade as the weight to be moved. The same mode of estimate will apply to the vice-handle, the windlass, and the brace-bit. Every one is aware that a heavy weight, as a pail of water, is easily lifted when the arm is extended downward, but with extreme difficulty when thrown out horizontally. In the latter case, the pail acts wiih a powerful leverage on the elbow and shoulder-joint. For this reason, all kinds of hand labor, with the arms pulling toward or pushing directly from the shoulders, are most easily per- formed, while a motion sidewise or at right angles to the arm is fai; less effective. Hence great strength is applied in rowing a boat or in using :i drawing-knife, and but little strength in turning a brace-bit or working a dasher-churn. Hence, too, the reason that, in tuining a grindstone, the pulling and thrusting part of the motion is more powei'ful than that through the other parts of the revolution. This also explains why two men, working at right angles to each other on a windlass, can raise seventy pounds more easily than one man can raise thirty pounds alone. This principle should be well understood in the construction or selection of all kinds of machines for hand labor. CHAPTER IX. MODELS OF MACHINES. Serious errors might often be avoided, and sometimes gross impositions prevented, by understanding the differ ence between the working of a mere model, on a miniature 114 MECHANICS. Bcale, and the working of the full-sized machine. It is a common and mistaken opinion that a well-constructed model presents a perfect representation of the strength and mode of operation of the machine itself. When we enlarge the size of any thing, the strength of each part is increased according to the square of the^ diameter of that part ; that is, if the diameter is twice as great, then the strength will be four times as great ; if the diameter is increased three times, then the strength will be nine times, and so on. But the weight increases at a still greater rate than the strength, or according to the cube of the diameter. Thus, if the diameter be doubled (the shape being similar), the weight will be eight times greater ; if it be tripled, the weight will be twenty-seven times greater. Hence, the larger any part or machine is made, the less able it becomes to support the still greater increasing: weisjht. If a model is made one-tenth the real size intended, then its different parts, when enlarged to full size, become one hundred times stronger, but they are a thousand times heavier, and so are all the weights or parts it has to sustain. All its parts would move ten times faster, which, added to their thousand-fold weight, would increase their inertia and momentum ten thousand times. For this reason, a model will often work perfectly when made on a small scale ; but when enlarged, the parts become so much heavier, and their momentum so vastly greater, from the longer sweep of motion, as to fail entirely of success, or to become soon racked to pieces. This same piinciple is illustrated in every part of the works of creation. The large species of spiders spin" thicker webs, in comparison with their own diameter, than those spun by the smaller ones. Enlarge a gnat until its whole weight be equal to that of the eagle, and, great as that enlargement would be, its wdng will scarcely have attained the thickness of writing-paper, and, instead of supporting the weight of the animal, would bend down WORKS OF CREATION FREB FROM MISTAKES. 115 ifrom its own weight. The larger spiders rarely have legs BO slender in form as the smaller ones ; the form of the Shetland pony is quite different from that of the large cart-horse ; and the cart-horse has a slenderer form than the elephant. The common flea will leap two hundred times the length of its own body, and the remark has been sometimes made that a man equally agile, with his present size, would vault over the highest city-steeple, or across a river as wide as the Hudson at Albany. Now, if the flea were increased in size to that of a man, it would become a hundred thousand times strongei*, but thirty million times heavier; that is, its weight would become three hundred times greater than its corresponding strength. Hence we may infer that the enlarged flea would be no more agile than a man ; or that, if a man were proportionately reduced to the size of a flea, he could leap to as great a distance. All this serves to illustrate in a striking manner the great difference in the working of models and of machines. CHAPTER X. CONSTRtJCriON AND USE OF FARM IMPLEMENTS AND MA- CHINES IMPLEMENTS FOR TILLAGE. The application of mechanical principles m the struc- ture of the simpler parts of implements and machines has been already treated of. It remains to examine more particularly those machines chiefly important to the farmer, and to show the application of these principles in their use and operation. J16 MECHAiaCS. Farm implements and machines for working the soil should be, as fai- as possible, simple and not complex, be- cause they mostly meet with an irregular resistance, con- sisting of hard and soft soil and stones variously mixed together. A locomotive is made up of many parts ; but having a smooth surface to traverse, the machinery works uniformly and uninjured; but if in its progress it met with formidable obstructions and uneven resistance, it would be soon racked and beaten to pieces. Hence the long-continued and uniform success of the simple plow ; as well as the failure of complex digging machines, unless worked exclusively in soils free from stone. A complex machine, that meets with an occasional severe obstruction, receives a blow like that of a sledge ; and when this is repeated frequently, the probability is that some part will be bent, twisted, knocked out of place, or broken. If the machine be light, the chances are in its favor ; but if lieavy, its momentum is such that it can scarcely escape severe injury. If composed of many distinci parts, the derangement or breakage of one of these is sufficient to retard or put a stop to its working, and men and teams must stand idle till the mischief is repaired. Hence, after the trial of the multitude of implements and machines, we fall back on those of the most simple form, other things being equal. The crow-bar has been employed from time immemorial, and it will not be likely to go out of use in our day. For simplicity nothing ex- ceeds it. Spades, hoes, forks, etc., are of a similar char- vjter. The plow, although made up of parts, becomes a single thing when all are bolted and screwed together. For this reason, with its moderate weight, it moves through the soil with little difficulty — turning aside from obstructions, on account of its wedge form, when it can- not remove them. The harrow, although composed of many pieces, becomes a fixed solid frame, moving on through the soil as a single piece. So with the simple* IMPORTANCE OF SIMPLICITY IN MACHINES. 117 cultivators. Contrast these with the ditching machine (Pratt's) considerably used some yeais ago, but ending in entire failure. It was ingeniously constructed and well-made, and when new and every part uninjured, worked admirably in some soils. But it was made up of many parts, and weighed nearly half a ton. These two facts fixed its doom. A complex machine, weighing halfa ton, moving three to five feet per second, could not strike a large stone without a formidable jar ; and con- tinued repetitions of such blows bent and deranged the working parts. After using a while, these bent portions retarded its working ; it must be frequently stopped, the horses become badly fatigued, and all the machines were finally thrown aside. This is a single example of what must always occur with the use of heavy complex machinery working in the soil. Mowing and reaping machines may seem to be exceptions. But mowers and reapers do not work in the soil or among stones ; but operate on a soft, uniform, slightly resisting substnnce, made of the small stems of plants. Every firmer knows what becomes of them when they are repeatedly driven against obstruc- tions by careless teamsters. There is another foimidable objection to complex ma- chines — this is, their cost. Even with some of proved value, the expense is a serious item with moderate farm- ers. Mowers and reapers, $130; grain drills, 880 or $90; thrashing machines, $100 to $400 ; horse rakes, $45 ; hay tedders, $80 to $100 ; iron rollers, $50 to $100; and even some of the efficient new potato diggers are offered for not less than $100. Placing all these sums, and many others for necessary tools together, the whole will be found a la^ge outlay — more economical by far, it is true, than doing without them; but greater simplicity and consequent cheapness, as well as durability, would facilitate progress in agiicultural improvement. A single machine, Comstock's spader, is offfered at $250 — ^twenty 118 MECHANICS. Fig. 116. times the price of the best cast-iron plow, and ten times that of the most finished steel plow. And yet it is ap- l^licable only to land free from stone. The object of these remarks is to caution farmers against investing money in newly invented con- trivances of high promise at first, which are liable to the objection point- ed out ; and also in- ^ooUx) PUm. ventors and manufacturers themselves against engaging in enterprises having at hand golden promises, but with failure in the distance. PLOWS. The simplest plow, used probably in the earlier ages of the world, and found at the present day only among de- graded nations, is the crooked limb of a tree, with a pro- jecting point for tearing the surface of the earth. The above figure represents an improvement on the first rude implement, and is found at the present day in Northern Fig. 117. Moorish Plow. India. Fig. 116 shows the Kooloo j^low, consisting wholly of wood, except the iron point. Fig. 117 exhibits the implement now used in Morocco, which resembles the India plows, with the addition of a rude piece of tim- ber as a mould-board. Both these perform very imperfect PLOWS. 119 work, and have remained with little change for centuries, the owners not enjoying the benefit of agricultural read- Fig. 118. ing and intelligence. Fig. 118 is a step in advance, and represents a plow still used in some parts of Europe. In the less improved portions of Germany, the Baden plow, Fiir. 119- Fig. 120. Baden Plow. represented by Fig. 119, is employed, and does not difier greatly from the " bull plow " commonly used in this country at the beginning of the present century. Great im- provement has been made Avithin the past fifty years, among others by the ingenuity and labors of Jethro Wood, and more recently by a great number of inventors and manufacturers in difierent parts of the country. Wood introduced the cast-iron plow into general and successful use, ^^"^'^ ^^^'^^ ^^' by cheapening its construction and perfecting its form, 120 MECHANICS. and others liave made important improvements, including the steel mould-board now largely employed at the West. Cast-iron plows have been generally used throughout the Eastern States ; but for the peculiar soil of the West, it has been found absolutely necessary to use steel plows exclusively ; and for the purpose of keeping them at all Fiff. 121. Moliiie Flow. times sharp for cutting the vegetable fibre and separating the parts of the soil readily, the practice is common to carry a large file or rasp for this purpose. These steel plows are made of plate previously rolled. They are be- coming partially introduced also at the East, although in hard and gravelly soils the cast-iron mould-board is pre- ferred by many, and Fi-. 122. regarded as even more durable. The steel plate plow is lighter than the cast- iron, but is more expensive. The ac- companying figure AStedPlow. (Fig. 121,) represents the celebrated "Moline plow," made by Deere & Co., of Moline, III, one of the best and most extensively introduced among the Western steel imple- ments ; and Fig. 122 shows the more common form of the steel plow as made by several "manufacturers at the CHARACTER OF A GOOD PLOW. 121 East. Good steel plows cost about double those made of cast-iron. (See page 282.) CHARACTER OF A GOOD PLOW. Every good plow should possess two important quali- ties. The first relates to its working. It should be easily- drawn through the soil, and run with uniform depth and steadiness. The second refers to the character of the work when completed. The inversion of the sod, especially if encumbered with vegetable growth, should be complete and perfect ; and the mass of earth thus inverted should be left as thoroughly pulverized as practicable, instead of being laid over in a solid, unmoved mass. This is of the greatest importance on heavy soils, and is highly useful on those of a lighter character, except, it may be, clear sand or the lightest gravels. The harrow, at best, is an imper- fect loosener; it pulverizes the surface, but its weight, and that of the team, press down the mass below. Whatever loosening, therefore, can be accomplished in plowing is a gain of vital importance. THE CUTriN^G EDGE. The point and cutting edge of the plow perform the first work in separating the furrow-slice from the land. It is important that this edge should not only do the work well, but with the greatest possible ease to the team. The force required to perform this cutting is greater than many sup- pose. The gardener who thrusts his sharp spade into the hard earth uses more force than afterwards in lifting and inverting the spit. We may hence infer that a lai'ge part of the power of the team is expended in severing the fur- row-slice. This inference has been proved correct by the use of the dynamometer, in connection with carefully con- ducted experiments, which have shown the force usually 6 122 MECHANICS. expended for cutting off the side and bottom of the iarrow- slice, in firm soils, to exceed all the rest of the force re- quired to draw the plow. The point or share should therefore be kept sharp, and form as acute an angle as practicable, as shown in Fig. 123. Some jjIows which other- Fij?. 123. Pig. 124. Fi?. 125. Fi, as shown by cross section in figure 166 ; one part, d^ containing wheat, barley, and other medium- sized grains, and the other, c, for com, peas, and the larger seeds. This fiarure shows the Fi^. 167. T £ ^'^> mM '^' Sliding Eeversible Bottom of Hopper. opening in the side- plates, through which the grain is discharged. As these two divisions must be used on separate occasions, the 154 MECHANICS. openings between them and the hopper are opened and closed at pleasure by a sliding bottom, with a single movement of the hand. This sliding bottom is shown in fig. 167, and forms hoppers with sloping sides, down which the grain passes freely. The ends of the tubes, which are shod with steel, are made to pass any desired depth into the mellowed soil, and depositing the seed, it is immediately covered by the falling earth, as the drill passes. This drill is furnished with an attachment for sowing plaster, guano, or any other concentrated manure, and also with a grass-seed sower. A great improvement has been made in the mode al- ready described, of discharging the seed ; foimerly, seed- drills generally were furnished with a revolving cylinder, in the surface of which small cavities were made, for car- rying off and dropping measured portions of the grain ; these often broke or crushed the seed, and were liable to derangement. Others were furnished with circular, re- volving brushes, for pressing the seed through holes in the bottom of the hopper ; but this contrivance was im- perfect, nnd the brushes were liable to wear out. In the discharging apparatus of the drill jnst described, the seeds are never crushed, and the whole being substantially made of cast-iron, it may be run a lifetime. The best grain drills are sold for |80 or $90. setmoue's broadcast soweb 18 an excellent machine for sowing plaster, ashes, guano, salt, or any other concentrated fertilizer, as well as com- mon grain and grass seed. The disagreeable, and even dangerous, as well as heavy and laborious work of sow- ing these manures by hand renders such a machme de- sirable on every farm. It is drawn by one horse, sows COKN PLANTERS. 155 ten feet wide, and the operator rides in a seat. Seymour's Plaster Sower sows these fertilizers, whether wet or dry. These machines are sold at about 870. COEX PLANTERS. Among the best one-horse corn planters, which make one drill at a time, are Emery's, Harrington's, and Bil- lings'. The last-named is represented in the annexed cut. It drops in hills, eleven inches apart in the row, or, if de- sired, twenty-two inches, the perfora- tions in the slides regulating the number of grains. It is so constructed as to drop any desired amount of BUlings" Corn Planter. plaster, guano, Or other concentrated manure, without coming in contact with the seed. This, and other one-horse drills, are well adapted to ])lantiug fields of considerable size, for cultivating in rows but one way. On a larger scale, two-horse drills are employed. Wheat drills are often used for this pur- pose, employing only two of the tubes. Another class of corn planters, for planting in hills, the rows running both ways, consist of hollow tubes, which contain the seed, and which, by striking or pressing on the soil, drop and cover a hill at one stroke. (See page 285.) TRUE S POTATO PLANTER. For field culture, this implement has proved an import- ant saver of liand labor. It is drawn by one horse, and cuts, drops, and covers the potatoes at one operation. It is usually employed on ground which has been plowed 156 rjLiciiANics. and harrowed only, the driver forming the drills by the eye, as the planting proceeds. Straighter rows may be made by first marking the land with a good corn-marker, and then employing a small boy to ride, directing him to keep the horse on the line. The driver has then only to Figr. 1G3. True'a Potato Planter. watch the working of the machine before him. If the ground is rough, or rather dry, it u better to furrow the land previously with a single horse, running the planter in these furrows. For using this machine successfully, the seed potatoes must be previously assorted, so that those of nearly equal size may be used at a time. It is common to assort them into two sizes, which may be done -in winter, or on rainy days. Each potato passes the throat of the hopper sin- gly ; and if one in a bushel liappens to be too large, it will choke the opening. After passing the hopper, each potato is sliced into pieces of the desired size, which then, one by one, drop down the hollow coulter, and are buried. The throat of the Iiopper is readily contracted or expanded, and adapted to any assorted size of seed. One man, with a horse, will plant several acres in a day, and if the ground be ia good order, with nearly or quite HAND DRILLS AND SEED SOWERS. 157 as much accuracy as by hand, and with more uniformity of depth. HAND DRILLS, OK ST:ED SOWERS. These are great savers of labor for sowing the seeds of ruta-bagas, carrots, Fi-?. no. field beets, and other farm root crops, besides peas and beans. One of tlie best in use is Harrington's, represented by fig. ITO, and made by F. F. Ilolbrook & Co., Boston. The Harnngfm's Hand Seed Sower. side chains mark the rows, and it makes its own drill, Fij,'. iTi. drops, and covers the seed with ac- curacy, at one operation. It is readily changed to tlie hand culti- vator, by remov- ing the dropper, and attaching the EarringtmCs Hand (Mtivator cultivator teeth, ' Bhown in fig. 171. It then becomes a convenient imple^ ment for running between the rows, in small fields. Matthews' Hand Planter is similar in construction to th« above. Allen's *^ Planet Drill" has a cylindric brass seed-hopper, which revolves with the wheels, and is readily adapted to seeds of different sizes. It never clogs, and sows and covers readily. 158 MECHANICS. CHAPTER XII. MACHINES FOR HAYING AND HARVESTING. MOWING AND EEAPIXG MACHIiSTES. The cutting part of the mowers and renpers made at the present day consists of a serrated blade, as shown by Fi-. 172. fip^. 172, which passes througli narrow slits in each of the linofcrs, shown m fiir. IT Fi-. r Cutk7'-bar. forming, Avhen thus united, tlie cutting ap- paratus, as ex- hibited in the an- nexed figure, of VTood'^s Mowing- machine (figure 174). When the Fi.?. 174. machine is used, the motion of the wheels on which it runs is multiplied by means of the cog- wheels, imparting quick vibrations, end- wise, to this blade, shearing oif the grass smoothly as it ad- vances through the meadow, like a large number of scissors in exceedingly rapid motion. Wood's Mower. The finger-bar, the most important part, now adopted MCWEES AND REAPEES. 159 in all mowing and reaping machines, was invented by Henry Ogle, of Alnwick, England, in 1823, and his machine was put in successful operation, after much experimenting, by T. & J. Brown, of that place. But so strong was the prej- udice of the working people against labor-saving machine- ry, that they threatened to kill the manufacturers if they persevered ; and the enterprise for a time was given up.