Mm TheModernGasTractor ITS CONSTRUCTION, OPERATION, ^PLICATION and REPAIR, >ooocr3ooo < — >ooo< — >cxx>c >uuuerr>oooc=>i PRIVATE LIBRARY H. Harold Sunderlin BOOK NO. ^otzr>ooo(==30ooc==>ooac==>oooc=)Ooo<=>oooc=} ooocrxo ^UL3undcrliq. THE MODERN GAS TRACTOR Its Construction, Utility, Operation and Repair A Practical Treatise Defining Every Branch of Up-To- Date Gas Tractor Engineering, Driving and Mainten- ance in a Non-Technical Manner. Considers Fully All Types of Power Plants and Their Components, Methods of Drive and Speed Changing Mechanisms. Describes Design and Construction of All Parts, Their Installation and Adjustment As Well As Prac- tical Application of Tractors in the Field. By VICTOR W. PAGE, M.E. Author of " The Modern Gasoline Automobile ", etc., etc. Invaluable to the Student, Farmer, Machinist, Blacksmith, Implement Dealer, Rancher and All Others Wishing Reliable Information On Gas Motor Propelled Traction Engines and Their Use OVER 200 ILLUSTRATIONS AND FOLDING PLATES NEW YORK THE NORMAN W. HENLEY PUBLISHING 132 Nassau Street 1914 COMPANY Copyrighted 1913 by THE NORMAN W. HENLEY PUBLISHING COMPANY ALL RIGHTS RESERVED FIRST IMPRESSION Nearly every illustration in this book has been specially made by the publishers: the use of any without permission is prohibited COMPOSITION, ELECTROTYPING AND PRESSWORK BY MACGOWAN & SLIPPER, NEW YORK, U. 8. A. PREFACE The internal combustion motor has been responsible for many developments in the industrial sciences, but its greatest achievement has been the promotion of econom- ical and efficient transportation. The improvements in the design of the modern gas tractor, which have made it an entirely practical and satisfactory source of power, have also opened up fields where it can be used to ad- vantage and profit that would have been impossible with steam traction engines formerly the vogue, or other forms of power. It is not the writer's intention to underestimate the advantages and utility of the steam tractor; it has and still is performing work of great value. The gas tractor, however, in its modern forms, is able to accomplish everything the steam propelled type can do, and has important advantages the other construction does not possess. It does not require services of a skilled engineer to operate, it has a wider range of action, is more in- dependent of fuel and water supply in that it does not consume much liquid in cooling, and is more economical of fuel because it utilizes a larger proportion of the potential energy or heat units of the combustible by burning it directly in the cylinders. The many advantages of the internal combustion or gas motor have made it the recognized prime mover where economical operation and minimum attendance is required, so it is but natural that it should reign su- preme in the field of general transportation. This treatise is intended as a guide for the average x Preface farmer and mechanic. It is not presented as a technical or engineering exposition, yet endeavor has been made to present some principles of design in a simple manner so they may be readily understood by those without technical know edge. The object of the writer has been to discuss the engineering features of various construc- tions only with a view of familiarizing the reader with the salient points of design, so the advantages of the various systems of construction may be intelligently analyzed in order that the mechanism best adapted to individual requirements be selected. There is a large field to select from. Tractors may be obtained ranging from motor propelled lawn mowers or ploughs capable of use as light traction power to the heavier constructions employed in tilling the broad township farms of the Middle West. Special designs have been evolved applicable to use in swamps or rice fields of the South or the snow bound lumber camps of the extreme North where no other form of power can work, so the range of utility of the gas tractor is practically unlimited. The chapters on maintenance and repair should be of special value, while the various applications described cannot fail to offer the up-to-date farmer some suggestions whereby he can improve his present methods and save money. The student is always interested in construc- tion and design, the practical man wishes more specific information. This treatise is intended to bridge the gap existing between the purely technical work and the manufacturers' instruction book dealing with one specific construction. If it has accomplished this, the writer will feel amply repaid for the time and labor expended on its compilation. November, 1913 THE AUTHOR. ANNOUNCEMENT The Author desires to acknowledge his appreciation of the valuable assistance accorded him by manv of the leading firms in the field of Tractor Manufacture and associated industries. Many of the illustrations have been furnished by progressive manufacturers whose publicity efforts and excellent product have done so much to popularize the gasoline farm tractor, and many valuable suggestions regarding treatment of the subject have been obtained from the literature so kindly sup- plied by them. The following list of firms contributed materially to making this work complete and of value : Rumely Products Company, La Porte, Ind. The Gas Tractor Company, Minneapolis, Minn. The Avery Company, Peoria, 111. The Hart-Parr Company, Charles City, Iowa. International Harvester Company, Chicago, 111. The J. I. Case Company, Racine, Wis. The Bates Tractor Company, Lansing, Mich. Aultman Taylor Company, Mansfield, Ohio. Phoenix Tractor Company, Winona, Minn. George Morris, Racine, Wis. Minneapolis Steel & Machine Co., Minneapolis, Minn. Holt Caterpillar Co., Peoria, 111., and New York. Pioneer Tractor Manufacturing Co., Winona, Minn. Buckeye Manufacturing Company, Anderson, Ind. The Russell & Co., Massillon, Ohio. Auto Tractor Company, Chicago, 111. This Work Is Respectfully Dedicated To The Backbone Of Our National Prosperity THE AMERICAN FARMER xiii TABLE OF CONTEXTS CHAPTER I. The Scope, Advantages and Applications of Power Traction. Influence of Mechanical Power on the Arts — Application of Power in Agriculture — Advantages of Power Traction — Comparison Between Work of Horse and Tractor — Thermal Efficiency of Horse — Tractor Furnishes Power for Various Farm Machines — Economical Aspect of Power Traction — Analysis of Requirements of Ideal Tractor — Practical Prime Movers — Comparing Steam and Gas Power from a Practical Point of View — Efficiency of Steam and Gas Power — Why Gas Tractors are Most Popular. 33-60 CHAPTER II. Review of Conditions on Which Tractor Design is Based. Elements of Tractor Design Outlined — Selection of Power Plant — Power Needed for Hauling — Energy Absorbed by Ploughs — Power Delivery under Belt — Why Proper Dis- tribution of Weight is Essential — Influence of Weight on Traction — Influence of Road or Field Surface on Traction — Effect of Grades on Traction — Types of Tractors — Traction Engines for Small or Medium Sized Farms — Large Capacity Tractors — Parts of Typical Tractors Outlined — Some Distinctive Designs 61-91 CHAPTER III. Design and Construction of Gas Tractor Power Plants. Power Rating Basis — Indicated, Brake and Drawbar Horse- power — Types of Gas Engines — Comparing Two and Four xviii Table of Contents CHAPTER X. Traction Engine Troubles and Their Elimination. Location of Defects and Remedies — Loss of Power — Poor Compression — Carbon Deposits — Valve Grinding — Timing Valves — Care of Piston and Rings — Noisy Operation — Adjusting Bearings — Mixture Troubles — Ignition System — Derangements — Cooling and Lubrication Group Faults — Running Gear Derangements — Tractor Hitches — Utility and Uses of Modern Gas Tractor — Home-made Gas Tractors — Auto Tractor Attachment — Future Possi- bilities 366-436 CHAPTER XI. Miscellaneous Rules and Formulae. Cost of Various Fuels Per Brake Test Horse-power — Rules for Calculating Horse-power — Horse-power Formulae — Calcu- lating Brake Horse-power — Anti-freezing Solutions — Road Signs of American Motor League — Composition of Common Alloys — Melting Points of Metals — Rust Removers and Preventives — How to Measure Grades Without a Grado- meter — Rules and Tables for Figuring Capacity of Cylin- drical and Rectangular Tanks — Strength of Modern Automobile Steels — Rule for Changing Common Fraction to Decimal — Decimal Equivalents of Fractions of an Inch — Money Conversion Tables, English, French and German Coins to American Values — Thermometer Scale Conversions — Metric Conversion Table — Revolutions of Various Size Road Wheels Per Mile — Irrigation Tables — Horse-power for Pumps — Horse-power of Shafts for Given Diameter and Speed — Horse-power Belting Will Transmit — Rules for Determining Speed of Pulleys 437-462 LIST OF ILLUSTRATIONS Frontispiece — The Tractor and the Plough, an Invincible Twentieth Century Combination. Fig. 1 — The Method of Ploughing in Vogue for Over 5,000 Years, Animal Drawn Single Furrow Plough ... 34 Fig. 2 — The Modern Method of Soil Tillage. Mechanical Power Furnished by Gas Tractor Pulls Six Ploughs at Once. Some Tractors Powerful Enough to Make Fourteen Furrows at a Time 36 Fig. 3 — A Man Easily Carries Fuel and Water Enough for an Extended Period of Operation When Gas Engine is Used for Power 40 Fig. 4 — The Caravan Needed to Keep a Steam Traction Engine Supplied With Fuel and Water is a Large Item in Operating Costs 43 Fig. 5 — Side View of Holt Illinois Traction Engine, Showing Location of Important Parts 46 Fig. 6 — Typical Large Capacity Gas Tractor of Latest Approved Design with Important Parts Clearly Shown 48 Fig. 7— The Lambert "Steel Hoof" Tractor, a Three Wheel Form Suitable for Orchard Cultivation and General Small Farm Work 52 Fig. 8 — The Wolverine Eighteen Horse-power General Purpose Gas Tractor Utilizes Two Cylinder Power Plant 53 Fig. 9 — The I. H. C. Twenty Horse-power Tractor Utilizes Single Cylinder Engine for Power 58 Fig. 10— The Russell Gas Tractor with Four Cylinder Power Plant, and Single Front Steering Wheel .... 60 Fig. 10a — Side View of Phoenix Tractor, a Compact Design 63 Fig. 11 — Diagram Showing Method of Calculating Grade Percentage 64 xx List of Illustrations Fig. 12 — The Denning Motor Machine Carries a 16" Plough under Driver's Seat and is Well Adapted to General Farm Work 78 Fig. 13 — The Hackney Auto Plough Carries Three Plough- shares under Frame and Uses Front Wheels for Traction 80 Fig. 14 — The Hackney Auto Plough With Road Scraper Attachment, a Practical Machine for Highway Work . 82 Fig. 15 — Parts of the Pioneer Tractor Outlined ... 84 Fig. 16 — Folding Plate, Side Elevation Holt Caterpillar Tractor Showing all Important Parts and the Relation to Each Other ... 85 Fig. 17 — Holt Caterpillar Tread Tractor. A Distinctive Design Suitable for Soft Soils or Any Other Condition Where Wheel Tractors Would Work at a Disadvantage 86 Fig. 18 — The Avery Farm Truck, a General Purpose Machine Powerful Enough for Traction Work in Field, Capable of Hauling on Roads and Its Engine is Suitable for Stationary Power if Desired 89 Fig. 19— An English Tractor With Three Bottom Gang Plough. This Machine Driven by Two Cylinder Vertical Motor Utilizes Front Wheels for Steering and Traction Duty as Well 90 Fig. 20 — Simple Diagram to Show One Method of Making a Brake Test of Small Engine 93 Fig. 21— Making a Brake Test in the Field ... 95 Fig. 22 — The Kennerson Traction Dynamometer, an Efficient and Simple Instrument for Measuring Draft . 96 Fig. 23— Sectional View of Ellis Three Port, Two-Cycle Engine, Showing All Important Parts .... 98 Fig. 24 — Longitudinal Sectional View of Four - Cycle Engine of Ohio Tractor With Working Parts Clearly Indicated 100 Fig. 25 — Views of Simple Four-Cycle Engine Showing Methods of Charging Cylinder With Explosive Gas and Compressing It Prior to Ignition 102 Fig. 26 — Views of Simple Four-Cycle Engine Showing Effect of Explosion and How Burnt Gases are Ex- hausted from Cylinder 104 Fig. 27— Defining Action of Two Port Two-Cycle Motor . 107 Fig. 28 — How Three Port Two-Cycle Engine Operates . . 109 List of Illustrations xxi Fig. 29— Single Cylinder Power Plant Used on I. H. C. Two Speed Light Tractor Ill Fig. 30 — Diagram Showing Advantages of Multiple Cylinder Motors and Why They Deliver Power More Evenly Than Single Cylinder Types .112 Fig. 31— Fly Wheel Side of Two Cylinder Horizontal Motor Used in "Oil Pull" Tractors 115 Fig. 32 — Double Opposed Motor of 45 Horse-power Used on I. H. C. Mogul Tractor ... ... 116 Fig. 33 — Sectional Views of Three Cylinder Vertical Motor, Forming Power Plant of One Model of Russell Gas Tractor 118 Fig. 34 — Sectional Views of Typical Four Cylinder Tractor Motor That Follows Automobile Practice . . . 120 Fig. 35— The Holt Four Cylinder Power Plant With Valves Opening Directly into the Cylinder Heads . . . 122 Fig. 36 — Four Cylinder Engine Used on "Tiger Pull" Tractors 123 Fig. 37 — Views of Well Designed Four Cylinder Power Plant Used in "Twin City" Gas Tractor. Top View Shows Water Manifolds and Mechanical Oiler; Bottom View Presents Valve Side and Shows Induction and Exhaust Manifolds, Carburetor and Magneto .124 Fig. 38— Single Cylinder Four-Cycle Motor With One Half of Cylinder and Crankcase Removed to Show All Important Parts 126 Fig. 39— Cylinder With Both Valves on One Side, Four Ring Piston and Marine Type Connecting Rod . 130 Fig. 40 — Sectional View of "L" Head Cylinder Showing Water Spaces Around Combustion and Valve Chamber ........... 131 Fig. 41 — Sectional View of Valve-in-Head Vertical Motor Used on Hart-Parr Tractors, Cylinder and Head Integral . 132 Fig. 42 — Valve-in-Head Cylinder Used on I. H. C. Horizontal Engine With Separable Head 134 Fig. 43— Exterior Face of Detachable Cylinder Head Shown at A Outlines Valve Retention by Cages. Interior Face Shown at B Indicates Large Valves Possible by This Construction 135 xxiv List of Illustrations Fig. 75 — Two Cylinder Battery and Coil Ignition System . 210 Fig. 76 — Four Cylinder Ignition System Utilizing Battery Current 212 Fig. 77 — Diagram Explaining Action of Four Cylinder Magneto Ignition System Used on "Big 4-30" Gas Tractor 214 Fig. 78 — Simple Exterior Wiring of Four Cylinder High Tension Magneto Ignition System 215 Fig. 79 — Illustration Showing Advance and Retard Positions of K. W. Magneto Breaker Box 216 Fig. 80 — Part Sectional View of Water Jacketed Motor Cylinder ... 220 Fig. 81 — Action of Simple Thermo-Syphon Cooling System Outlined .... 222 Fig. 82 — Forced Water Circulation Method of Cooling Engine Cylinders 223 Fig. 83 — Sectional View of Hart-Parr Horizontal Power Plant Showing Oil Cooling Method. Folding Plate . 225 Fig. 84 — Simple Form of Centrifugal Pump for Circulating Cooling Liquid 226 Fig. 85 — Cooling Fan Necessary Unless Large Volume of Water is Carried 227 Fig. 86 — Simple Combined Cooler and Water Container . 229 Fig. 86A — Radiator Used on Holt Tractors Has Detachable Cooling Sections 230 Fig. 87— Oiling by Gravity Feed Oil Cup .... 235 Fig. 88 — Sectional View of Four Cylinder Engine Showing Passages for Oil Distribution in Crankshaft . . . 237 Fig. 89— Method of Supplying Oil Troughs of Holt Tractor Motor Crankcase 238 Fig. 90 — Mechanical Oiler Attached to Motor. Note Leads to Cylinders and Timing Gear Case .... 239 Fig. 91 — Sectional View of Simple Mechanical Lubricator Showing Parts 240 Fig. 92 — Sectional View of Motor Showing Complete Constant Level Splash Lubricating System . . . 242 Fig. 93 — Method of Lubricating Main Bearings from Oil Reservoirs Integral With Crankcase .... 243 Fig. 94— Side View of I. H. C. Mogul Tractor, Showing Location of Clutch 246 List of Illustrations xxv Fig. 95 — Sectional View of Simple Clutch, Showing Principal Parts 249 Fig. 96— Sectional View of Master Clutch Used on Holt Tractors 251 Fig. 97— Clutch of Avery Tractor is Provided With Three Clutch Shoes 252 Fig. 98— Clutch of Rumely Tractor Utilizes Three Friction Shoes Acting on Interior of Wheel Rim .... 253 Fig. 99 — Side View of Power Plant and Friction Disc Clutch of Heider Tractor 255 Fig. 100 — Explaining Action of Heider Double Disc Friction Clutch 257 Fig. 101 — Clutch and Transmission Assembly of Ohio Tractor 258 Fig. 102 — Outlining Action of Ohio Friction Roller Clutch. A — Friction Roller in Neutral Position. B — Roller in Forward Drive Position. C — Roller Placed to Obtain Reverse Motion 260 Fig. 103 — Master Clutch and Reversing Mechanism of Typical Tractor . . . 262 Fig. 104 — Showing Arrangement of Clutches and Drive Gears of Holt Caterpillar Tractor 264 Fig. 105 — Diagram Showing Action of Speed Changing Gearing 268 Fig. 106 — Plan View of Morris Tractor Mechanism, Out- lining Arrangement of Engine Crankshaft, Speed Changing Mechanism and Rear Axle .... 270 Fig. 107 — View of Transmission and Differential Unit With Cover Removed 272 Fig. 108— View of Change Speed Gearing of I. H. C. Two Speed Tractor With Sliding Gear in Neutral Position . 273 Fig. 109— Sliding Gear of I. H. C. Two Speed Transmission in Low Speed Position 274 Fig. 110 — Sliding Gear of I. H. C. Two Speed Transmission in Direct Drive Position 275 Fig. Ill— Sectional View of Typical Countershaft With Differential Gear in Place 277 Fig. 112— The Differential Spider With Bevel Pinions and Spur Drive Gear Attached 279 Fis. 113 — Countershaft With Differential Spider Outlined at Fig. 112 Removed 280 xxvi List of Illustrations Fig. 114 — Frame and Running Gear Assembly of I. H. C. '•Mogul" Tractor 284 Fig. 115 — Frame Assembly of Typical Gas Tractor, Showing Driving and Steering Gearing 286 Fig. 115a— Frame of the "Twin City 40" Gas Tractor Built of Standard Structural Shapes, Such as Angles and Channels Joined Together by Flat Bars and Braced by Plates. An Exceptionally Substantial Design Representative of Best Construction . . . .287 Fig. 116— Rear End of I. H. C. Tractor Frame, Showing Substantial Cast Members Serving to Support Counter- shaft and Rear Axle Bearings 2ss Fig. 117 — How Pivoted Solid Front Axle Permits Frame Movement Without Distortion by the Three Point Support. A — On Level Ground. Z?— Rear Wheel Surmounting an Obstacle 289 Fig. 118 — Showing Arrangement of Ackerman Front Axle to Obtain Three Point Support of Tractor Frame . 291 Fig. 119 — Method of Mounting Front End of Phoenix Tractor Frame on Springs Designed to Permit Three Point Suspension Principle 292 Fig. 123 — Showing Advantages of Large Wheels for Tractor Driving Members 293 Fig. 121 — Tractor Driving Wheel Showing Method of Attaching External Spur Bull Gear to Wheel Hub and Rim 295 Fig. 122 — Tractor Driving Wheel and Hub Casting. Note Internal Spur Drive Gear and Method of Attaching to Hub and Rim 297 Fig. 123— Traction Wheel of Gas Tractor With Spring Members to Remove Shocks from Driving Gsars . 298 Fig. 124 — Driving Wheel of Tractor Utilizing Chain Drive 299 Fig. 125 — Cross Section of Hart-Parr Rear Hub Showing Wheel Bearing and Method of Lubrication . . . 300 Fig. 126 — Traction Wheel Rims Showing Cleats or Grouters of Various Types Utilized to Increase Frictional Adhesion With Ground 301 Fig. 127 — Extension Rims Designed to be Attached to Regular Traction Wheels to Obtain Greater Contact Area When Used on Soft Ground 302 List op Illustrations xxvii Fig. 128 — Showing Construction of Caterpillar Tread Traction Member of Holt Tractor 303 Fig. 129 — Comparison Between Wheel and Caterpillar Tread Traction Members 305 Fig. 130 — Tabular Comparison Between Caterpillar and Wheel Types of Traction Engines 306 Fig. 131 — Showing Two Methods of Steering Four Wheeled Traction Engines. A — Tight and Loose Chain Method. B — -Worm and Sector Gear and Ackerman Axle 307 Fig. 132— Front View of I. H. C. "Mogul" Gas Tractor Frame Showing Centrally Pivoted One Piece Axle . 309 Fig. 133— Front View of I. H. C. Tractor Using Ackerman Type Front Axle With Elliot Pattern Steering Knuckles 310 Fig. 134— Front View of Three Wheel Hart-Parr Gas Tractor Frame Utilizing One Wheel for Steering Purposes 312 Fig. 135 — Sectional View of Front Wheel of Hart-Parr Three Wheel Tractor Showing Method of Supporting Steering Member 313 Fig. 136 — Outlining Application of Automatic Steering Arrangement to '"Big 4-30" Gas Tractor .... 315 Fig. 133a— The Cuddy Automatic Steering Device Applied to Ackerman Type Front Axle 316 Fig. 137 — Showing Important Members of Conventional Power Transmission System 317 Fig. 138 — Front View of Hackney Gas Tractor Which Has Traction Members at Front End and Single Rear Wheel for Steering 319 Fig. 139— Rear View of Holt Caterpillar Tractor Showing Chain Drive to Traction Members from Cross Shaft . 321 Fig. 140 — Sectional View of Worm Drive Gearing Used in Connection With Live Rear Axle 323 Fig. 141 — Sectional View of Half of Rear Axle of Live Type Used in Connection With Worm Gear Final Drive . 324 Fig. 142 — Side View of Morris Tractor Showing Operator's Platform and Control Levers 328 Fig. 143 — Governors of the Centrifugal Type Form Im- portant Part of Tractor Power Plant Control System . 329 Fig. 144 — Small Engine Used to Start Large Power Plant of I. H. C. "Mogul" Tractor 331 xxx List of Illustrations Fig. 176 — Ploughing, Packing, Harrowing and Seeding This Ground Accomplished in One Operation. "Twin City 40" Gas Tractor Furnishes Power When Utilized in This Manner at Extremely Low Cost .... 407 Fig. 177 — Outfit of Berland & Lee, Brady, Mont., Plough- ing With Disc Plough and Packing With Stone Drag . 408 Fig. 17S — Simple Three Drill Hitch Easily Made by Any Farmer 409 Fig. 179— Wrought Iron Pipe Drill Hitch for Three Drills . 409 Fig. 180— Practical Application of Drill Hitch . . .410 Fig. 181 — Hansmann Patent Five Drill Hitch Very Useful in Seeding Large Areas as It Covers a Strip Sixty Feet Wide 410 Fig. 182— Avery Gas Tractor Outfit Owned by D. M. Circle, Kiowa, Kansas, Pulling a Double Disc and Lever Tooth Harrow 411 Fig. 183 — Details of Easily Constructed Harrow Hitch for Four Ten Foot Disc Harrows 412 Fig. 184 — Practical Application of I. H. C. "Mogul" Tractor in Road Grading Work 412 Fig. 185— Avery Gas Tractor Pulling Western Wagon Loader and Elevator Grader ' . . 413 Fig. 183 — -Practical Hitch for Pulling Three Road Scrapers Simultaneously 415 Fig. 187 — Special Wagon Adapted to be Used in Train Hauled by Gas Tractor 416 Fig. 188 — Combination Road Roller and Tractor, an Extremely Useful Machine for General Contractors or Municipal Use. A — Machine With Roller for Steering and Auxiliary Rims on Traction Members. B — Roller Removed from Front and Wheels Substituted, Making Practical Tractor for Road or Field Work . 417 Fig. 189 — Harvesting With Avery Gas Tractor in North Dakota 418 Fig. 190—1. H. C. Gas Tractor Pulling Three McCormick Harvesters 419 Fig. 191— The Threshing Outfit Entrained Ready for Trip to Destination in Upper View. Outfit at Work in Field in Lower View 421 Fig. 192— Gas Tractor Not Only Cuts but Stores the Fodder 422 List of Illustrations xxxi Fig. 193 — Holt Caterpillar Tractor Demonstrates Its Worth In Swampy Ground 424 Fig 194 — The Modern Gas Tractor Makes Hauling of Heavy Logs a Commercial Proposition .... 425 Fig. 195 — An Auitman & Taylor Tractor Operating in Deep Snow, Shows That All the Year Round Service May be Obtained from the Modern Gas Tractor . . .421) Fig. 196 — Ingenious Home-made Light Tractor Saw Constructed by F. J. Jantz of Hilsboro, Kansas . . 427 Fig. 197 — Home-made Gas Tractor Outfit Built by John H. Sands, Cavalier, North Dakota 428 Fig. 198 — Method of Installing Auto-tractor Under Rear Axle of Car and General Construction of the Attach- ment Outlined 429 Fig. 199 — Side View of Automobile, Equipped With Auto- tractor Attachment 431 Fig. 200 — Rear View of Automobile With Auto-tractor Attachment, Showing Practical Application in Plough- ing 434 Fig. 201 — Plan of Easily Constructed Prony Brake for Making Power Tests 443 Fig. 202 — A Simple Method of Determining Grade Per- centages Without a Gradometer ..... 447 Fig. 203 — Road Signs of American Motor League That Give Warnings of Interest to Tractor Operators or Motorists 450 Fig. 204 — Belt Driven Centrifugal Pump Suitable for Irrigation Purposes May be Driven by Direct Connec- tion With Belt Pulley of Gas Tractor Power Plant . 461 THE MODERN GAS TRACTOR CHAPTER I. THE SCOPE, ADVANTAGES AND APPLICATION OF POWER TRACTION. Influence of Mechanical Power on the Arts — Application of Power in Agriculture — Advantages of Power Traction — Comparison Between Work of Horse and Tractor — Thermal Efficiency of Horse — Tractor Furnishes Power for Various Farm Machines — Economical Aspect of Power Traction — Analysis of Requirements of Ideal Tractor — Practical Prime Movers — Comparing Steam and Gas Power from a Prac- tical Point of View — Efficiency of Steam and Gas Power — Why Gas Tractors Are Most Popular. Influence of Mechanical Power on the Arts. — The discovery of the expansive power of steam and the de- velopment of the practical steam engine by Watt was the inception of the era of supremacy of mechanical power and the decline of animal energy in the mechanical arts. The first steam engine was devised to draw water out of mines with greater celerity than prevailed with animal power, the only source of work available when natural forces, such as wind or falling water could not be used and though crude in form, it was not long before it had conclusively demonstrated its superiority as a prime mover and was generally used to replace animal power in the industrial establishments and workshops of the day. When the steam engine had been developed still fur- ther, other inventors sought to apply it to the wide field 33 34 The Modern Gas Tractor of transportation. Early in the 19th century the steam- boat contrived by Robert Fulton proved without ques- tion that navigation by mechanical power was possible, and a little later, road vehicles were devised that ran without horses. The opposition of the ignorant public prevented further development and some countries, notably England, passed laws excluding such self-pro- Fig. 1.— The Method of Ploughing in Vogue for Over 5,000 Years. Animal Drawn Single Furrow Plough. pelling vehicles from the highways. Ignorance has always been a bar to progress, and thus the antipathy of an uneducated populace delayed the development of the modern automobile by over half a century. While the steam engine and other forms of prime mov- ers soon displaced horse and human power in the field of mechanical engineering and general manufacturing, ani- The Modern Gas Tractor 35 mal power has remained for years supreme in the oldest and most important industry of mankind, agriculture. In most countries it is the horse, ass or ox that is used for drawing the ploughs and other machines utilized for til- ling the soil. In India and parts of Africa the elephant is used, in Asia the camel furnishes power. Domesti- cated buffalo, reindeer, or dogs serve as motive power in other localities while the pioneer Doukhabor farmer of Canada, when too poor to purchase horseflesh har- nessed ten or twelve women to the plough and thus tilled the virgin soil that soon gave him a competence. Application of Power in Agriculture. — Agricul- ture is the basis of any country's prosperity. It is the most important of the occupations of man because it fur- nishes the majority of the foodstuffs that sustain life. A country that cannot grow enough food for its population is always in grave danger, and no matter how large its other resources may be, it is always at the mercy of those states that are able to feed their people. Of late years, a number of conditions have served to direct public inter- est to the farmer and the important bearing his work bears to the general welfare of the people. The increas- ing cost of living, the high prices for the bare necessities of life demands careful consideration and scientific appli- cation of principles that will increase the farmer's effi- ciency. It is more important that the cost of producing the food of man be reduced than that of any other thing. It takes good food and plenty of it to conserve human and animal life and efficiency. , Just as mechanical power increased production and reduced cost of our manufactured products to such an extent that the luxuries of kings of but a century ago are available to the poorest workman of to-day, so its general application to the farmer's work will increase 36 The Modern Gas Tractor the productiveness of his fields. It will give him more time for the intelligent direction of his activities by reducing the daily grind of incessant toil heretofore his lot; and increase his wealth and purchasing power and thus benefit the public at large in many ways. The pos- sibilities of expansion of our already large agricultural industry by application of mechanical power to the fields, Fig. 2. — The Modern Method of Soil Tillage. Mechanical Power Furnished by Gas Tractor Pulls Six Ploughs at Once. Some Tractors Powerful Enough to Make Fourteen Furrows at a Time. workshop and even households of our rural population can be adequately grasped only by a study of sociology and economics that is obviously not within the scope of a mechanical treatise. The Modern Gas Tractor 37 Advantages of Power Traction. — Theie is no point about the farm where power is more necessary than in the fields, and it is said that more energy is spent in plowing annually than in the combined factories of the world during the same period. The earliest plow was a crotched stick and served to till the ground for the first of our primitive ancestors who conceived the idea that breaking the ground was the first step and one of the most important that had bearing upon the growth of the seed sowed therein. Plowing has always demanded more expenditure of energy and time than all other lines of farm work combined. History records that the Chinese Emperor Shen Neng who assumed the sceptre nearly 3,000 years before the beginning of the Christian era, "first fashioned timber into plows." For over 5,000 years ploughing has been done by animal power and the feet of the larger majority of our farmers are still in the furrow, their arms still control and guide the plough. The call first came for power to pull the plough, to make many furrows in the time usually taken to make one. The earth must be ploughed at a certain time, and under sharply defined conditions. To violate any of the rules, either of time or thoroughness of tillage makes material difference in the quality and quantity o£ the crops. The amount of land tilled depended upon the equipment of the farmer and the endurance of his employees and horses. At best, the area ploughed was generally but a small percentage of the ground available for cultivation. The crops were limited and the pro- ductive ability of the farm was relatively low in com- parison to what power makes possible. The first steam ploughing engine is credited to J. W. Fawkes, and was buKt in 1858. It drew eight plows in prairie sod at the rate of three miles per hour. The first 38 The Modern Gas Tractor gasoline tractor was placed on the market in 1893 but could not compare with the steam tractor because of the crudeness of the gasoline engine of that period. It was not until 1903 that the gas tractor became a com- mercial success. The development of the practical internal combustion tractor was even more important than the invention of the mechanical reaper and binder or the threshing machine. It gave the agricultural industry the power that was needed, and its advent marks the greatest jump of progress in the history of agriculture. From its advent, barely a decade ago, the story has been one of steady progress. Difficulties have been gradually