* The limits of this work permit only a brief notice of bome of the chief Fig. 175. points in mow- ers and I'capers ; and a few ma- chines are refer- red to, out of a large number of kinds, which are ^^^ made in the dif- , ^^^^fe 8SBUgUBap|| M y?-^^f^'l^-5V'<>.^ ferent States, ^"^^^^^ wp^^|p TO|iij '/I and which have '^^^^^^^^^^^^^S^^ii*^^™' ^ proved them- The Klrby Machine as a Alaiver. selves w^orthy of the confidence of farmers. Fig. iTG. The operation of mowing is shown in fig. 175, which rep- resents the Kirby mow^er, one of the best single - wheel machines, cutting a swath five feet wide, as fast as the* horses advance. Buckeye Mmoer with Folded Bar. Various contriv- ances are adopted for lifting or folding the cutter-bar when the machine 13 not in operation, or in passing from one field * WoodcrorU ICO 3IECHANICS. to another. A neat and convenient form is used in tlie Buckeye Mower, represented in the accompanying cut, (fig. 176) where the bar is folded over in front of the driver's feet. In the mowing-machine, the cutting apparatus is nar- Fig. 177. row, causing the newly cut grass to full evenly behind it, coverinj? the whole surface of the ground. The reap- ing-machine is simi- lar in construction, ,,,™_M!™,,,, „ with the addition of ^;^^^l^l^^l^r^^^m!i^Jim^<^^ ^ platform for hold- Kirby Reaper ^ with Uand Rake. hucf the jrrain aS it falls, as shown in the annexed figure of the Kirby machine, changed to a reaper (fig. 177). This figure represents the reel, which is attached to, and is worked by the machine, causing the grain, as it is cut, to drop smoothly Fig. 178. upon the platform. When la sufiicient quantity lias collected there, it ij swept off by the hand rake, and is afterwards l)ound in a sheaf. The annexed cut exhibits the Cayu- ga Chief, (an excellent Cayuga Chief— Combined Mower and Reaper. two-wheeled machine) as a reaper, in which the opera- tion of hand-raking is distinctly represented. SE:,r-i:AKixG l-eapees. Mowing-machines need but one man for their man- agement, who merely drives the horses that draw it. SELF-r.x\.KlXa K EATERS. IGl Reapers, as usually made, require another man besides the driver, to rake off the bunches of cut grain, which is se- vere labor. Various self-raking contrivances have been used to obviate this labor, several of which have been made to do excellent work, and are coming into general use. One of the first successful self-raking attachments to the reaper was tliat used by Seymour & Morgan, of Brockport, N. Y. It was one of the kind which sweeps across the platform, in the arc of a circle, delivering the gavel at the side of the machine. The ordinary reel is used with this class of rakes. An objection to them is, that the grain is seized for throwing off at a point behind the cutters. Owen Dorsey introduced an improvement in the form of what are termed reel-rakes, which strike the grain forward of the cutters. A series of sweeps or beaters were employed, combined with one or more rake:^, the gavel being delivered from the platform at each cir- cuit of the rake. At first, tlie horizontal motion of these arms i:)re vented the driver from riding on the machine. An improvement was ef- fected, so that the arms and rakes, after passing the platform, were made to rise to "a nearl y vertical posi- tion, thus passing the driver freely. The accompanying engraving, (fig. 179) representing the self- raker used on the Kirby machine, shows the position of the anns when in motion — one of them serving as a rake at each revolution. There arc several modifications of this class of rakes, made by different inventors. Marsh's machine consists of beaters and rakes combined, and de- Fis. 179. The Kirby Self-raker. 162 MECHANICS. livers one or more gavels at each revolution, according to the number of rakes used at a time. Johnson'^s rake is furnished with rake-heads for each of the arms, which are so arranged as to dip low into the grain forward of the cutters, and afterwards to rise in passing over the plat- form. To discharge the grain, the driver uses a latch- 1 cord and lever, so that the path in which the rake travels is changed by opening a switch or gate, permitting one of the rakes to pass low enough to sweep the platform. The Cayuga Chief, Buckeye, Hubbard, and other reapers, use this self-raker. The Kirby machine employs a self-raking attachment of its own, already represented i:i fig. 179. Two or three of the arms, or beaters, at the option of the driver, bring the grain on the platform ; the other one or two carry the rake-head. The driver may tlirow off a gavel, or two gavels, at each revolution; or the rake may be made to run continuously, at regular intervals, without attention on the part of the driver. The arms, or rakes, are so made as to be adjustable to the heiglit of the grain. The Dropper is a simple contrivance, (represented in the annexed en- Fig. iso. graving) consist- ing of a light plat- form, which holds the grain until the gavel is large enough, when it suddenly drops and discharges it. It is much used at the West, and, al- though hardly so ]ierfect as some self-rakers, is preferred by many farmers, the gavels being delivered behind the machine, and thus keeping the binders up to their work, in clearing the way for the next passage of the I'caper. Cayuga Chief wUh Dropper. ■w*'-^ MARSH S HARVESTER. 163 BINDERS. Fi'T. 181. Several machines for binding grain have been invented, possessing considerable merit, but so far they do not ap- pear to be adapted to general introduction. Marshes Harvester^ much used at tlie West, is so con- structed, that two men may readily bind as fast as the harvester does its work. The binders stand on a small platform, furnished witli a guard or rail, and the grain, as fast as it is cut, is carried up by an endless apron to a platform, where each man alter- nately makes his band, and receives and binds his sheaf. As they expend no The Mars/i IlaiTesUr. time ill StOOping, Or in passing from gavel to gavel, they are enabled to >vork Avith case and rapidity. The wciglit is only that of one man more than on a hand-raker. (See page 286.) JSeaders are reaping-machines employed for cutting the heads of wheat with a small portion of the straw, leaving most of the straw standing. Tliey are usually driven by four horses, and are thrust forward ahead of the team. A two-horse wagon, in addition, is driven along side, to re- ceive from an endless apron the heads, as they are cut by the reaper. They are only used on the extensive fields of j the West, and a difference of opinion prevails as to their general value. DURABILITY AND SELECTION-. Mowing and reaping-machines, being complex, or made up of many j^arts, would soon be broken and destroyed, 164 MECHANICS. if the resistance they meet with were irregular ai.d full of obstructions, like those which the plow encounters. Standing grain and grass present a soft and uniform re- sistance, and hence, well-made machines will last several years without much repair. The Report of the Auburn trial of mowers and reapers gives five years as the aver age " lifetime " of these machines. Much will depend on the amount of work performed in a season ; an extensive farmer states, that he usually cuts about five hundred acres with each machine before it needs renewing. Much, also, depends on the care which the machines receive ; such as keeping them always well sheltered from the weather, and thoroughly cleaning every part, and care- fully wiping the journals and bearings before they are laid aside for the season. In selecting mowers and reapers, there are several points which the purchaser should carefidly observe ; as, for example — 1. Simplicity of construction. 2. Use of best material for knives and other parts used in manufac- ture. 3. Finish and perfection of gearing and running parts. 4. Durability, as proved by use. 5. Ease of draught. 6. Freedom from side draught. 7. Quality of work. 8. Ease of management. 9. Convenience and safety of driver. 10. Adaptation to uneven sur- ■faces. A part of these points can be fully determined only by thorough trial ; and it is always safest to purchase of those manufacturers whose machines have been long enough in general use to establish their char- acter in these respects. Fortunately, there are many in difierent parts of the country, who have secured a good reputation, from whom machines, or parts for repairs, may be obtained without sending long distances. The report of the Auburn trial, in 1866, states, that out of twenty different mowing-machines, which were tried on a rough meadow, every one, with two exceptions, '' did good woik, which would be acceptable to any farmer ; and the HAY TEDDERS. 165 appearance of the whole meadow, after it had been raked over, was vastly better than the average hand mowing of the best farmers in the State." Since that trial, a con- tinued improvement in manufacture has been taking place, and the machines are becoming more perfect. The price of a good two-horse mowing-machine is about $120 J and of a combined mower and reaper, about $170. HAY TEDDING MACHrfTES. Machines for stirring up and turning the drying hay have long since been known and used in England, and a few were introduced into use in this country. But as they were heavy and cumbersome, they never came into common use. A pj„ is2. few years since, Builard'sIIayTed- der was invented, and has been wide- ly used. It scatters and turns the hay with great rapidi- ty, and consists of several forks, held nearly upright, but worked by a com- pound crank, so as to scatter the hay .7 /. ^1 BullardTs Ilay Tedder. m the rear or the machine. The close resemblance of the movement of these forks to tlie energetic scratching of a lien presents a ludicrous appearance to one w'lo sees it for the first time. The use of the tedder is found greatly to hasten the drying process, especially on heavy meadows, and to enable the farmer to secure his hny in so short a time as frequently to avoid damaging storms. 166 MECHANICS. A new macliinc, remarkable for its simplicity and per- fection of working, is the American Hay Tedder^ made by the Ames Plow Company, of Boston. It is repre- P5,^ 133 sented in the accompanying cut. It is furnish- ed with sixteen forks, attached to a light reel in such a manner that they re- volve rapidly, with a rotary, continuous, and uniform motion. It never clogs, may be easily backed, and roadily passes over ordinary obstruc- tions, without any attention on the part of the driver. Hay tedders should be used on the meadow about, three times a day, which w^ill enable the farmer to cut his crop in the morning, and draw it in the same day ; giving him, also, more uniformly dried, and better hay. The price of hay tedders varies from 8T5 to I^IOO. Vae Aiiurkan Ilaj Tedder. HOESE nAY-KAlIEG. The simplest and original form of the horse-rake is represented in fig. 184. It was made of a piece of strong scnntling, three inches square, tapering slightly toward the ends, for the purpose of combining strength with lightness, and in ^vhich were set horizontally about fif- teen teeth, twenty-two inches long, and an inch by an inch and three-fourths at the p!ace of insertion, tapering on the under side, with a slight upward turn at the points, to prevent running into the gi'ound. The two outer teeth Avere cut off to aI)out one-third their first length, and draught-ropes attached. If these pieces were HORSK HAY-RAKES. 16T too short, the teotli were hard to guide ; if too long, the rake was unloaded with difficulty. Handles served to guide Fig. 184. Simple Horse-rake. the teeth, to lift the rake from the ground in avoiding ob- structions, and to empty the accumulated hay. In using this rake, the teeth were run flat upon the ground, passing under, and collecting the hay. AVhen full, the hors(3 was stopped, the handles thrown forward, the rake emptied and lifted over the windrow thus formed. The windrows, as in other horsc-rakes, vrere made at right angles to the path of the rake, each load being do- posited opposite the last heap formed, in previously cross- ing the meadow. A few hours' practice enabled any one to use this rake without difiiculty ; the only skill required was to keep the teeth under the hay, and above the ground. In addition to raking, this implement was employed for sweeping the hay from the windrow, and drawing it to the stack. It was also useful for cleaning up tiie scattered hay from the meadow, at the close of the work ; for rak- ing grain-stubble, and for pulling and gathering peas. If made of the toughest wood, and with the proper taper in the main parts for lightness and strength, according to the principles already pointed out in a previous chapter, it was easily lifted, and its use not attended with severe labor. 168 MECHANICS. This simple lioree-rake has nearly gone out of use, and yet, on account cf its simplicity and cheapness, it is wor- thy of being retained on small farms, and especially on meadows with uneven surfaces. The cost need not be more than three or four dollars. From twelve to fifteen acres could be raked with it in a da3^ The Revolving Horse-rake (fig. 185) was next generally adopted, possessing the great advantage of unloading Fig. 185. Rn'olvnig Horse-rake without lifting the rake or stopping the horse. It has a double row of teeth, pointing each way, which are brought alternately into use as the rake makes a seniii-revolution at each forming-windrow, in its onward progress. They are kept flat upon the ground by the pressure of the square frame on their points, beneath the handles ; but as soon as a load of hay has collected, the handles are slightly raised, throwing this frame backwards, off the points, and raising them enough for the forward row to catch the earth. The continued motion of the horse causes the teeth to rise and revolve, throwing the back- ward teeth foremost, over the windrow. In this w^ay, each set of teeth is alternately brought into operation. The cost of this rake is from $7 to $10, and twenty acres or more could be raked Avith it in a day. A further improvement has been made in the revolving ralie, by attaching it to a sulky, on which the operator REVOLVING HORSE-RAKES. 169 rides, enabling him to do a larger amount of work with less fatigue. There arc several modifications, some of ^^s- 1S6. which place the rake in front of the sulky wheels, and others, in the rear. One of the best and most widely used is *' Warner's Sulky Revolver," manu- factured by Bly- myer. Day & Co., of Mansfield, Ohio, and by others. It is represented in the annexed cuts, fig. 186 shoAving it in the operation of raking, and fig. 187, the same machine, witli the rake thrown p^„ jg^ upon the wheels, for driving from field to field. The head is the same as the com- mon revolving rake- head — the teeth be- ing tipped vv'ith mal- leable iron. The rake is operated by means of a lever, at- tached to a journal at the centre of the rake-he.id. By means of cams, stop, and spring, the lever and head are entirely at the will of the operator. A slight pressure, equal to seven or eight pounds, on a lever, causes the rake to revolve ; and it is also readily elevated for back- ing, or for passing obstructions. These rakes are now generally superseded by the lighter and more effective steel-tooth rakes described on the fol- lowing pages. 170 MECHANICS. SPRING-TOOTH RAKE. Fij?. 188. Tlie original form of the spring-tootli rake is shown in fig. 188. The teeth were made of stiff, elastic wire, on the points of which the rake ran, and not on the flat sides, as in those already described. They bent in pass- ing an obstruction, and sprung back again to their place. This rake was un- loaded by simply lifting the handles, which was easily done, the rake be- ing light, and '•'prm^-too/h Hirse-rake. about one-half the weight being sustained by the horse. All the spring-tooth rakes made and used at the present time are attached to wheels, and a seat is furnished for the driver. There are many patented modifications, some possessing advantages of greater simplicity, or ease of management ; but all appear to be good and efticient rakes, enabling the operator to gather about twenty-five acres in a day. These teeth are made in the form of a semi-circle, with ^he ends pointing forward, and the gathering hay accu- mulates in the concave space formed by their curvature. When well loaded, the operator, with a slight movement, raises all the teeth together, and the }\ay is dropped at tl>e winrow. In some rakes this is effected with the simple pressure of the foot ; in others, a hand-lever is employed. THE HAY-SWEEP. 171 The use of steel- fcootli rakes reduces materially the cost of the crop in the great saving of labor ; a boy can effec- tively accomplish the work of many men using the old implements. Not only are these rakes valuable for col- Fig. 189. lecting hay, but are successfully employed for gleaning grain stubble. They are also especially useful in raking up rowen. Their present cost is about $30. The above cut, fig. 189, represents the style of steel-tooth rake made by Wheeler, Melick & Co., Albany, N. Y. THE HAY-SWEEP. Where the hay is secured in stacks, or in hay-barns situated contiguous to the meadow, the use of the hay- sweep, in connection with the horse-fork, would probably Fi^. 190. enable two or three men, and two boys, with three horses, to draw" and pack away thirty tons a day^ or more. The hay -sweep, invented many years Eay-Sweep. ago by W. R. Smith, of Macedon, N. Y., is but little known. The accompanying figures (190 and 191) exhibit its construction and use. It is essentially a large, stout, coarse rake, with teeth pro- 173 MECHANICS. jecting both ways, like tliose of a common revolver ; a horse is attached to each end, and a boy rides each horse. A horse passes along each side of the windrow, and the two Fig. 191. Jlay-sweep in Operation. thus draw this rake after them, scooping up the hay as they go. When 500 pounds or more are collected, they draw it at once to the stack, or barn, and the horses turn- ing about at each end, causing the gates to make half a circle, draw the teeth backward from the heap of hay, and go empty for another load — the teeth on op[)osite sides being thus used alternately. To pitch easily, the back of each load must be left so as to be pitched first. The dimensions should be about as follows : — Main scantling, below, 4 by 5 inches, 10 feet long ; the one above it, same length, 3 by 4 inches ; these are three feet apart, connected by seven upright bars, 1 by 2 inches, and 3 feet long. The teeth are flat, 1|- by 4 inches, 5 feet long, or projecting 2^ feet each way ; they are made tapering to the ends, so as to run easily under the windrow. A gate, swinging half way round on very stout hinges, is hung to each end of this rake, and to these gates the horses are attached. Each gate consists of two pieces of scantling, 3 inches square, and 3 feet long, united by two bars of wood, 1 by 2 inches, and a third, at the bottom, 3 inches square, and tapering upwards, like a sled runner; HOKSE HAY-FORKS. 173 these runners project a few inches beyond tlie gate. The whiffle-trees are fastened a little above the middle of the gate, and should be raised or lowered so as to be exactly adjusted. This machine may be made for $6 or $7. In using, not a moment is lost in loading or unloading. No person is needed \n. attendance, except the two small boys tliat ride the horses. If the horses walk three miles an hour, and travel a quarter of a mile for each load, they will draw 12 loads, or three tons an hour, or thirty tons in ten hours, leaving the men wholly occupied in raising the hay from the ground, by means of another horse, with the pitchfork. It will be obvious, that this rapid mode of securing hay will enable the farmer to elude showers and storms, which might otherwise prove a great damage. HORSE HAY -FORKS. Every farmer who has ever pitched off from a wagon in one day ten or twelve tons of hay is aware that no labor on the farm can be more fatiguing. The horse- fork, in its various forms, which, to a considerable extent, has been brought into use, has afforded great relief, severe labor being not only avoided, but much greater expedition attained. The effective force of a horse is, at least, five times as great as that of a stout man ; and if half an hour is usually required for him to unload a ton of hay, then only six minutes would be necessary to accomplish the same result with horse-power. Actual experiment very nearly accords with this estimate. ^^''^^""^ Horse-fark. A simple form of the horse pitchfork was described in Yis. 192. 