eliminated and to-day one may say that many of the tractors sold have reached a high efficiency, while all made by reputable manufacturers are practical and capable of wide application. It is estimated that over seventy-five firms are offering gas tractors of all varieties and the sales at the present time run well up into the thousands yearly. They have been shipped to all parts of the civilized world, yet the indus- try is but in its infancy. Power traction is superior to animal energy because it will do more work in a given time at less expense than possible with any other traction means. It can be adapted to tasks that cannot be accomplished by any other power and it is always ready for work. When intelligently managed its operating cost is so much less than that of horses necessary to do the same work or the amount of work done in a given time is so much greater than possible with any other form of power of the same cost that its merits are apparent to any one able to analyze its performance. Comparing Work of Horse and Tractor. — A brief summing up of the comparative merits of horse-power The Modern Gas Tractor 39 and mechanical energy show clearly the reason why the animal is doomed to give way to the gas tractor on everything except, perhaps, very small farms, and even in this field of application, some of the lighter tractors are available and will do anything the animal can and much work that the horse cannot be made to perform. In the prime advantage of economy, both in time and money, the tractor is cheaper by a wide margin. A tractor works in any kind of weather without fatigue. The horse is affected by extremes of temperature, either hot or cold. The horse is subject to all ills that flesh is heir to, if the animal breaks down, nature is the only possible repairman and it works slowly. The tractor is machinery, any one of average intelli- gence can replace worn or broken parts with but slight delay. The tractor feels neither heat or cold. It will work equally well in the torrid heat of summer or the icy blasts of winter. A tractor can be housed cheaper than the number of horses needed to do the same work can, it requires no care and does not eat when not in use as horses do. Its days work is limited only by the num- ber of hours in the day and the endurance of its operators. Its working period is not measured by periods of 6, 8, or 10 hours, with frequent stops for rest. The tractor will work 24 hours per day, and pull as strong the last minute of the period as when first started. To be convinced of the relative value of horse and mechanical power, one can compare the original cost of any tractor with the first cost of a sufficient number of horses to do an equal amount of work. The comparison favors the tractor. If one compares the maintenance cost of the two outfits, the machine is overwhelmingly superior to the animal. Compare the amount of work 40 The Modern (J as Tractor accomplished by them and its approximate cost, you will soon appreciate the value of the tractor. A farmer cannot afford to feed and house the number of horses necessary to do the work a 50 or 60 horse-power tractor can. Fig. 3. — A Man Easily Carries Fuel and Water Enough for an Extended Period of Operation When Gas Engine is Used for Power. Thermal Efficiency of the Horse. — The horse may be considered as a motor in the sense that it utilizes the heat units contained in its food, which represents the fuel that is burnt in the cylinder of the gasoline engine or under the steam boiler. The ratio between the energy given out by the animal and the amount of fuel consumed i espresents the thermal efficiency, or utilization of heat re- lative to work done. There are different methods of com- The Modern Gas Tractor 41 paring the efficiency of the horse and the inanimate engine. The engineer considers the ratio of the heat units delivered by the motor as useful work to the total heat units in the fuel supply. The student of animal physi- ology first determines the number of digestible elements contained in a given food and considers this the fuel value of the feed. It is said that 30 per cent, of the fuel value of food is lost in the energy expended by the ani- mal in chewing and digesting it. In addition to a food having a fuel value it also has a maintenance value. The amount of external work that can be obtained when the animal is given a certain definite amount of food is termed the "production value." Even when the horse is working a certain proportion of energy is being con- sumed in moving its body and as it is able to deliver work only when in motion the thermal efficiency of the horse is very low, being given as not more than 6 to 10 per cent. This is exceeded by most internal combustion tractors. Experts of the U. S. Department of Agricul- ture have obtained an efficiency of 20 per cent, under laboratory conditions. While this may be true of scien- tifically fed animals under careful supervision, the horses that work under actual farm conditions have a much lower efficiency. Many experiments have been made to determine the actual power of a horse. James Watt, the inventor of the steam engine, placed the working power of a 1,500- pound animal as the ability to lift 33,000 pounds to a height of one foot each minute or > 550 pounds to the same height each second. This originated the term "horse-power" which has been used in the mechanical world ever since these classical experiments were made as a unit for the measurement of power delivered from, or consumed by mechanical devices. 42 The Modern Gas Tractor Recent experiments seem to indicate that the work performed by the average animal approximates 22,000 foot-pounds per minute, or two-thirds of a horse-power. Other investigators declare that the average horse will deliver three-quarters of an actual horse-power. The working ability of a horse is measured by its pulling power which is called "draft" and it is on this basis that traction engines are compared to horse flesh. The pull- ing power of the animal is given at one-tenth of its weight when working continuously ten hours each day pulling some object at the rate of 23^ miles per hour. Under these conditions a 1,200-pound horse will develop but eight-tenths of a horse-power and a 1,500-pound ani- mal one horse-power. For short periods the horse may exert a maximum draft of about one-half its weight but obviously this work cannot be done continuously and the amount of energy can be exerted for but a short time without injury. The pulling power of the average plough horse is given as 150 pounds. One horse-power is equal to a draft of 187.5 pounds at the rate of two miles per hour. It is evident that no matter whether one considers the horse from a practical or scientific point of view that mechanical power shows a marked advantage over ani- mal energy. Tractor Furnishes Power for Various Farm Ma= chines. — We have seen that the horse can do its best work only when pulling a load. If used for power through the medium of a tread-mill, for operating vari- ous forms of machines, the efficiency is still lower and the ratio between useful work obtained and amount of food consumed is such that it is not economical to utilize the animal in this way. The usefulness of a tractor is more varied than that of any other farm machine. It The Moderx Gas Tractor 43 is not only the most economical power for ploughing hut it operates with equal economy all the machines and appliances necessary for raising and harvesting crops. These include disk harrows, seeders, drills, packers, binders, etc. It can be used for hauling grain to the elevator, pulling stumps and hauling all kinds of lumber and supplies to WATER YYACOH KhmttJtf' ' J - ' — 111*-- ) 7* Fig. 4. — The Caravan Needed to Keep a Steam Traction Engine Supplied With Fuel and Water is a Large Item in Operat- ing Costs. the farm. Most tractors can be used for stationary power and a belt may be run from the pulley provided for the purpose to operate threshers, shellers, shredders, pumps, sawing outfits and any other form of machine needing power. It has sufficient power to run a large number of machines at a time if the main drive is con- nected to a line shaft which will turn a number of ma- chines in unison. II The Modern 7. - — M = ctf 0> — H b9 1 Ph o ^ o — CHAPTER II. REVIEW OF CONDITIONS ON WHICH TRACTOR DESIGN IS BASED. Elements of Tractor Design Outlined — Selection of Power Plant — Power Needed for Hauling — Energy Absorbed by Ploughs — Power Delivery Under Belt — Why Proper Dis- tribution of W T eight is Essential— Influence of Weight on Traction — Influence of Road or Field Surface on Traction — Effect of Grades on Traction — Types of Tractors — Trac- tion Engines for Small or Medium Sized Farms — Large Capacity Tractors — Parts of Typical Tractors Outlined — Some Distinctive Designs. Elements of Tractor Design Outlined. — The main part of the gas tractor is the power plant. Next in im- portance comes the traction mechanism. For the most part the gas engines used in tractor work contain the same essential components as stationary gas engines do. Most of the earlier tractors used the common form of horizontal cylinder stationary engine as a power plant in the one and two-cylinder forms. Many of the present day successful machines utilize engines that are sold by the same manufacturers for stationary work. Some of the latest tractors depart from the old method of con- struction and the power plants are based more on the lines of automobile motors than of the stationary engines. The supporting frame, driving wheels, differential and power transmission gearing are not radically different from the same parts of a steam tractor. 61 62 The Modern Gas Tractor The engines of single-cylinder tractors usually run at three hundred to four hundred revolutions per minute. At higher speeds than these, the vibration becomes excessive and all parts of the mechanism are severely stressed. Two and three-cylinder engines, which have a better running balance, are usually run at somewhat higher speeds, and the four-cylinder type, which is prac- tically in perfect balance, both in that of the mechanical parts and torque, due to rapid sequence of explosions, are run at higher speeds. Some of these attain seven and eight hundred revolutions per minute. Gas tractors may be roughly divided into low, medium, and high- speed types, depending on the type of power plant em- ployed. The group usually considered as the power plant con- sists of other elements besides the engine. Some form of vaporizer must be provided to change the liquid fuel to a gas that can be exploded in the cylinder. It is im- perative that some means of igniting the compressed charge of gas be included. The power plant must be automatically lubricated, this calling for various devices for supplying a regular quantity of lubricant. To keep the engine from overheating some method of cooling the cylinder is always included in the power-plant outfit. It will be seen that the power-plant group consists of, first, a gasoline or kerosene engine; second, a method of supplying and vaporizing liquid fuel, these members usually forming part of the carburetion system; third, some means of igniting the gas, usually composed of a number of electrical devices to form a complete ignition system; fourth, a water tank or radiator, or an oil-cool- ing tank, a circulating pump for keeping the liquid in motion around the cylinders and forcing it to the cooler where the heat absorbed is dissipated to the air. These The Modern Gas Tractor 63 various devices form a cooling system. Fifth, the lubri- cation system which comprises positive mechanical means for supplying lubricant. All of these are of suffi- cient import to merit a detailed consideration, and will be discussed fully in proper sequence. The transmission system comprises a clutch, which is used to connect the engine power to the wheels and to release the engine when desired; a change speed and Fig. 10a. — Side View of Phoenix Tractor, A Compact Design. reversing gearing, which is necessary because the gas engine as ordinarily used is not reversible and not as flexible as the steam engine; and positive power trans- mission means, usually chains or gears, to transmit the engine power from the change-speed gearing to the trac- tion members. A frame of substantial construction is needed to sup- 64 The Modern Gas Tractor port the parts and this in turn must be carried on rolling members. Some forms of tractors utilize a three-wheel frame, the single front wheel being used for steering, while others employ four wheels, the two smaller front members being provided with some operating means by which the course of the machine can be changed at the will of the operator. Selection of Power Plant. — The type and size of engine needed depends on many varying conditions. 30° Angle with Base One in 2 or 50 Percent One in 3 or 33% Percent One in 4 or 25 Percent One in 5 or 20 Percent One in 70 or JO Percent 0ne-in~T5-or-6 2 /% Percent One in 20 or 5 Percent WOO Feet Fig. 11. — Diagram Showing Method of Calculating Grade Percentage. The weight of the tractor and its capacity are the first things to be considered. The purpose for which the tractor is intended and the nature of the country in which it is to be operated are also factors of some moment. Another important point is the proposed selling price. One would not expect to find a highly refined and expen- sively built motor on a light or cheap tractor. Then The Modern Gas Tractor 65 again there would be nothing gained by installing an engine of large capacity in a machine built only for relatively light work. If the tractor is a type that is likely to be used by the farmer of comparatively small means, the engine should be a simple one that will be easily understood and cared for, without too much trouble or expense. Single-cylinder engines are invari- ably used on low-powered machines. The two and three- cylinder motors are used on machines of moderate capacity, while the four-cylinder power plant is installed in the highest types of construction. Power Needed for Hauling. — A tractor used for hauling purposes does not need to be as powerful as one used in ploughing or breaking because of the difference in draft required by wheeled vehicles and ploughs. The tractive effort on various surfaces, which means the amount of pull or push necessary to move wheeled vehicles on level roads as given by Norris follows: On rails or plates 5.16 pounds per ton weight Asphalt or hardwood 12.24 " " " " Macadam 30.60 " " " " Loose gravel 150 to 200 " " " " Sand 400 " " " " From the foregoing, it will be seen that the better the surface of the highways over which the load is hauled, the less the amount of power needed to move a definite weight. If it is necessary to haul a wagon train, weigh- ing ten tons over a macadam road, it would require a draft of 306 pounds. To move the same weight through sand will take 4,000 pounds draft. We have seen that a horse-power was equivalent to a draft of approximately 187 pounds at the rate of two miles per hour. In the first case, where the highway surface is good, a drawbar pull equivalent to that exerted by two horses would be 66 The Modern Gas Tractor sufficient to pull ten tons. A 5 to 6 horse-power tractor, if properly designed would be adequate to move this load, provided that there were no grades or stretches of unfavorable highway to be encountered. At the other hand where the road conditions were poor a pull equiva- lent to that exerted by twenty horses would be needed and a very efficient tractor equipped with a 35 or 40 horse-power motor would be called for. Other factors besides the condition of road surfaces must be given consideration. The factor of wind resist- ance, which is so important in figuring power required of motor cars, locomotives or other rapidly moving vehicles can be neglected, but the effect of velocity and gradient must be considered in this connection. The relations of velocity and gradient on traction will be con- sidered fully later. Energy Absorbed by Ploughs. — If the tractor is to be used for breaking and ploughing it will have to be a powerful one if it is to do an amount of work worth while. Soils differ greatly in their cohesive properties and the amount of draft required to operate a single plough share will vary within wide limits. The average draft of ploughs as determined in an old English test for a furrow 5 inches deep by 9 inches wide made in five different soils was as follows: Loamy sand 227 pounds Sandy loam 250 pounds Moory soil 280 pounds Strong loam 440 pounds Blue clay 661 pounds This represents an extreme range of 194 per cent. One heavy horse would be needed to pull a plough in sandy loam and in doing this he would be exerting a draft, having a value greater than one horse-power. A team of The Modern Gas Tractor 67 two heavy horses would be needed to pull the shares through strong loam, while in ploughing the blue clay, three heavy or four light horses would be required to pull the plough continuously for a working day. Fifty-seven tests in the varying soils of Missouri gave an average draft of 5.26 pounds per square-inch area of / the cross section of the furrow slice turned. Seven trials in clover gave an average of 6.47 pounds per square inch, while six in oat stubble averaged 4.68 pounds. Plough- ing in virgin gumbo sod requires a draft of 13.75 to 16.3 pounds per inch. The shape of the plough, the weight, and the adjustment must all be taken into consideration as well as the depth and angle of the cut. The situation may be summed by sa3 r ing that for ordinary widths and depths of ploughing, the draft per square inch of cross- section ranges from a minimum of three pounds in sandy soil to seven or eight in clay, six or seven in tame clover sod, and ten to fifteen pounds turning the sod of the vir- gin prairie. The draft of a 6xl4-inch furrow would thus present an extreme range of from 250 to 900 pounds, while 400 to 500 pounds is given as an average for old land in the middle West. From the foregoing it will be evident that in ploughing the full capacity of a tractor must be used. A 30 horse- power tractor, which delivered 50 per cent, of its brake horse-power or 15 horse-power at the drawbar would exert a pull equivalent to 2,810 pounds at the rate of two miles per hour. In soil requiring a draft of 200 pounds per plough it could pull a fourteen-bottom gang, while in exceptionally heavy soil, requiring a draft of 500 pounds per ploughshare its capacity would be but a six- bottom gang. It will be seen that the lighter tractors having comparatively low-powered engines cannot be used as economically as the larger ones for extensive 68 The Modern Gas Tractor ploughing, though they are practical for hauling pur- poses, or for ploughing on small farms. Power Delivery Under Belt. — Most traction engines are provided with a pulley by which the motor may be coupled to any form of machinery that can be driven by a belt. In this work practically the entire brake horse- power of the motor is available, as there is but little loss in transmission. When it is used for traction purposes part of the power is being used in moving the machine over the ground and part is being lost in friction in change speed and driving gearing. An engine that may deliver 30 horse-power under belt would not deliver more than 15 horse-power at the drawbar under ordinary con- ditions. Why Proper Distribution of Weight is Essen= tial. — To get the largest proportion of power at the drawbar the gas tractor designer is forced to consider a number of important conditions. First, the engine must be strong and durable and the friction losses through gears and shafting must be reduced to a minimum. Second, the design of the machine and the distribution of weight must allow the engine to travel over a great variety of soils. The weight must be so distributed and carried that it will consume the least possible amount of power to drive the engine. The successful traction engine must be capa- ble of running over wet, and sometimes muddy ground, over soft-ploughed ground, or over rough field surfaces. Every horse-power that is used to move the engine is lost and only that available at the drawbar can be counted in traction work. The engine designer should consider concentrating the weight of the engine where it can be carried to best advantage. If the bulk of the weight is placed at the center of the frame so the load is The Modern Gas Tractor 69 carried on both front and rear axles, the amount of power delivered at the drawbar is greatly reduced unless the machine is a four-wheel drive or other special design. The front wheels should not carry any more load than will hold them in contact with the ground with sufficient pressure to insure positive steering. The smaller the front wheels are in diameter and the more weight carried by them the greater the amount of power it requires to force them ahead and the more difficult it is to control the tractor. In order to secure the greatest tractive efficiency the greater part of the weight should be carried over the rear axle. The engine should be placed at such a point that the front end will not be overloaded or the frame stressed unduly. When the motor is placed parallel with the frame and when the bulk of the gearing is carried by the rear axle the greater portion of the strain due to weight and vibration will pass directly to the ground. The degree of adhesion between the rear-driving mem- bers and the road or field surface depends upon the amount of weight that keeps them in contact with the ground. It should not be inferred that tractors having the engine placed in front or in the middle of the frame are not practical, as many of these have given exception- ally good results in practice. Influence of Weight on Traction. — When a motor- propelled vehicle travels on a level course its tendency to forward motion is resisted by three main items. The most important of these is the rolling resistance at the point of contact of the wheels with the ground. Of the other two, the friction in the rear axle and driving mechanism and the air resistance; the influence of the latter may be neglected in such slow-moving vehicles as tractors. If the vehicle is travelling up a grade the power 70 The Modern Gas Tractor required to lift the weight up the incline should also be considered. The road resistance, as we have seen, de- pends to some extent on the character of the road sur- face, but another factor is the diameter of the wheels and the speed at which the vehicle travels. In the table previously given, we have seen that on a good macadam road a pull of 30.6 pounds would move a ton, therefore the heavier the tractor the greater the amount of power needed to overcome the resistance of the road. The horizontal effort required to pull a tractor up a grade is equal to about 1 per cent, of its weight for each per cent, of the grade. If we have a tractor weighing 10,000 pounds and we wish to pull it up a 10 per cent, grade it will require a pull equal to 10 per cent, of the weight or 1,000 pounds. This added to the traction resistance of 30.6 pounds per ton means that an added pull of 153 pounds must be considered in connection with the amount of force needed to climb the grade. Obviously a lighter tractor would not require so much power on grades and could be operated by an engine of less power. At the same time as the amount of adhesion between the wheels and the ground would be less in case of the light machine, its traction capacity would be reduced in direct proportion. It will be apparent that there are extremes which the careful designer will avoid. A heavy machine with an inadequate power plant or with an inefficient system of transmission will not be practical because it could not surmount grades and would not have the range of work that its size would indicate. At the other hand the mis- take can be made of using too large a power plant in a light machine. This would mean that while it would prove to be a good hill climber or have a capacity for hauling, it would not have weight enough to insure the The Modern Gas Tractor 71 delivery of its full drawbar horse-power on account of the limits in traction imposed by the light weight on the rear wheels. This is overcome in some constructions, notably in the combined self-contained ploughing and traction machines where the ploughs are carried under the frame of the tractor in such a way that the resistance offered by the earth to the cutting action of the plough will hold the wheels firmly against the ground and thus increase the available tractive effect. In this way a light machine that would not be adequate to pull a trailer plough will handle the ploughs provided as a part of its structure with ease. Influence of Road or Field Surface on Traction. — We have seen by the table, previously considered that the draft required to haul wagons varied according to the nature of the road surface. The harder the surface over which the wheels rolled, the less the amount of pull needed to keep the vehicle in motion. The following Grade. Ft. per Per mile. cent. Level 53 1 106 2 158 3 211 4 21)4 5 422 8 528 10 634 12 792 15 Macadam Road. 2,135 2,405 2,675 2,945 Firm Earth Road Not Sticky. II. P. Draft H.P. 3,21516 3,485 4,295 4,835 5,375 6,185 34 6 500 12 770 14 040 15 310 16 58018 850 19 660 23 200 26 740 29 550 33 Soft Muddy Road. Draft 650 ,920 190 460 730 000 810 Soft Field. H.P. Draft 350 27 890 29 ,700 33 040 310 580 850 120 390 200 740 •_N) 090 H.P. 15.40 16.77 18.14 19.51 20.88 22.44 26.35 29.08 31.82 35.93 72 The Modern Gas Tractor table gives the horse-power and draft required to pull a 133^2-tons tractor over various grades and road surfaces at a net speed of 1.9 miles per hour and shows clearly the effect of varying road and field surfaces on traction. Brief study of the table will show that the varia- tion in draft for different road surfaces is not as great as for wagons. The amount of pull needed ranges from 160 to 225 pounds per gross ton. These figures are higher than are usual with wagons and may be ascribed to the greater internal friction existing between the vari- ous parts of the mechanism. In a test a ton of engine weight required a draft 20 per cent, greater than the same weight of wagon and load. If a constant figure or allowance for the friction of gearing could be made and substracted from the draft per gross ton in each case the difference in draft due to road surface would be more strongly emphasized. As it is, it required from 40 per cent, to 50 per cent, more power to pull the tractor over soft-field surface than it did over macadam road. Effect of Grades on Traction. — On grades the in- ternal friction and ground resistance are constant fac- tors, providing that the road surface on the gradient is the same as obtains on the level highway. In the above table the variation between the power needed to move a tractor on the level and on grade is due to the effort expended in lifting the tractor. Under actual service conditions, the internal friction to be allowed for would depend entirely upon the design of the transmission mechanism and the care taken to keep the various bear- ings, gears, etc., well lubricated and in line. An authority has stated that allowing 250 pounds of resistance per ton of weight would not be too much in estimating the power required to move the average tractor over an ordinary road. Each per cent, of grade The Modern Gas Tractor 73 adds 1 per cent, of the tractor weight to the resistance or 20 pounds per ton. For example, it is desired to esti- mate power required to move a 12-ton tractor up a 10 per cent, grade at 2.5 miles per hour. The following equations show the method of determining this: (12x250) +(12 Xl0x20) = 5,400 pounds. 5,400x2.5 13,500 375 375 = 36 horse-power. Considerable difference of opinion obtains as to the methods of calculating grade percentages and some con- fusion may exist in the mind of a non-technical reader regarding the difference between the percentage and angle of a grade. A diagram is given at Fig. 11, which shows the method in vogue graphically. If it is assumed that the base of the triangle represents a line 1,000 feet long and that the first sloping line represents a road having a rise that brings it 50 feet above the starting point this would be considered as a rise of 50 feet in 1,000 feet or one in twenty and would correspond to a 5 per cent grade. The rise is based on the length of the base line not of the hypothenuse of the triangle, which is represented by the inclined roadway. A grade which represents 100 per cent, corresponds to an angle of but 45 degrees and not 90 degrees, or perpendicular, as is commonly supposed. When the grade becomes steep enough so the angle of inclination is over 30 degrees, gravitjr overcomes traction and some positive method of drive such as gear wheels running on toothed tracks are necessary to climb greater gradients than 30 degrees angle. The following table gives the percentages and corres- ponding angles of inclination for gradients ordinarily met with, except in the very mountainous sections of the countrv: 74 The Modern Gas Tractor TABLE OF GRADIENTS. Grade. Equal to Rise or Fall in Angle of One Mile, Feet. Per Cent. Units. 20 1 in 5 11° 19' 1,056 17 1 in 6 9° 26' 880 14 1 in 7 8° 09' 754 12.5 1 in 8 7° 08' 635 11 1 in 9 6° 17' 586 10 1 in 10 5° 43' 528 9 1 in 11 5° 11' 480 8 1 in 12 4° 46' 440 7.75 1 in 13 4° 24' 406 7 1 in 14 4° 05' 337 6.5 1 in 15 3° 49' 352 6.25 1 in 10 3° 35' 330 6 1 in 17 3° 22' 310 5.5 1 in 18 3° 11' 293 5 1 in 20 2° -52' 204 Types of Tractors. — The various constructions that can be termed "gas tractors" vary from the small self- propelling lawn mowers to the heaviest machines equipped with engines of over 100 horse-power. Of the many types of tractors offered the public the most com- mon and that which enjoys the widest sale is the medium capacity outfit that will handle about six ploughs as well as any of the other farm machines generally used on medium sized farms. The field for the very light tractor is not a large one inasmuch as these are suitable only for hauling and for work under the belt. Their capacity is not large enough to make them profitable in anything except the lightest forms of work. While traction engines are on the market with power plants as low as 10 horse-power they are not as practical for The Modern Gas Tractor 75 general service as those which have twice the power and cost but little more. In some special classes of work the light tractor has a field but in general the practical type is seldom equipped with less than a 20 horse-power engine. Tractors have been designed for use in orchards that are moderately light, if compared to the large machines used on the prairie farms of the Middle West. They are entirely suited for the work they are to do and give good results in practical use. A man owning a small farm, such as one that would find work for about four horses can use the lighter tractor to advantage,inasmuch as it will do all the ploughing that the horses will and when not employed in the field the engine can be utilized in all of the various duties which require stationary power where horseflesh could not be used. Tractors having 30 horse-power engines are quite common and are generally used in road work as well as on medium sized farms. Tractors vary in type at present just as widely as did automobiles of a decade ago. Owing to the infancy of the gas 'tractor industry there has been no attempt at standardization as is now the case in automobile con- struction. Some tractors on the market are very rough in construction, and appear to have been evolved by a cut-and-try method, rather than attempting to follow any definite plan or design. Others show evidence of careful thought and study of engineering principles. In some of the cheaper machines cast iron is widely used as a material of construction. Power is transmitted through inefficient cast gears which are exposed to the dirt and grit of the field and which can never be adequately lubri- cated. The power plants are heavy stationary engines and the entire mechanism is inefficient and crude. The 7(i The Modern Gas Tractor machines that are carefully designed use steel forgings instead of castings, utilize power plants of the automo- bile type, employ the best cut steel gearing, thoroughly encased, to protect it from the dirt and well lubricated to insure long life and efficient operation. The mechan- ism is thoroughly protected from the elements and the control members are conveniently placed so that they may be easily handled by the operator . As can be> expected, the machines using the best con- struction and materials and based on correct engineering principles are more costly than the hastily designed and crudely constructed machines. This is a case where first cost is of less importance than after cost or mainte- nance expense. The well-designed machine will be ser- viceable under conditions that will quickly consign the cheap mechanism to the scrap heap. The farmer who intends to purchase a tractor should look into the con- struction and engineering features of the various types very carefully before purchasing. Many who condemn gas tractors as impractical pieces of machinery do so because they purchase poorly designed machines, either through ignorance of mechanical principles or because the low selling price proved attractive. A farmer would not expect the amount of work out of a cheap horse, or in fact, any farm machine that he would get out of the more expensive one. As a rule one gets no more than one pays for and this applies just as well to the purchase of a gas tractor as to a mowing machine, cultivator, or any other farm implement. Traction Engines for Small and Medium Sized Farms. — Many farmers are of the opinion that traction engines are only suitable for large farms where extensive areas must be cultivated. This is a misconception that is not borne out by the actual facts. Even if the area The Modern <1as Tractor 77 under cultivation is not a large one power traction would permit of more thorough soil tilling than is possible with horses. On every farm forage plants must be chopped, corn shredded and shelled, wood sawing must be done during the winter months, and water must be supplied in abundance at all times in the year. Engine power is the only practical energy for this work. In many districts, a great advanatge can be gained from deep ploughing, which is necessary to liberate the fertility of new soil. Deep ploughing is not possible with horse-power because the average farmer who has humane instincts hesitates to plough as deep as may be desirable through fear of cruelly abusing his animals. It will be seen that even the small or medium sized farm can use a tractor to advantage in ploughing work, providing that it can be adapted to other labors at periods when plough- ing is over. Disking and thorough harrowing are neces- sary to prepare a good seed bed and proper pulverization of the soil is necessary to retain moisture. The advan- tage of an engine on a small farm is that it can do this work as well as ploughing and in many cases the same power plant to which ploughs are attached will do the disking and harrowing at the same time. Many of the smaller farmers are just beginning to recognize that animal power is slow and that the in- creased number of horses made necessary by the modern methods of farming are not only expensive in first cost but necessitate setting aside some of the most valuable land for raising hay and grain to feed the animals. A number of tractor manufacturers are furnishing medium weight machines equipped with 30 horse-power engines that will do the work of fifteen horses at the drawbar. These have been designed especially to meet the general demands of the smaller corn belt farms of the Middle The Modern Gas Tractor The Modern Gas Tractor 79 West. Such a machine will pull a four bottom gang in breaking and six in ploughing. From ten to fourteen acres a day can be ploughed and harrowed in one opera- tion. These machines are easily handled as they will turn short and work closely into the corners of the field. It is claimed that two good sized boys with a machine of this character will easily do the same amount of work that twelve horses and four men will do in a day. Such a tractor will run up to a 32-inch separator and will operate corn huskers, shellers, shredders or any similar machinery. Any farmer working 160 acres can use such an outfit with profit. Even the small farmer can use one of the combined self-contained ploughing machines to advantage as there are some on the market that cost less than four horses and that will accomplish more work of an all- around nature than the animals will. Such a machine is shown at Fig. 12 and has the plough hung under the operator's seat and about midway of the frame. With a 16-inch plough a man can do as much work as he would with four horses, as .the machine will travel on the low gear as fast as a good team will ordinarily walk and will be much faster on the high gear. The low ratio of speed is used for ploughing and other heavy work, requiring considerable draft, and the high gear is employed for cultivating, hauling a light load, or travelling on the road. For ploughing the share is set inside of the frame with the front end of the beam .attached to a malleable casting under the front end of the frame. The driver sits directly over the plough, which is in full view at all times. The right-hand steering wheel runs in the fur- row ahead of the plough and the traction wheel in the next furrow behind the plough, thus putting two wheels 80 Tin: Modern Gas Tractor The Modern Gas Tractor M carrying seven-eights of the load in the bottom of the furrows where the ground is solid. The makers claim that it takes less power to push the machine under these conditions than if running in loose soft stubble ground or over rough prairie sod. This motor machine will pull a seeder or drill in conjunction with a two-section har- row, thus doing the work of two men and two teams on the small farm. It will pull a six or seven-foot d sk har- row, which requires three or four horses and do it at less expense. In addition to the work in the field it will run a medium sized ensilage cutter for filling a silo and will furnish power for all the other farm tasks that can be performed by an engine. This machine is recommended for orchard cultivation because it is low enough to permit it to get around under the low branches of the trees. Many orchardists do not care to handle horses around their trees because they are awkard and need constant watching to prevent them from nibbling at the young shoots and nipping off the tops of small trees. A machine of this size also has the advantage that it may be easily stored in any shed or barn that will house the ordinary horse-drawn vehicle. Many of the odd jobs that need to be done, such as haul- ing a load of manure or hay can be accomplished with this machine. The convenience and ease in handling makes a tractor of this size practical for many things that the larger ones could not be used for. It is as easy to control as a horse and as it will back up as well as go forward it can be moved around in nooks and corners where a horse and wag- on outfit could be handled only with difficulty. Another form of self-contained ploughing machine with the parts clearly indicated is shown at Fig. 13. This has larger capacity and is a more powerful mechanism than that 82 The Modern (Ias Tractor previously described. Three ploughs are provided under the frame, these being controlled by the operator sitting above them. They may be removed and a road scraper attached under the machine as at Fig. 14, or this attach- ment can be dispensed with and the machine used for general hauling and power purposes. Fig. 14. — The Hackney Auto Plough With Road Scraper Attachment a Practical Machine for Highway Work. Large Capacity Tractors. — The first class of gas tractors, in which those having power plants ranging from 18 to 30 horse-power are included, are capable of handling three or four ploughs in ordinary sod breaking and are used on medium sized farms. The second class is provided with engines of 40 to 50 horse-power and will handle up to seven ploughs in heavy work. This and the largest class, which ranges from 60 to 75 horse-power with the ability to pull from eight to ten ploughs under the same conditions are used on the larger farms. Some large machines have been made, which will pull twelve ploughs, but these have not been sold as extensively as the medium weight outfits because they are so large and powerful that they cannot be used on anything but The Modern Gas Tractor 83 large farms to advantage. These machines require two men to handle them, one to run the engine and the other to handle the load of ploughs. While costly to purchase and operate, they have such a large capacity that they are economical if operated at capacity. The very large machines have some disadvantages. Owing to their weight they tend to pack the ground and it is only in ploughing that their full capacity can be used to advantage. Many operators of large farms prefer to divide the initial investment required for one of these massive machines and purchase a number of the medium sized tractors, even though it takes more help to operate them, and do the same amount of work that the large machine will perform. It is safer to have the work divided among a number of machines rather than employing an extremely large one, because failure of one of several tractors will not prove so serious as when the one large machine refuses to operate. Except in unusual cases, even the operators of very large farms prefer the medium class tractor to the heavy types. Parts of Typical Tractors Outlined. — The plan view presented at Fig. 15 shows clearly the various parts of a typical gas tractor and their relation to each other. The machinery is carried on a frame made of structural steel supported at the front end by an axle of the pivoted type, having steering knuckles to which the front wheels are attached. In this construction the axle does not move, but the wheels can assume the angle required for describing a curve, because the tiebar which joins the steering arm actuates both wheels in unison. The front wheels of a tractor of conventional design are always smaller than the rear members because they are gener- ally used only for steering, and do not carrj' a large pro- portion of the tractor weight in most constructions. 84 Front Wheel \ The Modern Gas Tractor Steering Knuckle Radiator Fan A x i e Cylinders Belt Pulley — Driving Pinion Rear Axle Draft Bar Change Speed Gears Fig. 15. — Parts of the Pioneer Tractor Outlined. , Fro. 16- SIDE ELEVATION HOLT "CATERPILLAR" TRACTOB SHOWING ALL IMPORTANT PARTS AND THE RELATION To EACH OTHER Crank Bearing Cap — long i Side Plate— Right Side Plate— Left oil Pump Phut: Oil Gauge Crank Shaft Timing Gear Key for (Tank shah Timing « Oun Shaft Timing Gear Key for Cam Shaft Timing « Cara8h""' Magne ( iea'r < i Magnew Magneto Shaft Magneto Bracket Magneto Coupling Magneto Tappet Tappet Guide— High Tappet Guide— Left Tappet (luidi — CniM . Breather Cylinder \L Cam Shaft Etnl Bnshu AN Gear Guard o Shaft Brocket HB Cylinder Gasket. lock BE Cylinder Head BF Long Stud for Cylinder Head BG short Stud for Cylinder Head BK Valve Stem V BL Valve Stem8 BQ Push Rod BR Push Rod End BS Water Heads- BT Water Header Stud BU Priming Cup BV Spark Plug mv Pi her Tube UX Fiber Tube Claim. BY Exhaust Manifold BZ Inlet Munif Belt Pullev Bearing EP Belt Pulley Bearing Cap Eli B.vel Union Shaft K\ Flange. i ( '...upline Hull' EZ Bevel Gear PA Friction Wheel FD Pin for Frielii FK Friction Shifter Ring FL Friction Shifter Arm FP Shifting Link Stop PQ Rod End- Wide Jaw PR Left shift Rod FS Right Shift Rod FT < tear Supporting Roller fit Supporting Rolf i Brat I et FV^ Supporting Roller Shaft >tli FY Main Friction Bearing FZ Main Friction Bearing i !ap GA Shaft End Cap GB Drive Chain Link GC Drive Chain Pin GD Chain Sprocket— Right GE Chain Sprocket— Left GF Spring Driver — Right GG Spring Driver l.efi i. II Spring Driver Key GI Spring Driver Spring GJ Main Drive Shaft GK Center Truss GL split Collar GM Main Drive Shaft Bearing gn Track Drive Sprocket GO Key for Track Drive Sprocket ( i P Rear Thrust Rod Bearing GO Rear Thrust Rod Bearing Cap Track Pin Track Pin Keeper GY Rear Thrust Rod 11 B Front Thrust Rod Nut hi Roller Fi- ll n Gudgeon Wedge Iio Blank Sprocket Shaft HP Blank Sprocket lie;inie: HQ Blank Sprocket Bearing ( !ap UK Blank Sprocket US FrontTbn 1IV Steering Wheel i ring Rod Bearing HZ Motor Control < .niadr.it. I I \ Motor Control Lever IB Coupling Steering Rod K 1 Steering Worm ID Steering Gear Worm " ■. It ; Steering Rod Clamp 1,1 Steering Gfl 1 K Steering ' iear segment 11, Front \\ I.e. I .. IM Side Holler Bracket |\ Cast Iron Pipe lo Front Axle IR Wheel Huh i \ Radiator Head ■ IV Radiator Tnhes jb Radiator Sight Glow .jc Radiator I lange JD Pet Cock The Modern > -.1 s-. 5j o = H ia at p3 7 0) O 1* cm o CD p-f - CD = CZ2 ctf T " CD CD ou ho _ - *H w = P4 +3 r^ 0) d cd C/l o - eft eS O -i rt o Sao s = s- «rt cr! h |Jh '— J- : > CD <1 — - CD £, - H U fe no The Modern Gas Tractor and has a pulley for driving stationary machines. A drawbar is provided for pulling ploughs and other ma- chines requiring draft. The weight of this truck is car- ried on four wheels, therefore when used for ploughing ballast must be put over the driving wheels in order to provide proper traction. As the machine is spring mounted and adapted to speeds from two to fifteen miles _$ MOTOR *i/ COMBINED TRACTION AND STEERING 'wMEtL BELT & ULLEY Fig. 19. — An English Tractor With Three Bottom Gang Plough. This Machine Driven by Two Cylinder Vertical Motor Utilizes Front Wheels for Steering aud Traction Duty as Well. per hour it can be used for a wide variety of work. In- stead of using rubber tires as the ordinary motor truck does, the wheels are provided with wooden plugs to adapt the tractor to hard roads. Traction on soft ground is provided by an extension rim with a number of mud lugs attached, which is so fastened to the wheel that these automatically grip the soil when the wheels sink to a certain depth. It is also possible to move a hand The Modern Gas Tractor 91 lever on each driving wheel which causes a series of sharp spikes to project beyond the periphery of the wheel to increase traction when desired. A machine of this nature is shown at Fig. 18 which clearly outlines the general construction. As will be seen in general form it does not differ radically from the usual type of motor truck. As it is provided with a wagon bed it will haul grain, hay, stock, coal, lumber, milk, fruit, vegetables and other kind of merchandise. It has suffi- cient tractive power to pull three 14-inch ploughs and a harrow in ordinary stubble ploughing and will plough an acre an hour. It will pull two disks, two spike harrows, two seeders, two binders, corn planters, a road grader, a train of loaded wagons, or any other machinery. It has a draft equal to ten horses. This general purpose ma- chine, therefore, is ideal for the small or medium sized farm as it will not only haul loads of all kinds on its own both' but will do field work and serve as a portable belt- power plant when desired. Many other special tractor forms have been evolved, ranging from crudely fashioned home-made contrivances to highly specialized types adapted to do only certain kinds of work. Obviously the general purpose tractor must suffer if compared to one designed to do a specific kind of work, but its wide adaptability gives it an advan- tage over the specialized forms that more than compen- sates for its lack of capacity in any specific work. CHAPTER III. DESIGN AND CONSTRUCTION OF GAS TRACTOR POWER PLANTS. Power Rating Basis — Indicated, Brake and Drawbar Horse- power — Types of Gas Engines — Comparing Two and Four Stroke Cycle Power Plants — Operating Principles of Four- Cycle Engine — How Two-Cycle Engine Works — Advantages of One Cylinder Motors — Features of Multiple Cylinder Motors — Heavy Duty and Medium Duty Engines — One Cylinder Tractor Engines — Two Cylinder Engines — Three Cylinder Power Plants — Tractor Motors with Four Cyl- inders. Power Rating Basis. — In referring to the power of the various internal combustion engines used as prime movers, a number of terms are employed in dealing with the subject that may prove confusing to the layman. Therefore, before going into the theory of engine opera- tion to any extent it will be well to define the various methods of rating. Many believe that there is a differ- ence between a gasoline or electrical horse-power, that produced by a steam engine or from the animal itself. The unit of work remains the same regardless of the source of energy and whether the power is produced by steam, gas, electricity, wind, water or horses. Various equivalents for a horse-power are used, for example an electrical horse-power is 746 watts. There are actually four common methods of horse-power rating in use, each of which carries an intelligent idea of its meaning. Indicated, Brake and Drawbar Horse=power. — Indicated horse-power is the amount of energy devel- oped within the cylinders of any heat engine. It is 92 The Modern (i.vs Tractor 93 determined by an instrument called the indicator, which gives a card or graphic chart showing the pressure in pounds per square inch exerted upon the piston of the engine. This is most commonly used in steam-engine practice and is a unit of interest mainly to the engineer or designer because it does not give the actual power developed by the motor. There are mechanical losses that must be considered before the actual power output of the power plant can be ascertained. Fig. 20. — Simple Diagram to Show One Method of Making a Brake Test of Small Engine. Brake horse-pow r er represents the indicated horse- power, less the losses in friction of the working parts of the motor itself. It is the power actually delivered to the crankshaft or belt pulleys of the motor. The brake horse-power is easily determined by any form of absorp- tion dynamometer of which the Prony brake is the simplest form. The application and use of this form of power indicator can be clearly understood by refer- ring to Fig. 20 and from table given in Appendix. Any one can make the simple testing device illustrated, without any other instructions than given in the cuts. Good stout 4 X4-inch lumber, free from knots; two !>4 The Modern Gas Tractor blocks curved to conform to the periphery of the belt pulley; two bolts as indicated and an ordinary platform scale are all that is needed. The length of the horizontal brake beam represented by the letter B is not arbitrary, it being necessary only to make sure that this should be short enough and have sufficient strength to prevent breaking when under test. When making a test, the first thing to do is to have the engine running at its normal speed and under proper conditions to get steady power. The brake blocks do not bear against the belt pulley with any force except that produced by their weight. The nut on one of the bolts is then tightened to bring the brake blocks in forci- ble contact with the pulley. This tends to depress the end of the brake beam resting on the load transfer mem- ber, which is supported by the platform of the weighing apparatus. The brake beam should always point in the direction toward which the fly-wheel is turning. The rule for obtaining the power delivered by the motor is a simple one. Multiply the speed at which the engine pulley is turning by the number of feet in the circumference of a circle having a diameter twice that represented by the radius B and then multiply this result by the net pounds lifted on the scale when the two nuts on the top end of the bolts have been screwed down suf- ficiently so that the brake blocks are bearing on the engine pulley as hard as possible without reducing the motor speed. Divide this result by 33,000 and the quotient will equal the actual power of the engine. As an example, consider that the distance B between the center of the brake pulley and the portion of the beam resting on the scale is 4 feet. The circufnference of a circle of this radius would be 2X4X3.1416 which equals 25.1328 feet. If the engine pulley is running 200 The Modern Gas Tractor 95 revolutions per minute and the lift on the scales is 100 pounds, we have the following expression: 25. 13 x 200 x 100 33,000 = 15.23 horse-power. Fig. 21. — Making a Brake Test in the Field. At Fig. 21 the method of making a brake test of a tractor power plant in the field is clearly indicated. Drawbar horse-power is the amount of power actually exerted in doing useful work, such as in hauling. We have seen that the difference between indicated horse- power and brake horse -power represented the amount of power lost by friction in the engine. If we deduct the power lost by friction in the power transmission mechan- ism, owing to transmitting it through bearings and gears, and the power necessary in propelling the tractor itself over the ground from the brake horse-power at the pulley, we obtain the drawbar horse-power. This cannot be determined as accurately and as easily as brake horse-power because it depends to a consider- able degree upon the condition of the ground and the 96 The Modern Gas Tractor adhesion between the driving wheels of the tractor and the surface over which they are moving. Under favor- able conditions where the slip is very slight, the draw- bar horse-power of a well-designed gas tractor would be about 2 /i of the actual brake horse-power. It will not be as high as this unless the power-transmission mechanism is very efficient and the weight distribution, wheel and gear construction is such as to get the most perfect tractive effort. Gauge Fig. 22. — The Kennerson Traction Dynamometer, an Efficient and Simple Instrument for Measuring Draf*:. The drawbar pull of a tractor is determined by means of some form of traction dynamometer, such as shown at Fig. 22. This instrument is placed between the source of power or drawbar of the tractor and some immovable body, such as a large tree. The tractor is started and the maximum amount of pull is indicated in pounds upon the gage just before the tractor-wheels The Modern Gas Tractor !»7 slip or the engine stops. This dynamometer may also be used to indicate the tension in tow line or draft gear. As will be apparent, an instrument of this nature may be used very easily in making comparative tests between the tractive power or drawbar pull of various forms of engine and will also indicate the amount of draft needed to haul a wagon, pull a plough or do any other work. The most easily understood rating, and one generally used in describing a tractor to the average farmer is the horse equivalent horse-power. This enables one who wishes to know how the work of a tractor will compare with the actual work of farm horses to make an intelli- gent approximation. It is difficult to make exact com- parisons inasmuch as no two horses can do exactly the same amount of work, and furthermore the average animal is more flexible in its exertions than any mechni- cal tractor. We have seen that the horse is able to exert two or three times its average power for a short distance in the field, while a tractor has no such great overload capacity. The horse equivalent power of a tractor is consider- ably less than its drawbar horse-power and represents the number of actual average farm horses that a tractor can replace in every-day work. It may be approximated by dividing the drawbar pull, exerted by a tractor travel- ling at two miles an hour by 200. If the tractor shows a drawbar pull of 2,000 pounds at that speed its drawbar horse-power or horse equivalent power will be equal to that produced by ten animals of average size. Types of Gas Engines. — Two types of gas engines have been applied generally to furnish power for trans- portation purposes. These differ in construction and operating cycle to some extent, though in all forms power is obtained by the direct combustion of fuel in the cylin- us The Modern Gas Tractor ders of the engine. In all standard engines a member known as the piston travels back and forth in the cylinder with what is known as a reciprocating motion, and this in turn is changed into a rotary motion by suitable mechanical means to be described fully in proper se- To Tank -Inlet Port Piston Pin ^Bronze Bushing 'Piston Rings Crank Case -Crank Shaft -Crank Pin Drain Cock Fig. 23.— Sectional View of Ellis Three-Port, Two-Cycle Engine, Showing All Important Parts. The Modern Gas Tractor 99 quence. Gas engines may operate on either the two- cycle or four-cycle principle, the former being the sim- plest in action, though the latter is easiest to under- stand. Comparing Two and Four=stroke Power Plants. — The sectional view of a two-cycle engine depicted at Fig. 23 shows the three moving parts employed. The gas is introduced into the cylinder and expelled from it through ports cored into the cylinder walls, which are covered by the piston at a certain portion of its travel and uncovered at other portions of the stroke. The three moving parts are the piston, connecting rod and crank- shaft. If this type of power plant is compared with the four-cycle engine shown at Fig. 24 it will be apparent that it is much simpler in construction. In the four-cycle engine the gas is admitted into the cylinder, through a port at the head closed by a valve, while the exhaust gas is expelled through another port controlled in a similar manner. These valves must be operated by mechanism distinct from the piston. In addition to the three main moving parts used in the two-cycle engine there are a number of auxiliary moving members that are part of the valve-operating mechan- ism. The four-cycle engine is more widely used because it is the most efficient type. The two-cycle engine is simpler to operate and very smooth running but it is not as economical as the four-cycle because a portion of the fresh gas taken into the cylinder is expelled through the open exhaust port with the burnt gases before it has a chance to ignite. As a four-cycle engine is more gener- ally used its method of operation will be described first. Operating Principles of Four=cycle Engines. — The action of the four-cycle type will be easily under- stood if one refers to the illustrations at Figs. 25 and 26. The Modern Gas Tractor The Modern- Gas Tractor 101 It is called a four-stroke engine because the piston must make four strokes in the cylinder for each explosion or power impulse obtained. The principle of a gas engine is similar to that of a gun, i. e. ; power is obtained by a rapid combustion of some explosive or other quick- burning substance. The bullet is driven out of a gun barrel by the powerful gases liberated when the charge of powder is ignited. The piston of a gas engine is driven toward the open end of a cylinder by the expansion of gases resulting from combustion. The first operation in firing a gun or securing an ex- plosion in the cylinder of a gas engine is to fill the com- bustion space with combustible material. The second operation is to compress this and after compression, if the charge is ignited, the third operation of the cycle will be performed. In the case of the gun the bullet will be driven out of the barrel, while the piston of the gas engine will be forced toward the open end of the cylinder. As the bullet leaves the mouth of the gun the barrel is automatically cleared of the burnt powder gases which escaped to the outer air because of their pressure. The gun must be thoroughly cleared before the introduction of a new charge of powder. In a gas engine the fourth operation or exhaust stroke is performed by the return stroke of the piston. The parts of a simple engine have been previously indicated, and in order to better understand the action it will be well to consider briefly the various parts and their functions The cyl'nder is an important member because it is in this portion that practically all the work is accomplished. The cylinder is provided with three ports, one through which the gas is admitted, controlled by an inlet valve, another through which the burnt gas is expelled, closed by the exhaust valve, and the third in 102 The Modern Gas Tractor The Modern Gas Tractor 103 which the spark plug used to ignite the compressed gas is screwed. The reciprocating motion of the piston, which is the member moving up and down in the cylin- der, is transformed into a rotary motion of the crank shaft by means of a connecting rod and crank pin. In the simple engine shown at Figs 25 and 26 the inlet valve is an automatic one, while the exhaust member is raised from its seat by a mechanism including the cam- shaft, cam, valve-operating bell crank and plunger. At Fig. 25-A the piston is starting to go down on the first stroke of the four necessary to produce a complete cycle of operations. As the piston descends it creates a suc- tion in the combustion chamber, the automatic valve is drawn down from its seat and a resh charge of gas is drawn into the cylinder through the inlet pipe which communicates with the gas-supply device or carburetor. The inlet valve will remain open until the piston reaches the bottom of its stroke. As soon as the pressure inside the cylinder is equal to that outside which condition obtains as soon as the piston has reached the end of its downward stroke and the cylinder is filled with gas the inlet valve is closed and the piston starts to return on the next stroke as shown at Fig. 25-B. As both valves are closed the combustible vapor with which the cylinder is filled is compressed into a much smaller volume. The reason for compression is that any agent which gives out energy through the expansion of gases is rendered more efficient by confining it in a re- stricted space and directing the whole energy against some one spot. A tuft of gun cotton could be ignited while lying loosely in the hand and it would burn freely but without explosion. If it is confined in a gun barrel and exploded it will drive the bullet out with a great amount of force or burst the metal walls of the con- 104 The Modern Gas Tkactou Uj o The Modern (Ias Tractor 10.