174 MECHANICS. Fig. 193. the Albany Cultivator, in 1848, from which a subscriber in Bradford County, Pa., made the first used in that re- gion. Some years later, he stated that there were at least two hundred in use. The preceding figure represents this simple and original fork. A is the head, twenty- eight inches long, and two and a half inches square, made of strong wood. A G is the handle, five and a half feet long, mortised into the head, with an iron clasp or band of hoop iron fitting over the head, and extending six inches up the handle, secured by rivets. The prongs of the fork are made of good steel, one- half an inch wide at the head, twenty inches long, and Pilching Hay through a Window with Horse-power. eiofht inches apart, with nuts to screw them up tight. Rivets are placed on each side of the middle ones, to prevent the head from splitting. The rope is attaclied to staples at the ends of the head. The single rope D extends over a tackle-block, at- tached to a rafter at the peak of the barn, about two feet within the edge of the bay. The rope then passes down to the bottom of the door-post, under another tackle- block, and to the outside of the barn, where the working horse is attaclied to it. A small rope or cord G is attached to the end of the handle, by which it is kept level, as it ascends over the mow. The cord is then slackened, and CLADDING'S HORSE-FORK. 175 the hay tilts the fork, discharging its load. The horse is then backed up, ready for another fork load, the only labor of the workman being to drive the fork into the hay and keep the cord steady. An important advantage is gained, besides the saving of time ; for the man on the load, being relieved from the severe labor of pitching, is fresh and vigorous for throwing on another load in the field. The length of the handle made it difficult to use this fork under low roofs, and an improvement was made by Glad- ding^ by which the head of the rake only was tilted, leaving the handle in its horizontal position. A hinge- joint is placed at the connection of the head and handle, so that, at any moment, by a jerk on the cord which passes up a bore in the handle, the fork is dropped, as shown in fig. 194, and its load depos- ited. This may be done instantane- ously, at the mo- ment it happens to be swung to the most favorable spot. Its weight causes the head to fly back of its own accord, and resume its former position, ready for another forkful. The rope suspending the fork should be fastened to the highest portion of one of the rafters, over the mow, and a smooth board should be placed, vertically, against the face of the mow, for the hay to slide on as it ascends. By attaching this rope in front of, and within a window, the hay is carried with ease into the window, and thus lofts over sheds, carriage- houses, -etc., where the old horse-fork could not be used, are filled by the use of Gladdinrfs improvement. This is one of the best forks, adapted to all kinds of pitching, Gladding" s Ilay-fork. 176 MECHANICS. and has unloaded a ton of hay in about three minutes; and over a beam twenty-two feet high, under a low rafter, in about nine minutes. In using horse forks, as already stated, their operation is much facilitated by providing a board slide, to be placed vertically against tlie face of the mow, or bay, on which the hay moves upward. In pitching into a win- dow, the bottom of this board slide should be placed out a few feet from the building, and the top sliould rest on the base of the window. When convenient, the back end of the wagon load should be placed towards the win- dow. There is no limit to the height at which the pitch- ing may be easily performed — giving the use of the horse-fork a great advantage over hand pitching ; and barns, with high posts, may be built for the storage of hay. Other forms have been adopted for pitching under roofs, by using shorter handles. One of the best is Palmer's Fii:. 105. Fi:,'. 10;i. Palmet'^s Fork. Fork^ made by Wheeler & Co., Albany, and Palmer v>,**ijji the stack. As the Palmer's Hay stacker. horse backs, the weight drops again to the ground, taking up the slack rope from under the horse's feet, and the weight of the fork causes the arm of the derrick to revolve back over the loa MECHAXICS. figure that the spindle is horizontal, and the face of the stones vertical. The frame is of iron. The diameters of the stones vary from sixteen to thirty inches, and the weight from 400 to 1,500 lbs. The smaller size may be run with a power of one to four hoi*ses; the larger, with that of ten to thirty horses. Prices $150 to $375. The manufacturers claim that it will grind from one and a half to three bushels per hour, for each horse-power used in driving it. (See page 290.) THE COTTOX GIN. Since the invention of the Cotton Gin by Eli Whitney, great improvements have been made, by which the cotton is cleaned with great rapidity and in a perfect manner. Fiff. 224. Emery's Cotton Gin — Section. The machine formerly made by H. L. Emery, of Albany, is one of the best for this purpose. It is represented in section in fig. 224. The hopper, at the right, is furnished with what is termed a Picker Boll Syp2^orte7\ which re- volves within the hopper, in the direction shown by the arrow, and prevents the cotton from becoming packed. It emery's cotton gin. 197 is then taken by the teeth of the saw cylinder, which re- duce the cotton to a tine condition. These teeth are swept by the brush cylinder, which, running in the same direction with the teeth, and slightly faster, carries the cotton off from them. Fig. 225 represents the operation, the seed escaping from tlie bottom of the hopper and the Fi":. 225. Emery's Cotton Gin, with Condenser. cotton thrown to tlie rear into the condenser, which fin- ishes the cleaning process and packs or condenses the lint cotton within a •limited space. The arrows shown in the section indicate the direction of the revolutions of thej picker, saws, and brush cylinder, and also the course which the cotton takes in passing through the gin and condenser. (See page 290.) PART II. MACHINERY IN CONNECTION WITH WATER GENERAL PRINCIPLES. Hydrostatics * treats of the weight and pressure of liquids when not in motion; HYDRAULics,f of liquids in motion, as, conducting water through pipes, raising it by- pumps, etc.; and HydrodyxamicsJ; includes both, by- treating of the /o?'ces of the Hquids, whether at rest or in motion. CHAPTER I. HYDROSTATICS. UPWARD PRESSURE. A remarkable property of liquids is their pressure in all directions. If we place a solid body, as a stone, in a vessel, its weight will only press upon the bottom ; but if we pour in water, the water will not only press upon the bottom, but against the sides. For, bore a hole in the side, and the side pressure will drive out the water in a stream ; or bore small holes in the sides and bottom of a tight wooden box, stopping them with plugs ; then press this box, empty, bottom downward, into water, allowing none to run in at the top. 'Now draw one of the side plugs, and the water will be iriimediately driven into the * From two Greek words, hudor^ water, and statos, standing, or at rest, t From two Greek words, hudor, water, and aulo.<<, a pipe. X From two Greek words, hudor, water, dwiamis, power. 198 UPWARD PRESSURE OF LIQUIDS. 199 box by the pressure outside. If a bottom plug be drawn, the water will immediately spout up into the box, show- ing the pressure upward against the bottom. Hence the pressure in all directions^ upward, sideways, and down- ward, is proved. The upward pressure of liquids may be shown by pour- ing into one end of a tube, bent in the shape of the letter U, enough water to partly fill it ; the upward pressure will drive the water up the other side until the two sides are level. On this principle depends the art of conveying water in pipes under ground, across valleys. The water will rise as high on the opposite side the valley as tlie spring which supplies it. The ancient Romans, who were unac- quainted with the manufacture of strong cast-iron pipes, conveyed water on lofty aqueducts of costly masonry, built level across the valleys. Even at the present day, it has been deemed safest to build level aqueducts for con- veying great bodies of water, as in very large pipes the pressure would be enormous, and might result in violent explosions. If the valleys are deep, the pipes must be correspond- ingly strong, because, the higher the head of water, the greater is the pressure. For the same reason, dams and large cisterns should be strongest at bottom. Reservoirs made in the form of large tubs require the lower hoops to be many times stronger or more numerous than the upper MEASUREMENT OF PRESSURE AT DIFFERENT HEIGHTS. The amount of pressure which any given height of wa- ter exerts upon a surface below may be understood by the following simple calculation : If there be a tube one inch square (with a closed end), half a pound of water poured into it will fill it to a height 200 MACHIXEKY IX COXNECTIOX WITH AVATER. of fo Fig. 226. 2 lbs. 56 in. iy?.lbs..42in. lib 28111- iirteen inches;* one pound will fill it twenty-eight inches ; two pounds, fifty-six inches ; ten pounds, twenty-three feet ; twenty pounds, forty-six feet, and so on. Now, as the side pressure is the same as the pressure downward for the same head of water, the same column will, of course, exert an equal pressure on a square inch of the side of the tube. Or, if the tube be bent, as shown in the annexed figure (fig. 226), the pressure upward on the end of the tube, at a, will be the same for the various heights. Now, as tlie pressure of a column fifty feet high is about twenty-two pounds on a square inch, the pressure on the four sides is equal to eighty- eight pounds for one inch in length. Hence the reason that considerable strength is required in tubes which much head of water, to prevent their being torn by its force. V2 lb. 14 in. DETEEMIXING THE STREXGTH OF PIPES. The question may now arise, and it is a very important one, How thick must be a lead tube of this size to pi-event danger of bursting with a head of fifty feet, or of any other height ? To answer it, let us turn to the table of the Strength of Materials in a former part of this work, where we find that a bar of cast lead one-fourth of an inch square will bear a weight of fifty-five pounds. If the * This is nearly correct, for a cubic foot (or 1,728 cubic inches) of "vvatci- ueig-hs 62 lbs. Consequently, one pound will be 2T.9 cubic inch- es, and will fill tlie tube nearly 2S inches high. CALCULATING THE STRENGTH OF TUBES. 201 tube be only one-sixteenth of an inch thick, one inch of one of its sides will possess an equal strength, that is, will bear fifty-five pounds only, and the tube would conse- quently burst with fifty feet head. If one-tenth of an inch thick, the tube would just bear the pressure, and, to be safe, should be about twice as thick, or one-fifth of an inch. Half this thickness would be sufficient for twenty- five feet of water, and would require to be doubled for one hundred feet. A round tube, one inch in diameter, having less surface to its sides, would be about one-third stronger. A tube twice the diameter would need twice the thickness; or if less in diameter, a proportionate de- crease in thickness might take place. If, instead of cast lead, milled lead were used, the tube would be nearly four times as strong, according to the table of the strength of materials already referred to. SPEINGS AND ARTESIAN WELLS result from the upward pressure of water. Rocks are usually arranged in inclined layers (fig. 227), and when Fig. 227. d h ^ rain falls upon the surface, as at e df, it sinks down in the more porous parts between these layers, to c. If the lay- ers happen to be broken in any place below, the water finds its way up through the crevices by the pressure of the head above, and forms springs. If there are no open- ings through the rocks, deep borings are sometimes made 9* 202 MACHINERY IX CONNECTION "V^'ITH "WATER. artificijilly, through which the water is driven up to the surface, as at «, forming what are termed Artesian Wells. The head of water which supplies them may be many miles distant, the place of discharge being on a lower level. It has sometimes been found necessary to bore more than a thousand feet downward before obtaining water which will flow out freely at the surface of the earth. flg T S Jl =^^ — ' — - . :^~ri:^i =r^^-=| ■ -— ^-Ii DETERMINING THE PRESSURE ON GIVEN SURFACES. The pressure of liquids upon any given surface js always exactly in proportion to the height, no matter what the yig 228. shape of the vessel may be. If, for instance, the vessel a (fig. 228), be one inch in diameter, and the vessel h be three inches in diameter, the water being equally high in both, the press- ure on the whole bottom of b will be nine times as great as on the bottom of a / or any one inch of the bottom of b will receive as great a ])ressure as the bottom of a. Again, if the vessel c, broad at the top, be narrowed to only an inch in diameter at bottom, the press- Fig. 229. ure upon that inch will still be the same, most of the weight of its con- tents resting against the sides, d d. If the vessel, A (fig. 229), be filled with water to a heio-ht of fourteen inches, the pressure will be half a pound on every square inch of the bottom, or upon every square inch of the sides fourteen inches below the surface. If the tube, C, be an inch square, the water Avill be driven into it with a force of half a pound, and will press wdth that force against the one-inch surface of the stop-cock, C. If A PFZZLE EXPLAINED. 203 the tube, B, be now filled to an equal height, the same force will be exerted against the other side. To prove this, let the stop-cock be opened, when the two columns of water will lemain at an exact level. If enough water be now poured into the tube, B, to fill it to the top, it will immediately settle down on a level with the water in A, raising the whole surface in the lat- ter. This result has seemed strange to many, who can not conceive how a small column of water can be made to balance a large one, and it has been therefore termed the Hydrostatic Paradox. But the difficulty entirely vanish- es, and ceases to appear a paradox, when we remember that the water in the larger vessel rises as much more slowly than it descends in the smaller, as the large one exceeds the smaller ; thus acting on the principle of vir- tual velocities in precisely the same manner that a heavy weight on the short end of a lever is upheld by a small weight on the long end. The great mass of water is sup- ported directly by the bottom of A, in the same way that nearly all the weight on the lever is supported by the fulcrum. A man who was seeking a solu- tion to the absurd mechanical problem of perpetual motion, and who supposed that the large mass in A would overbalance the small column in B, and drive it upward, constructed a vessel in the form shown in fig. 230, so that the small column, when ^^^'^^ ^^LJl ^^"^^^^ upward, M'ould flow back into the ^== ^ larger vessel perpetually. He was, how- Attempted Perpetual , . ^ i/a-i- Motion. ever, greatly surprised to see the fluid m both divisions settle at the same level. This principle may bo further explained by the following experiment : A B (fig.231) represents the inside of a metallic vessel, with a bottom, C, which slides up and down, water- tight. If water be poured in to fill the lower or larger part only, it will be found to press on the sliding bottom. Fig. 230. 204 MACHINERY Ij^ COXNECTION WITH WATER. A D ^ D - — - p - i^ ^= HUH!'" '"flilfllwil 1 ( ? u with a force exactly equal to its own weight ; that is, if there is a pound of water, it will press on the bottom with a force equal to one pound. Now, if the bottom be pushed Fig. 231. upward, so as to drive the water into the narrow part of the vessel, the pressure upon the bottom becomes instantly much greater, or equal to many pounds, the water being the same in quantity, but with a much higher head than before. Suppose the nar- row part of the vessel is twenty times smaller than the larger part, then, in pushing ( I the bottom up one inch, the water is driven twenty inches upward in the tube. So then, according to the rule of virtual velocities, it will require twenty times the force, because it moves u|)warcl twenty times faster.* This, then, is precisely similar to the in- stance where a pound on the longer end of a steelyard balances twenty pounds on the shorter rig. 232. end. In this instance, the upper parts, D D, of the vessel operate as the fulcrum of a lever, and olFer resistance to the slid- ing part as soon as the water begins to ascend the tube. HYDROSTATIC BELLOWS. This principle is shown in the -Sy- drostatlc Bellows (fig. 232), which con- sists of two round pieces of board. Hydrostatic Bellows. connected by a narrow strip of strong leather; into it is inserted a long, narrow tube, B, with a small funnel, e, at the top. When water is poured into this tube, it will raise a weight as much greater than the weight of the * The pressure will be as great upou tke bottom us if the vessel con- tinued a uuiform size all the u ay up. HYDROSTATIC PEESS. 205 water in the tube as tlie surface of the upper board ex- ceeds the cross-section of the tube. Thus, if a pound of water fills a tube half an inch in diameter, and the bellows are two feet in diameter, then this pound will raise more than two thousand pounds on the bellows (if it be strong Bnough), because the surface of the bellows is more than two thousand times greater. In the same way, a strong, iron-bound hogshead may- be burst with the weight of a single gallon of water by pouring it into a long and narrow tube set upright in the bung of the filled hogshead. If, for instance, the inner surface of the hogshead be 20 square feet, or 2,880 square inches, a tube of water 23 feet high will press with a force of 10 pounds on every square inch, or equal to a force of 28,800 pounds, or 14 tons, on the whole surface. HYDROSTATIC PRESS, The Hydrostatic Press owes its extraordinaiy power to a similar principle ; but, instead of a bellows, there is a moving piston in a strong metallic cylinder; and instead of being worked by the mere weight of the water, it is* driven into the cylinder by means of the lever of a pow- erful forcing-pump. An instrument of this sort, possess- ing enormous power, was used to elevate the great tubula** iron bridge in England. It was found necessary to make the sides of the cylinder into which the water was driven no less than eleven inches thick, of solid iron ; and so great was the pressure given to the confined water, aa to have forced it up through a tube higher than the summit of Mont Blanc. In the port of New York, ves- sels of a thousand tons' burden have been lifted by the hydrostatic press. This machine has been applied in compressing hay, cot- ton, and other bulky substances into a compact form, so that they may occupy but little space, for conveyance to 206 MACHINERY IN CONNECTION WITH WATER. distant markets. The following figure (fig. 233) exhibits the different parts of this powerful machine. A is a cis- tern to supply water, which is raised by working the han- dle, B, of the forcing-pump; the water passes through the valve, C, opening upward, and through the spring valve, Fis. 233. Hydrostatic Press. D, opening toward the large cylinder, E. Being thus driven into the space, E, it raises the piston, F, and exerts a prodigious pressure upon the mass of hay or cotton, G. The piston is lowered by turning the screw, H, which al- lows the water to pass back into the cistern at I. In the figure the hay or cotton is shown as visible to the sight, in order to represent the whole more plainly ; but in prac- tice it is thrown into a square box or chamber of strong plank, of the size of the intended bundle. One side is HYDROSTATIC PRESS. 207 hung upon stout hinges, and is opened for the removal of the bale when the pressing is completed. To estimate the power of this machine, divide the square of the diameter of the piston, F, by the square of the diameter of the piston of tl)e forcing-pump, and multi- ply the quotient by the power of the lever, B. For ex- ample, suppose the piston, F, is 16 inches in diameter, and the piston of the forcing-pump is 2 inches in diameter. The square of 16 is 256 ; divide this by 4, the square of 2, and the result will be 64. If the lever, B, increases the power five times, the whole power of the macliine will be 320; that is, a force of one pound applied to the lever will raise the Lirge piston with a force equal to 320 pounds ; or, if a force of 100 pounds be given to the lever, the power will be 32,000 pounds, or 16 tons. Reducing the diameter o-f the smaller piston to half, an inch, and in- creasing the force of the lever to twenty times, the whole power exerted will be thirty-two times as great, or equal to 960 tons. In ordinary practice, it is more convenient and economical to reduce the diameter of the larger piston to a few inches only, making the forcing-pump correspond- ingly small, the power depending entirely on the dispro- portion between them. Such presses may be worked rap- idly by horse, water, or steam power. One great advantage which the hydrostatic press pos- sesses over those worked by screws results from the little friction among liquids, nearly the only friction existing in the whole machine being that of tlie two pistons, which is comparatively small. Another is the smallness of the compass within wliich the whole is comprised ; for a man might, with one not larger than a tea-pot, standing before him on a table, cut through a thick bar of iron with as much ease as he could chip pasteboard with a pair of shears. 