~» tainer. Gasoline vapor and air will ignite and burn freely at atmospheric pressure and a gasoline engine could be made to run without compression. The expan- sion of the unconfined gases would not be great enough to do effective work, however, and the fullest efficiency of the fuel is obtained by compacting it into the smallest possible space and then igniting it at the instant when it is compressed the most. Any chemical action requires close contact between the materials producing it, if it is to occur under the most favorable conditions. That which occurs when a mixture of gasoline vapor and air are brought into contact with the flame or arc of the electric spark is practically in- stantaneous if the gases are crowded together. If the gas is not properly compressed, the action becomes more dilatory, extending to a slow combustion wherein the temperature is not raised enough to expand the gases efficiently as the degree of compression is lessened. A good example of slow combustion is the decay of wood, while the phenomenon that we call "burning" may be taken as an illustration of quick combustion. It is said that the same amount of heat is produced by either combustion but only the latter produces it quickly enough to be not'ceable. The comparatively slow combustion of the gases in the engine cylinder, when at atmospheric pressure would not permit the energy derived from the heat to act all at once. When the gases are compressed the particles of vapor are in such intimate contact that combustion is practically instantaneous and the gases give off maximum energy by expanding their utmost due to the high tem- perature developed. The piston is also in a position to be acted upon most readily as the force due to pressure of the gas is directly against it and not exerted through 10(5 The Modern <1ax Tractor an elastic cushion of half-ignited gas as would be the case if the charge was not compressed before ignition. When the piston reaches the top of its second stroke the compressed gas is exploded by means of an electric spark between the points of the spark plug and the piston is driven down toward the open end of the cylin- der, as indicated at Fig. 26-C. At the end of this down stroke the pressure of the gases is reduced to such a point that they no longer have any value in producing power. At this time the cam, which is operated in timed relation to the crank-shaft travel, raises the exhaust valve from its seat and the burnt gases are expelled through the open exhaust port until the cylinder is practically cleared of the inert products of combustion, the natural scavenging ac- tion being assisted by an upward movement of the piston. The piston once more begins to descend, as shown at Fig. 25-A and the inlet valve opens to admit a new charge. The rest of the cycle of operations follow in the order indicated and are repeated as long as the cylinder is supplied with gas and this is ignited. How Two=cycle Engines Work. — The two-cycle engine works on a different principle, as while only the combustion chamber end of the piston is employed to do useful work in the four-cycle engine, both upper and lower ends are called upon to perform the functions necessary to two-cycle engine operation. Instead of the gas being admitted into the cylinder, as is the case with the four-cycle engine, it is first drawn into the engine base, where it receives a preliminary compression, prior to its transfer to the working end of the cylinder. The views at Fig. 27 show clearly the operation of a two-port, two-cycle engine. Assuming that a charge of gas has just been compressed in the cylinder and that the upward movement of the piston while compressing the The Modern Gas Tractor 107 o < be 108 The Modern. Gas Tractor gas above it has drawn in a charge through the auto- matic intake valve in the crank case, it will be apparant that as soon as the piston reaches the top of its stroke and the gas has been properly compressed that the ex- plosion of this charge by an electric spark will produce power in just the same manner as it does in the four- cycle motor. As the piston descends due to the impact of the expanding gases, it closes the automatic inlet valve in the crank case and compresses the gases con- fined therein. When the piston reaches the bottom of the cylinder it uncovers the exhaust port cored in the cylinder walls and the burnt gases leave the cylinder because of their pressure. A little further downward movement of the piston uncovers the intake port, which is joined to the crank case by a by-pass passage, at which time a condi- tion exists as indicated at Fig. 27-B. The piston has reached the bottom of its stroke and both exhaust and inlet ports are open. The burnt gases are flowing out of the cylinder through the open exhaust port, while the fresh gases are being transferred from the crank case, where they had been confined under pressure to the cylinder. The fresh gas is kept from passing out of the open exhaust port opposite the inlet opening by a deflec- tor plate cast on the piston head, which directs the enter- ing stream of fresh gas to the top of the cylinder. As the piston goes back on its up stroke the exhaust and inlet ports are closed by the piston wall and the charge of gas is compressed prior to ignition. As the piston travels up on its compression stroke, the inlet valve in the crank case opens, due to the suction pro- duced by the piston and admits a charge of gas, through the open crank case intake port. It will be seen that an explosion is obtained every two strokes of the piston The Modern Gas Tractor lid The Modern Gas Tractor instead of every four strokes, as is the case with a four- cycle engine. In the two-cycle form one explosion is obtained for each revolution of the crank shaft, while in the four-cycle two revolutions of the crank shaft are necessary to obtain one power impulse. The operating principle of the three-port two-cycle engine outlined at Fig. 28 is just the same as that pre- viously described except that the gas from the carburetor is admitted to the crank chamber through a small port in the cylinder wall, which is open when the piston reaches the top of the stroke as shown at A. The three- port method of construction makes it possible to dis- pense with the automatic inlet valve shown in Fig. 27, and an engine of this kind is a true valveless type. Advantages of One=cylinder Motors. — As the first power plants developed for general use were of the one- cylinder pattern and this type motor has been improved to a point where it is very efficient it is but natural that the first gas tractors would utilize the perfected one- cylinder engine then so widely used for farm power in stationary installations. It was not a difficult matter for the designer of the early gas tractor to take a running gear and driving mechanism, similar to that employed in steam tractors and to replace the boiler and steam engine with a horizontal single-cylinder stationary form of power plant. A typical one-cylinder motor of the horizontal type such as used on the lighter I. H. C. gas tractors is shown at Fig. 29. The single-cylinder engine offers a main advantage of extreme simplicity. This is of considerable import- ance in the lighter all-purpose tractors that are to be operated by inexperienced help. Among some of the disadvantages that may be cited against the single- cylinder power plant are great weight in proportion to The Modern Gas Tractor 111 power developed, lack of even power application because only one stroke out of four made by the piston is effec- tive. A one-cylinder engine lacks the even turning movement and steady running qualities that a multiple cylinder power plant possesses. If run faster or slower Fig. 29. — Single Cylinder Power Plant Used on T. H. C. Two Speed Light Tractor. than the critical speed for which it is designed there will be considerable vibration. Despite these faults, the single-cylinder engine is very practical in applica- tions to light, slow-speed tractors. Features of Multiple Cylinder Motors. — Power is obtained in the multiple cylinder motor by using a num- ber of cylinders instead of one large member. The cylinders are arranged in such a way that any multiple- cylinder motor may be considered as a number of single- cylinder engines joined together so that one cylinder starts to deliver power to the crankshaft where the 112 Tub Modern Gas Tractor other leaves off. By using a number of smaller cylinders instead of a large one all of the revolving parts may be made lighter and the reciprocating members are easier to balance because the weight of the parts in one cylinder often counter-balances the reciprocating mass in the other that works in connection with it. THIS DIAGRAM REPRESENTS ONE CYCLE IN WHICH THE PISTON TRAVELS 20 INCHES i REPRESENTS POWER i ' REPRESENTS NO POWER Fig. 30. — Diagram Showing Advantages of Multiple Cylinder Motors and Why They Deliver Power More Evenly Than Single Cylinder Types. Multiple-cylinder engines may be run faster than single-cylinder ones of the same power, are not so heavy in proportion to the power developed and produce a more even turning effect at the crankshaft. No matter how well designed the single-cylinder power plant is, the power impulses will come in jerks, and a very heavy fly- wheel member, or pair of fly-wheel members is needed to equalize the intermittent power strokes. In a multiple- cylinder engine where the explosions follow each other in rapid succession the power application is obviously much more even. A single-cylinder engine will give but one useful power stroke when of the four-cycle type, to every two revolutions of the crankshaft. A two-cylinder motor will give one explosion every revolution, while a three-cylinder power plant will give three explosions every two revolutions. The Modern Gas Tractor 113 The real value of a multiple-cylinder motor is more apparent when four or six cylinders are used because in the former one obtains a power impulse every half revo- lution of the fly-wheel, while in the latter three-power strokes are delivered every revolution. The diagram presented at Fig. 30 compares in a graphic manner the useful power impulse of engines having a cycle in which the piston travels twenty inches. The shaded parts represent periods where power application obtains, while the unshaded portions represent no power. In the one-cylinder engine it will be evident that less than one-quarter of the cycle represents useful energy. In the two-cylinder engine the explosions are evenly spaced but are separated by appreciable spaces where no power is developed. Eve,n in the four-cylinder engine there are periods (corresponding to the early opening of the exhaust valves on the power stroke) where no useful energy is directed against the crank shaft. The torque, or power applica- tion is uniform enough for all practical purposes, except where the utmost refinement is desired, as in high-grade motor car power plants. In the six-cylinder engine, however, there are no periods in the cycle of operation where the crank shaft is not positively driven. In fact, the explosions overlap each other and a very smooth- acting power plant is obtained. For tractor service, however, a four-cylinder motor will prove to be very satisfactory and will operate with minimum vibration. Heavy Duty and Medium Duty Engines. — It is possible to divide the multiple-cylinder motor class into two general groups. One will include all engines having horizontally disposed cylinders, while the other group will be composed of power plants having vertical cylin- ders. The horizontal group may be divided into sub- 114 The Modern Gas Tractor divisions, where some of the motors will have the cylin- ders on one side of the crank shaft and the other where half of them are on one side and half on the other side of crank-shaft center. The form in which the two cylinders are placed side by side is preferred because of compact- ness, though this advantage is counteracted by difficul- ties which obtain in proper balancing. Where the cylin- ders are opposed the tendency to vibration is neutralized because a better balance of reciprocating parts is obtained and the explosions follow in regular sequence. The vertical motor has a number of advantages over the horizontal type. There is less liability of the cylinder walls wearing out of round and it is easier to lubricate the cylinder when the head is at the top. As a rule, multiple-cylinder engines of the vertical type are much more compact and easier placed on the tractor frame than horizontal engines of the same power and number of cylinders would be. Tractor power plants are often referred to as medium- duty or heavy-duty engines. The heavy-duty type is one where all the bearings and working parts have been proportioned unusually large. It is believed these engines are more suitable for continuous duty at full load than the lighter engines where the bearings are not so large. This is apt to prove confusing, however, because many engines considered heavy-duty power plants must be built very heavy to withstand the vibra- tion and stress present while they are in operation. Many medium-duty engines would be capable of doing more work and operate for a longer period than power plants where the reciprocating and. rotating members were very much larger. •Reciprocating parts produce strains and vibration no matter how perfectly an engine is balanced and the The Modern Gas Tractor 115 extent of these stresses is dependent on the weight of the moving parts and the piston velocity. In order to prevent undue depreciation heavy-duty engines which have large parts must operate at a slower speed than the medium-duty power plants where the weight of the re- ciprocating masses is less. Heavy-duty engines are usu- ally of the horizontal type and have one or two cylin- Fig. 31.— Fly Wheel Side of Two Cylinder Horizontal Motor Used in "Oil Pull" Tractors. ders, while the medium-duty types are almost invari- ably of the four-cylinder vertical pattern. In the vertical motor of the four-cylinder type the parts may be made lighter than in the other forms and as the weight of the piston and connecting rod is entirely removed from the walls of the cylinder, these parts 11 fi The Modern Gas Tractor practically float in a film of oil and the weight is carried in such a way that the least wear is imposed on the cylinder walls, the piston and piston rings. The load is carried by the easily adjusted main bearings of the engine rather than the cylinder, which can be restored to true bore when worn only at considerable expense. Fig. 32. — Double Opposed Motor of 45 Horse-power Used on 1. H. C. Mogul Tractor. The. vertical motor construction makes it possible to use a very efficient lubricating system and the difficulty that obtains in a horizontal engine of flooding the cylin- der head with oil is not present in the vertical cylinder. The oil is also more evenly distributed in a vertical motor because there is no tendency for it to collect at The Modern Gas Tractor 117 the lowest point, which is the wall of the cylinder directly under the piston of the horizontal engine. Another advantage of the vertical cylinder construc- tion is that the vibratory stresses travel in vertical lines and are resisted by parts best adapted to receive them as the axles and wheels. In a horizontal motor, vibra- tion must be absorbed by the frame and gearing and considerable stress is placed on parts not well adapted to resist them. It is not the writers intention to con- tend that horizontal motors are not practical, but it is evident that where these are used the frame parts and gearing must be heavier because they are called upon to take vibratory stresses as well as carry the weight of the engine. As a rule the vertical cylinder motor is more accessible than the horizontal engine. The vital parts which need more or less attention, such as the valves, spark plugs, ignition wiring, water piping, etc., are more easily reached than in the horizontally disposed power plant. Either a medium-duty or heavy-duty engine is suitable for tractor propulsion, though the preference of most designers is for the former because of the advan- tages previously enumerated. One=cyIinder Tractor Engines. — The construction of a typical one-cylinder tractor power plant can be easily understood by referring to Fig. 29. The motor is a long-stroke, heavy-duty type with an inclosed crank case. The cylinder is supported by a substantial cast- iron bed, which in turn is attached to the substantial I beams, forming the main frame members. The fly- wheels are large and are mounted one on each side of the crank shaft. The heavy fly-wheels are necessary to equalize the intermittent power application and are arranged in the manner indicated in order to distribute the twisting strain evenly on the crank shaft. If one 118 The Modern of 148 The Modern Gas Tractor boring out the fly-wheel hub so it is a tight fit on the crank shaft and then driving in a key between the shaft and hub into suitable keyways machined in these mem- bers to prevent the fly-wheel from turning. A better method of fly-wheel retention is outlined at Fig. 51. In this a flange is formed integral with the crank shaft and the fly-wheel member is firmly secured to this by means of substantial retaining bolts. When these are properly fitted it is practically impossible for the fly-wheel to become loose, as sometimes happens in the simple-keyed construction. Fig. 51. — Typical Fly- Wheel and Method of Attaching to Crankshaft Flange by Bolts. The diameter of a fly-wheel must be held to certain limits and the weight one can put at the rim is restricted by the limits imposed on circumferential speed. It is stated that a safe speed for a cast-iron pulley is about a mile a minute for any point on its circumference. The The Modern Has Tractor 14!> slower the speed of the engine, the larger the diameter of the fly-wheel one can use and the more effective it becomes as a balancing member. A fly-wheel 3 feet in diameter would have a circumference of approximately 10 feet. As any point on the rim would turn this dis- tance in a revolution, in order not to exceed the safe peripheral speed the fly-wheel should not revolve faster than 500 revolutions per minute. If a fly-wheel was 6 feet in diameter its circumference would be twice as great as the small member previously mentioned and its speed would be limited to 250 revolutions per minute. Engine Base and Bearings. — All gasoline engines require a substantial base member to which the cylinder or cylinders are attached and which supports the crank shaft as well. The engine base must be of substantial construction in order to keep all parts of the motor in alinement and will vary widely in form depending upon the type of engine. Engine bases used on the simpler tractor power plants are made of cast iron, though some of the engine bases used with the multiple-cylinder en- gines of the automobile type are made of aluminum. Cast iron is a suitable material for this purpose, and while it is somewhat brittle and unreliable in nature when made in light sections, there is not the need for saving weight in a tractor engine that exists in automo- bile practice, so strength is obtained by using a little more iron. A simple engine bed such as used for a single-cylinder stationary type power plant is shown at Fig. 52, and it will be noticed that the lower portion of the crank-shaft bearings are formed integral with the engine bed. On the multiple-cylinder engines the form of the crank case will depend upon the number of cylinders and their dis- 150 The Modern Gas Tractor position. They are often approximately cylindrical members, which may be divided horizontally along the crank-shaft center line or which may be in one piece, hav- ing end plates to support the main bearings and large openings through which the interior mechanism can be inspected. It is obvious that the diameter of the crank case must be large enough to permit the crank shaft and connecting rod big ends to turn inside of it, and its length is controlled by the number of cylinders and their arrangement. Fig. 52. — Base for Single Cylinder Heavy Duty Motor. The crank case of a single-cylinder or double-opposed cylinder, horizontal type, would be about the same in length. ■ That of a four-cylinder engine will depend upon the method of casting the cylinders. A shorter crank case is utilized when the cylinders are cast in pairs than when individual cylinder castings are employed. The crank case shown at Fig. 53 is a type used on a three- cylinder engine and is somewhat shorter than would be necessary with four cylinders. As will be evident, it consists of two parts. The upper portion serves as the The Modern 1 Gas Tractor 151 engine-bed proper and carries the cylinders and crank shaft. The arms by which the engine is supported on the tractor frame are cast integrally with the upper member. The lower portion of the crank case serves merely as an oil container and cover for the working parts and may be easily removed to permit thorough repairing of the interior mechanism. A superficial examination of the parts is made possible Fig. 53.— Crankease of Russell Three Cylinder Tractor Motor Composed of Two Halves and is Split Longitudinally at Crankshaft Center Line. by means of readily removable plates at the side of the crank case, though when repairs of a serious nature are made, such as adjusting the connecting rods or main bearings, it is best to remove the lower half of the engine base. A four-cylinder crank case of the barrel type is 151* The Modern Gas Tractor shown at Fig. 54. As will be seen this construction calls for the use of end-bearing plates, which carry the front and rear main journals, while the three main bearings inside the crank case are attached to the partitions which separate the lower portion into four compartments. The cylinders are held in place by a series of stud bolts screwed into the top of the case. In order to gain access Fig. 54. — Crankcase of Holt Tractor Engine, a One Piece Casting With Removable Side Inspection Plates. to the interior large openings are provided at both sides of the crank case and are closed by substantial cover plates, such as shown leaning against the engine base when the assembly is completed. The main object in engine-base design is to have the member a substantial one that will keep the crank shaft rigidly in line with the connecting rods and pistons and which will be of such design that the various parts will be accessible for inspec- tion or adjustment without having to dismantle the entire power plant. CHAPTER V. MAKING AND EXPLODING THE GAS. The Liquid Fuels — Gasoline — Kerosene — Alcohol — Elements of Carburetion — Simple Mixing Valves — Float Feed Carbure- tor Action — Automatic Carburetors — Parts of Carburetors — Typical Gasoline Carburetors — Carburetor for Two- cycle Engines — Action of Kerosene Vaporizer — Methods of Exploding Charge — Advantages of Electric Ignition — Methods of Producing Current — Dry and Storage Batteries — Function of Induction Coil — Producing Spark in Cylin- ders — Mechanical Generator Advantages — Types of Mag- netos — Oscillating Armature Forms — Types with Revolv- ing Armature — True High Tension Device — Low Tension Ignition System — Simple Battery Ignition Methods — Action of Magneto Ignition System — Timing the Spark. The Liquid Fuels. — The great advance of the in- ternal combustion motor can be attributed more to the discovery of suitable liquid fuels than to any other factor. The first gas engines made utilized ordinary illuminating gas as a fuel, and while this is practical for use with stationary power piants wherever it is available, such as the natural gas fields of the Middle West, or in cities and towns having a central gas pro- ducing plant, it is obvious that it could not be very well applied to portable self-propelling power plants used for tractor propulsion. When it was discovered that certain of the liquid fuels belonging to the hydro- carbon class, which includes petroleum and its distillates, benzol and benzene, which are coal tar products, and alcohol, were suitable, the gas engine became widely used as a prime mover. 153 154 The Modern Gas Tractor The liquid fuels have the important advantage that a quantity sufficient for an extended period of engine operation can be easily carried in a container that will not tax the capacity of the engine and that requires but comparatively little space in any out-of-the-way portion of the frame. When used in connection with a simple vaporizing device, which mixes the liquid with sufficient quantities of air to form an inflammable gas, the fuel is automatically supplied to the engine without any attention being demanded from the operator as long as the supply in the tank is sufficient to produce a flow of liquid through the pipe joining the mixing device and fuel container. Gasoline. — Up-to-date the most important fuel used in connection with gas engines has been one of the distillates of crude petroleum, known generally to the trade as "gasoline." This liquid, which is a clear white very light bodied substance, evaporates very rapidly at ordinary temperatures. This feature made it especially adaptable for use with the early forms of mixing valves because it mixed so readily with air to form an explosive gas. Fifteen years ago there were very few industrial uses for gasoline and it sold for less than five cents a gallon in some cases. During the past decade the demand for it has increased by leaps and bounds, and it now sells for four times as much as it did when the gasoline engine was first introduced. The specific gravity of gasoline varies from sixty to seventy-six degrees, though very little of the latter is now obtainable except by special arrangement with the oil producing company. It was formerly thought that gasoline any heavier than seventy-six degrees would not work satisfactorily in the cylinders of the gas engine, and while this is true of the early crude and The Modern Gas Tractor 155 inefficient vaporizers, modern mixing devices have been evolved which handle gasoline of sixty-two degrees specific gravity and even heavier. The percentage of gasoline produced from crude oil in proportion to the other elements is very small, and as the demand has increased to such proportions, the tendency of the producer has been to make gasoline heavier or of lower Grad. A Grad. B Grad. C Fig. 55. — Graduate A Shows Proportion of Different Products Obtained From Kansas Crude Oil. The Fractional Dis- tillation of Gasoline is Shown in Graduate B. Method of Making Baume Test Shown at C. specific gravity by distilling off som? of the heavier oils with it to increase the bulk produced. If one refers to graduate A shown at Fig. 55, the proportion of gasoline obtained by distillation from 1 5<> The Modern Gas Tractor crude petroleum may be easily learned. The term "gasoline" is now applied to all products testing over fifty deg. Baume. Less than six per cent of the bulk of the petroleum base becomes light gasoline of over sixty-four degrees. The larger bulk of the petroleum is refined into kerosene which tests from forty to fifty deg. Baume. The crude petroleum is broken up into three main groups of products, as follows: Highly volatile, gasoline, benzine, and naphtha, eight to ten per cent; light oil, such as kerosene and light lubri- cating oil, seventy to eighty per cent; heavy oils or residuum, five to nine per cent. In order to make clear the enormous consumption of gasoline in this country, experts have estimated that if all the internal combus- tion engines in use which depended on this fuel were to be operated continuously for a day of ten hours, over seven million five hundred thousand gallons of liquid would be consumed. Kerosene. — In order to understand thoroughly the action of fuels in an internal combustion engine and their value, one should understand to some extent the process of distillation to which the crude oil is subjected. The petroleum is pumped into a large steel boiler or still, from which a pipe leads to a condenser. The liquid is gradually heated, and as the gas rising from the crude oil escapes through the condenser, it is cooled at this point and again becomes a liquid. The liquid flowing from the condenser is constantly tested with a Baume tester, and as the specific gravity of the distillate changes to the different weights, the liquids are run off into separate storage tanks. The lighter liquids testing about eighty deg. Baume come off first, and as the crude oil becomes hotter the heavier constituents are volatilized and the substance The Modern Gas Tractor 157 coming from the condenser gradually becomes heavier. The process continues till nothing is left of the crude oil but a species of solid matter resembling coke which is composed of carbon and the various earthy matters that were contained in the crude product. The refineries obtain gasoline varying in quality from eighty degrees down to fifty degrees, kerosene from fifty degrees down to forty degrees, distillate from forty degrees down to twenty-nine degrees, and below that lubricating oils. The various proportions are clearly shown in graduate A at Fig. 55. Kerosene, as sold to-day, varies between forty-two deg. and forty-five deg. Baume. Heretofore it has been the common belief that because gasoline is more easily evaporated and exploded than kerosene, it gives more power, but actually the properly vaporized kerosene contains more heat units than gasoline and this applies just as well to the lower grades of oil which are sold under various names, such as distillate, solar oil, fuel oil, etc. The graduate at B, Fig. 55, shows the various proportions in which gasoline may be divided. As will be evident it consists of quite a number of liquids having different specific gravities. These are mixed together and the resulting gasoline has a specific gravity that is an average of the various grades mixed together to form the product. The liquid known as kerosene is not composed of such a widely varying number of constituents as is gasoline and it remains more constant in quality. The difficulty which has obtained and which has militated against the general use of kerosene has been the diffi- culty met with in vaporizing it at ordinary tempera- tures. It is practically impossible to start an electrically ignited engine on kerosene when cold. The metal parts 158 The Modern Gas Tractor of the combustion chamber and vaporizer must first be raised in temperature before kerosene can be used successfully. The grades of gasoline now sold for fuel will evaporate in winter without much difficulty, but kerosene will not give off vapors unless heated to nearly the boiling point of water. Where kerosene is used for fuel it is customary to provide an auxiliary gasoline supply which may be used to operate the engine until it has become hot enough to run on the heavier fuel. As so large a pro- portion of the crude oil yield is distilled into kerosene its price is considerably lower than that of gasoline and many of the modern gas tractors are provided with mix- ing devices that will use gasoline to start the engine on and then kerosene or distillate after the power plant becomes heated. The method of making a Baume test is outlined at Fig. 55-C. The tester is a species of hydrometer. This consists of a glass tube having an enlarged lower por- tion filled with air in order that it may float in a liquid and a small ball filled with shot at the lower end to keep the device vertical in the liquid in which it is floated. The stem of the hydrometer is provided with a scale, calibrated to read in degrees, and the specific gravity of the liquid is clearly indicated and its nature may be easily determined by this test. The stem will sink lower in the lighter liquids, so the figures denoting the liquids of higher specific gravity are nearer the top. Alcohol. — Gasoline and kerosene are derived from natural mineral deposits which will become more and more depleted as the demand for the product becomes greater. Petroleum was formed ages ago, presumably from decaying vegetation, and like coal the supply is not inexhaustible. While there is no immediate fear The Modern Gas Tractor 150 of a petroleum famine, considerable experimenting is being carried on by engineers to attempt to use alcohol as a substitute for the hydrocarbons commonly used at present. Alcohol is the one fuel that can be produced in quan- tities that could be increased as the demands for it augmented. It is produced by distilling various vege- table substances, and as these are reproduced each cycle of seasons, the raw material from which alcohol may be manufactured, in addition to being found in all parts of the world, would be renewed periodically. Alcohol differs materially from gasoline in that it is less volatile and requires more heat to vaporize it. It cannot be used successfully in engines designed for gas- oline or kerosene as higher degrees of compression than are practical with either of these commonly used fuels must be provided in order to burn alcohol efficiently. Experiments have been made with a view of permitting one to use alcohol in engines of present design by passing alcohol vapor through calcium carbide before it enters the cylinder. As alcohol contains water, this substance liberates acetylene gas when it comes in contact with the carbide and the resulting alcohol-acetylene gas can be burned in engines of conventional design and satis- factory results obtained. The fire risk with alcohol is much less than with either gasoline or kerosene, as while water only serves to spread burning petroleum products, it will extinguish an alcohol fire. Some authorities contend that alcohol will be the fuel of the future, but in this work the writer intends to deal only with practical matters of to-day so that but brief mention of the character and possibili- ties of alcohol as fuel is considered necessary. Elements of Carburetion. — Carburetion is a pro- 1(50 The Modern Gas Tractor cess of combining the volatile vapors evaporating from the hydrocarbons previously mentioned with enough air to form an inflammable gas. The amount of air needed varies with the character of the liquid fuel and some mixtures burn much quicker than others. If the fuel and air mixture is not properly proportioned the rate of burning will vary and either an excess of fuel or air will reduce the power obtained from combustion materially. The proportions of air and liquid needed vary according to the chemical composition of the liquid. Gasoline, which is that commonly used at the present time, is said to comprise 84 per cent carbon and 16 per cent hydrogen. Oxygen and nitrogen form the main elements of the air and the former has a great attraction for the main constituents of hydrocarbon liquids. What we call an explosion is merely an indica- tion that the oxygen of the air has combined with the carbon and hydrogen of gasoline. In figuring the proper amount of air to mix with a given quantity of fuel one takes into account the fact that eight pounds of oxygen are required to burn one pound of hydrogen and that two and one-third pounds of oxygen are neces- sary to insure the combustion of one pound of carbon. As air is composed of one part of oxygen and three and one-half portions of nitrogen by weight, for each pound of oxygen one needs to burn either hydrogen or carbon, four and one-half pounds of air must be allowed. About sixteen pounds of air must be furnished to insure com- bustion of one pound of gasoline, the hydrogen consti- tuent requiring six pounds of air while the carbon com- ponent needs ten pounds of air. Air is not usually considered as having much weight, but at a temperature of 62 deg. Fahr. fourteen cubic The Modern (Ias Tractor Itil feet of air will weigh a pound. Two hundred cubic feet of air will be needed to burn a pound of gasoline according to theoretical considerations. The element nitrogen, which is the main constituent of air, is a deterrent to burning as it does not aid combustion or burn itself. Therefore, it is usual practice to provide four hundred cubic feet of air to each pound of gasoline. Mixtures varying from one part of gasoline vapor to from four to thirteen parts of air can be ignited, but the best results are obtained when five to seven parts of air are combined with one of gasoline vapor. This mixture produces the most rapid combustion, the high- est temperature and, consequently, the most pressure. Simple Mixing Valve. — All devices that will mix gasoline vapor and air in proper proportions so the mixture will burn are called vaporizers. This general class may be divided into two distinct types of car- buretor. The simplest of these is termed a mixing valve and its principle of operation is very easily understood. A sectional view of a typical simple mixer is shown at Fig. 56. It consists of a cast bronze body in the shape of an elbow having a valve seat machined about half way in its interior. A mushroom valve seats against the brass body and separates the device into two parts, as the valve head is held normally in contact with the valve seat by means of a light coil spring. The fuel supply is led to a small branch member at- tached to one side of the main body of the mixing valve and having a small passage that communicates with one of the walls of the valve seating member. The area of this passage is regulated by a needle valve which may be turned conveniently by a large knurled head. The passage is normally kept closed by the head of the mushroom valve. The device is attached to the 1C.2 The Modern Gas Tractor engine at the connection marked "Mixture outlet" and the other end has free access to the air. When the piston draws in a charge of air on its intake stroke it will open the air valve which at the same time uncovers the gasoline spray passage and a stream of gasoline mixes with the incoming air current and is ai r valve: AIR 5 PRAY PASSAGE! MIXTURE OUTLET Fig. 56. — Sectional View of Simple Vaporizer Valve. vaporized when it reaches the interior of the cylinder. As soon as the inlet valve of the motor closes, the small air valve of the mixing device is returned to its seat by the coil spring and both air and gasoline passages are shut off simultaneously. The mixture proportions may be regulated by varying the amount of gasoline The Modern Gas Tractor 163 supplied, which is done by altering the area of the spray passage with the needle point of the gasoline regulating valve. Another simple mixing valve which combines a suc- tion gasoline feed from a tank placed lower than the intake valve is outlined at Fig. 57. In the'device shown at Fig. 56 it is necessary to place the gasoline tank Pig. 57. — Sectional View Explaining Action of Gray Fuel Vaporizer. 1H4 The Modern (Ias Tractor higher than the vaporizer body and depend upon a gravity feed. This means that the gasoline supply must be shut off every time the engine is stopped, in order to prevent flooding. When a suction feed is used, the gasoline supplied the vaporizer stops flowing auto- matically when the engine stops. When the piston A moves forward a partial vacuum in the firing chamber B is created. This causes the inlet valve E to lift from its seat D and air rushes into the combustion chamber through the supply pipe I and then past the inlet valve E. The air pipe is restricted around the spray nozzle Q so that the air rushing past this point must flow faster on account of the constricted passageway and considerable suction is present at the point of the spray nozzle. Thus when the needle valve H is opened slightly gasoline from the tank T passes up the fuel feed pipe K and is sprayed into the chamber F where it mixes with the air current and the resulting vapor is drawn into the combustion chamber B by the vacuum created by the piston. A check valve is placed in the gasoline pipe at J so the level of gasoline will remain at that point while the engine is running. When the piston reaches the end of its suction stroke the valve E closes and the gases in the compression chamber are compacted and fired at the proper point by an electric spark. Float Feed Carburetor Action. — The simple mix- ing valve forms have disadvantages of some moment, the main defect being that they are somewhat erratic in action and that the mixture cannot be as well regu- lated as when float feed carburetors are used. While the primitive forms gave fairly good results with high grade gasoline they do not carburate the lower grades of fuel used to-day properly and do not supply enough gas of proper consistency for the present types of engines. The Modern Gas Tractor 165 The most efficient modern power plants utilize float feed carburetors instead of simple mixing valves. The advantage of the float construction is that the gasoline is maintained at a constant level regardless of engine speed. In the simple forms of generator valves in which the gasoline opening is controlled by a poppet valve a leak in either valve or valve seat will allow the fuel to flow continuously whether the engine is drawing in a charge or not. During the idle strokes of the piston when there is no suction effect exerted to draw in gaso- line vapor, the liquid fuel will collect around the air opening, and when the engine does draw in a charge it is excessively rich because it is saturated with globules of liquid fuel. With a float feed construction a constant level of gasoline or other fuel is maintained at the right height in the stand pipe, and will only be drawn out of the jet by the suction effect of the entering air stream. The objection to the simple mixing valves utilizing suction feed is that the tendency is to draw off only the more volatile constituents of the fuel and that after a time the heavier elements comprising gasoline will remain in the container and will not be properly vaporized. Obviously the engine is not capable of utilizing all of the fuel. With a float controlled spray nozzle the spray is composed of all the constituents of the liquid and the lower grade portions that are mixed with those having higher evaporation points are drawn into the cylinder and burnt instead of settling to the bottom of the tank. The simplest form of float feed carburetor is shown at Fig. 58. In this the principle of mixing the gasoline vapor and air is the same as in the simpler mixing devices but the method of fuel supply is different. 166 The Modern The Modern (Ias Tractor mixing device, as sometimes supplied with two-cycle engines, is shown at Fig. 65. This is based on the fuel injection principle and while it is not used at the present time on a tractor power plant, the principle of opera- tion is a valuable one and is given because it illus- trates clearly another possible method of vaporizing the liquid fuel. The vaporizer shown is used on the Ellis two-cycle stationary power plant and has proven to be very practical and efficient. The device has three principal parts: the fuel reservoir, the atomizing disk, and the heating chamber. In order that the action be more easily understood, the fuel reservoir is shown to one side of the engine, instead of in the position it actually occupies. This reservoir has a heavy plate glass body, through which the fuel level can easily be seen. An air pipe leading from the lower part of the cylinder is connected to the top of the reservoir, while two pipes are attached to the bottom of the float chamber. One of these is the supply pipe, leading from the fuel tank, while the other joins the bottom of the fuel reservoir to the seat of the atomizing disk. The amount of fuel passing to the disk is regulated by a needle valve. The cork float and the fuel reservoir shut off the supply of fuel when the level reaches the proper height as previously described. As the piston moves upward in the cylinder it produces a suction in the fuel reservoir, this drawing up a supply of liquid from the tank until the fuel reservoir is filled to the proper level. When the piston moves down- ward, creating compression in the top of the fuel reser- voir, the liquid is prevented from returning to the tank by a ball check valve. The atomizing disk regulates the proportions of air and fuel and positively shuts off the liquid when the current of air stops. It also va- The Modern Gas Tractor 177 porizes the liquid by allowing it to be injected under pressure into the moving current of air from the by- pass. The liquid is thus converted into a fine mist, and the vaporized fuel and air are then drawn into and exposed to the intense heat of the heating chamber. Thus carburetion is effected by a combination of me- chanical atomization and a vaporizing effect due to heat. Just before the transfer port is opened by the piston on its downward stroke, the lower edge of the piston uncovers the end of the air pipe leading to the fuel reservoir and the compressed air which is trapped into the top of the float chamber forces the liquid fuel through the opening in the seat of the atomizing disk. As the piston uncovers the transfer port, the compressed air in the crank case, which has been drawn in through a suitable valve when the piston was on its up stroke, rushes past the atomizing disk and atomizes the fuel forced in from the fuel reservoir. The mixture of air and liquid vapor is then directed to the top of the cylin- der by the deflector on the piston head. The action is the same as in any two-cycle engine, one explosion being obtained each revolution of the crank shaft. Action of Kerosene Vaporizer. — In order to insure proper combustion of kerosene when used in carburetors of the conventional form, it is necessary to start the engine on gasoline, until all parts are thoroughly heated. If proper means are taken to heat the carburetor and the intake manifold to prevent condensation of kero- sene, it may be used just as soon as the various working parts have been properly heated. A float feed carbu- retor of conventional design arranged to burn kerosene is shown at Fig. 66. It will be noted that the float cham- ber is surrounded by a jacket, through which hot water The Modern Gas Tractor The Modern Gas Tractor 170 can enter at Q and pass out at H, this heating all parts of the float chamber. The kerosene enters the device through the connection F and passes into the float chamber through the usual form of float controlled valve. In the ordinary automatic carburetor, as the speed increases and the tendency is to draw in more fuel, an automatic air valve opens to admit an auxiliary supply of air to dilute the liquid. The carburetor illustrated utilizes the auxiliary valve in a different manner. The spray nozzle, instead of being the conventional form, is a small standpipe having numerous fine holes on one side and it is called a spray turret. This is shown at A. At the bottom of the spray member the float bowl upper wall is shaped in such a way that a small pool of liquid fuel is allowed to collect in the bottom. The main air intake is divided and is alone sufficient only to run the motor idle. The air that enters the primary intake passes directly over the pool of fuel and a rich mixture is obtained for starting on. The auxiliary air enters through the opening D and before it enters the cylinders it must pass the spray turret. This lifts the fuel up in the standpipe, where it is drawn through the fine holes in the form of a spray. The greater the amount of air that is passing through, the higher the fuel rises in the spray turret, until with the throttle wide open it is sprayed from all the holes in the standpipe, as indicated at B. The condition with a partially opened throttle is shown at sectional view A and it will be noticed that the kerosene spray is coming through only the holes at the lower part of the standpipe. The amount of liquid sprayed into the mixture is regulated by the needle valve C. In order to burn kerosene successfullv water is introduced into 180 The Modern Gas Tractor c3 — > c -O £ Tl ~ :.. 0> o w = 3 a a The Modern Gas Tractor 181 the mixture through the auxiliary spray nozzle I. This supplies an extra amount of oxygen and insures a more complete combustion of the kerosene vapor than would be the case if just air was used. Another method of using the cheaper liquid fuels is shown at Fig. 67, though this is seldom used except on stationary engines designed to run at a constant speed. The liquid is injected into the hot C3'linder head through a special fitting when the piston reaches the top of its stroke, and as the fuel strikes the vaporizing spoon, which projects into the combustion chamber, it is vaporized on account of the intense heat of that part. The action of the engine is based on the two- stroke principle. A charge of pure air is drawn into the crank case when the piston is going up on the com- pression stroke. After the liquid is injected into the combustion chamber, the heat which is present at the end of the compression stroke is sufficiently high to explode the charge of gas without any other means of supplying heat. To start the motor the bulb at the end of the cylinder head is heated by the flame of a gasoline or alcohol torch until it reaches the proper temperature for firing the charge. After the engine is once started the heat is furnished by the successive explosions. Secor=Higgins Kerosene Carburetor. — The fuel supply system of the Rumely "Oil Pull" tractors is arranged so that kerosene, distillate and other low grade oils may be burned successfully. This, the Secor system, so named after its inventor, does not involve specially designed engines as any motor intended for operation on gasoline can be used successfully with kerosene if fitted with a Secor-Higgins carburetor. This is not a new system, by any means, because it 1X2 The Modern Gas Tractor was developed over fourteen years ago and has received practical application in thousands of power plants used for agricultural purposes during this period. The following matter, reproduced from the "Scientific American Supplement," clearly outlines the essential features of the Secor system and also of the vaporizer used in connection with it: " Stated in brief terms, the system covers: (1) An automatic variation in the quantity of fuel mixture in accordance with the slightest variation in speed and load; (2) A degree of compression dependent upon the quantity of the mixture inhaled; (3) A correct proportioning of the mixture under all conditions, involving relatively weaker mixtures for higher compres- sions and increasingly stronger mixtures for lower com- pressions; (4) A temperature of combustion exactly adapted to the quality of fuel used and the compres- sion; (5) Automatic control of the internal temperature through the admission of water as part of the fuel mixture; (6) Thorough and uniform mixture of fuel, water and air charge by mechanical means and without the application of additional heat; (7) Automatic variation in the time of firing in response to variations in speed and power; (8) Means for changing the limits of speed within which all factors are simultaneously controlled; (9) And means for starting on a limited supply of volatile fuel, all of which factors are vital to the control of internal heat, the transformation of heat into power and power production The adapta- bility of the system described to the lower grade oils is secured through its providing a co-ordination of all factors at all times, this being considered necessary owing to the more difficult vaporization and combina- tion of less volatile oils. The throttling governor, The Modern Gas Tractor 183 taking a different quantity of fuel mixture for each cycle as the load varies, naturally produces a varying compression within the cylinder. It is well known that at higher compression leaner fuel mixtures may be, and should be used, and vice versa. One great factor in the success of the system is that through the mechan- ism of the special carburetor, the proportions of fuel, air and water are automatically varied in relation to each other as the compression changes. By this means the conditions within the cylinder, whether the engine is run at heavy load or light, are constant so far as they affect the completeness of combustion. Complete combustion eliminates the deposit of carbon which has been regarded as an insurmountable objection to the use of heavy fuels, and the unified automatic con- trol results in the securing of splendid regulation. The automatic control of the quantity of water is an original feature of the system, and is advantageous for several reasons. In the first place it makes for clean combustion by controlling the temperature of vaporization and combustion so that there is practically no cracking of the low-grade oil with its attendant carbon deposit. The water allows the use of higher compression, consequently greater power from the same bore, stroke and speed. The effect of the water in producing a slower-burning mixture is seen in a lower explosion pressure and a flatter indicator card. This results in as high a mean effective pressure as is found in gasoline engines of similar proportions, without the strain and instability produced by a violent initial shock. There is further, undoubtedly, a disso- ciation of water into nascent hydrogen and oxygen. The latter, being much more active than the diluted oxygen of the atmosphere, has naturally a greater LS4 The Modern Gas Tractor affinity for any free carbon that may have been deposited at the moment of explosion. The hydrogen set free probably burns with the oxygen of the air as the tem- perature falls toward the end of the stroke, but it is doubtful whether enough steam is thus formed to exert any considerable expansive effect upon the piston. The process does, however, effectively scour the cylinder. The explosion is converted into a long, steady push instead of a short, sharp blow, and the water apparently gives an increase of power of at least 15 per cent over a similar engine without it. The water is not only controlled as to amount, but is brought into play automatically. As the load increases, the throttle opens and more air is sucked through the carburetor. Not until about half load is reached does the suction become strong enough to lift the water, hence it is not present to hinder ignition at light loads, nor to allow preignition at any time, being neither too heavy for ignition at heavy loads nor too light to control the temperature of vaporization. Crank shaft, cam shaft, governor, magneto, carbu- reter, valves and piston act as a positively controlled unit in engines equipped with the new system, hence no one mechanical factor deserves to be set apart from the others in importance. However, the special car- bureter, which makes possible the application of the new system, is of sufficient novelty to warrant especial attention. A fly-ball governor, through a first-class lever and a link coupling, operates a sliding brass valve which is clearly shown in Fig. 67a. The carbureter sits above the cylinders, with the short inlet manifold presenting little opportunity for the mixture to stratify before it is completely vaporized. It contains constant- level chambers for kerosene and water, an overflow The Modern Gas Tractor 185 AOJUJT/ne PLtTt j — Position of sliding valve at light load. *— Longitudinal section of carbureter. Fig. 67a. — Views of Secor-Higgins Carburetor, Used on Rumelv "Oil Pull" Tractors. Position of Sliding Valve at Light Load at Top, Side Sectional View of Device Showing Control Device, Air and Mixture Ports, and Fuel and Water Regulation at Bottom. 186 The Modern Gas Tractor being provided for each. It has also, for starting pur- poses, a chamber for gasoline which is filled by hand pump. This chamber, which holds about a pint, is connected by a siphon with the mixing chamber. Turn- ing the engine over creates suction enough to draw upon the contents of this chamber, but a vent is provided so that if a start is not made immediately the siphon will not continue to act and drain the chamber. Fig. 67a shows the position of the valve plate at light load. Two air inlets are then open, providing a large ratio of admission to outlet area and thus greatly re- ducing the relative vacuum in the mixing chamber. As the load increases, the governor throws the sliding valve forward, increasing the area of the outlet to the cylinder, increasing the air inlet in the middle, and decreasing or entirely closing the air opening at the right. Thus the ratio of admission to outlet area decreases, the relative vacuum becomes greater, and more fuel in quantity, though not in proportion, is picked up by the incoming air and carried to the cylinder. A sectional view from the side shows the arrangement of the kerosene and water needle valves, the overflow, etc. It will be noted that the water level is lower than the kerosene level. The suction therefore is not great enough, until the engine reaches about half load, to lift the water to the point (H2) where it can flow down the tube surrounding the needle valve. From half to full load, the ratio of water to fuel increases rapidly until the amounts of fuel and water used are practically equal. The carburetor is so designed that the fuel needle-valve (K) should be adjusted at the full-load position, when the plate is farthest to the right. This order of procedure is important, since at this position the adjustable plate has no effect upon the area of the The Modern Gas Tractor 187 air inlet openings. The adjustment of the air should be made at the "no-load" position and after once made, need never be changed, unless the engine enters a very different altitude. This adjustable plate allows each carburetor to be adjusted to the engine it is to serve, hence the slight variations in manufacturing are fully taken care of. The sliding plate is the only moving part in the carburetor, and that is positively controlled. There are no springs, floats or check valves. The device is simple, the parts are large and there is no possibility of the device getting out of order or failing to supply a correctly proportioned mixture as long as the pumps supplying fuel and water are functioning properly and the fuel and water containers are kept full. Methods of Exploding Charge.— When the gas engine was first developed the compressed gas was ex- ploded by means of a naked flame which was permitted to communicate with the combustion chamber by means of a slide valve which moved at the proper time to per- mit the flame to ignite the gas back of the piston. This system of ignition was practical only on the primitive gas engines where the charge was not compressed to any degree. When it became desirable to compress the gas before firing it, the hot tube system of ignition was used. This method involved the use of an incan- descent platinum, porcelain or nickel tube in the combus- tion chamber, the tube or ignitor being kept in a heated condition by a flame burn ng in it. Another method which has been previously described, and which is illustrated at Fig. 61, depends upon the property of gases firing themselves if compressed to a sufficient degree, provided that a certain amount of heat was stored in the cylinder head to insure complete vaporization of the gas and help produce the proper kindling temperature. 188 The Modern Gas Tractor Advantages of Electrical Ignition. — Practically all of the gas engines in use at the present time, except a few employed in the oil fields, utilize electrical ignition systems. In all tractor power plants the compressed gas is exploded by a minute electric arc or spark in the cylinder, the current for which is produced by some form of chemical or mechanical generator of electricity. The early forms of ignition systems had a disadvantage in that they were not flexible and could be used suc- cessfully only on constant speed engines. None of these methods are practical in connection with gas tractor power plants because they do not permit the flexible engine action that is so desirable. While electrical ignition systems are somewhat more complicated than the other simpler types, they are the most efficient, and as their peculiarities are now generally understood, there is no difficulty in applying them successfully. Two forms of electric ignition systems are in general use, the most popular being that in which a current of electricity under high potential or pressure is forced to leap an air space between the points of a spark plug which is screwed into the cylinder. The other system, which is used to a limited extent on gas tractor engines, is known as the low tension system because a current of comparatively low voltage is utilized instead of the high pressure current used in the more popular systems. Whereas the spark is produced in the high tension system by the current heating up the air particles between the points of the spark plug, it is produced in the combustion chamber when the low tension method is employed by moving electrodes which come in contact with each other and which produce a spark as they separate. The essential elements of any electrical ignition The Modern Gas Tractor 189 system are: First, a simple and practical method of current production; second, suitable timing apparatus to cause the spark to occur at the right point in the cycle of engine action; third, some form of igniter to produce the spark in the combustion chamber; fourth, apparatus to transform the low tension current obtained from batteries or dynamo to one of greater value before it can produce a spark in the cylinder; and fifth, suit- able wiring, switches and other apparatus to convey the current produced by the generator to the auxiliary apparatus and from these to the spark producing mem- ber in the cylinder head. Methods of Producing Current. — There are two common means for obtaining the electrical current used to produce the spark in the cylinder, one of these de- pending on a chemical action, the other an electro- magnetic action. The first class includes the various forms of primary and secondary batteries, while the second group includes the various mechanical ap- pliances, such as dynamos and magnetos. Dry and Storage Batteries. — The simplest method of current generation, and the cheapest as well, is by means of a simple chemical cell, generally known as the "dry battery." These belong to the primary cell class because a current of electricity is generated by the oxidation of one of the elements of which the cell is composed by the electrolyte. Any primary battery consists of three main elements: First, a plate of some material which will be acted on by the electrolyte. Second, an electrolyte which may be a solution of a salt or acid in water, which will have a chemical affinity for the active element. Third, a neutral plate which serves to collect the electricity produced by the chemical combination of the electrolyte and active elements. 