208 MACniNERY IN CONNECnON WITH WATER. SPECIFIC GRAVITIES. Fig. 2:M. In connection with Hydrostatics, the suhject of the specific gravities of bodies is one of impoitance. The specific gravity of a substance is its comparative weight with some other substance, an equal bulk of each being taken. Water is usually the standard for comparison. To ascertain the specific gravity, weigh the body both in and out of •water, and observe the difference ; then divide the whole weight by this diff*ereiice, and the quotient will be the specific gravity sought. For example, if a stone weighs 12 lbs. out of water and 7 lbs. in water, divide 12 by 5, and the quotient is 2.4, which shows that the stone is 2*1,^ times heavier than water. Figure 234 shows the mode of weighing the body in water, by suspending it be- neath a balance on a hair or thread. It was in a similar way that Archimedes is said to have succeeded in detecting the suspected fraud in the manu- facture of the golden crown of the nncient king of Syra- cuse. He first weighed it, and then found that it dip- placed more water when plunged in a vessel just filled than a piece of pure gold, and also that it displaced less than silver, whence he inferred the mixture of these two metals. When the specific gravity of a substance lighter than water is to be ascertained, it is loaded down by a weight, BO as to sink in water, for which allowance is made in the calculation. A very simple way to determine this in dif- ferent kinds of wood is to form them into rods or sticks of uniform size throughout, and then to observe what portion of them suik when placed endwise in water. Instrument for takiui. GtavUies. Specific TABLE OF SPECIFIC GRAVITIES. 209 A knowledge of the specific gravities of various sub- stances becomes useful in many ways, among which is ascertaining the weiglit of any structure, machine, or im- plement, by knowing that of the material used in its man- ufacture ; determining the cost, by the pound, of such material ; or knowing the bulk or size of any load for a team. The latter may often be of great use in ordinary practice, by enabling the teamster to calculate beforehand the amount of load to give his liorses, whether in timber, plank, brick, lime, sand, or iron, without first subjecting them to overstraining exertions in consequence of error in random guessing. Tables of specific gravities, for this purpose, and weights of a cubic foot of difierent substances, are here given. TABLE OF SPECIFIC GKAVITIES. Metals. Gold, pure 19.36 " standard 17. 16 Mercury 13.58 Lead 11.35 Silver 10.50 Copper 8.83 Iron 7.78 " east 7.20 Steel 7.82 Brass, comuion 7.82 Tiu 7.29 Zinc 6.86 Stones and Earths. Brick 1.90 Chalk 2.25 to 2.66 Cby 1.93 Coal, luitliracite, about 1.53 Coal, bituminous 1.27 Charcoal 44 Earth, loose, about 1.50 Flint 2.58 Granite, about 2.65 Gypsum 1.87 to 2.17 Limestone 2.38 to 3.17 Lime, quick 80 Marble 2 56 to 2.69 Peat 60 to 1.H2 Salt, common 2.13 Sand J 1.80 Slate 2.67 Wooda — dry. Green wood often loses one-third of its weight by seasoning, and •ometiraes more. The same kind varies in compactness with soil, growth, exposure, and age of the trees. 210 MACHINERY IN CONNECTION WITH WATEE. Apple 68 to .79 Ash, white 72 to .84 Beech 73 to .85 Box 91 to 1.32 Cherry .. 71 Cork 24 Elm 58 to .67 Hickory 84 to 1.00 Maple 65 to .75 Piue, white 47 to .56 Pine, yellow 55 to 66 Oak, English 93 to 1 . 17 " white 85 " live 94 to 1.12 Poplar, Lombardy 40 Pear 66 : Plum 78 Sassafras 48 Walnut 67 Willow 58 Beeswax. Butter 94 Honey 1.45 Lardl 94 Milk 1.03 Oil, linseed 94 Miscellaneous. ,. .96 Oil, whale 92 " turpentine 87 Sea water 1.02 Sus:, ^, having openings cut in the centre. Horizontally aci'oss these openings, draw very fine wire, which shall be exactly at equal heights above each end of tlie bar of wood, to adjust which, one should be capable of shding, and be screwed or wedged to its place at pleasure. The bar is placed on a common com- pass staff, as shown in Fig. 240. the cut, turning at the "ball and socket, below the spirit level. A tripod (fig. 240) is better, if it can be had. A small spirit-level should be se- cured across the bar, so that it may he adjusted both ways. When the bar is made perfectly level, as shown by the air-bubble, by sighting through at the two wires, the levelness or descent of the land may be determined. To ascertain whether these threads are both of equal heights above the bar, let a mark be made where they in- ARCHIMEDEAX SCREW. or tcrsect some distant object; then reverse the instrument, or turn it end for end, and observe whether the threads cross the same mark. If they do, the instrument is cor- rect ; but if they do not, then one of the sights must be raised or lowered imtil it becomes so. In laying out canals and rail-roads, where extreme ac- curacy is needed, the spirit-level^ attached to a telescope, is used. So great is the perfection of this instrument, that separate lines of levels have been run with it for six- ty miles, without varying two-thirds of an inch for the whole distance. The use of a cheap and simple instrument to determine the position aad descent of ditches with ease and preci- sion, before commencing with the spade, will save a vast amount of the trouble and expense which those often meet with whoso only method is to " cvt and try,'*'' HYDRAULIC MACHINES. AECniMEDEAX SCREW. Machines for raising water are of frequent use on every farm. One of the simplest contrivances, in piinciple, for this purpose, is the Screw of Archimedes. It may be Fig. 241. The Screw of Archimedes easily made by winding a lead tube around a wooden cylinder or rod (fig. 241), in the form of a screw. When 10 21« MACIIINEUY IN CONNECTION WITH AVATER. j^laced in an inclined position, with one end in water, and made to revolve, the water resting at the lower side of each turn of the screw is gradually carried from one end to the other, and discharged at the upper extremity. Its simplicity and small liability to get out of order render the Archimedean screw sometimes useful where water is to be raised from an open stream to a short distance, as for irrigation, the motion being easily imparted to it by means of a small water-wheel, driven bv the stream. Fi-x. 21-2. PUMPS, Great improvement has been made in the common pump for farms within a few years. The best cast-iron pumps, made almost wholly of this metal, ex- ceed in durabilitv and ease of working those formerly con- structed of wood, and excel others in cheapness. Fig. 242 exhibits the working of the common pump, the water first passing through the fixed valve below, and then through the one in the piston ; both opening upward, it cannot flow back without instantly shut- ting them. The water is driven up by the pressure of the at- mos[)here, explained in the next chapter. Fig. 243 is an iron cistern pump, showing the mode of bolting it to the floor or platform, and rep- resenting, also, its neat and com- pact form, occupying but little Common Pump : b, lower or fixed . . valve, G, piston ivt'Ji valve, a, spacc at ouc Side, or 111 the comcr opening vjward ; D d, piston- /> i • , i , i rod ; F, spout. oi a kitchen, over the cistern. PUMPS. 219 Fio;. 244. Fig. 244 represents a cistern or well pump, so constructed that the working parts are about 20 inches below the plat- form, or base of the pump, and it is therefore well adapt- ed for outdoor work. If the well or cistern is kept covered tight, the pump will not freeze below the platform. It will succeed in any well not over twenty feet deep, and by means of its various couplings may be made to draw water in a hoiizontal or in- clined position, provided the whole height is not much over twenty feet. Fi" 243. Cistern Pump. Non-freezinrj Pump, An excellent deep- well pnmp, for wells of thirty feet depth or more, is represented by fig. 245 ; the working part, being placed at the bottom of the well, is adapted to any depth of water, the rod working safely within the pipe. The lower part of the cylinder is fur- nished with a strainer, and is plugged at the bottom, to 220 MACHIXERY IX CONNECTION WITH AVATKR. Fig. 246. Fig. 245. prevent the ingress of sand and J mud. The connecting pipe between the cylinder at the bottom and the \ standard at the top is wrought or galvanized iron. The pump, of course, needs bracing, to prevent swinoring: when worked. Drive. Pumps. — Fig. 24G rep- resents the new mode of making wells, by simply driving into the earth common iron gas-pipe, pointed 1: at the lower end, and perforated at the sides, near the lower extremity Deep-wetl Pump, DRIVE PUMPS. 221 for the Ingress of water — thus obviating entirely the cost and labor of digging wells. If driven through a subter- ranean spring, a stratum of water, or a wet layer of sand or gravel, it is obvious that the water will immediately flow through the perforations into the pipe ; and, by attaching a good pump to the pipe and pumping for a time, all the par- ticles of sand and fine gravel will be drawn out ; and the cavity thus formed around the perforations will remain filled with pure water. These tubes and pumps are admiiably adapted to localities where large beds of wet gravel exist fifteen or twenty-five feet below ; and, in fact, to all soils where large stones are not abundant. Where these occur, the pipe must be withdrawn, and tried in a new place, imtil success is attained. In the Chain Pump^ a partial cross-section of which is Fior. 247. Fisr. 248. Chain Pump. Section. Rotary Pump, for Barrels, etc. here shown, (fig. 247), the chain is made to revolve rapid- ly on the angidar wheel by means of a winch attached to 222 MACHINERY IN CONNECTION AVITH WATEE. Fig. 249 ^ < 1 1 li 1 JiPi I 1 ^ the upper one, and being furnished with a regular succes- sion of metallic discs, which nearly fit the bore in the tube, «, the water is carried up in large quantities. When the motion is discontinued, the water settles down again into the well, and consequently this pump is not liable to accident by freezing. By sweeping rapidly through the water, it preserves it in better condition, and prevents stag- nation. The friction being very small, it will last a long time without wearing out. Rotary Pumps. — A succes- sion of cavities made in the exterior of a short cylinder receive the water from the pump-tube below, and force it away into the elevating tube. When driven fast, it pumps with great rapidity. It possesses this advantage over the common pump, that the motion being continuous, no force is lost by repeatedly checkins: the momentum. In the figure on the preceding page, the pump is represented as inserted in a barrel of oil, which is to be emptied into the reservoir above, and is Suction and Fm-cing-pvmp. worked by hand. Larger rotary punips arc driven by horse and steam power. TURBINE WATER-WHEELS. 223 Sicction and Forcing-Pamp. — The accompanying cut (fig. 249) represents a suction and forcing-pump combined in one, for the purpose of drawing water from a well or cistern, and forcing it to tanks in upper stories, or throwing water into upper rooms in case of fire. By lengthening the rod, the working parts may be placed at the bottom of a deep well, and the whole used as a deep well pump. TFRBIi^E WATER-WHEELG. The large wooden wheels formerly used for the appli- cation of water power to mills and other machinery are rapidly giving place to iron Turhmc wheels. Overshot wheels, the best kind formerly employed, were turned by the weight of the water, the whole of which was held in the slow^ly descending buckets of the w^heel. Turbine wheels do not hold the water, but merely receive and im- part the force of the rushing current, the water being held by the flume above. Hence, a turbine Avheel of quite small size niay impart to machinery nearly the whole force of a j)Owerful current of water. Turbine wheels are j)laced in a horizontal position, witn vertical axes. Being under water, they never freeze ; and they are not impeded by back-water when a flood occurs. There are two principal kinds amoniic those in common use, — those, Fiff. 250. like the Reynolds wheel, which liave a single opening at the side. Section of Reymids' Wheel. through which the Wa- ter is admitted; and such as the Leffel and Van de Water wheels, into w^hich the water is admitted through several openings around them. 224 MACHINERY IX COXXECTION WITH WATER. Fie:. 252. Tiew of Jieyndds' Thirfdne Wheel. Fig. 250 is a section of the Reynolds wheel ; (7, the Fig. 251. gate for admitting the water ihrouorh the hori- zontal shute from the flume ; A, A, the circu- lar pnssnge for the water, which is gradually di- minished in volume as it strikes tlie buckets or blades, -5,j5, and escapes through the bottom and top of the wheel. The arrows sliow the currents, and the curved dotted lines the openings through which the Fig. 253. Avater esc.ipes — the curved arrows exhibiting the re- bounding of the current against the blades, before passing out through the is- sues. Fig. 251 is an exterior view of the Avheel, showing the gate for the admission of the water ; and tig. 252 represents the shaft and Fig. 254. Section of Van de Water Wheel. buckets separate. Fig. 253 is a section of the Yan de Water wheel, G, G, G, G, being the gates for admitting wa- ter, and ^, ^, the buck- ets — the arrows rep- resenting the entering currents. H shows, by dotted lines, the position Van de Water WTieei. of One of the gates when closed. The water, after entering the buckets, passes out TURBINE WATER-WHEELS. 223 below, where the blades nre curved backwards, to receive all the force of the escaping water. Fig. 254 is a view of this wheel, showing the admission gates, arid the wheel at the top, for opening and shutting the gates at one movement. The Reynolds wheel is placed under water, outside the flume, and the current admitted at the side, as aheady stated. The Van de Water wheel is placed within, and on the bottom of the flume, in the floor of which a circu- lar hole is cut, through which the water escapes. James Leffel & Co., of Springfield, Ohio, are extensive mani-- facturers of excellent turbine wheels, of which there are now over 7,000 in successful operation in driving flour- ing mills, saw-mills, and various other machinery. Turbine wheels, of the best construction, do not lose more than one-seventh or one-eighth of the whole descend- ing force of the water. Hence, the power of any stream may be determined beforehand with much accuracy, if the descent or head and the number of cubic feet of wa- ter per minute are known. It has been already shown in this work, that a single horse-power is equal to lifting 33,000 lbs. one foot, per minute. This is equivalent to raising 530' cubic feet of water to the same height, or .53 cubic feet, ten feet high. A stream, then, which falls 10 feetj and discharges 53 cubic feet in a minute, or nearly 1 per second, has an inherent force of one horse-power. Add one-seventh, making it about 63 cubic feet, and we have the size of a stream for one horse-power, at ten feet ,fall. Twenty feet descent would double the power, forty, quadruple it, and so on ; and a similar increase result from employing a larger stream. As examples, a small wheel, seven or eight inches in diameter, will be sufficient for such a purpose. One of this size, with 20 feet head, and discharging 70 or 80 cubic feet of water per minute, will possess about three horse-power ; and with forty feet head, requiring over 100 cubic feet per minute, it will have a power of eight or nine horses. 10* 226 MACHIXERT IN CONNECTION WITH WATEB. The simple rule given in the second paragraph of the present chapter, for determining the velocity of a current of water spouting out under any given head, will enable any one who understands arithmetic to calculate the proper speed of a turbine wheel, which varies with the head and the diameter of the wheel. It is found that the buckets or blades should move with about tw^o-thirds the ve- locity of the current as it rushes from tlie flume; hence, as an example, under a head of 16 feet, which drives out a stream about 22 feet i)er second, the exterior of the turbine wheel should move about 14 or 15 feet per second. If 1 foot in diameter, it should tiierefore revolve five times per second ; or, if 2^ feet in diameter, only twice per second. Otiier examples may be readily computed. There are occasional opportunities for employing water power for driving farm machinery — as thrashing ma- chines, mills for grinding feed, corn shellers, wood saws, straw cutters, etc., by bringing streams along hill-sides, or over bluff's ; in which cases, turbine wheels would be cheaper than steam-engines, and require neither food nor fuel. The water of small streams might be saved in dams or ponds, giving a power of five or six horses for one day in each week for grinding, thrashing, and other purposes. THE WATER-RAM. One of the most ingenious and useful machines for ele- vating water is the Water-ram. It might be employed with great advantage on many farms, were its principle and mode of action more generally understood. By means of a small stream, with only a few feet fall, a current of water may be driven to an elevation of 50 feet or more above, and conveyed on a higher level to pasture-fields for irrigation, to cattle-yards for supplying drink to domestic animals, or to the kitchens of dwellings for cu- linary purposes. THE WATER- RAJVf. 227 Fii?. 255. Its power depeiuls on the momentum of the stream. Its principal parts are the reservoir, or air-chamber, A, (fig. 255), the supply pipe, ^, and the discharge pipe, C. The running stream rushes (Town the drive, or supply- pipe, £y and, striking the waste valve, J>, closes it. The stream being thus suddenly checked, its momentum opens the valve, ^, up ward, and drives the water into the reser- voir, A, until the air within, being compressed into a smaller space by its elasticity, bears down upon the water, and again closes the valve, U. The water in the supply- pipe, ^, has, by this time, expended its mo- mentum, and stopped running ; therefore the valve, J), drops open again, and j^ermits it to escape. It recommences running, until its force again closes the waste valve, J>, and a second Water-ram. portion of water is driven into the reservoir as be- fore, and so it repeatedly continues. The great force of the compressed air in the reservoir drives the water up the discharge-pipe, C, to any required height or distance. The mere weight of the water will only cause it to rise as high as the fountain head ; but like the momentum of a hammer, which drives a nail into a solid beam, which a hundred pounds would not do by pressure, the striking force of the stream exerts great power. The discharge pipe, C, is usually half nn inch in diame- ter, and the supply-pipe should not be less than an inch and a fourth. A fall of three or four feet in the stream, with not less than half a gallon of water per minute, with a supply-pipe forty feet long, will elevate water to a height as great as the strength of common half-inch lead 228 MACHINERY IN CONNECTION WITH WATER. pipe will bear.