190 The Modern (Ias Tractor The dry battery is so called because the electrolyte is in the form of a paste instead of a liquid. The dry cell consists of a zinc can filled with electrolyte and a depolarizing chemical in the center of which a carbon rod or plate is placed. The function of the depolarizer is to keep the cells active for a longer period than would be the case if only a simple electrolyte was used. The zinc can serves as a container for the electrolyte and also forms the active member. The carbon rod is the neutral or collecting member. A terminal is attached to the zinc can and is known as the negative, commonly indicated by a minus sign thus ( — ) while the terminal attached to the carbon is known as the positive con- nection (commonly indicated by a plus sign (+). It is to these terminals that the wires forming the external circuit of the cell are attached, the internal circuit being completed by the electrolyte and depolarizer. A single dry cell does not have enough power to produce a spark, so a number of these are generally joined to form a battery. The common method of connecting dry cells is in series; this means that the positive terminal of one cell is always coupled to the negative terminal of its neighbor. When cells are coupled in this manner, the battery has a voltage equal to that of one cell times the number of cells so joined. For instance, four dry cells would have a potential or cur- rent pressure of six volts, as one dry cell has a pressure of one and one-half volts. The amount of current produced by the batteries is measured in amperes and the battery capacity will depend upon the size of the active element and the strength of the electrolyte. The ordinary No. 6 dry cell which is six inches high by two and one-half inches in diameter will indicate a current strength of about twenty amperes. When The Modern (Jas Tractor 191 cells are joined in series the amperage of the set is equal to that of but one cell. If it is desired to obtain greater amperage, the cells are joined in multiple, which means that all terminals of similar polarity are joined together. A battery of four dry cells connected in this manner would deliver a current of about eighty amperes. When dry batteries are used for ignition purposes, they are generally coupled together in a series-multiple connection to obtain the proper voltage and current strength. The dry battery has a number of advantages, chief among which are its cheapness, ease of installa- tion, compactness and simplicity. It has the dis- advantage of being limited in capacity and not suited for continuous work, which it shares with all other forms of primary battery. When dry cells are exhausted there is no method of renewing them to efficiency and they must be replaced. This is not a serious factor, however, as an entire new set of six cells will cost but $1.50. The storage battery is a chemical current producer that is capable of being recharged when it is exhausted by passing a current of electricity through it in a reverse direction to that of the current given out. Storage batteries are composed of elements of practically the same material and can only become active when a current of electricity is passed through them. The materials generally used are grids of lead filled with a paste composed of lead oxide. When the current of electricity passes through these plates, they become enough different in nature so that a difference of elec- trical condition exists between them, and when the cell is fully charged, a current may be drawn from it in just the same way as from a primary battery. Storage batteries have the advantage that they may 1!>2 The Modern Gas Tractor be used for continuous current production, and as they may be recharged when exhausted, it is not necessary to replace them with new members when they will no longer produce current. The storage battery is called a "secondary cell" because it can only give out energy after a current of electricity has passed through it, where- as a primary battery in good condition will produce electricity as soon as it is completed. The storage battery uses an electrolyte composed of dilute sulphuric acid and water, while a dry battery uses an alkaline electrolyte composed largely of sal-ammoniac and chloride of zinc. The average form of storage battery used for igni- tion purposes is really composed of three cells, which are placed in a common carrying case of wood or hard rubber. The connection between the cells is made by plates of lead which are burned to the elements, leaving but two terminals free, one of which is a nega- tive member while the other leads from the positive plates. To prevent spilling of the electrolyte the top of the cell or battery is sealed with a hard rubber plate over which is poured a pitch and rosin compound. The electrolyte is renewed through a small vent in each cell which is covered by a removable hard rubber cap. These vents also allow for the escape of the gases evolved when the cell is being charged or when it is delivering a current of electricity. The average ignition battery has a capacity of 60 to 80 ampere hours and a current pressure of about 6.6 volts when fully charged. Functions of Induction Coil. — The current ob- tained from a dry or storage battery is not sufficiently powerful to leap the gap that exists between the points of a spark plug utilized in the high tension ignition system. This space offers a resistance to the passage The Modern Gas Tractor 193 of the current that requires a pressure of several thousand volts to overcome, and as the ordinary ignition battery produces but six volts it will be apparent that unless the current strength is increased it could not over- come the resistance of the air gap between the spark plug points. A simple device known as an "induction coil" is employed to transform the low tension battery current to a current of sufficient voltage to jump the air gap at the plug. The current from the battery is first passed through the primary coil, which is composed of several layers of coarse wire wound around a core of lengths of soft iron wire to form an electro-magnet. Another coil composed of a large number of turns of finer wire is wound over the primary coil. When a current of electricity of low voltage passes through the primary coil, a current of high electro-motive force is delivered from the terminals of the secondary winding. The induction coil is usually provided with a device known as a "vibrator," which is an automatic circuit breaker actuated by the magnetism of the core. Every time the circuit is made and broken at the vibrator contact points an electrical impulse is induced at the secondary winding, and the more rapid the vibration, the greater the number of impulses in the secondary current. A simple coil, such as used for single cylinder ignition, is shown at Fig. 68. As will be seen, three ter- minals are provided on the coil exterior, one leading to the battery, one to the commutator, and the re- maining one to the spark plug. The vibrator spring A carries one of the contact points and the knurled head aduj sting screw B carries the other. The ampli- tude of vibration is varied by moving the adjusting screw B or by increasing or decreasing the strength 194 The Modern Gas Tractor of the vibrator spring. An induction coil for use with a multiple cylinder engine is composed of a number of simple coils fastened together in a common case and having enough terminals to make the proper connec- tions in the outer circuit, as will be described in proper sequence. When the vibrator is in operation it moves so rapidly that it makes a buzz like that of some fast flying insect and when properly adjusted it may even give a definite musical note. If the vibrator action is Fig. 68. — Induction Coil Used in Connection With Batteries to Produce Electric Spark in Gas Engine Cylinder. not rapid the amount of secondary current produced will not be as great nor will it have as high voltage because the current output is dependent not only upon the number of impulses flowing through the primary coil but also upon the rapidity of the contacts at the vibrator. Producing Spark in Cylinders. — The two common The Modern Gas Tractor 195 appliances for producing an electric spark in the com- bustion chamber are shown at Fig. 69. That at A is a low tension igniter plate having a movable electrode. One of the spark points is carried in a fixed member or anvil which is shown detached so the construction may be understood and which is installed in and insu- lated from the main body of the igniter plate. The movable member, which is actuated by a bell crank, carries the other contact point and is normally in con- tact with the anvil. When it is desired to produce Termina, Spnrk Point Anuil Insulator Spark Points Fig. 69. — Devices for Producing Spark in Engine Cylinder- A — Low Tension Igniter Plate. B — High Tension Spark Plug. a spark the hammer is pulled away from the anvil by some mechanical means, usually a tappet rod operated by a plunger and cam in just the same manner as a valve is lifted. At the instant of breaking contact a hot spark takes place between the points and this explodes the mixture. There are other forms of low tension igniters but the type described is the most 196 The Modern Gas Tractor common, and has demonstrated that it is the most practical. The obvious disadvantage of this construction is that the moving member in the hot combustion chamber may become fouled with carbon, or the points may become burnt and covered with scale to such an extent that the electrical connection made when they touch will be very poor. Then, as is true of all moving mech- anism, the factor of deterioration enters into considera- tion. Considerable difficulty is experienced in keeping the joint around the hammer spindle tight and the result is that as soon as this wears the action of the igniter becomes erratic and mixture troubles may result due to dilution of the charge by air which leaks into the combustion chamber through the worn hammer bearing. The factor of wear is an important one in that it also affects the timing and on a multiple cylinder engine it may be found difficult to secure proper firing of all the cylinders. Those in which the mechanism is worn most will not fire at the same relative time in the cycle of operations as will the other members that are not worn so much. The result of the explosions not fol- lowing in regular sequence is irregular engine operation and lack of smoothness in power delivery. Low tension igniters are entirely practical on simple forms of low speed engines but are not suited to higher speed mul- tiple cylinder power plants. One of the marked advantages of the low tension igni- tion system is that it will produce a spark having a greater heat value than will the ordinary high tension system. This advantage is of some moment when using the lower grade fuels that will not ignite as readily as will a gasoline vapor. It is claimed by those who The Modern (Ias Tractor 197 favor the low tension system of ignition that it will ignite a greater range of mixtures than the thinner and less hot high tension spark. The simplicity of the conventional form of spark plug used with the various high tension ignition systems is clearl^v outlined at Fig. 69-B. Not only is the device more simple than the low tension igniter plate but it has no moving parts. It will be seen that the main member of the plug is a steel shell, which is provided with a thread at the bottom by which the plug is screwed into the cylinder. One of the electrodes is attached to this shell as indicated. The other electrode is in the form of a light rod or wire, carried through the center of some insulating medium which in this case is a por- celain bushing. This bushing is capped with a terminal nut by which the device is connected into the outer circuit. The porcelain insulator is held against a pack- ing or gasket by a threaded gland which screws into the upper portion of a plug body. Spark plug construction varies widely, but all operate on exactly the same principle. The arrangement of spark points may be different and mica or glass may be used instead of porcelain insulation, but the action remains the same. As will be evident, the only parts of the plug that are exposed to the hot gases are the spark points and the lower portion of the porcelain insulating bushing. There is practically no part that will cause trouble or that will wear in service and the device needs but little attention after it is once in- stalled. Even if it should fail to work because of a cracked insulator or a defective spark point the entire device may be renewed for fifty or seventy-five cents and, as is true of the dry cell battery, it is often cheaper to renew them than to attempt to make repairs. 108 The Modern Gas Tractor In most forms of spark plugs the porcelain is easy to remove and if a spare insulator is at hand it may be readily substituted for the imperfect ones by any- body who is able to handle a wrench. There is no more or less complicated mechanism to time and if the insulator is kept free from carbon and soot and the spark points separated by the proper gap, there is no opportunity for irregular ignition. As the spark plug may be screwed tightly into the cylinder it is easy to obtain a gas tight joint, and the mixture troubles and hissing incidental to worn igniter plates are not present. Mechanical Generator Advantages. — Taking elec- tricity from either a dry or storage battery is com- parable to drawing a liquid from a reservoir filled with a certain definite supply. As the demands upon the reservoir increase, its capacity and the amount of liquid it contains become less in direct proportion. Batteries cannot maintain a constant output of electricity for an indefinite period and their strength is reduced according to the amount of service they give. A mechanical generator of electricity produces current without any actual deterioration or depreciation of chemicals and plates, as is true of a battery. There is some wear present in a mechanical generator but this is so small compared to the amount of service it will give that its effect is practically negligible as regards current out- put. A simple analogy that will enable one to appreciate the merits of the mechanical generator may be made with a pump system of drawing a liquid from a prac- tically inexhaustible reservoir. As long as the pump is turned it will supply liquid. The same thing is true of a mechanical generator of electricity which will The Modern Gas Tractor l!»!i supply current as long as the rotating parts are turned. With batteries, when the engine speed increases and the demands upon them become greater the current strength decreases at a time it should be strong. With a mechani- cal generator of electricity the current output increases as the speed, and as these devices are usually driven directly from the engine, when this member demands more electricity the mechanical generator will supply it automatically because it is being driven faster. Types of Magnetos. — There are two forms of mecha- nical generators commonly used and the principle of action is somewhat the same. They differ widely, however, in construction and method of application. The first forms used to replace batteries were pat- terned after the dynamo electric machines used for supplying current for electric lighting and other indus- trial purposes. The dynamo was later simplified by the elimination of one set of windings and it was made lighter and more efficient. This form of mechani- cal generator is called a "magneto" because perman- ent magnets are utilized instead of wire wound or elec- tro magnets. The dynamo form of generator is used where currents of considerable value are needed, while the magneto is generally applied for ignition purposes. Another advantage of the magneto is that it may be made so it will contain a complete ignition system in itself, whereas when a dynamo is employed practi- cally the same conditions obtain as though batteries were used. The dynamo merely replaces the chemi- cal current producer. A mechanical generator of electricity produces cur- rent by an induction action. It is a known fact that if an insulated wire is wound around a bar of iron or steel and a current of electricity is passed through it, 200 The Modern Gas Tractor the metal will become magnetized, i. e., it possesses the property of attracting other pieces of iron or steel to it. As a current of electricity flowing through a wire wound around a bar of steel will make a magnet of it, if a magnet is inserted into an inactive coil of wire it will generate a current of electricity by a reversal of the phenomena first mentioned. In other words, a current of electricity will be produced in a conductor by a magnet if either of these is moved in such a way Fig. 70. — Oscillating Armature Low Tension Magneto and Integral Igniter Plate a Complete Ignition System. that the field of magnetic influence is traversed or cut by the wire. In a dynamo or magneto a number of coils of wire are mounted on a revolving member, termed the armature, which is placed between the pole pieces of the energizing or field magnet. The faster the arma- ture rotates, the more rapidly do the armature windings pass through the magnetic field and the greater the num- ber of electrical impulses produced because one of these The Modern Gas Tractor 201 is created every time a loop of wire passes through the magnetic field. Oscillating Armature Forms. — The armature of a magneto is not always a revolving member except when this device is used to produce a continuous flow of current. In some ignition systems a single electric impulse is all that is needed to produce the spark. A number of low tension magnetos are made on the oscil- lating armature principle. One of these is clearly shown at Fig. 70. Instead of the armature being a revolving member it is an oscillating member and does not make a complete revolution. In the device shown the armature is replaced by an inductor member which carries no wire and which oscillates freely between the pole pieces of the magnets. The form depicted is really a unit with the igniter plug and is adapted to be bolted to the side of the cylinder in such a way that while the igniter points project into the combustion chamber, the device is in a position close to the cylinder head where it may be readily operated by means of a push-rod and trip from the engine cam shaft. The device is so arranged that when a spark is desired between the ignitor points, the inductor is given a quick movement which produces a flow of magnetic energy through the windings. At the same instant that the flow of electricity takes place through the coils, the ignitor points are separated and a spark is produced in the cylinder. The action of a device of this character is automatic, and each time that the magneto push- rod trips the inductor the points of the ignitor separate and a spark is obtained to ignite the compressed gas. It is apparent that this method of current genera- tion will take but very little power from the engine and that there can be no depreciation that will tend to 202 The Modern Gas Tractor diminish the amount of current at a time that the engine needs a hot, fat spark. This device forms a complete ignition system and is suitable for practically all sta- tionary engines of the single cylinder or two cylinder patterns. It would not be advisable to furnish this form of magneto for more than two cylinders because a separate device is needed for each cylinder and the mechanical complication incidental to the use of four of these devices with the trip rods, etc., would not be desirable. /sll ira^F r "^^mr^^ - ^MAGNETS ARMATURE (ENCASEDA COMMUTATOR^ (ENCASED) t FRICTION DRIVE PULLEY, bBBI BRUSHES lit (ENCASED) \ x> illflll^ jji GOVERNOR 'brush holder (encased) ■ Fig. 71. — Revolving Armature Magneto Delivering Low Ten- sion Current. Used in Connection With Induction Coil, Timer and Spark Plug to Form Complete Ignition System. Type With Revolving Armature. — The revolving armature type of magneto is the form that is generally used for supplying current whenever a constant flow The Modern Gas Tractor 203 is desired. When a device of this nature is intended to replace batteries it is of the low tension direct current form, as shown at Fig. 71. The magnetic field is produced by a pair of permanent magnets attached to pole pieces between which the armature revolves. The electricity produced in the coils of wire in the armature is collected by means of two brushes which form the terminals cor- responding to the positive and negative poles of a battery. As a device of this character is intended to be driven at a constant speed, an automatic governor is usually provided which becomes inoperative when the safe speed of magneto rotation is exceeded. The form shown is intended to be driven by means of a friction drive pulley bearing against the flywheel. This pulley drives the armature by frictional contact between the governor arms and the outer tapered face of the drive pulley. This member is faced with fiber or leather where it bears against the engine flywheel in order to secure greater frictional adhesion. The governor arms are carried by a fitting which is attached to the armature shaft, while the friction drive pulley is free to rotate on the armature shaft except at those times when the governor arms are in contact with its face. When the speed increases to a point where the governor arms will fly out because the centrifugal force is greater than the tension of the coil springs holding them in contact with the pulley, the drive is interrupted, and the friction drive pulley turns at one speed while the armature, which now revolves only by its own momentum, tends to slow down. The armature speed finally slackens to a point where centrifugal force is not strong enough to keep the weighted governor arms out of contact with the friction drive pulley. The ten- sion springs then act and the armature is driven from 204 The Modern Gas Tractor The Modern Gas Tractor 205 the friction pulley until the safe speed is again exceeded at which time the driving connection will be auto- matically broken again. The device shown is wired into the circuit just as the set of batteries would be and an induction coil and timer will be needed to complete the ignition system. High Tension Device. — The high tension magneto is the form that is generally used in automobile igni- tion systems and its popularity is increasing among gas tractor manufacturers as well. The advantages of the true high tension magneto are that it comprises in one device all the elements of the current generating and intensifying devices and all that is needed in con- nection with a high tension magneto are the spark plugs and the wires by which they are connected to the instru- ment. A high tension magneto for a four cylinder engine is but very little more complicated than one used on a two cylinder power plant. The only difference is in the number of contacts in the distributor and the speed at which the device is driven. A typical high tension magneto utilized in connection with a four cylinder engine is outlined at Fig. 72 and all the parts are clearly shown. The armature is a two pole type having an approximately H section and it is wound with two coils of wire. One of these is a comparatively coarse one corresponding to the primary winding of an induction coil, while the other is a fine winding having many turns that correspond to the secondary coil. The armature shaft is mounted on ball bearings to insure easy rotation. The magnetic field is produced by means of three pairs of horseshoe mag- nets which are attached to pole pieces which form the armature tunnel. Mounted on and turning with the armature is a condenser which is placed in shunt con- 206 The Modern Gas Tractor nection with the contact points in the magneto breaker box. The armature is driven by means of positive chain or gear drive and it is timed in such a way that the contact points of the magneto contact breaker separate only when a spark is desired in the engine. On a four cylinder motor the magneto is driven at crankshaft speed, the contact breaker cams being ar- ranged in such a manner that the contact points sepa- rate twice during each revolution of the armature. Every time the contact points are separated a current of elec- tricity leaves the armature by means of a high tension brush which bears on the insulated contact ring carried at one end of the armature shaft and is led to a dis- tributing brush at the center of the secondary current distributing member. The spark plugs are attached to wires which lead to the segments in the distributor, there being one segment for each spark plug. The distributor shaft is revolved at half armature speed by means of gears and the revolving contact brush makes contact with one of the segments each time that the spark points separate, so that the current of electricity is directed to the plug which is in the cylinder about to fire. It will be seen that this device includes the current generating and commutating means as well as the timing mechanism. A magneto for a two cylinder engine would have but two distributor segments and would be driven at cam- shaft speed or half that of the crank shaft. A magneto for a three cylinder engine would have the segments spaced 120 degrees apart in the distributor and would be driven at three-quarters crankshaft speed. On a six cylinder motor the magneto would be driven at one and one-half times crankshaft speed and there would be six segments in the distributor, spaced 60 degrees The Modern Gas Tractor 207 apart. In the four cylinder form shown the distributor segments are arranged on quarters of the circle or 90 degrees apart. The contact breaker, which corresponds to the timer of a battery ignition system, consists of a fixed member which carries one of the platinum contact screws while the movable bell crank lever carries the other platinum contact. The condenser is used to absorb a surplus current which is due to self induction between the various windings of wire and to prevent the excess cur- rent so generated from producing a spark that would tend to burn the contact points as they separate. The safety spark gap is interposed between the high tension brush and the ground in such a way that any excess current that might injure the windings if it was allowed to go through the instrument in the regular manner will be allowed to flow to the ground without passing through the external circuit. This device performs the same function for the magneto as a safety valve does for a steam boiler, in that it provides a means of escape for excess pressure that might injure the device if no means were provided for its disposal other than the regular channels of distribution. The action of the magneto ignition system will be described more in detail when considering the operation of complete ignition groups. Low Tension Ignition Systems. — The practical application of a low tension ignition system to a four cylinder engine is clearly outlined at Fig. 73. Two sources of current are provided, one a mechanical generator while the other is a battery of ten dry cells in series. A two-way switch is provided so either battery or magneto may be used as desired. As a general rule the magneto is used for regular ignition and the battery 208 The Modern Gas Tractor is called upon to deliver current only for starting and in event of emergencies in which the mechanical genera- tor might get out of order. The four igniters are con- nected to a common conductor or bus bar which is insulated from the metal portions of the engine and which is connected to the top of the switch lever by means of a single wire. A wire runs from the magneto collector brush to one side of the switch, while a conduc- tor from the spark coil, which is in series with the bat- teries, connects to the other side of the switch. One of Battery - f Co/7 Mag/ieto Battery Fig. 73. — Typical Four Cylinder Low Tension Ignition System. the battery terminals is attached to the frame or base of the engine and one of the magneto leads is also grounded. It will be evident that when the switch lever is in central position, as shown, neither magneto nor battery and coil set is in service and that there can be no spark in the cylinder. If the switch lever is placed on one contact button the battery ignition system can be The Modern Gas Tractor 209 used, and if it is moved to the other contact button, the current for ignition will be obtained from the me- chanical generator. Simple Battery Ignition Methods. — The compon- ents of a simple battery ignition system are shown in outline form at Fig. 74, the ignition system being that for a single cylinder engine. As is true of the low tension system previously described, two methods of current generation are provided, a two-way switch being in- Fig. 74. — Simple Ignition System for One Cylinder Engine Using Battery and Magneto. stalled in the circuit of both magneto and battery leads. The switch F is attached to the outside of the battery box, which carries the dry cells B and the induction coil M. The secondary terminal of the induc- tion coil is attached to spark plug E which is placed in the combustion chamber of the cylinder. One terminal of the induction coil M is grounded on the engine, as 21(1 The Modern (!as Tractor at Q. The central terminal of the switch F goes to the insulated terminal of the timer D. One of the leads of the battery D is attached to one of the contact but- tons of the switch while the other goes to the remaining primary terminal of the induction coil. The magneto H is similarly connected, one of the Fig. 75. — Two Cylinder Battery and Coil Ignition System. leads going to one side of the switch while the other goes to the primary terminals of the coil M. Either magneto or battery may be used, depending uoon the position of the switch lever. When the switch is thrown in contact the circuit is still broken until such time that The Modern <1as Tractok 211 the timer D makes contact between the two members. When this occurs the current from the battery or mag- neto, depending upon which is thrown in circuit at the switch, will pass through the primary coil of the induction coil M. This produces a secondary current of sufficient magnitude to produce a spark between the points of the spark plug E. As soon as the timer breaks contact the primary circuit is interrupted and the spark between the points of the spark plug ceases. In actual practice contact at the timer D is established only for an instant every two revolutions of the crankshaft and the parts are arranged and timed in such a manner that the spark takes place only when the piston has reached the end of its compression stroke and the compressed charge of gas is ready to be exploded. The ignition system for a two cylinder opposed engine is outlined in diagram form at Fig. 75. In this the only source of current supply is a set of six dry cells, wired in series. The switch is a two-point type and either a battery or magneto may be coupled to the free terminal just the same as in the simple ignition system pre- viously described. The spark coil, which is the trans- former form used in the high tension ignition system, is composed of two distinct units wired together in a common case leaving five exposed terminals. Those located at the top of the coil are joined to the primary circuit, one of the three that is marked "battery" going to the central terminal of the switch while the other two that are marked '"commutator" (com.) are attached to the insulated terminals of the two-point timer. The two terminals at the side of the coil are high tension leads, one for each coil unit, and are joined to the spark plugs by the usual form of conductor. With this system each unit of the coil fires one of the cylinders and the 212 The Modern Gas Tractor two-point timer serves to establish the circuit required to produce a spark at the proper time. As the explo- sions occur in regular order the contact points of the timer, which is driven at half the engine speed, are spaced on the halves of the circle or 180 degrees apart. A typical four cylinder ignition system in which batter- ies alone are employed to generate electricity is clearly High Tension Wires Induction Coil Switch Primary Circuit Storage Buttery Fig. 76. — Four Cylinder Ignition System Utilizing Battery Current. outlined at Fig. 76. The commutator, or timer in this case, is a four point type, having four insulated con- tacts and one revolving member which establishes the proper connection with each of the insulated members as it revolves. The timer is driven at half of the crank- shaft speed, and as