* The greater the height, in proportion to the fall of the stream, the less will be the quantity of wa- ter elevate*^, as compared with the quantity flowing in the stream, or escaping from the waste valve. H. L. Emery gives the following rule for determining the quantity of water elevated from a stream: — Divide the elevation to be overcome by the fall in the drive-pipe, and the quotient will be the proportion of water, (passing through the drive-pipe), which will be raised, — deducting, also, for waste of ])Ower and friction, say one-fourth the amount. Thus, with 10 feet fall, and 100 feet elevation, one-tenth of the water would be raised if there were no friction or loss ; but, deducting, say one-fourth for these, seven and a half gallons in each hundred gallons would be raised, the rest escajung, or being required to accomplish this result. Or, if the fall of the water in the sup|)ly-pipe be 3 feet, and the elevation required in the discharge pi i)e be 15 feet, about one-seventh pait of all the water will be elevated to this heisrht of 15 feet. But if the desired height be 30 feet, then only about one-four- teenth part of the water will be raised ; and so on in about the same i-atio for different heights. A gallon per minute from the spring would elevate six barrels five times as high as the fall, in twenty-four hours, and at the same rate for larsrer streams. With a head of 8 or 10 feet, water may be driven up to a height of 100, or even 150 feet, provided the machine and pipes are strong enough. The best result is obtained when the length of the drive-pipe and the momentum it produces are just suf- ficient to overcome the reaction caused by the closing of * When water is raised to a considerable elevation by means of the water-ram, the reservoir must possess great strength. If the heiglit be 100 feet, the pressure, as shown on a former paije, is about forty-four pounds to the square inch. With an internal surf ice, therefore, of only 2 square feet, the force exerted by the column of water, tending to burst the reservoir, would be equal to more than twelve thousarj pounds. THE WATER-RA!Sr. 229 the waste valve at each pulsation, and prevent the current of water from being thrown backward or up the drive- pipe ; hence, the greater the disproportion between the fall and tiie required elevation, the longer or larger must be the drive-pipe, in order to obtain sufficient momentum. A descent of only a foot or two is sufficient to laise water to moderate elevations, but the drive-pipe should be of large bore. This pipe should always be very nearly straiglit, so that the water, by having a free course, may acquire sufficient momentum to compress the air in the ram, and push the water up the discharge-pipe. Water may be carried to a distance of a hundred rods or more, but as there is some friction in so long a discharge-pipe, a greater force is required than for sliort distances. Tlie discliarge-pipe should, therefore, be larger, as the length is increased. Half an inch diameter is a ccmimon size, but long pipes may be five-eighths or three-fourths ; and, when practicable, it is more economical to reach an eleva- tion with a short and strong pipe, and to use a lighter and weaker one for the upper part. A pit, lined with brick or smooth stone, for placing the ram, protects it from freezing ; and both pipes should be under ground for the same reason. The supply or drive-pipe is usually 40 to 50 feet long ; but where the fall is 8 or 10 feet, it should be sixty or seventy feet. Unlike a pump, there is no friction or rubbing of parts in the water-ram, and, with clean water, it will act for , years without repairs, continuing through day and night its constant and regular pulsations, unaltered and unob- served. A small quantity of sand, or of dead grass or other fibre, in the water, will be liable to obstruct the valves, and render frequent attention necessary. WATER-ENGINES, including those for extinguishing fires and for irrigating gardens, are constructed on a principle quite similar to 230 MACHINERY I>- CONNECTION WITH W.VTI:R. Fig. 25G. Fig. 257. Garden-engine that of the water-ram. I.i- steacl, however, of compresc- ing the air, as in the ram, by the successive strokes of a column of running water, it is accomplished by means of a forcing-pump, driving the water into the reservoir, from which it is again ex- pelled \\\t\\ great power, by means of the elasticity of the compressed air. Fig. 256 represents a garden-engine, movable on wheels, which may be used for watering gardens, washing windows, or as a small fire-engine. Fig. 257 is another, of smaller size, for the same purposes, and in a neat and compact CvUndncal Garden-engine. form, the working part being within the cylindrical case. THE FLASH-WWEEi,, FOR IIAISING WATER. 261 THE FLASH-WHEEL is employed with great advantage where the quantity of water is large, and is to be raised to a small height, as in draining marshes and swamps. It is like an undershot wheel with its motion reversed; in fig. 258 the ar- rows show the direction of tlie current when driven up- ward. It must, of course, be made to fit the channel closely, without touching and causing friction. In its best form, its paddles incline backward, so as to be nearly up- Pijj. 258. Flash or fen wlicclfot raising ivatcr rapidly short distance!^. right at the time the water is discharged from them into the upper channel. It has been much used in Holland, where it is driven by wind-mills, for draining the surface- water off from embanked meadows. In England, it has* been driven by steam-engines; and in one instance, an eighty-horse-power engine, with ten bushels of coal, raised 9,840 tons of water six feet and seven inches high, in an hour. This is equal to more than 29,000 lbs. raised one foot per minute by each horse-power, showing that very little force is lost by friction in the use of the flash-wheel. 232 3IACHINERY IN CONNECTIOX WITH WATER. WAVES. NATURE OF WAVES. An inverted syphon, or bent tube, like that shown in fig. 259, may be used to exhibit the *'^'- '^'•^• principle on which depends the motion of the waves of the sea. The action of the waves on shores and banks, and the inroads which they make upon farms situated on the borders of lakes and large rivers, present an interesting sub- ject of inquiry. If the bent tube (fig. 259) be nc:"irly filled with water, and the surface be driven down i:i one arm by blowing suddenly into it, the liquid will rise in the other arm. The increased weight or head of tliis raised column will cause it to fill again, its momentum carrying it down belov/ a level, and driving the water up the other arm. The surfaces will, therefore, continue to vibrate until the force is spent. The rising and falling of waves depend on a similar action. The wind, by blowing strongly on a por- tion of tlie water of the lake or sea, causes a depression, and produces a corresponding rise on the adjacent surface. The raised portion then falls by its weight, with the add- ed force of the wind upon it, until the vibrations increase into large waves. THE WATER NOT PROGRESSIVE. The waves thus produced have a progressive motion, (for reasons to be presently shown), as every one has ol> served. A curious optical deception attending this ad- vancing motion has induced many to believe that the water itself is rolling onward ; but this is not the fact. The boat which floats upon the waves is not carried for- ward with them j they pass underneath, now lifting it on WATER OF WAVES NOT PROGRESSIVE. 233 their summits, and no^v dropping it into the hollows between. The same effect may be observed with the wa- ter-fowl, which sits npon the surface. It often happens, indeed, that tlie waves on a river roll in an opposite di- rection to the current itself If a cloth be laid over a number of parallel rollers, so far apart as to allow the cloth to fall between them, and a progressive motion be then given to them, the cloth remain- ing stationary, a good representation of waves will b« afforded, and the cloth will appear to advance ; or if a strip of cloth be laid on a floor, repeated jerks at one end will produce a similar illusion. It is only the form of the wave, and not the water which composes it, which has the onward motion. Let the dark line in fig. 260 represent the suifaceof the water. Fig. 2(50. A B A. is the crest of one of the waves, and beino^ hisrher than the surface at J?, it has a tendency to fill, and H to rise. But the momentum thus acquired carries the^e points so far that they interchange levels. The same change takes place with the other waves, and the dotted line shows the newly formed surface as the water thus sinks in one place and rises in another. The same process is again repeat- ed, and each wave thus advances further on, and its pro- gressive motion is continually kept up. BREADTH AND VELOCITY OF WAVES. Each wave contains at any one moment particles in all possible stages of their oscillation ; some rising, and some falling; some at the top, and some at the bottom; and the distance from any row of particles to the next row that is in precisely the same stage of oscillation is called 234 MACHINERY IN CONNECTION WITH WATER. breadth of the wave, that is, the distance from crest to crest, or from hollow to hollow. There is a striking similarity between the rising and falling of waves and the vibrations of a pendulum, and it is a very interesting and remarkable fact, that a wave al- ways travels its own breadth in precisely the same time* that a pendulum, whose length is equal to that breadth, performs one vibration. Thus, a pendulum 39^ inches long beats once in each second, and a wave whose breadth is 39^ inches travels that breadth in one second. The length of a pendulum must be increased as the square of the time for its vibrations; that is, to beat but once in two seconds, it must be four times as long as for one second ; to beat once in three seconds, it must be nine times as long, and so on. In the same way, waves which travel their breadth in two seconds are four times as wdde as those traveling their breadth in one second ; and thus their breadth, and consequently their speed, increases as the square of the time. Large waves, therefore, roll on- ward with far greater velocity than small ones. If only tliirty-nine inches wide, they move about two and a quar- ter miles an hour, and pass once each second; if 13 feet wide, tliey move 43^ miles an hour, passing onee in 3 seconds. .52 do. do. 9 do. do. 4 do. 209 do. do. 18 do. do. 8 do. 836 do. do. 36 do. do. 16 do. Although the water itself does not advance where there is much depth, yet when it reaches a shore or beach, the hard and shallow bottom prevents it from falling or sub- siding, and it then rolls onward with a real progressive motion from the momentum it has acquired, breaks into foam, and laches the earth and rocks. The sea billows are sometimes twenty-five feet in elevation,* and when these advance upon a stranded ship on a lee shore, with * No authentic measurement gives the perpendicular height of wave* more than twenty-five feet. PREVENTING THE INROAD OF WAVES. 2o5 the speed of a locomotive, their effects are in the highest degree appalling; and iron bolts are snapped, and massive timbers crushed beneath their violence. PREVENTING THE INROAD OF WAVES. To prevent the inroads of lake waves upon land, the remedies must vary with circumstances. The difficulty would be small if the water always stood at the same height. The greatest mischief is usually -done when they rise over the beach of sand and gravel which they have beaten for centuries. Wooden bulwarks soon decay. Where loose stones can be had in large quantities, form- ing sloping rip-rap walls, they may be cheapest ; but they are not unfrequently placed too near low-water mark to protect the banks. Substances which offer a gradual im- pediment to the waves are often quite effectual, though not formidable in themselves. It is curious to observe how 80 slender a plant as the bulrush, growing in water several feet deep, will destroy the force of Avaves. If it grew only near the shore, where the water has progressive mo- tion, it would soon be dashed in heaps on the beach. Parallel hedge-rows of the osier willow, protected by a wooden barrier until well giown and established would, in many cases, prove efficient. Stones and timber bulwarks are often made needlessly Fig. 261. liable to injury by being built nearly ] terpen dicular, and the waves break suddenly, and with' full force, like the blows of a sledge against them. A better form is shown in fig. 261, where a slope is first presented, to weaken their force without imposing a full resistance, and their strength is gradually spent as they rise in a curve. A 236 MACHINERT IN CONNECTION WITH WATER. 3iore gradual slope than the figure represents would be nill better. It is on this principle that the stability of the world-renowned Eddystone light-house depends. The base spreads out in every direction, like the trunk of a tree at the roots ; and although the spray is sometimes dnshed over its lofty summit by the violence of the storm, it has stood unshaken on its rocky base far out in the sea, against the billows and tempests, for nearly a century. An instance occurred many years ago in England, where the superiority of knowledge over power and capital without it was strongly exemplified. The sea was mak- ing enormous breaches on the Norfolk and Suffolk coast, and inundated thousands of acres. The government com- missioners endeavored to keep it out by strong walls of masonry and breakwaters of timber, built at great ex. pense ; but they were swept away by the fury of the bil- lows as fast as they were erected. A skillful engineer visited the place, and, with much difficulty, persuaded them to adopt his simple plan. Observing the slope of the beach on a neighboring shore, he- directed that suc- cessive rows of fagots or brush be dej^osited for retaining the sand, which was carted from the hills, forming an em- bankment with a slope similar to that of the natural beach. Up this slope the waves rolled, and became grad- ually spent as they ascended, till they entirely died away. The breach was effectually stopped, and this simple struc- ture has ever since resisted the most violent storms of the German Ocean. CONTENTS OF CISTERNS. Connected with the subject of hydraulics is the collec- tion and security of water falling upon roofs, in all oases where a deficiency is felt by farmers in the drought of summer. The amount which falls upon most farm-build- ings is sufficient to furnish a plentiful supply to all the CONTENTS OF CISTERNS. 237 dDinestic animals of the farm when other supplies fail, if cisterns large enough to hold it were only provided. Generally speaking, none at all are connected with barns and out-buildings, and even when they are furnished, they are usually so small as to allow four-fifths of the water to waste. If all the rain that descends in the Northern States of the Union should remain upon the surface, without sink- ing in or running off, it would form, each year, a depth of about three feet. Every inch that falls upon a roof yields two barrels for each space ten feet square; and seventy-two barrels a year are yielded by three feet of rain. A barn thirty by forty feet supplies annually from its roof eight hundred and sixty-four barrels, or enough for more than two barrels a day for every day in the year. Many farmers have in all five times this amount of roof, or enough foi* twelve barrels a day, year- ly. If, however, this water were collected, and kept for the dry season only, twenty or thirty barrels daily might be used. In order to prevent a waste of water on tlie one hand, and to avoid the unnecessary expense of too large cisterns, their contents should be determined beforehand by calcu- lation. RULE FOR DETERMINING THE CONTENTS. A simple rule to determhie the contents of a cistern, circular in form, and of equal size at top and bottom, is the following : — Find the depth and diameter in inches; square the diameter, and multiply the square by the deci mal .0034, which will give the quantity in gallons* for one inch in depth. Multiply this by the depth, and divide by * Tliis is the standard j^allon of 231 cubic inches. The gallon of tht StJite of New York contains 221.184 cubic inches, or 6 pounds at it maximum densitj. 238 MACHINERY IN CONNECTION WITH 'WATEI?. 31 1^, and the result will be the number of barrels the cis- tern will hold. For each foot in depth, the number of barnls answer- ing to the different diameters are, For 5 Icet diameter 4.66 barrels. 6 " 6.71 " 7 " 9.13 " 8 " 11.93 " 9 " 15.10 " 10 " 18.65 " By the rule above given, the contents of barn-yard cisterns and manure tanks maybe easily calculated for any size whatever. The size of cisterns should vary according to their in- tended use. If they are to furnish a daily supply of water, they need not be so large as for keeping supplies for summer only. The average depth of rain which falls in this latitude, although varying considerably with season and locality, rarely exceeds seven inches for two months. The size of the cistern, therefore, in daily use, need never exceed that of a body of wnter on the whole roof of the building, seven inches deep. To ascertain the amount of this, multiply the lengtli by the breadth of the building, reduce this to inches, divide the product by 231, and the quotient will be g.iUons for each inch of depth. Multiply- ing by 7 will give the full amount for two months' rain falling upon the roof. Divide by 31^, nnd the quotient will be bariels. This will be about fourteen barrels for every surface of roof ten feet square when mensured hori- zontally. Therefore, a cistern for a barn 30 by 40 feet should hold one hundred and sixty-eight barrels ; that is, as large as one ten feet in diameter, and nine feet deep. Such a cistern would supply, with only thirty inches of rain yearly, no less than six hundred and thirty barrels, or nearly two a day. Cisterns intended only for drawing from in times of drought, to hold all the water that may fall, should have about three times the preceding capacity. PART III. MACHINERY IN CONNECTION WITH AIR CHAPTER I. PRESSURE OF AIR. Pneumatics treats of the me- chanical properties of the air. The actual weight of the air may be correctly found by weigb- inor ;| stroiio: o-lass vessel furnished with a stop-cock, a (iig. 262), after the air lias been withdrawn from it by means of an air-pump. Let it be accurately balanced by "weights in the opposite scale ; then turn the stoi>cock and admit 4. the air, and it will immediately descend, as shown in the figure. The weight of the admitted air may be ascertained by adding weiohts mitil it is ao-ain balanced. Fisr. 262. Balance for Weighing Air. HEIGHT AND WEIGHT OF THE ATMOSPHERE. The atmosphere which covers the earth extends upward to a height of about fifty or sixty miles. At the surface of the earth the air is about eiofht hundred times liirhter than the water, and the higher we ascend, the rarer or 239 240 MACHINERY IN CONNECTION WITH AIR. lighter it becomes, from the diminished ])ressui-e of the weiglit above. At seven miles high, it is four times light- er than at the surface ; at twenty-one miles, it is sixty- four times lighter; and at fifty miles, about twenty thou- sand times lighter. At this height it ceases to refi'act the rays of the sun so as to render it visible at tlie earth's sur- face ; but if it decreases at the same rate upward, at a hundred miles high it must be nearly a thousand million limes rarer than at the earth. If the atmosphere were uniformly of the same density, with its present weight, it would reach only five miles liigh. Although so much lighter than water, yet, from its great height, it presses upon the surface of the earth as heavily as a depth of thirty-three feet of water. This is nearly equal to fifteen pounds on every square inch, or more than two thousand pounds to the square foot. This enormous weight would instantly crush us, did not air, like liquids, press in every direction, so that the upward exactly counterbalances the downward pressure, and the air within the body counteracts that without. The weight of the atmospliere is strikingly shown by means of an air- pump, which pumps the ail- from a glass vessel, placed mouth downward upon the brass plate of the machine (fig. 263). When the air is pumped out, and the upward or counter- balancing air remov- ed, so heavy is the load upon the glass ^'■'■■^'"^' vessel, that a strong man could scarcely remove it from the plate, although it Fi":. 2(53. AVEIGHT OF THE ATMOSPHERE. 241 be no l.'U'gcT tlian a, small tumbler. A glass jar with a mouth SIX inolies across would need a force equal to nearly four hundred pounds to displace it. If Fig. 264. there be a glass vessel open at both ends, the hand placed on the top may be so firmly held by the pressure that it can not be removed until the air is again admit- ted below (fig. 2G4). If a thin plate of glass be placed on the top of this open m rn^vi fastened vessel, on pumping out the air, the ^^ ^"^' weight will suddenly crush it with a noise like the report of a gun. Some interesting instances occur in nature of the use of atmospheric pressure. Flies walk on glass by means of the pressure against the outside of their feet, the air having been forced out beneath. In a similar way, some kinds of fishes cling to the sides of rocks under water, so as not to be swept ofl^ by the current. Dr. Shaw threw a fish of this kind into a pail of water, and it fixed itself so firmly to the bottom, that, by taking hold of the tail, he lifted up the pail, water and all. It is the i)ressure of the atmosphere upon water that drives it up the barrel of a pump as soon as the air is pumped out from the inside. Hence the reason that pumps can never be made to draw water more than thirty- three feet below the piston, a height corresponding to the weight of the atmosphere. In practice they never draw water even to this height, as a perfect vacuum can not be made by pumping. THE BAROMETER. On the same principle the Barometer is made. It con- sists of a glass tube, nearly three feet long, open at one end, and which is first filled with mercury, a liquid nearly fourteen times heavier than water. The open end is then 11 243 MACIIIXEKY I.V CONXECTIOX WITH A IK. placed downward in a cup of mercury. The vrcight of the mercury in the tube causes it to descend until the pressure of the atmosphere on the mercury in the cup preserves an equilibrium, whicli takes place when the col- umn in the tube has fallen to about two feet and a half high, the upper part of the tube being left a perfect vacuum, as no air can enter (fig. 265). Xow, as the height of the colunm of mercury depends aL)ue upon the weight of the atmosphere, then, whenever the air becomes lighter or heavier, as it constantly does during the changes of the weather, the risinof or fallings of the column indicates these changes; and, what is very important, it shows the approaching changes of the weather several ^fS-"^" hours before they actually take place. Hence it becomes a valuable assistant in foretelling the weather. AVhen the mercury foils, showing thnt the atmosphere is becoming lighter, it indicates the approach of storms or rain ; when it rises, a settled or fair sky follows. These are often foreshown before there is any change in the appearance of the sky. For this rea- son the barometer is sometimes called a weather-glass. It is of the greatest value to navigators at sea. Long voyages, which formerly required a year, have been made in eight months by means of the assistance afforded by the barometer, admitting a full spread of canvas by night as well as by day, from the certainty of its predictions. On land its indications are not so certain, and at some places less so than at others. Sometimes, and more com- monly during autumn and winter, the sinking of the mer- cury is followed only by wiml instead of rain. There is, however, no doubt that its use would be of much advant- age in large farming establishments, more especially dur- ing the precarious seasons of haying and harvesting. The barometer is an instrument of great value in de- termining with little labor, and with considerable accuracy, THE BAROMETER. 243 the heights of mountains, hills, and the leading points of an extensive district of country. In rising above the level of the sea, the weight of the air above us becomes less ; that is, the pressure of the air upon the barometer de- creases, and the column of mercury gradually falls as we ascend. To determine, therefore, the height of a mount- ain, we have only to place one barometer at its foot while another stands at the top, and then, by observing the difference in the height of the mercury, we are enabled to calculate the height of the mountain. The following ta- ble shows how much the barometer falls at different alti- tudes, thirty inches being taken for the sea-level :* At 1,000 feet above the sea, the column fiills to 28.91 inches. 2,000 " " " " " 27.80 " 3,000 " " " " " 26.85 " 4,000 " " " " " 25.87 " 5,000 *' " " " *' 24.93 " 1 mile " " " " 24.67 " 2 " " " " " 20.29 ** 3 " " " " " 16.68 " 4 " " " " " 13.72 *' 5 " " " " " 11.28 '* in (t (( u (( u 4 24 *' 15 " " '* " " 1.60 " 20 " " ** " " 0.95 " At the level of the sea, the barometer falls about one hundredth of an inch for a rise of nine feet, or a little more than the tenth of an inch for a rise of one hundred feet. At a height of one mile it requires about eleven feet rise to sink the mercury a hundredth of an inch. in selecting land in mountainous districts of the coun- try, where degrees of frost increase with increased alti- tudes, and where the height of one portion above another has an important relation to the cost of drawing loads up * The mercury rarely stands as hvj:h. as 30 inches at the level of the eea, the mean height being about 29.5 inches. But this does not affect the measurement of heiiihts, which is determined, not by the actual height, but by the difference in heights. 244 MACHINERY IN CONNECTION WITH AIR. and down liill, the barometer might become of much 2)ractical value. THE SYPHON. The 8yphon operates on a principle quite similar to that of the pump ; but, instead of pumping out the air of the tube through which the water rises, a vacuum is created Fig. 266. by the weight of a column of water, in the following way : Fig. 266 represents a syj)hon, which is nothing more than a tube bent in the form of a letter U in- verted. Now, if this be filled through- out with water, and then placed with the shorter arm in the vessel of water, A, the weight of the column of water in the longer arm, which is outside, will over- balance the weight of the other column, and will therefore run out in a stream. This tends to cause a vacuum in the tube, which is instantly filled by the water rushing up the shorter arm, being driven up by the press- ure of the atmosphere. A stream Avill consequently con- tinue running through the syphon until the vessel is drained. The syphon may sometimes be very usefully employed in emptying pools or ^'^^- ^^• ponds of ^vater on high ground, with- out the trouble of cutting a ditch for this purpose. For instance, let a (fig. 267) represent a body of water which it is desirable to drain off; by placing the lead tube, b e, so that the arm, e, may be lowest, and applying a pump at this arm to withdraw the air and fill the syphon with water, it will commence running, and continue until the WIKDS. 245 water has all been , Liquids are found to conduct heat very slowly, and they were for a long time considered perfect non-conduct- ors. Some interesting experiments have been performed in illustration of this property. A large glass jar may be filled with water (fig. 286), in which may be fixed an air thermometer, which is always quickly sensitive to small quantities of heat. A shallow cup of ether, floating Fio- 287 y^^^ above the bulb, may be set on fire, and will continue to burn for some time before any effect can be seen upon the thermometer. The upper surface of a vessel of water lias been made to boil a long time with a piece of unmelted ice at the bottom. Liquids are found, how- ever, to possess a conducting power in a very slight degree. When a vessel of water is heated in the ordinary way over a fire, the heat is carried through it merely by the motion of its partic^.es. The lower portion becomes warm, and expands ; it immediately rises to the surface, and colder portions sink down and take its place, to ascend in their turn. In this way, a constant circulation is kept up EXPANSION BY HEAT. 2G;J among tlie particles. These rising and descending cur- rents are shown by the arrows in fig. 287. This result may be easily shown by fil.ing a flask with water into which a quantity of sawdust from some green hard wood has been thrown, which is about as heavy as water. It will traverse the vessel in a manner precisely as shown ill the figure. These results indicate the importance of applying heat directly to the bottom of all vessels in which water is in- tended to be heated. A considerable loss of heat often occurs when the flame is made to strike against the sides only of badly arranged boilers. EXPAXSIOX BY HEAT. An important effect of heat is the expansion of bodies. Among many ways to show it, an iron rod may be so tit- ted that it will just enter a hole made for the purpose in a piece of sheet-iron. If the rod be now heated in the fire, it expands and becomes larger, and can not be thrust Fiff. 288. in::o the hole. The expansion maybe more visibly shown and accurately measured by means of an instrument called the Pyrometer (fig. 288). The rod a h^ secured to its 264 HEAT. place by a screw at a, presses against the lever c, and this against the lever or index d^ both of which multiply the motion, and render the expansion very obvious to the eye when the rod is lieated by the lamp«j. If the rod should expand one-fiftieth of an incli, and each lever multiplies twenty times, then the index (or second lever) will move along the scale eight inches ; for 20 times 20 are 400, and! 400-50ths of an inch are 8 inches. Many cases showing the expansion of heated bodies oc- cur in ordinary practice. One is afforded by the manner in which the parts of carriage wheels are bound together. The tire is made a little smaller than the wooden part of the wheel; it is then heated till, by exj^anding, it be- comes large enough to be put on, when it is suddenly cooled with water, and, by its powerful contraction, binds ev'ery part of the wheel together with great force. Hogs- heads are firmly hooped with iron bands in the same way, with more force th;in could ever be given by driving with blows of the mallet. This principle was very ingeniously applied in drawing together two expanding brick walls of a large building in Paris, which threatened to burst and fall. Holes were drilled in the opposite walls, through which strong iron bars across the building projected, and circular p'ates of iron were screwed on these projecting ends. The bars were then heated, which increased their length ; the })lates were next screwed closely against the walls. On cooling, they contracted, and drev/ the walls nearer together. The process was repeated on alternating bars, until the walls Avere restored to their perpendicular positions. All tool^, where the wooden handles enter iron sockets, will hold more firmly if the metal is heated before insert- ing the wood. The metallic parts of pumps sometimes become very difficult to unscrew, and a case has occurred where two strong men could not start the screws, until a bystander EFFECTS OF SUDDEN EXPANSIOX. 265 suggested that the outer piece be heated, keeping the in- ner cool, when a force of less than ten pounds quickly separated tliem. In other cases, where the large iron nuts have been thoughtlessly screwed, while warmed with the hands, on the cold metallic axles of wood-sawing ma- chines in winter, they have contracted so that the force of two or three men has been insufficient to turn them. The sudden expansion of bodies by Iieat sometimes causes accidents. Thick glass vessels, when unequally heated, expand unequally, and break. Heated plates of cast-iron or cast kettles are liable to be fractured by suddenly pouring cold water upou them. The same ef- fect has been usefully applied in splitting the scattered rocks which encumber a farm, and which are too large to remove while entire. Fires are built upon them ; the up- per surface expands while the lower remains cold, and large portions are successively separated in scales, and sometimes the whole rock is severed. The only care needed is to observe attentively and remove with an iron bar any parts which may have become loosened by the heat, and which would prevent the heat from passing to other portions. One man will thus attend to a large number of fires, and will split in pieces ten times as many rocks in a day as by drilling and blasting. -pw, 239. THE STEAM-ENGINE. The Steam-engine owes its power to the enormous expansion of water at the moment it is converted into steam, which is about 1,600 times its bulk when in a liquid state. The principle on which the steam-engine acts may be understood by a simple instrument, represented in fig. 289. A glass tube with a small bulb is furnished with a solid, air- tight piston, capable of working up and 12 266 HEAT. down. The water in the bulb, «, is heated with a spirit-lamp or sand-bath ; the rising steam forces u]) the piston. Now, immerse the bulb in cold water or snow, and the steam is condensed again into \vater, the tube i^ left vacant, and the pressure of tlie atmoi^phere forces down the piston. By thus alternately applying heat and cold, it is driven up and down like the piston of a steam- engine. The only difference is, the steam-engine is fur- nished with apparatus so that this application of heat and cold is performed by the machine itself. The bulb repre- sents the boiler, and the tube the cyUnder; but in the steam-engine, the boiler is separate, and connected by a pipe with the cylinder ; and instead of applying the cold water directly to the cylinder, it is thrown into another vessel, called the condenser, connected with the cylinder. When Newcomen, who made the first rude rogulirly working engine, began to use it for pumping watei*, he employed a boy to turn a stop-cock connected with the condenser, every time the piston made a stroke. The boy, however, soon grew tired of this incessant labor, and endeavored to find some contrivance for relief. This he *^ffected by attaching a rod from the piston or working- beam to the cock, which wns turned by the machine itself at every stroke. This was the origin of the first self- actinor enorine. The different parts ot a common steam-engine may be understood from the following figures, one representing the boiler, and the other the working machinery. The boiler, B (fig. 290), contains water in the lower part, and steam in the upper; F B i^ the fire ; -y o is the feed-pipe y v, a valve, closed by the lever b c «, whenever the boiler is full enough, by means of the rising of the float, S, and opened whenever the float sinks from low water, iff, barometer gauge, to show the pressure of the steam ; tr, weight on the lever, e b, for holding down the safety-voice : this lever being graduated like a steelyard, THE STEAM ENGITJ'E. 267 the force of the steam may be accurately weighed. Uis a valve opening downward, to prevent the boiler being crushed by atmospheric pressure, by allowing the air to jmss in whenever the steam liappens to decline. Two Fi''. 290. Boiler of Steam-engine. tubes, with stop-cocks, c and c?, one just belov/ the water- level, and the other just above it, serve to show, by open- ing the cocks, whether the water is too high or too low. The Avorking part of the engine is represented in the figure on the following page (fig. 291). The steam enters by the pipe, 5, from the boiler on the other side of the brick wall, as shown in fig. 290. The steam ])asses through what is called a four-way-cocli^ a^ first into the lower, then into the upper end of the cylinder, C, as the piston, P, moves up and down ; this is regulated by the levers, y y. The piston-rod, E^ is attached to the working-beam, B -F, turning on the centre, A. The rod, F B, turns the fly- wheel, H H^ and drives the mill, steamboat, or machinery to be set in motion. 268 HEAT. The condenser, J, shown directly under tlie cylinder, re- mains to l)e described. It is hnmersed in a cistern of cold water, and is connected by pipes with the upper and lower end of the cylinder. Through tliese j^ipes the steam Fi- 2!)1. Low-prtssurt Sleum-tngine. passes out of the cylinder, first from one end nnd tlien from the other, and is condensed into water by a jet of cold water thrown into it by the hijection-cock. When condense;!, it is pumped out by the jnimp, 0, into the well or reservoir, TTJ and then again into the feed-pipe of the boiler. Warm Avater is thus constantly supplied to the boiler, and effects a great saving of fuel. The supply of steam and the motion of the engine are regulated by tlie ^o?;e^^^or, G. When the motion is too fast, the two suspended bulls, which revolve on a vertical or upright axis, and which hang loosely like pendulums, are thrown out from the axis, producing the movement of a rod which shuts the steam-valve. When the motion QUALITIES OF THE STEAJNI-ENGINE. 269 is too slow, the balls approach the axis, and open the valve. In high-pressure engines, the steam is not condensed, but escapes into the open air at every stroke of the piston, . which produces the loud, successive pu^o of all engines of this kind. The steam-engine, in its most perfect form, is a striking example of human ingenuity, and its qualities are thus described by Dr. Arnott : "It regulates with perfect ac- curacy and uniformity the number of its strokes in a given time, and records them as a clock does the beats of its pendulum. It regulates the quantity of steam ; the brisk- ness of the fire ; the supply of water to the boiler ; the supply of coals to the fire. It opens and shuts its valves witl) absolute precision as to time and manner; it oils its joints; it takes out any air accidentally entering parts which should be vacuous ; and when any thing goes wronor which it can not of itself rectifv, it warns its at- tendants by ringing a bell ; yet, with all these qualities, and even when exciting a force of six hundred horses, it is obedient to the hand of a child. Its aliment is coal, wood, and other combustibles. It consumes none while idle. It never tires, and wants no sleep. It is not sub- ject to any malady when originally well made, and only refuses to work when worn out with age. It is equally active in all climates, and will do work of any kind; it is a water-pumper, a miner, a sailor, a cotton-spinner, a weaver, a blacksmith, a miller, a printer, and is indeed of all occupations ; and a small engine in the character of a steam pony may be seen dragging after it, on an iron rail- way, a hundred tons of nierchatidlse, or a thousand per- sons with the speed of the wind." Steam-en Of ines have been much used on laro;e farms in Enorland for thrashinoj, o-rindinor the feed of animals, cut- o coo ' ting fodder, and for other purposes. A successful English farmer has used a six-horse steam-engine to drive a pair 270 HEAT. of mill-stones, for thrashing and cleaning grain, elevating and bagging it, pumping water for cattle, cutting straw, Fig. 29:2. turning a grindstone, and driving liquid ma- nure through pipes for irrigating his fields,; employing the waste steam in cooking food for cattle and swine. In tl lis country, Avhere horse labor is cheaper, steam-engines have not come into so general use; but on large farms, where a WaxTs Farm Engine. ten - horse - power or more is required, they liave been employed to much advantage, consuming no food, and requiring no care FiL'. 2!):]. Wood^s Engine on Wieels, wiih Hpe Folded Down. when idle. Excellent steam-engines for this purpose are manufactured by A. X. Wood & Co., of Eaton, wood's steam-exgine. 271 Madison Co., N. Y., a representation of which is given in the accompanying figure (fig. 292.) Wlien intended to move from place to place, these engines are furnished ready mounted on wheels (fig. 293). The twelve-horse-power engines cost about |1,()00, and have thrashed over a hund- red bushels per hour, using half a cord of wood, or 300 or 400 lbs. of coal for ten hours. A Western farmer thrashed 14,250 bushels of wheat in five consecutive weeks, working five and a half days each, Mdth one of these en- gines. The smoke-pipe is guarded, so that straw placed within a few inches cannot be set on fire. (See page 29^.) More difficulty obviously exists in adapting the steam- engine to plowing than for stationary purposes. In order to possess sufficient power, when used as a locomotive, the engine must be made so heavy as to sink in common soft soiJ even with large and broad wheels ; and this tendency is increased by the jar of the machinery which these \\heels support. For this reason, all locomotive plows have failed. Better success has attended the use of stationary engines, employed for drawing gangs of plows, by means of wire rope, across the fields. In Eng- land, where much of the soil is tenacious, and where fuel and manual hibor are cheap, and horse labor expensive, this mode of plov,-ing has been found profitable when em- ployed on an extensive scale, and is now much used. EXCEPTIOX TO EXPANSION BY HEAT, A striking exception to the general law of expansion by aeat occurs in the freezinsc of water.* Durino- its chancre to a solid state, it increases in bulk about one-twelfth, and this expansion is accompanied with great force. The bottoms of barrels are burst out, and cast-iron kettles are split asunder, when water is suffered wholly to freeze in * There are a very few other substances which expand on passing from a liquid to a solid state. 