two explosions occur each revolution the insulated timer segments are spaced ninety degrees apart. The induction coil employed is a four unit type. The Modern Gas Tractor l'1:'» The four individual members are carried in a common case and wired so a minimum number of terminals to which wires must be attached are on the outside of the case. The switch, which is a two point type, is mounted on the face of the induction coil box. Two sets of batteries are provided, one of the dry cell form, the other a six volt storage battery. The negative terminals of both storage battery and dry battery are joined by a common wire which is grounded on the engine base. The positive terminals of each battery are led to the two primary terminals immediately under the switch at the bottom of the coil. Four large, well insulated wires lead from the bottom of the coil to the cylin- ders, while the four primary conductors join the in- sulated contact members of the timer and the pri- mary terminals at the top of the coil. The central revolving member of the timer is grounded so that the effect, as far as the circuit is concerned, is just as though the negative wire from both sets of bat- teries were connected directly with it. When the switch lever is placed on the button at the right, the storage battery is thrown in the circuit and the ignition current for regular running is obtained. When the lever is switched over to the other side the dry batteries, which are usually reserved for emergency duty, are put into action. The operation of this system is identical with that of the simple one cylinder ignition system, pre- viously considered, excepting that the various units of the coil are brought into the circuit progressively in the proper firing order. The four cylinder engine illus- trated has a firing order of 1, 2, 4, 3. The front cylinder fires first during the first half of the first revolution of the crankshaft, while the second cylinder, which is the one immediately back of it, fires during the second half 214 The Modern Gas Tractor of the first revolution of the crankshaft. The fourth cylinder delivers a power stroke during the first half of the second revolution, this being followed by the third cylinder, which delivers power to the crankshaft the second half of the second revolution. Action of Magneto Ignition Systems. — In order to simplify the explanation of the action of a typical High Tension Wire to Distributor Segment Distributor Brush - Secondary Winding Primary Winding- Stationary Windin Win to Intulaiad Contact Platinum Tipped Screw Fig. 77. — Diagram Explaning Action of Four Cylinder Magneto Ignition System Used on "Big 4-30" Gas Tractor. high tension magneto, the various essential parts that are in circuit are shown at Fig. 77. The magneto shown has a revolving inductor member instead of the conven- tional form of armature and a stationary double coil mounted in the center of the device in such a way that the magnetic influence from the field magnet is directed through the coil at the time that a spark is desired in The Modern Gas Tractor 215 w J < / 216 The Modern Gas Tractor the cylinder. As will be observed, one of the leads from the stationary primary winding goes to the ground while the other is led to the insulated contact point of the contact breaker. The condenser is interposed in the circuit so that it is in shunt or parallel connection with Fig. 79. — Illustration Showing Advance and Retard Positions of K. W. Magneto Breaker Box. the contact points. As the two members comprising the condenser are insulated from each other the primary current cannot flow through this device. One of the high tension leads from the secondary winding is directed The Modern Gas Tractor 217 to the ground while the other goes to the revolving distributor brush of the distributing device. Four wires lead from the distributor to the various spark plugs of the engine. When the points in the contact breaker are separated by the cam point a current of electricity is induced in the stationary winding because the inductor is at such a position between the pole pieces that a maximum current of electricity is being produced. The high ten- sion current is distributed to the spark plug in the cylin- der about to ignite, the spark plugs being brought into action progressively as the magneto distributor brush establishes contact with the insulated segments to which the plug wires are attached. The application of a typical true high tension magneto to a four cylinder gas tractor power plant is outlined at Fig. 78 and attention is directed to the simplicity of the external wiring. Timing the Spark. — The contact breaker of either a magneto or battery ignition system should be arranged in some manner so that the time of sparking may be varied. In starting the engine by hand it is imperative that the spark be retarded, which means that it should occur later than the correct ignition point and only after the piston has started to go down again after it has reached the top of the compression stroke. When the spark takes place under these conditions the piston is always driven in the right direction and the engine cannot back fire. If the engine were started with the spark advanced the explosion would take place before the piston had reached the end of its compression stroke and it would be driven back in a direction opposite to that in which it should normally revolve. This will tend to knock the starting crank or flywheel out of the operators grasp and may result in a permanent injury 218 The .Modern Gas Tractor to the wrist or arm if this is not removed out of the path of the incorrectly rotating starting handle. While a late spark is desirable for starting and run- ning an engine at low speed it is necessary to advance the spark when it is desired to operate the motor at a higher speed. To do this the timer case is usually rocked so the contact will be broken sooner between the points of the magneto contact breaker or estab- lished earlier in a timer for a battery ignition system. The positions of a magneto contact breaker when in advance and retard positions are clearly shown at Fig. 79. It will be seen that to obtain an advance spark the timer case is rocked so that the roller on the movable timer lever is brought into contact with the point of the cam sooner. In other words, to advance the time of the spark, the timer case is rocked in a direction opposite to that of rotation of the circuit breaking cam, whereas to retard the spark the contact breaker casing is oscillated in the same direction as that of cam rota- tion so the points of the contact breaker would be sepa- rated after the piston has started to go down on its explosion stroke. CHAPTER VI. COOLING AND LUBRICATING THE POWER PLANT. Reason for Cooling Engine — Thermo-syphon System — Forced Circulation Method — Oil Cooling Features — Parts of Cool- ing System — The Pump — The Cooling Fan — The Radia- tor — Why Engines are Oiled— Different Lubricating Med- iums — Simple Gravity Oil Cup Method — Mechanical Oiling Systems — Constant Level Splash Systems. Reason for Cooling Engine. — It is apparent that power is produced in an internal-combustion engine by a series of explosions in the cylinder. As the temperature of the explosion is over 2,000 deg. Fahr. in some cases, the rapid combustion and continued series of explosions would soon heat up the metal parts of the combustion chamber to such a point that they would show color unless cooling means were provided. Under these condi- tions it would be impossible to lubricate the cylinder because even the best quality of lubricating oil would be burnt. The piston would expand sufficiently to seize in the cylinder and the valves would warp so that they could no longer hold compression. Premature ignition of the charge would probably take place long before the engine was put out of commission by the distortion of the parts. The fact that the ratio of engine efficiency is dependent upon the amount of useful work delivered by the heat generated from the explosion makes it important that 219 212(1 Tin: Modern Gas Tractor the jackets be cooled to a point where the cylinder will not be robbed of too much heat. The losses through the water jacket of the average gas-tractor power plant are over 50 per cent of the total fuel efficiency. While it is very important that the engine should not get too hot, it is equally de- sirable that it is not cooled too much. The object of cylin- der cooling is, therefore, to keep the heat of the cylinder metal below the danger point but a t the same time keep the engine hot enough to ob- tain maximum power from the gas burnt. Two general systems of cyl- inder cooling are in general use on farm en- gines, though the simpler air-cooled types are never found on gas tractors of regular manufacture, because air cooling is not considered practical for heavy-duty motors of the bore and stroke used as gas tractor power plants. Water Fig. 80. — Part Sectional View of Water Jacketed Motor Cylinder. The Modern- (i.\s Tractor l'l'1 cooling is the most popular method in all fields of endeavor in which the gasoline engine has been applied successfully with the exception of the motor cycle and aeroplane. When a liquid is employed for cooling it is circulated through jackets which surround the cylinder castings, and when the excess heat is absorbed, the hot liquid (usually water but sometimes oil) is led to a cooler where the heat is abstracted from it by means of air currents. The cooled liquid is then taken from the cooler and again circulated around the cylinders of the motor. The sectional view of a typical cylinder at Fig. 80 shows the liberal space provided for water circulation. Two methods of keeping the cooling liquid in motion are used. The simplest system is to utilize a natural principle that a hot liquid being lighter than a cold liquid will tend to rise to the top of the cylinder when it becomes heated, while cool water, which is heavier, takes its place at the bottom of the water jacket. The slightly more complicated system generally favored is to use a positive circulating pump of some form which is driven by the engine to keep the cooling liquid in circulation. Thermo Syphon System. — Some eminent tractor designers contend that the rapid circulation of liquid obtained by means of a pump may cool the cylinders too much and the temperature of the engine may be reduced to a point where its efficiency will be somewhat lower than if the engine were allowed to run hotter. For this reason many designers, especially in the auto- mobile field, use the natural method of water circulation. The cooling liquid is applied to the cylinder jackets below the boiling point and the water issues from the top of the jacket after it has absorbed enough heat to raise it just about to the boiling point. The simplicity of 222 Thk Modern Gas Tractor the thermo syphon system of cooling is clearly outlined at Fig. 81. With this system of cooling it is necessary to use more liquid than with pump circulated systems and the water jackets of the cylinders, as well as the water spaces in the radiator and the water inlet and dis- charge manifolds, must have greater capacity and be free Fig. 81.— Action of Simple Thermo-Syphon Cooling System Outlined. from sharp corners that might impede the flow of liquid. The direction of flow of the currents of water are clearly depicted and there should be no difficulty in understand- ing the action of this form of cooling system. The Forced Circulation Method. — A system of cooling in which a pump is depended on to promote cir- The Modern Gas Tractor culation of water is shown at Fig. 82. The radiator is generally carried at the front end of the tractor frame and serves as a combined water tank and cooler in most cases. It is usually composed of upper and lower water tanks, joined together by a series of pipes, which may be round and provided with a number of corrugated flanges to radiate the heat, or which may be flat in order to have the water pass through in thin sheets and cool more COLD WATER Fig. 82. — Forced Water Circulation Method of Cooling Engine Cylinders. easily. The cold water which settles at the bottom of the cooler is drawn from the lower part of the radiator by a gear-driven pump and is forced through a manifold to the water jackets surrounding the exhaust valve chamber of the cylinder. As the water becomes heated it passes out of the top of the water jacket into the 224 The Modern Gas Tractor upper portion of the radiator, but as a general rule the rate of circulation is dependent upon the power of the pump rather than the degree of temperature of the water. On account of the more rapid flow of liquid, the radiator and piping may be of less capacity than when the simple thermo-syphon is employed. Oil=cooIing Features. — Some tractor manufactur- ers use oil as a cooling medium instead of water because this material is claimed to be more satisfactory in cold weather. Water will freeze unless it is mixed with some anti-freezing solution such as wood alcohol, glycerine mixtures and calcium chloride solutions. Many tractor operators do not care to use anti-freezing compounds either because of expense or on account of a chemical action and salt deposit which is present when the cheaper alkaline solutions are used. If pure water is used in the cylinder jacket as a cooling medium, it must be drained from the cylinder and cooler as soon as the engine is stopped if the temperature is below 32 deg. Fahr. The Hart-Parr oil-cooling system is outlined at Fig. 83. This is claimed to have been in successful operation for a number of years without any question ever having been raised regarding its efficiency. The system is very similar in action to that of the conventional forced cir- culation water-cooling group, except that the radiator and cylinder jackets are filled with a special cooling oil which takes the place of the usual water supply. As the oil never boils and as there is no waste because of evapo- ration, the original oil supply furnished with the tractor should last as long as the engine itself. Any loss due to leakage may be cheaply renewed. The radiator is constructed of numerous thin corru- gated sections, with a conical hood and short stack at the top. The exhaust is piped into the hood and the exhaust Flo. 83.— Seotional View of Hart-Part Horizontal Power riant Showing Oil Cooling Method. The Modern Gas Tractor 225 gases are discharged upward from the exhaust pipe through numerous holes, this causing a powerful draft through the cooler because of an ejector action and also acting as a muffler for the exhaust by softening the sharp reports so that they are not annoying. The cylinder is kept sufficiently cool for successful operation of the en- gine in even the hottest weather, or when worked under full load continuously for any number of consecutive hours. The circulating pump is mounted at the top of the engine and is driven by positive means. The method by which the various pipes are joined to the pump, water jacket and cooler, and the construction of all parts of the power plant, as well as the cooling system, are so clearly shown that further description is unnecessary. Parts of Cooling Systems. — It will be seen that the parts of the simplest cooling system used in practical work are not very complicated, consisting simply of a container for water, which may or may not combine the functions of a cooler as well, and suitable piping to con- nect the water jackets of the motor to the water tank. With a pump circulation system this and its driving means are practically the only additions to the simpler natural circulation method. The Pump. — Pumps used in connection with water- cooling systems are of two general forms, those in which the water is circulated by revolving gears or paddle wheel and the other and more positive form which is of the plunger type. The rotary pumps are more popular than the reciprocating members because there is no neces- sity for forcing the water along under pressure to any great extent. The simpler forms which promote circulation by keeping the water in motion are all that are needed. The pump is usually driven by positive means, oftentimes by gearing direct from the motor crank shaft or cam shaft. 226 The Modern Gas Tractor The principal parts of a simple centrifugal pump are clearly outlined at Fig. 84. The impeller or paddle- wheel member is secured to the center of the shaft which is supported at each end by bearings in the members comprising the pump casing. This is made in two parts, usually divided vertically along the center line of the impeller wheel. The halves of the pump casing are faced IMPELLER DISCMARGE INTAKE Fig. 84. — Simple Form of Centrifugal Pump for Circulating Cooling Liquid. off so that the joint matches well and a water-tight point of junction is insured by a packing between the halves held positively in place by means of through bolts hold- ing the two halves of the casing together. To obtain proper service from a centrifugal pump the vanes of the impeller wheel should be a fair fit in the pump casing. Other forms of rotary pumps in which a pair of gears or an eccentrically placed revolving element are incorpor- ated are also used, but not so widely as the simple form of centrifugal pump described. Tin: Modern (Ias Tractor 21*7 The Cooling Fan. — As gas tractors are compara- tively slow-moving machines, one cannot depend on the circulation of air through the radiator tubes by the natural draft, as is the case in many automobiles travel- ing at high speed. This condition is met in two ways, the simplest expedient being to provide a water con- tainer of large capacity, having a large amount of radi- DR!Vir\!G PULLEY \ PUMP Fig. 85. — Cooling Fan Necessary Unless Large Volume of Water is Carried. ating surface. In the better designed tractors, the lack of natural draft is compensated for by using a positively driven four or six-blade fan back of the radiator, the blades being inclined at such an angle that air is drawn in through the radiator spaces. These fans, one of which is shown at Fig. 85, are driven 228 The Modern Gas Tractor by leather belts running over flanged pullies, as a rule, though sometimes more positive gear-driving means are employed. When a belt is used for driving the fan some method of adjustment by which the belt tension may be maintained to the proper degree to insure positive drive is provided. With gearing this is not necessary, though it is advisable to provide some form of friction member between the fan hub and the positive driving means to prevent throwing off a fan blade should the engine action become "jerky" and fan drive irregular. When a fan is employed the positive circulation of air insured by its use enables the tractor designer to obtain adequate cooling with much less water than would be needed if the fan were not used. The argument offered against its use that it introduces an item of complication in the tractor mechanism is true to a limited extent but the construction of the fan is so simple and the means employed in driving it so apparent that it is not likely to cause any trouble to even the inexperienced gas trac- tioneer. The Radiator. — The simplest form of radiator is shown at Fig. 86. This is really a combined water tank and cooler. The lower portion is a galvanized iron tank which carries a couple of headers or supporting brackets at each end to which corrugated pieces of sheet metal resembling to some extent the metal face of a washboard are attached. At the top of these corrugated, inclined members are the water discharge pipes from the top of the water jacket of the engine. Under the influence of the pump the cold water pumped into the bottom of the water jacket is constantly forcing the hot water through the pipes of the cooling system to the perforated pipes at the top of the cooler. The large number of small holes insures that the same number of streams of water will be The Modern Gas Tractor 229 WATER SPRAY PIPE \ COOLING WA X /" ?}Mclei\ / \Timron } WATER TANK Fig. 86. — Simple Combined Cooler and Water Container. discharged which trickle down the corrugated surface of sheet metal. As this is cooled by exposing a large sur- face to the air and as the water is divided, in a series of very thin streams from which the heat is readily ab- stracted when it reaches the bottom or tank portion, it has become cooled enough so it can be forced back into the water jacket of the engine again. A much more efficient type of cooler is shown at Fig. 230 The Modern Gas Tractor 86-A. This is composed of an upper and lower header, which are joined together by a number of readily detach- able units, each comprising four pipes around which a large number of light sheet metal flanges are attached to Fig. 864.— Radiator Used on Holt Tractors Has Detachable Cooling Sections. The Modern Gas Tractor 231 increase the effective area of metal exposed to the air. This type of radiator has the advantage of permitting the ready removal of any one of the sections should it become damaged in any way without putting the cooler out of commission. All that is necessary is to stop up the holes by means of a plate and packing. As the water in descending from the top container to the lower por- tion of the radiator must pass through a large number of tubes and as a positive air current is induced by means of a power-driven fan, placed in back of them, very satis- factory cooling is obtained without the necessity of carrying a large amount of water, as is needed with the simpler types of radiator shown at Fig. 86. Other radiators are composed of rectangular section tanks or cylindrical containers through which a large number of light steel or copper tubes pass in just the same manner as the tubes of a fire tube boiler. The cooling air currents are drawn through the tubes to cool the mass of water surrounding them, which is the reverse to the process employed in a boiler where hot gases are passed through the tubes to heat the water. When this form of radiator is used it is necessary to supply a fan to produce a positive air draft and insure adequate cool- ing without the use of excessively large water capacity. Why Engines Are Oiled. — All bearing surfaces, no matter how smooth they appear to be to the naked eye, have minute projections, and when examined under a microscope the surface of even a finely finished bearing appears rough. If bearings were run without oil, the projections on the shaft and on the bushing or box in which the shaft revolves would tend to interlock and a great amount of friction would result. This would mean that much of the power developed by the engine would be utilized in overcoming friction. Without some means 2'A2 The Modern Gas Tractor of minimizing this loss considerable heat would be gen- erated if the bearings were run dry and the result would be that the overheated bearings would soon depreciate and would give signs of distress long before they failed by becoming firmly burned together. The reason that a lubricant is supplied to bearing points will be readily understood if one considers that the close-fitting surfaces of the shaft and bushings are separated by means of an elastic substance which not only fills up the minute depressions, thus acting as a cushion, but which absorbs the heat generated by fric- tion as well. In properly lubricated bearings the oil takes all the wear that would otherwise come on the metallic bearings. The grade of oil and amount to use depend entirely on the bearing points where it is to be applied. An oil that would be entirely suitable for lubricating the interior surfaces of the gas-engine cylin- der would not be suitable for bearings in some cases if these were subjected to heavy pressures. At the other hand the semi-fluid oil or grease which cushions the teeth of the driving gearing so well could not be used in the cylinders of the engine. When used for gas-engine lubrication an oil must be capable of withstanding considerable heat in order that it will not be evaporated or decomposed by the hot metal of the cylinder. The oil used for cylinders or bearings should have a low cold test, i. e., it should not thicken up at low temperatures so that it will not flow freely. All authorities contend that lubricants must be free from acid which will corrode the metal surfaces to which the oil is applied. A lubricant must have suffi- cient body to prevent metallic contact of the parts to which it is applied, and between which it is depended upon to maintain a resilient film. It should not have The Modern Gas Tractor 233 too high a body or too much viscosity because a lubricant that is too thick will have considerable friction in itself and will not flow readily between bearing surfaces. If the lubricant is to be used in slow-moving, high- capacity bearings, such as those of a rear axle, or in gearing where great cushioning qualities are desired in addition to positive lubrication, it must have a heavy body and the semi-solid greases are the best materials to use for this purpose. The grease or oil should also be free from injurious adulterants of either vegetable or animal origin, because these invariably contain fatty acids that will decompose and attack metal surfaces or gums which will coagulate or oxidize by exposure to air and retard the action of the bearings. The best lubri- cants for tractor use are derived from a crude petroleum base with the exception of commonly employed graphite which is a form of pure carbon that is a good lubricating medium. Different Lubricating Mediums. — Oils of organic origin, such as those obtained from animal fats or veget- able substances, will absorb oxygen from the atmosphere which may cause them to become rancid. As a rule these oils have a very poor cold test because they solidify at comparatively high temperatures. Their flashing point and fire test are also so low that they are not suit- able at points where considerable heat exists, such as the interior of a gas engine. The only oil that is used to any extent in lubricating gas engines that is not derived from a petroleum base is castor oil which is obtained by press- ing the seeds of the castor plant. This has been used on high-speed racing automobile engines and on aeroplane power plants, where it is practically pushed right up past the piston and out of the combustion chamber with the exhaust gases so that fresh oil must be supplied all 234 The Modern Gas Tractor the time to replace that ejected from the engine. Obvi- ously this method of oiling would not be considered economical and would not be suitable on either business or pleasure automobiles or gas tractors. Among the solid substances that have been used for lubrication to some extent may be mentioned tallow, w r hich is obtained from the fat of certain animals, such as cattle and sheep; graphite, which is a natural product, and soapstone, which is also of mineral derivation. Tal- low is usually employed as a filler for some of the greases used in slow-speed bearings or in transmission gearing but should never be utilized at points where it will be exposed to much heat. Graphite is obtained commer- cially in two forms, the best known being flake graphite, where it exists in the form of small scales or minute sheets, and the deflocculated form, where the graphite has been ground or otherwise divided into a dust. It is usually mixed with oil of high viscosity and used in con- nection with lubrication of running gear parts, though it has been mixed with cylinder oil and applied to engine lubrication with some degree of success. Graphite is not affected by heat or cold, acids or alkali, and has a strong attraction for metal surfaces. It remains in place better than an oil and as it mixes readily with oils and greases their efficiency for many applications is increased by its use. The oil that is to be used in the gasoline engine must be of high quality and for that reason the best grades are distilled in a vacuum so the light distillates will be separated at a much lower temperature than ordinary distilling practice permits. When distilled at the lower heat the petroleum is not so apt to decompose and de- posit free carbon. A suitable lubricant for gas-engine cylinders has a vaporizing point at about 200 deg. Fahr., The Modern Gas Tractor 235 a flash point of 430 deg. Fahr., and a fire test of about 600 deg. Fahr. Cylinder oil is one lubricant that must be purchased very carefully. A point to remember is that the best quality oils, which are the most efficient, can only be obtained by paying well for them. The few cents saved in using a cheap oil is not of much moment when compared to the repair bill that may accrue from its use. The cheap oil will not only deposit carbon very freely in the cylinder heads but is liable to gum up the piston rings and valves and detract much from the smooth operation and power capacity of the motor. Bearings lubricated with it will also have more friction and consume more power than when good oils are employed. Grauity' Oil Cup Oil Groove Fig. 87. — Oiling by Gravity Feed Oil Cup. Simple Gravity Oil Cup Method. — One of the simplest devices for supplying lubricant to the gas- 23G Thio Modern Gas Tractor engine cylinder is the sight-feed oil cup, which has been widely employed in general steam engineering practice for some time. This consists of an oil container usually composed of metal flanges at the top and bottom between which a glass body, which permits one to see the height of oil in the container, is fastened. A central supply tube terminates in a small compartment under the main body which also has a glass wall so that the drops of oil may be seen dripping from the end of the supply tube. The amount of oil supplied is regulated by an adjustable needle valve which makes it possible to compensate for differences in temperature and viscosity of the oil and keep the supply to the amount needed. The application of a sight-feed oil cup is outlined at Fig. 87 though this shows it attached to the wall of a two-cycle engine cylinder. The same method of lubrica- tion would apply to a four-cycle type as well. It will be noticed that the oil is supplied to the cylinder walls at such a point so that when the piston is at the bottom of its stroke the oil supply will be to a point a little above the wrist-pin. As the piston moves up the oil collects in the chamber back of the supply pipe until the hollow wrist-pin registers with the opening. The oil flows into the wrist-pin and from this point to the lower crank- shaft bearing through a small copper tube which con- nects the upper and lower connecting-rod bearings. When the piston reaches the top of its stroke oil will flow into the annular oil chamber at the base of the cylin- der, and as the bottom of the piston dips into this oil groove at the end of every down stroke, enough oil will be carried up to insure adequate lubrication of the cylinder walls. The sight-feed oiler needs continual attention, so most of the modern tractors are provided with mechanical The Modern Gas Tractor 237 lubrication systems. When a positively driven oil pump is used one is sure that oil will be delivered to all bearing points, whereas in the sight-feed gravity oiler, if the oil thickens up or if the opening in the supply pipe becomes clogged with a small piece of lint or bit of wax, the oil feed stops and unless there happens to be a considerable amount in the crank case the engine may be injured by the failure of continuous oil supply. Fig. 88. — Sectional View of Four Cylinder Engine Showing Passages for Oil Distribution in Crankshaft. Mechanical Oiling Systems. — The simplest pos- sible form of a mechanical oiling system and one that gives very good results in practice is called the constant level splash system. The other method, which calls for the use of a multiple positive drive oil pump, is also used to some extent. At Fig. 88 the cross-sectional view of a four-cylinder four-cycle power plant clearly shows the 238 The Modern (Jas Tractor application of a three-lead positive oil-pump system. The crank shaft is provided with passages indicated by the heavy lines. An oil lead goes to each main bearing, and after it has served its purpose there the oil is taken through the passage in the crank shaft and led to the four connecting rod bearings, from which it is thrown around the interior of the motor by centrifugal force from the rapidly revolving crank shaft. The interior of the engine is filled with a continual mist or spray of oil and all parts are thoroughly lubricated. The excess oil drops into the crank case, which it fills to the level 0ILTR6UGM5 Fig. 89.