272 HEAT. them. Lead pipes filled with ice expand ; but if it is often repeated, they are cracked into fissures. A strong brass globe, the cavity of whicli was only one inch in di- ameter, was used by the Florentine academicians for the purpose of trying the expansive force of freezing water, by which it was burst, although the force required was calculated to be equal to fourteen tons. Experiments were tried at Quebec, in one of which an iron plug, nearly three pounds in weight, was thrown from a bomb-shell to the distance of 415 feet ; and in another, the shell was burst by the freezing of the water which it contained. This expansion has a most important influence in the pulverization of soils. The water which exists through all their minute portions, by conversion to frost, crowds the particles asunder, and when thawing takes place, the whole mass is more completely mellowed than could pos- sibly be eflTected by the most perfect instrument. This mellowing is, however, of only short duration, if the ground has not been well drained to prevent its becoming again packed hard by soaking wath water. But this is not the most important result from the ex- pansion of water. Much of the existing order of nature and of civilized life depends upon this property ; without it the great mass of our lakes and rivers would become converted into solid ice ; for, as soon as the surface became covered, it would sink to the bottom, beyond the reach of the summer's sun, and successive portions being thus add- ed, the great body of all large rivers and lakes would become permanently frozen. But instead of this disas- trous consequence, the ice, by resting upon the surface, forms an effectual screen from the cold winds to the wa- ter below\ LATENT HEAT. If a vessel of snow, which has been cooled down to several degrees below freezing by exposure to the sever 3 LATENT HEAT. 273 3old of winter, be placed over a steady fire with a ther- mometer in the snow, the mercury will rise by the increas- ing heat of the snow until it reaches the freezing point. At this moment it will stop rising, and the snow will be- gin to melt ; and although the heat is all the time passing rapidly into the snow, the thermometer will remain per- fectly stationary until it is all converted to water. The heat that goes to melt the snow does not make it any hot- ter; in other words, it becomes latent (tlie Latin word for hidden)^ so as neither to aifect the sensation of the hand nor to raise the thermometer. Now it has been found that the time required to melt the snow is sufficient to heat the same quantity of water, placed over the same fiie, up to 172 degrees, or 140 degrees above freezing; that is, 140 degrees have become latent, or hidden, in melting the snow. This same amount of heat may be given out again by placing the vessel of water out of doors to freeze. A thermometer will show that the water is growing colder by the escape of the heat, until freezing commences. Af- ter this it still continues to pass off, but the water becomes no colder until all is frozen, as it was only the latent heat of the water that was escaping. A simple and familiar experiment exhibits the same principle. Place a frozen apple, which thaws a little be- low freezing, in a vessel of ice-cold water. The latent heat of the water immediately passes into the apple and 'thaws it, and in an hour or two it will be found like a fresh apple and entirely free from frost; but the latent heat having escaped from the water next the apple, a thick crust of ice is found to encase it. The amount of latent heat may be shown in still an- other way. Mix a pound of snow at 32 degrees, or at freezing, with a pound of water at 172 degrees. All will be melted, but the two pounds of water thus formed will 12* 274 HEAT. be as cold as the snow, showing that for melting it the 140 degrees in the hot water were all made latent. APVANTAGES OF LATENT HEAT. If no heat became latent by the conversion of ice and snow to water, no time would, of course, be required for the process, and thawing would be instantaneous. On the approach of warm weather, or at the very moment that the temperature of the air rose above freezing, snow and ice would all dissolve to water, and terrific floods and inundations would be the immediate consequence. LATENT HEAT OF STEAM. A still larger amount of latent heat is required for the conversion of water into steam ; for, again place the ves- sel of water with its thermometer on the tire, it will rise, as the heat of the water increases, to 212 degrees, and then commence boiling. During all this time it will now remain stationary at 212, until the water is all boiled away. This is found to require nearly five times the period need- ed to heat from freezing to boiling ; that is, nearly one thousand degrees of heat are made latent by the conver- sion of water into steam. Wlien the steam is condensed again to water, this heat is given out. Hence the use made of steam conveyed in pipes for heating buildings, and for boiling large vats or tubs of water, by setting free this large amount of latent heat which the fire has imparted to it. GREEN AND DRY WOOD FOR FUEL. A great loss is often sustained in burning green wood for fuel, from an ignorance of the vast amount of latent heat consumed to drive off the water the wood contains. When perfectly green, it loses about one-third of its weight GREEN AND DRY WOOD FOR FUEL. 275 by thorough seasoning, which is equal to about 25 cubic feet in every compact cord, or 156 imperial gallons. Now all this water must be evaporated before the wood is burn- ed. The heat thus made latent and lost, being five times as great as to heat the water to boiling,- is equal to enough for boiling 780 imperial gallons in burning up every cord of green wood. The firmer, therefore, who burns 25 green cords in a winter, loses heat enough to boil more than fifteen thousand gallons of water, which would be saved if his wood had been 'previously well seasoned un- der shelter. The loss in using green fuel is, however, sometimes overrated. It has been found by experiment that one pound of the best seasoned wood is sufiicient to heat 27 lb<5. of water from the freezing to the boiling point.* This will be equal to heating and evaporating four pounds of water by every pound of wood. The 25 cubic feet of water, therefore, in every cord of green wood, weighing about 1,500 pounds, would require nearly 400 pounds of W(>od for its evaporation, or about one-seventh or one- eighth of a cord. Hence we may infer that seven cords of dry wood are about equal to eight cords of green. This imperfect estimate will apply only to the best hard wood, and will vary exceedingly with the different sorts of fuel ; the more porous the wood becomes, the greater will be the necessity for thorough seasoning. * The following results show the heating power of several combust- ibles : 1 lb. of wood (sea.-oned, but still holding 20 per cent of water) raised from 32° to 212° 27 lbs. water 1 lb. of alcohol 68 " " 1 lb. of charcoal 78 '* " 1 lb. of oil or wax 90 " " 1 lb. of hydrogen 216 " " It should be rememlK'red that by ordinary modes of heating water, a very la'rge proportion of the heat is wasted by passing up the chimney and into surrounding bodies, and the air. 276 HEAT. Superficial observation often leads to very erroneous conclusions. Seasoned wood will sometimes burn with great rapidity, and, producing an intense heat for a shoi't time, will favor an overestimate of its superiority. Green wood, on the other hand, kindles with difficulty, and bums slowly and for a long time; hence, where the draught of the chimney can not be controlled, it may be the most economical, because a less proportion of heat may be swept upward than by the more Solent draught pro- duced from dry materials. Where the draught can be perfectly regulated, however, seasoned wood should be always used, for convenience and comfort, and for economy. Where wood is to be drawn to a distance, the preceding estimate shows that the conveyance of more than half a ton of water is avoided in every cord by seasoning. CHAPTER n. RADIATION OF HEAT. The passage of heat through conducting bodies has been already explained. There is another way in which it is transmitted, termed radiation^ in which it is thrown oflf instantaneously in straight lines from hot bodies, in the same way that light is thrown off from a candle. A familiar instance is furnished by the common or open fire- place^ before which the face may be roasted with the radiated heat, while the back is chilled with cold. A screen held in the hand will intercept this radiated heat, showing that it flies in right lines like the rays of light. Radiated heat is reflected by a polished metallic surface RADIATION OF HEAT. 277 in the same way that light is reflected by a looking-glass. A plate of bright tin held near the lire will not for a long time become hot, the heat being reflected fi*om it Avithout enterino; and heatino; it. But if it be blackened with smoke, it will no longer reflect, but absorb the heat, and consequently will speedily become hot. This experiment may be easily tried by placing a new tin cup containing water over a charcoal fire, which yields no smoke. The heat will be reflected into the fire by the tin, and the wa- ter will scarcely become warm. But if a few pine shav- ings be thrown on this fire, to smoko the surface of the tin, it will then absorb the heat rapidly, and soon begin to boil. This explains the reason that bread bakes more slowly in a new tin dish, and that a i)olished andiron be- fore a fire is long in becoming hot. A concave burning-mirror, which throws the rays of heat to a focus or point, may be made of sheet-tin, by Fig. 294. beating it out concave so as to fit a regularly curved gauge. If a foot in diameter, and carefully made, it will , condense the rays of heat so powerfully at the focus, when held several feet from the fire, as to set fire to a pine stick or to flash gunpowder (fig. 294). The reflection of radiated heat may be beautifully ex- hibited by using two such concave tin mirrors. Place them on a long table several feet apart, and ascertain the focus of each by means of the light of a candle. Then place in the focus of one a red-hot iron ball, or a small chafinsr-dish of buminsr charcoal. In the focus of the 278 HEAT. other place the wick of a candle with a small shaving of phospliorus in it. The heat will be reflected, as shown by Fig. 295. the dotted lines (fig. 295), and, setting fire to the phos- phorus, will light the candle. If a thermometer be placed in the focus of one mirror while the hot iron ball is in the other focus, it will rise rapidly ; but if a lump of ice be substituted for the ball, the thermometer will immediately sink, and will continue to do so until several degrees lower than the surrounding air; because the thermometer radiates more heat to the mirrors, and then to the ice, than the ice returns. DEW AND FROST. All bodies are constantly radiating some heat, and if an equal amount is not returned by others, they groAv colder, like the thermometer before the lump of ice. Hence the reason that on clear, frosty nights, objects at the surface of the earth become colder than the air that surrounds them. The heat is radiated into the clear space above without being returned ; plants, stones, and the soil thus become cooled down below^ freezing, and, coming in con- tact with the moisture of the air, it condenses on them and forms dew, or freezes into white frost. Clouds return or prevent the passage of the heat that is radiated, which is the reason there are no night-frosts in cloudy weather. A very thin covering, by intercepting the i-adiated heat, will often prevent serious injury to tender plants. Even FROST IN VALLEYS. 279 a sheet of thin muslin, stretched on pegs over garden vegetables, has afforded sufficient protection, when those around were destroyed. FROST IN VALLEYS. On hills, where the wind blows freely, it tends to re- store to plants the heat lost by radiation, which is the reason that hills are not so liable to sharp frosts as still valleys. When the air is cooled it becomes heavier, and, rollnig down the sides of valleys, forms a lake of cold air at the bottom ; this adds to the liability of frosts in low places. The coldness is frequently still fuither increased by the dark and porous nature of the soil in low places radiating heat faster to the ciear sky than the more com- pact upland soil. A knowledge of these properties teaches us the import- ance of selecting elevated places for fruit-trees, and all crops liable to be cut off by frost ; and it also explains the reason that the muck or peat of drained swamps is more subject to frosts than other land on the same level. Therefore, corn and other tender crops upon such porous soils must be of the earliest ripening kinds, so as to escape the frosts of spring by late planting, and those of autumn by early maturity. REMARKABLE EFFECTS OF HEAT ON WATER. The effects of heat and cold on water are of a very in- teresting character. Without its expansion in freezing, the soil would not be pulverized by the frost of winter, but would be found hard, compact, and difficult to culti- vate in spring ; without its expansion into steam, the cities which are now springing up, and the continents that are becoming peopled, through the influence of rail- ways, steam-ships, and steam manufactures, would mostly re- 280 HEAT. main unbroken forests ; without the crystallization of wa- ter, the beautiful protection of plants by a mantle of snow, in northern regions, would give place to frozen sterility ; without the conversion of heat to a latent state in melt- ing, the deepest snows would disappear in a moment from the earth, and cause disastrous floods; without its con- version to a latent state in steam, the largest vessel of boihug Waaler would instantly flash into vapor. All these facts sliow that an extraordinary wisdom and forethought planned these laws at the creation ; and even what appears at first glance as ;m almost accidental exception in the conti'action of bodies by cold, and which causes ic3 to float upon water, preventing the entire masses of rivers and lakes from becoming permanently frozen, furnishes one out of an innumerable array of proofs of creative de- sis^n in fitting^ the earth for the comfort and sustenance of its inhabitants. PART V. RECENT MACHINES. During the past few years, and since the last revised edition of this work was prepared, constituting the previous pages, unexampled progress has been made in the improvement and manufacture of farm machinery. Its wide introduction has lessened the severity of farm labor, and increased the profits or reduced the losses of farminor. Plows have been made of harder materials — have been rendered more durable and incapable of clog- ging. Harrows and cultivators now perform much of the labor formerly executed by hand. Seed drills for sowing grain crops are almost universal in the North and West. Mowers and reapers have become eminent as labor-gavers, and their manufacture employs annually more than ten thousand men, turning out one hundred and fifty thou- sand machines, which sell for fifteen million dollars. Those which are now in use, save the labor of two mil- lion men in haying and harvests. Threshing machines have been highly perfected, and many machines of less prominence have been brought into general use. The ex- tensive manufacture and rapid introduction of steam en- gines for stationary work on farms, have conspicuously marked the last ten years. Some of these improvements will be described more in detail. PLOWS. Important improvements have been made in the use of the materials of which plows are constructed. When the wooden mould-boards of past ages gave way to the cast-iron plow, it was the custom for many years to 281 282 RECENT MACHINES. sell these plows to farmers, with the castings as rough as they came from the founder's moulds. The plowman, with much care and labor, succeeded, after some days of diligent work, in causing them to wear bright or scour by the friction of the earth as they passed through it. No plow is now offered for sale in a rough state, but the ^ shares and mould-boards are ground and polished at the shop. It was long the practice to harden the point of the plows by ^^ chilling," or causing the melted metal to come in contact with cold iron. But the mould-board and share, made of common cast-iron, were too soft to last many years, and steel mould-boards were substituted. These were much lighter, as well as more expensive. More recently, the chilling process is applied to the whole of the castings, and the plows thus obtained last many times longer, and are le:s liable to clog in adhesive or plastic soils. They are cheaper and heavier than the steel plows. Several of the best manufacturers have each a process of their own for hardening the iron, by which it is rendered equally hard throughout, and not merely on the surface, as with the old chilling process. Among the manufacturers of hard plows, are the New York Plow Company, who make the '^ Adamant Plow ; '* the Remington Agricultural Works, of Ilion, N. Y., who manufacture the *^ Carbon Plow ; " the Syracuse Chilled Plow Company ; the Wiard Plow Company, Batavia, N. Y. ; the Oliver Chilled Plow Company, of South Bend, Indiana ; Gregg & Company, Trumansburgh, N. Y., and the Gale Chilled Plow Company, of Albion, Michigan, i It has been already shown in this work, that with most plows more than half the force of draught is required to cut the furrow-slice. The importance therefore of maintaining a sharp edge is obvious, and a great point is gained by the use of the hardened metals. The friction of the plow on the bottom and sides, weighted by the sod, is at least oue-third additional. This friction is mate- PLOWS — HARROWS. 383 rially lessened by the use of the chilled metal, which is rendered as hard as cast-steel. The Sulky Plow (fig. 29G), made by Gregg & Co., of Trumansburgh, N. Y., Deere & Co., ^j 295 of Moline, 111., Furst & Bradley, of Chicago, the South Bend Works, In- diana, and others, secures the advan- tage of nearly removing the friction of the plow on the bottom of the furrow, its weight being mainly supported by the wheels on which it runs. The " ^ plowman rides, and controls, by means of levers at his hand, the depth and direction to the right or left. HARROWS. The Spring-tooth Harrow, the teeth of which are made of thin steel bars about two inches wide, and with a semi-circular curve, like the teeth of a steel-tooth horse- rake, possess the advantage of entering the soil easily with their forward-pointing sharp teeth ; of bending back in passing any fixed obstruction, without checking the team ; and of clearing themselves of rubbish by the constant tremulous or vibrating motion which the spring gives them. The Disc Harrows, of which there are different forms of construction, consist of circular, thin plates of steel, turning on a common axle, and set slightly oblique to the line of draught. The discs cut into the soil and, in turning, throw it sidewise. These harrows possess the advantage of rolling through the soil with little friction ; at the same time, consisting of several parts, they are more liable to derangement than the solid implement. Unlike the common harrow, they are not caught or im- peded by obstructions, and they may be employed for this reason for cultivating among trees. One form of the 284 RECENT MACHIIfES. ■^i-r. 017 Disc Harrow with Iron Frame. disc harrow has a stout wooden frame ; this form is made by Belcher & Taylor, of Chicopee Falls, Mass., and by the AVarrior Mower Company, of Little Falls, N. Y. ; the other form (fig. 297) is of iron, with a flexible axle, manufactured by the Wheeler & Melick Company, Albany, and by EA'erett & Small, Boston. The Thomas Smoothing Harrow (fig. 298), intro- duced a few years ago, is distinguished by its many round steel teeth, being double the number in other harrows, and for their backward slant at an angle of about 40 degrees. The many teeth produce fine pulverization of the soil, and the backward slope causes them to clear all obstructions and never to become clogged with rubbish. They effect a rapid and fine pulverization of spread manure, the teeth cuttinsf down through the lumps, and not pushing them ahead as with common harrows. They ffrind and The TJiomas Smoothing Harrow. destroy young weeds appearing at the surface, but rather benefit and do not disturb growth after plants are several inches high. Hence this harrow is extensively employed for cultivating corn broadcast, the teeth run- ning among the hills of corn without injury to it, but grinding and killing all young weeds, if taken early enough and repeated often. It is specially adapted to the broadcast culture of wheat, more Cheaply than by Fig. 298. PLANTJNG CORis^. 285 the English drill system, as this harrow sweeps the whole surface nine feet wide at a passing, and the operation may be repeated until the wheat is over a foot high. The Acme Harrow has proved an efficient implement for pulverizing several inches of the top soil, and when drawn by two horses, goes over a breadth of six feet at each passing. It has two rows of curved steel coulters, which cut down into and partly invert the soil. The coulters sloping backwards, it frees itself of rubbish and rarely becomes clogged. It is particularly adapted to pulverizing inverted sod, cultivating orchards, and cover- ing grain sown broadcast. It is manufactured by Nash & Brother, Millington, N. J. PLAisTING CORN. The old practice of depositing the seed by hand, is giv- ing way to the use of planting machines, which drop the seed in drills. The common introduction of grain drills enables farmers to employ them for planting corn. Only those tubes in the drill are used which drop rows at proper distances, two rows being planted at a time. The necessity for marking is thus obviated ; and the drills being parallel are easily cultivated. It is important to have clean land for drill culture, as the labor of hoeing the weeds is greater than with *' hills;" or to employ the smoothing harrow once a week or oftener to eradicate them, until the corn is a foot high. Drills yield, on an average, 25 per cent more corn than hills, and the quantity of fodder is correspond-* ingly greater. At the West, where land is cheap, and the corn is more commonly planted in rows both ways, planting machines, are employed for this purpose, taking two rows at a time. The land is previously marked, the planter crossing these markings at right angles. One person drives the horses, and another, riding on the machine, drops the seed on 286 RECENT MACHII^ES. each marking by a movement of the hand. A modifica- tion, termed *^ check-row " planting, is made by stretching across the field a steel wire, on which there are a succes- sion of * 'knobs" or projections, four feet apart, or wherever a hill of corn is to be dropped. This wire is parallel with the line on which the planter is driven, and is con- nected with it, and as it strikes each knob, the dropper is opened and the seed deposited and covered in passing. The wire is secured at each end to anchors, and is moved a distance equal to the width of two rows at each tui-n. This mode of planting insures great accuracy, and obviates the necessity for marking the land. The planting may, therefore, immediately follow the plowing, while the soil is yet freshly inverted. In cultivating corn, the labor is performed twice as rapidly by using a double, two-horse cultivator, instead of a single one drawn by a horse. The horses walk in two contiguous spaces between the rows, and the teeth of the cultivator follow in the same spaces. There are two kinds of these cultivators, the walking and the sulky cultivator. The walking cultivator is more accurate in its work ; the riding is easier for the laborer. There are several manufacturers of these implements, prominent among whom are, Furst & Bradley, of Chicago ; the Sandwich Manufacturing Company, Sandwich, 111.; and P. P. Mast & Co., Springfield, Ohio. MOWERS AND REAPERS. . There has not been great improvement in the general form and cutting of mowers and reapers, but important appendages have been added. Self-raking reapers have become efficient and general ; more recently, the self- binder has been so much perfected that it is now success- fully employed on large farms as a valuable saver of labor. There are now more than ten thousand self-binders in the hands of farmers. In most of them, annealed iron SELF-BIi^^DERS — HAY-LOADERS. 287 wire was employed for the bands, a large spool being at- tached to the reaper, from which the wire was drawn as used for securing the sheaves. One man only was neces- sary for each machine. He mounted the seat of the reaper, took the reins, and had nothing more to do than to drive along the standing grain, which was rapidly cut, bound, and dropped on the ground, out of reach of the horses at the next passing. He controlled the size of the sheaves by a touch of the foot, Avhen it was desirable to vary from the fixed regularity of distribution. SELF-BIKDERS. Cord is now exclusively used for reaping machines in- stead of wire, and the different machines perform the work by unlike machinery, but the following gives sub- stantially the mode by which the binding is performed : The grain is cut and carried up on an elevator, where it is taken by two arms called packers. They gather it into a bundle, which, when large enough, presses a trigger and throws the tying apparatus into gear. The arms at once close upon the bundle so tightly, that at the moment of tying there is little tension on the string. The binder may be set to any size for the bundle. The Marsh Harvester, described on page 163, is now entirely superseded by the self-binders. HAY-LOADERS. Foust's Hay-loaaer saves much hard labor on large and smooth meadows, obviating hand-pitching. It is attached to the rear of a common hay-wagon, operates by its on- ward motion, is driven astride the windrow, and carries up and drops the hay on the load. In heavy meadows it may be used without previously raking the hay. A ton may be loaded with it in five minutes. On large farms with smooth fields, the use of the mow- 288 RECEIPT MACHINES. ing-machine, hay- tedder, horse-rake, hay-loaders, horse- fork, and horizontal hay-carrier, has greatly reduced the labor and expense of manufacturing hay from standing grass, and has lessened the risk of loss by storms of rain. CORIsr-HUSKERS. Philips' and Jones' Corn-huskers operate on similar general principles, but differ in the nature of the corru- gated surfaces of the husking rollers, and in other details. The corn on the stalks is fed in mass to the machine, by which the ears are first separated or snapped off by pass- ing between fluted rollers ; the stalks pass througli the Fig, 299. Philips' Spiral Corn-Husker. rollers and are dropped in a pile ; the ears drop on a sloping bed consisting of rollers rapidly revolving in opposite directions, snatching the husks from the ears, which glide down the inclined bed and drop at the end of the machine, the husks falling beneath in a third pile. With either of these machines (one of which is shown in fig. 299), two horses will husk forty or fifty bushels in an hour, requiring two men in attendance. The cost is about $125 besides the horse-power for driving it. Al- though these have proved very efficient machines, their cost, and the labor required to draw all the stalks to them before husking, have prevented their general intro- duction to common farms. WIXD-MILLS — WIND-MILLS, 289 HAY-PEESSES. Eecent improvements in Pederick's hay-presses (see page 184) include a horizontal press driven hy horse or steam-power (lig. Fi<:. 300. 300), operating con- tinuously and form- ing successive bales as the hay is thrown in. One man is oc- cupied in latching the hay and an- DeUtrick's UorlzonUd Hay-Press. other in receiving and binding the bales with steel wire. Important facilities are thus afforded to farmers who market hay, and it likewise gives economy of room, neat- ness and cleanliness, and is safer against lire in other cases. WIKD-MILLS. Self -regulating Wind-engines, as now made, are of two Fig. 301. Fi-'. 302. |ol ^ ^^^5is3SSI ** V MNjSj >r %,^Mm ^ ' 9 ^*": w^m^i:^EmM I Sttfflff ""^^"- flw tf ^^!#V^p=^^^3^- The Halladay Wind-Mill. The Eclipse Wind-Mitt. kinds. In one, of which the Halladay wind-mill (fig. 301) is a prominent representative, the circle of fans faces 290 EEC EXT MACHIJSTES. the wind at all times, but their angle to the wind is changed with its force. The other is the *' solid-wheel/' the fans being all fixed, which swings round with its edge against the wind, when it becomes violent, by a self -regu- lating arrangement. This torm (fig. 302) is made by the Eclipse Windmill Company, of Beloit, Wis., and by others. Both these forms, when well constructed, per- form well on broad plains where the wind is uniform, for the various purposes of pumping water, grinding feed, sawing wood, and cutting fodder. COTTON GINS. The vast amount of cotton raised in the different Cot- ton States, requires a large number of gins to prepare it for manufacture, and among the best are those made by the Carver Gin Company, the Standard Machine Com- pany, the Winship, Daniel Pratt, and Hall machines. About seven thousand of these machines are made annu- ally in different parts of the Union. The larger gins, driven with steam-power, will give nine or ten bales in a day ; and the smaller ones, with horse or mule power, give four or five bales in a day, each bale containing about four hundred and fifty pounds of cotton. Before the invention of the gin by Eli AYhitney, the difficulty of freeing the seed was so great, that one person could clean but a single pound in a day ; but with the aid of modern machinery, several hundred pounds are easily prepared in a day by a single hand. FARM MILLS. The improvements which have been made in farm mills for grinding feed, may be classed under three heads. The simplest and cheapest mills are those which have no gearing, the horses, walking in a circle, being attached to the puter end of a lever. The grinders are FA IIM- MILLS. 291 corrugated steel or chilled iron, a large cone working in a hollow cone under the hopper. A mill of this kind is made by J. A. Field & Co., of St. Louis, and known as the *'Big Giant." Two horses will grind about six , bushels in an hour. When the grinders become worn, they are renewed with new faces. This mill requires a driver for the horse ; it is adapted to farms of moderate size, where much grinding is not required, aud the whole cost is not over one-third of the machinery required for mills worked with a tread-power. The second class are those which have flat grinders of steel, driven with horses or steam, driven with a velocity of four or five hundred revolutions a minute. The grinders for a two-horse mill are less than a foot in dia- meter, but will reduce to meal six or seven bushels of grain in an hour, worked with a tread-power, or a greater amount with a heavy team, and a single attendant only is required. This kind of mill is manufactured by W. L. Boyer and A. W. Straub & Co., of Philadelphia, by the the Foos Manufacturing Company, of Springfield, Ohio, and others. Under the head of the third class are the buhr-ston3 mills, the larger ones of which are driven with steam, performing nearly the same rate of work for each horse- power as those already described, a ten-horse engine grinding to flour fifteen to twenty-five bushels an hour. The stones are usually eighteen to twenty-two inches in diameter. The stones require dressing after grinding one thousand or one thousand and five hundred bushels, or oftener for very fine grinding. These mills are made by several manufacturers, who make them known through the usual advertising mediums. The price of these buhr-stones is not far from one hun- dred dollars, being about double that of those previously mentioned, but they are more perfect and enduring. For 29Ji RECENT MACHINES. fine flour, a fair average of the work of buhr-stones is two and a half bushels an hour for each horse-power. FEED CUTTERS. Since the general employment of feed-cutters for corn- stalks, the Hyde roller straw-cutters are superseded by the machines which cut half an inch or less in length, and are diiven with horse or steam-power, of which there are several manufacturers in different parts of the country. STUMP MACHINES. Stumps which are partly decayed may be twisted out with a long lever of stout timber, thirty feet or more in length, having a strong chain at the heavy end to hook into a large root, and passing around the stump. A team attached to the other end of the lever, driven in a circle, will twist it out. (See page 54.) Young trees, thirty or forty feet high, may be easily removed without cutting down, by fastening a strong rope near the top of the tree, and a team to the other end of the rope several rods distant, the long leverage of the tree enabling the team to draw the tree out, after cutting the largest roots. The rope should be held down near the horses, at the ground, by means of a heavy rolling weight, as for example, a heavy farm roller properly supported. The power thus secured may be estimated by comparing the hight of the tree to the hight of an ordinary stump. If, for example, the rope is fast- ened thirty feet high, the team will exert as much power as ten teams attached to a stump three feet high. TRACTION ENGINES. These engines are now manufactured which will run on common roads by their own power, at the rate of from DKAIIS^ TILE MACHINES— MANURE SPREADERS. 293 three to six miles an hoar, aud will ascend moderate grades, facilitating their conveyance from one place to another. When passing on public roads, it is necessary to attach a team in front to lessen the danger of frighten- ing the horses which they meet. DRAIN TILE MACHINES. In a large portion of the country, tile-draining has doubled the productive value of the arable land, and the manufacture of the tiles has been greatly facilitated by the use of the improved machines for this purpose. It is estimated that there are now one thousand and five hun- dred tile-making machines in the United States, each of which when in use, turns out thousands of tiles in a day. The best of these machines are made of iron and steel, and are driven by horse and steam-power. They take the clay from the natural bed, discharge the stones, and grind it into good condition for the tile, when it is driven through moulds and the pipe thus formed. Some of these machines turn out fifteen thousand two-inch tiles in a day, and a corresponding number of other sizes. It is estimated that with the aid of these machines, a million and a half acres of land are thoroughly underdrained annually in the United States, the cost of which, at thirty dollars an acre, would be forty-five million dollars, and the real value of the improvement a much larger sum. MANURE SPREADERS. An important invention is Kemp's Manure Spreader. It is a machine cart drawn behind the forward wheels of any farm wagon, the box having a movable bottom pass- ing over rollers like a common tread-power. When the loaded manure is taken to the place of distribution, the gearing is set at work and the manure is carried backward and passed between rapidly revolving spiked rollers, 294 KECEl^T MACHINES. which pulverize it and throw it out evenly behind on the laud. A ton of mauure is thus unloaded by the motion of the cart in two minutes, with no labor of the driver, in a finer condition and more evenly than can be done with ten times the labor by hand. It is regulated to spread dif- ferent and required amounts to the acre. On large farms, two carts should be used, and two men at the manure heap be constantly employed in filling, while a third, with the team, is employed in drawing out the loads, the team being alternately changed from one to the other. APPE NDIX. SIMPLE APPARATL'S FOR ILLUSTRATING MECHANICAL PRINCIPLES. For the assistance of lecturers, teachers, and home students, the fol- lowing li>t is giv'cn of cheap and simple apparatus and materials for performing most of the experiments described in the first part of this "vvoik. These experiraents, althougli simple, exhibit principles of much practical importance. 1. Inertia apparatus, p. 12. The concave post or stand is sufficient, the snapping being done b\' the finger, although a spring-snap performs tlie experiment more perfectly. 2. Weight with two hooks and fine thread, p. 13. 3. The inertia of falling bodies may be simply shown, and the pile- engine illustfated, by placing a large wooden peg or rod upright in a box of sand, and then dropping a weight upon its head at diff'erent heights, which will drive the rod iuto the sand more or less, according lo the distance passed through by the falling weight. 4. A stiaw-cutter, so made that the fly-wheel can be easily taken off, will show in a very striking manner the efficacy of this regulator of force. 5. Two lead musket balls Avill exhibit the experiment in cohesion, p. 27. Balls or lead weights with hooks may be separated bj' sus- pending weights, to show the amount of force required to draw them asunder. Metallic buttcms or plates an inch in diameter, with hooks, will show the great strength needed to separate them when coated with grease, p. 27. 6. Capillary tubes of diff'erent sizes, two straight small panes of glass, and a vessel of water, liighl}' colored with cochineal or other dye, to ex- hibit capillary attraction. 7. Glass tube, piece of bladder, and alcohol, for experiment described on p. 33. 8. The cylinder for rolling up the inclined plane, represented by fig. 18, p. 34, may be very easily made by using a round pasteboard box a few inches in diameter, and securing a piece of lead inside by loops made with a needle and thread. The object shown by fig. 19 may be cut in one piece out of a pine shingle, the centre rod being lengthwise with the grain ; the two extremities are shaved small, and wound with thick sheet-lead, and the whole then colored or painted a 295 296 APPENDIX. dark hue, to render the lead inconspicuous. The experiment witli the peuknives, p. 35, is very simple, cure being talicn to insert them low enough in the sticlc. 9. Irregular pieces of board, variously perforated with holes, and fur- nished with loops to hang on a pin, may be used to determine the centre of gravity, according to the principle explained by fig. 21, p. 35. 10. Portions of plank and blocks of wood, with the centre of giavity determined as in the last experiment, may have a plumb line (which may be a thread and small perlorated coin) attached to this centre, and then be placed on differently inclined surfaces, to show their upsetting just as this line of direction falls without the base. Toy-wagons, bought at the toyshops, may be variously loaded and used in experiments of this sort. 11. Experiments with the lever of the first kind may be easily per- formed by the use of a flat wooden bar, two or three feet in length, marked into inches, and placed on a small three-coincrcd block as a fulcrum. Weights, such as are used for scales, may be variously placed upon the lever. Levers of the second and third kind, which are lifted instead of borne down, may have a cord attached to the point where the power is to be applied, running up over a pulley or wheel, with a weight suspended to the otlier end. 12. An axle, furnished with wooden wheels Avith grooved edges, of diff"erent sizes, may be used to exhibit the principle of \\\g wheel and axle, in connection with scale-weights that are fiirniehed with hooks. The power of combined cog-wheels may be shown by a combination like that represented on p. 57, using weights for both cords. 13. Interesting experiments with the inclined plane, at diff'erent de- grees of slope, by a contrivance similar to that represented by lig. 96, p. 83, with the addition of a small wheel at the uj^per side for a cord to pass over. This cord is fastened at one end to a light toy-wagon, lun- ning up and down the plane, and at the other to a weight suspended perpendicularly just beyond the upper edge of the plane. The wagon is variously loaded with weights, to counterpoise the suspended weight at different degrees of inclination. 14. A lecturer may quickly demonstrate before a class the small in- crease in the length of a road, in consequence of a considei^able curve to one side of a straight line (as shown by fig, 69), by using a cord for measuring, the diagram being marked on a board or the wall. 15. A round stick of wood, and a long, wedge-shaj^ed slip of paper, easily show the principle of fig. 75, p. 70. 16. A cog-wheel with endless screw and winch (fig. 77, p. 71), exhibits distinctly the great power of the screw in this combination. 17. Pine sticks, two feet long, and one-fourth to one-half inch through, of different shapes and sizes, supported at each end, and with weights hung at the middle till they break, may be made to illustrate the princi- ples described on pp. 80, 81. 18. Some of the urinciples of draught may be shown, and especially APPARATTTS FOR EXPERIMENTS. 297 those in relation to tlie different angles of inclination for hard and soft roads, by usiiiWAY, NE^V IfORK. Gardening for Pleasure. A GUIDE TO THE AMATEUK IN THE FnuiT, Vegetable, and Ploweb Garden, J WITH FULL DIRECTIONS FOK THE GREENHOUSE, CONSERVATORY, AND WINDOW-GARDEN. By Petek HEisTDERsoisr. AUTHOR OP "gardening FOR PROFIT," AND " PRACTICAL PLORICULTURB." Illustrated. EDITORIAL NOTICES. One of the most popular works of recent j^ears on similar topics was the "Gardening for Profit" of Mr. Peter Henderson, the well-known florist of Jersey City. He has been equally fortunate in the title of a new book from his pen, just published by the Orange Judd Co., of New-York — " Gardening for Pleasure." The author has a happy faculty of writing for the most part just what people want to know — so that, although his books are neither exhaustive nor especially elaborate, they proceed to the gist of the subject in hand with so much directness and simplicity that they till a most important and useful sphere in our rural literature. — llie Culti- valor and Couatrij Gentleman, Aibamj, N. Y. It gives, in a clear, intelligible form, just the information that novices and even experienced cultivators wish to have always accessible, and will be specially valuable to those who keep house plants. — The Observer, Nexo- York City. Mr. Peter Henderson has followed up " Gardening for Profit " with "Gardening for Pleasure." into which is packed much useful information about window-gardens, the management of flower-beds, etc. — I'he Inde- pendent, New- York City. He is a thoroughly practical man, uses plain, common language, and not technical terms^in his statements and explanations, and puts the staff of knowledge directly into the hands of the amateur and sets him at work. — The Press, Providence, R. I. People who have monev to spend in adorning their grounds, are told here how to do it to the best advantage, and ladies are fully instructed in all the art and mystery of window-gardening. It will prove a useful guide to all who have a taste for flowers, and also contains practical instructions for the cultivation of fruits and vegetables.— TAe Transcript, Portland, Me. This volume is eminently clear in its style and practical in its direc- tions. Its appearance is timely, as it contains some valuable hints upon winter flowering plants and their proper cultivation, together with plain directions how to raise them from seed and to multiply them by cuttings. — Courier-Journal, Louisville, Ky. Price, post-paid, $1.50. O. JUDD CO., DAVID W. JUDD, Pres't. SAM'L BURNHAWI, Sec, 751 BROADWAY, NE\r YORK. Gardening for Young and Old. THE CULTIVATION OF GAEDEN VEGETABLES IN THE FARM GARDEN. By JOSEPH HARRIS, M.S., Luthor of "Walks and Talks an (he Faiin,'''' "■Harrison the Pig,'^ ''Talks on Manures,'''' etc CONTENTS. Introduction.— An Old and a New Garden.— Gardening for Boys.— How t(> Begin.— Preparing the Soil. -Killing the Weeds.— About High Farming.— Com- petition in Crops.— The Manure Question.- The Implements Needed.— Start- ing Plants in the House or in the Hot-bed. — The Window-box.— Making the Hot bed. — Cold Frames.— Insects.— Tlie Use of Poisons.- The Care of Poisons. —The Cultivation of Vegetables in the Farm Garden.— The Cultivation of Flowers. ILLLUSTRATED. l2mo. Cloth. Price, post-paid, $1.25. O. JUDD CO., DAVID W. JUDD, Pres't. SAM'L BURNHAM, Sec. 7 51 BROAD WAV, NEliT A'ORK. 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