— Method of Supplying Oil Troughs of Holt Tractor Motor Crankcase. determined by the height of the standpipes in each crank- case compartment. This height is just enough so the lower portions of the connecting-rod caps just skim over its surface and pick up some of the lubricant and by splashing it around the interior assist materially in its distribution. The oil is supplied to the main bearings under considerable pressure and must reach these bear- ing points. From that point the distribution is auto- matic through the passage drilled in the crank shaft The Modern Gas Tractor 239 and the splashing action of the connecting rods as they dip into the oil pools in the compartments at the lower portion of the crank case. The lubricating system outlined at Fig. 89 shows clearly the method of oil distribution by means of a connecting rod. The oil pump, which is driven by means of bevel gearing from the motor cam shaft, draws oil from the lower portion of the crank case and delivers it r*-«=5' MECHP!NlCf\L' OILER ' E§zr Fig. 90. — Mechanical Oiler Attached to Motor, to Cylinders and Timing Gear Case. Note Leads to a manifold pipe which supplies four troughs extend- ing across the crank case and into which the connecting rods dip as the crank shaft revolves. This is really a constant level splash system. All the interior parts of the motor are lubricated by the oil spray produced by the rapidly revolving connecting rod big ends. The application of an individual lead-system mechan- ical oiler to a four-cylinder engine is clearly shown at 240 The Modern Gas Tractor Fig. 90. It will be observed that six pipes lead from the bottom of this device, four of which go directly to the cylinders while one goes to the timing-gear case at the front end of the motor and the remaining one directly to the crank-case interior. The device is driven by gearing which is not shown in the illustration. The inter- ior of the mechanical oiler showing a sectional view taken . Lock nut J*Adjustment nut Chech plunger <^ Teed tubeTo Motor Fig. 91. — Sectional View of Simple Mechanical Lubricator Showing Parts. The Modern Gas Tractor 241 through one of the pumps is depicted at Fig. 91. The pump plunger is operated by means of a metal yoke which rides on the surface of the operating cam. The yoke is kept seated against the cam periphery by means of the yoke spring, and when the parts are in the posi- tion shown oil can flow into the pump cylinder through the two small holes immediately under the pump plunger. As the oiler cam shaft rotates, carrying the cam with it, the yoke is forced down by means of the yoke spring and the pump plunger is pushed into the cylinder with considerable force, this displacing the oil from the cylinder and forcing it past the check plunger (which opens be- cause of the oil pressure) through the feed tube attached to the motor by a conductor of flexible copper tubing. The amount of oil is regulated by an adjustment nut which may be screwed up or down on the stem of the yoke which projects through the cover of the device and which will thus limit the effective stroke of the pump plunger. Obviously, the greater the stroke the more oil will be supplied at each revolution of the cam shaft and each downward movement of the yoke to which the pump plunger is attached. The number of pumps varies with the number of bearings that are to be sup- plied, and as a general rule one pump is allowed for each bearing point. Those that require -large amounts of oil are arranged so the full stroke of the pump plunger is utilized, while the leads that do not require much oil are joined to pumps adjusted with a very short stroke, so the quantity of oil displaced by the plunger at each revolution of the cam shaft is relatively small. The entire interior of the device that is not occupied by machinery serves as a container for oil and a sight-feed gauge glass set into one corner of the lubricator body indicates the amount of oil available at all times. 242 The Modern Gas Tractor Wafer Ouf/ef Pipe r/oaf^ F//fer/n$ Screen OirOut/et Geared O// Pi/mp Fig. 92. — Sectional View of Motor Showing Complete Constant Level Splash Lubricating' System. Constant Level Splash System. — The constant level splash system has become very popular on motor cars and is also widely used on gas-tractor power plants that are based on automobile engineering practice. The application of a typical system of this kind is shown at Tin-: Modern <1as Tractor 2i:\ Fig. 92, and in view of the clear manner in which the various parts are outlined, very little explanation is necessary. The lubricant is carried in a sump or oil container at the bottom of the crank case which may be filled through the breather pipe conveniently arranged at the top of the crank case and having a removable cap to permit the introduction of lubricant to the crank case interior. The oil level in the sump is shown by means of an oil gauge carried by a small float which falls when the oil level decreases to the point where the sup- ply in the crank case must be renewed. Fig. 93. -Method of Lubricating Alain Bearings From Oil Reservoirs Integral With Crankease. The oil is taken from the sump by means of a geared oil pump and is discharged into the crank case. It fills the crank case to the level determined by the overflow pipe, the position of which may be varied as desired by rocking it in its bearings. The oil level is usually of such height that will permit the splasher or oil scoop on the bottom cap of the connecting rod to dip into it. With this system all of the interior mechanism is lubricated 244 The Modern Gas Tractor by means of the oil mist produced by the rapidly-revolv- ing crank shaft. All excess oil supplied flows back into the sump through the overflow pipe and is filtered through the screen at the oil outlet before it is again supplied to the crank-case interior. In this manner only clean oil is supplied and one filling of lubricant will last for a run of three or four hundred miles. At the end of this period all the old oil is cleared out of the crank case and oil sump through a suitable drain cock and the supply is replenished with new, unused oil. In the systems previously outlined the main bearings are lubricated either by oil supplied by individual leads or by a mist which is present in the crank case all times that the engine is in operation. Another method of lubricating main bearings, which has been applied to stationary engines with some degree of success and which is also suitable for tractor power plants where the cylinder is oiled from a sight-feed oiler, is shown at Fig. 93. The main-bearing pedestal is cored out, as shown at C, this forming an oil chamber which can be filled through the plug D. As the oil level at C is higher than the bottom of the bearing oil will be supplied con- tinuously through the passageway S which provides communication between the shaft and the oil container. The brasses B are thus covered with a film of oil which is maintained automatically as long as the oil level in chamber C is higher than the bottom of the bearing B. CHAPTER VII. FUNCTIONS AND CONSTRUCTION OF CLUTCH, GEAR- SET AND DIFFERENTIAL. Why Clutch is Needed — Action of Simple Clutch Described — Some Typical Tractor Clutches — Friction Disc and Roll Clutches — Why Reversing Mechanism is Needed — Typical Reversing Mechanism — Why Speed Changing is Necessary — Action of Simple Change Speed Gears Outlined — The Differential Gear and Its Use. Why Clutch Is Needed. — One of the important members of the power-transmission system of the gas tractor is the friction clutch employed to connect the power plant to the rear wheels or to break the driving connection between the power generating and traction members when desired. A clutch is absolutely neces- sary on a gas tractor, though on a steam tractor it is not customary to provide a clutch between the engine and the driving wheels, though in some cases this device is furnished on the steam-power plant as well. Steam engines are capable of delivering power considerably in excess of their rating, and as the steam which furnishes the power is stored under pressure in the boiler it is pos- sible to start the steam engine under load. The amount of power delivered from a steam engine may be varied by regulating the quantity and pressure of the steam going to the cylinders and a simple throttle-valve lever is all that is needed to control the speed of the steam tractor and to start or interrupt the drive when desired. 245 246 The Modern (Jas Tractor The Modern Gas Tractor 247 When a gasoline engine is used as a power plant, con- ditions are radically different. It is not possible to start any explosion motor under load, because the power is obtained by the combustion of fuel directly in the cylin- ders and there is no external source of energy to draw from, as is the case with the steam engine. The power produced by a gasoline engine depends upon the rapidity with which the explosions follow each other, and unless the engine is turning over at a certain speed, it is not delivering its full power. It has been demonstrated that a certain cycle of operations is necessary to secure gasoline-engine action. For example, consider the case of a single-cylinder engine, started under load. If there was a charge of gas already in the cylinder and this was exploded, the piston might make one stroke, but as there would be no further energy supplied, the crank shaft would come to a stop on account of the resistance. It will be apparent, therefore, that the gasoline engine must revolve free of load in order to start it. The piston must go through the functions of drawing in a charge of gas, compressing it, and then firing it before any power is produced. Even after the engine is started, it must attain a certain speed to supply the power needed to overcome the resistance that tends to prevent motion of the tractor, before it can be used in driving it. It is very desirable that the gas tractor be started or stopped independently of the engine. On a steam trac- tor it is possible to start it as soon as steam is admitted to the cylinder from the boiler, but with a gasoline engine it is customary, and in fact necessary, to inter- pose some clutch mechanism between the engine and driving wheels, which will make it possible to couple the power plant to the traction members and disconnect it at will. The friction clutch is the simplest method of 248 The Modern Gas Tractor accomplishing this result. This consists merely of a locking member, which is capable of joining the driving shaft to the crank shaft of the engine when desired. The location of a typical clutch is clearly shown at Fig. 94, as applied to a gas tractor. The clutch is usually oper- ated by a hand lever and as a rule the leverage is propor- tioned so that but little effort is needed on the part of the operator to apply or release the power. Action of Simple Clutch Described. — Clutches that utilize the driving properties of frictional adhesion have proven to be the most satisfactory in practical application. The most important requirement is that the clutch be capable of transmitting the entire power of the engine to which it is fitted without any loss due to slipping. The clutch should also take hold gradually because any "grabbing" will produce stresses that may seriously injure the mechanism. It is imperative that the two portions of a clutch member disengage positively when the clutch is released so that there will be no dragging or rotation of parts. Other factors to be con- sidered are to provide as much friction surface as pos- sible, to have the clutch members placed in an accessible position, and to provide adjustment so a certain amount of wear can be taken up. A simple friction clutch such as used in transmitting power from one shaft to another is shown at Fig. 95, which illustrates all the important parts of the mechan- ism. The clutch ring K is about half the diameter of the pulley and is attached to the arms or spokes by casting integral in some cases and by making it a separ- ate bolted member in others. The inner jaws Q on each arm are forced outward and the outer jaws H inward by means of the toggle levers SU which operate upon the levers E. This lever has its fulcrum between its points The Modern Gas Tractor 249 Fig. 95. — Sectional View of Simple Clutch, Showing Principal Parts. of connection with friction members Q and H and is operated by means of a inclined cam member, which is lifted by a roller or contact member carried at the end of the bell-crank lever U. As will be evident the friction members Q act against the inner periphery of the cast- iron clutch ring K while the friction members H act against the outer periphery of the same member. Four to six sets of friction members are provided, and when the bell crank U is operated by the toggle S, the end iT)!! The Modern Gas Tractor of the rocker lever F which carries the cam E is raised. This pushes the shoe Q up and pulls down the shoe H. The shoe H is provided with a friction block of well- seasoned maple X and the shoe Q is provided with a friction member of the same material at Y. The belt pulley revolves on a bushing which turns freely on the driving shaft when the clutch is discon- nected. The spider that carries the clutch members Q and H and their actuating mechanism is keyed to the shaft and revolves with it. To engage the clutch the col- lar Z is pushed toward the pulley, this clamping the ring attached to the pulley firmly between the driving shoes which are revolving with the shaft. When the pulley is locked to the revolving-clutch member it must turn with it and at the same speed because the lock is positive. If the friction blocks slip considerable power will be lost in transmission. To release the clutch the collar Z is pulled away from the pulley and the jaws Q and H spread apart, allowing the cast-iron driving-ring K to revolve freely between them. In this way it will be seen that motion may be imparted to a stationary shaft by means of a revolving pulley or vice versa. Some Typical Tractor Clutches. — A very efficient type of clutch used on the Holt tractors is shown at Fig. 96. This is a three-plate type and the cast-iron ring which acts as a driving member is clamped between the two driven members in much the same manner as pre- viously explained. The engine fly-wheel carries a clutch casing in which a floating driving plate is keyed. This plate must turn with the fly-wheel but may move back and forth on its keys. The engine crank shaft termin- ates in the hub of the fly-wheel while the drive is taken up by an independent shaft which runs into a telescopic bearing of the plain bushing type carried in the hub of The Modern Gas Tractor 251 Clutch Dn'uing Member Clutch Driving Plate- Bell Crank, ^Flywheel Rim 'Flywheel Hub 'Clutch Shifting Rod Fig. 90. — Sectional View of Master Clutch Used on Holt Tractors. the clutch case. The engine shaft and drive shaft are independent when the clutch is disengaged. That is to say, the drive shaft may remain stationary while the 252 The Modern Gas Tractor fly-wheel revolves. Attached to the driving shaft is a flanged member which carries a number of bell cranks spaced equidistantly or 120 degrees apart. This driven member also carries a plate which is keyed to it and which must revolve with the driven shaft. This plate can move back and forth on its key so the two clutch-driven plates are in contact with the driving plate only when the clutch lever has moved the clutch-link actuator to the CLUTCH CLUTCH BLOCK BELT_P_ULLEY BELT PULL ELY BRAKE CLUTCH SHIFTING BE.LL CRANK UTCH BLOCK Fig. 97.— Clutch of Avery Tractor is Provided With Three Clutch Shoes. position shown, where the toggle links are approximately vertical and the bell cranks are holding the driven and driving plates of the clutch into firm engagement. When the clutch-link actuator is moved back the bell crank is pulled away from the outer clutch-driven plate, and as there is no pressure to maintain frictional contact The Modern Gas Tractor 253 between the driven and driving members, the fly-wheel of the motor may continue to revolve while the mechan- ism attached to the drive shaft becomes stationary. Wear between the clutch plates may be taken up by an adjustable contact member carried by the bell crank. A clutch of this type may be applied gradually and may Fig. 98.— Clutch of Rumely Tractor Utilizes Three Friction Shoes Acting on Interior of Wheel Rim. be allowed to slip to some extent while getting the trac- tor under way without doing any injury. When the clutch lever is operated to the limit of its movement in one direction the clutch is firmly engaged, while moving 254 The Modern Gas Tractor it to the other extreme position will insure complete dis- engagement. Clutches shown at Figs. 97 and 98 are similar in con- struction. In these a series of contact blocks are carried at the end of counter-balanced, pivoted levers. The blocks are pushed out by means of a toggle linkage actuated by a clutch-shifting bell crank, in much the same manner as has been previously described. One member is attached to the crank shaft while the other rotates with the driving shaft. The clutch shown at Fig. 97 is used to bring a belt pulley into engagement with the engine shaft, though the principle may be reversed and the belt pulley represent a member at- tached to the engine fly-wheel while the spider which carries the clutch blocks and actuating mechanism would be attached to the independent transmission shaft. Friction Disk and Roll Clutches. — Some tractor designers employ friction-wheel clutches instead of the types described These operate on a different principle as the members are not locked together so that they revolve as a unit, but the driven member rotates the driving member which turns on a different plane. A double friction disk clutch such as used on the Heider is shown at Fig. 99, and its relation to the engine may be clearly ascertained. The fly-wheel has a fiber ring attached to it which serves as a driving member, while two disks are attached to the cross shaft which is placed at right angles to the crank shaft of the motor. These disks are adapted to be brought into contact with the fiber friction ring with a considerable degree of pressure. The sketch at Fig. 100 shows the principle of opera- tion. If the engine fly-wheel is turning in the direction indicated by the arrow and the friction disk A is brought in contact with it, the cross shaft to which the disk A is The Modern Gas Tractor Zoo 256 The Modern Gas Tractor attached will turn in the same direction, and as this carries a driving pinion which is in mesh with a driving gear on the differential casing of the counter shaft it will turn it in the opposite direction. As the connection from the counter shaft to the rear wheels is by chain and sprockets the rear wheels will turn in the same direction as the counter shaft does and the entire machine will move in the direction of the large arrow or forward. If conditions are reversed and the friction disk A is pulled out of engagement with the fly-wheel, while friction disk B is brought in contact with that member, the trac- tor will move backward because friction disk B will be revolved in a direction opposite to that friction member A turns in. Another form of friction clutch in which a friction wheel is employed is shown at Figs. 101 and 102. The view of the mechanism at Fig. 101 shows clearly the mounting of the friction wheels for driving a movable cross shaft, which in this case is parallel with the engine crank shaft. This main driving shaft, which extends across the frame, is provided with a friction driving wheel at each end and carries a pair of sliding gears which may be engaged with either one or two gears on the transmission cross shaft placed immediately back of the main driving shaft that carries the friction wheels. The gears on the transmission cross shaft are of different diameters, one being smaller than the other, as is true of the sliding gears on the squared main shaft. Before dis- cussing the method of obtaining speed changes or final drive it will be well to consider the action of the friction rollers. The engine carries two large fly-wheel members, which are so arranged, one at each side of the frame, that the friction wheels employed for driving fit in an annular The Moderx Gas Tractor 258 The Modern Gas Tractor The Modern Gas Tractor 259 channel machined between the inner and outer fly-wheel members. This is clearly shown at Fig. 102-A. The fly-wheel hub is enlarged and forms one driving member while the fly-wheel rim, which has a smooth and true inner periphery, forms the other driving member. When the friction driving wheels carried by the transmission main shaft are in the neutral position they are in the space between the inner and outer fly-wheel driving members, and as the friction roller is not in contact with either the hub or the rim of the fly-wheel, one member may revolve independently of the other. To obtain the forward drive, the main shaft is rocked so the friction wheels are brought in contact w T ith the inside of the fly-wheel rim. If this is turning in the di- rection indicated by the arrow, it will turn the friction roller in the same direction, and the main shaft is revolv- ing in the same direction as the motor crank shaft. To obtain a reverse motion of the main shaft the friction rollers are disengaged from the interior of the fly-wheel rim and are pushed against the exterior of the fly-wheel hub, as indicated at C. This will produce a motion of the main shaft opposite in direction to that of the crank shaft. The leverage is proportioned so that very little pressure is necessary at the operating lever to insure positive drive. The shaft on which the friction pulleys are keyed is hung on pivoted or eccentric bearings, which are located in such a way that when the friction surfaces are brought in contact with each other they will automatically produce pressure enough to move the load, and as the resistance augments the driving pressure becomes stronger and the rolls can transmit the full amount of power generated by the engine. The friction wheels are made of paper or strawboard fiber and may be very easily replaced when worn. 260 The Modern Gas Tractor The Modern Gas Tractor 261 It is claimed that the friction drive methods cannot be compared to the friction clutch because it will give a much smoother and more flexible drive than is possible with any form of friction clutch. It is contended that the clutch is too positive a lock betw r een the driving and driven parts, while the friction rollers are not so positive in their action. It is also advanced that in event of sud- den shock the friction roller will slip to some extent, while with the friction clutch, which is positively locked, a sudden strain will result in breaking a gear or stressing of some of the transmission parts. With either of the friction drives described, a one-lever clutch control is obtained and one can stait, stop, or reverse the tractor instantly by using but one control lever. The methods of obtaining the changes of speed on the Ohio tractor may be easily understood by referring to illustration, Fig. 101. If the sliding gears are shifted along the main shaft, so that the smallest pinion on the main shaft is in mesh with the largest gear on the trans- mission cross shaft the slowest rear-wheel speed is ob- tained. If the largest pinion on the main shaft is slid into engagement with the smallest gear on the transmis- sion cross shaft the highest rear-wheel speed will be obtained. If the sliding-gear member on the main shaft is placed at a neutral position so that it is not in mesh with either gear on the cross shaft, engaging the friction wheels and the fly-wheel will not produce motion of the tractor. The drive from the transmission cross shaft is by a pinion which engages a large gear attached to the differential spider. The differential gear is attached to a cross shaft to which the bull pinions, which drive the bull gears on the rear wheels, are attached. It will be apparent that with the friction roll clutch it will be possible to obtain the same number of speeds on the 2G2 The Modern Gas Tractor FLYWHEEb CLUTCH DRIVING GEAR OPERATING I LEVER BEVEL GEAR —A BE\(EL EAR 5 BULL PINION FRAME CASTING OULL PINION [STARTING CRANK Fig. 103. — Master Clutch and Reversing Mechanism of Typical Tractor. reverse drive as when the tractor is moving ahead. Why Reversing Mechanism Is Needed. — Another difference between the steam and gas engines used for tractor propulsion is that the direction of crank-shaft rotation of the former may be easily reversed by a sim- The Modern Gas Tractor 263 pie mechanism which will reverse the flow of steam to the cylinders while the latter, as ordinarily made, can only run in one direction. When a steam engine is used for power no separate reversing mechanism is needed, but when the gas engine is utilized, owing to the fact that it runs only in one direction, it is necessary to provide some form of gearing that will permit the motion of the road wheels to be reversed even if the engine continues to revolve in the same direction as when the tractor is moving ahead. Typical Reversing Mechanism. — A simple and efficient form of reversing mechanism is shown at Fig. 103. It consists of two bevel pinions placed on a con- tinuation of the engine shaft and a bevel gear at right angles to them and in mesh with both of the pinions. The bevel-gear shaft carries a driving pinion of the spur type which meshes with the differential driving gear which in turn imparts motion to the bull pinions mounted on the counter shaft. The bevel pinions of the reversing gear normally revolve freely on the engine-shaft exten- sion if the double-jaw clutch, which is keyed to the driving shaft, is in its neutral position. A master clutch is placed inside the engine fly-wheel so the driving shaft which carries the positive jaw clutch member may be placed out of engagement with the power plant when desired. The double positive clutch may be moved back and forth so that it can clutch either bevel gear A or bevel gear B to the driving shaft. When in the neutral position, if the master clutch is engaged, the tractor will not move because there is no driving connection between the bevel gearing and the driving shaft. When the positive jaw clutch is moved on the shaft so it engages bevel gear A the drive is through A to the bevel gear on the short cross shaft and from thence to 264 The Modern Gas Tractor ENGINE FLYWHEEL STEERING WHEEL / MASTER CLUTCH REVER5E GEAR A BELT PULLEY BtV PINION DRIVE CHAIN CROSS SHAFT DRIVE GEAR Fig. 104. — Showing Arrangement of Clutches and Drive Gears of Holt Caterpillar Tractor. The Modern Gas Tractor 2(;."> the differential gear which turns the counter shaft on which the bull pinions are mounted, so the tractor is moving ahead. If the clutch is engaged with bevel gear B, the motion of the short cross shaft is reversed, and as the train of gearing runs in the opposite direction to that which obtains when bevel gear A is clutched, the tractor will move backward. Another form of reversing gear, which operates on practically the same principle, is shown at Fig. 104. This is applied to the Holt Caterpillar Tread Tractor. In this mechanism, instead of the reduction between the driving shaft and the cross shaft being by means of spur pinion and gear, the drive is accomplished by a bevel pinion which drives the cross-shaft drive gear. The power is transmitted from the cross-shaft drive gear to the shaft on which small-diameter sprockets are mounted and from these driving chains are connected to the large driving sprockets which move the cater- pillar tread traction member. The shaft from the master clutch is continued right through the reverse-gear box to a bearing placed between the cross-shaft drive gear and one of the traction member clutches. To obtain forward motion the clutch is moved so that it locks the bevel gear B which carries at the other end of the sleeve on which it is mounted the main bevel drive pinion, and this is turned in the same direction and at the same speed as the engine crank shaft when the master clutch in the engine fly-wheel is engaged. If the positive clutch is moved toward the front of the tractor so that it is clutched to the reverse gear A this member is locked to the drive shaft and the drive is then through the inter- mediate bevel pinion which causes the forward drive gear B to turn in a reverse direction and thus makes the tractor run backward. Sometimes the reverse gear is 266 The Modern Gas Tractor incorporated with the change speed gearing as in auto- mobile practice, and on other forms of tractors it may be made a function of the friction disk or roll clutches as has been previously described. Why Speed Changing Is Necessary. — Those who are familiar with the action of steam tractors may not recognize the necessity for change-speed gearing which is such an essential component of the gas-motor-pro- pelled tractor. It has been demonstrated that the steam engine is more flexible than the gas engine and that the amount of power obtained can be varied by altering the amount of steam admitted to the cylinders. If the engine is running slowly and more power is needed the engine capacity may be increased materially without augmenting the speed of rotation and the power may be increased 50 or 100 per cent by using steam at higher pressure. The internal combustion motor is flexible to a certain degree, provided that it is operating under conditions that are favorable to accelerating the motor speed by admitting gas to the cylinders. The power capacity or the mean effective pressure of the explosion in the gas- engine cylinder is limited arbitrarily, and after a certain point is reached it is not possible to increase the power output by supplying vapor at high pressure as is possible with a steam engine. It is customary in all tractors of the gasoline or kerosene burning type, where combus- tion takes place directly in the cylinders, to interpose change-speed gearing which will give two or more ratios of speed between the engine and the traction members. There are occasions when a tractor is required to pull a heavy load slowly, as in plowing, where it is desir- able not to exceed a speed of two miles an hour, whereas The Modern Gas Tractor 267 in other work, as in hauling on the road or moving from place to place without a load, considerable time would be lost if the tractor was operated on the low speed. Four or five miles an hour is a practical speed for hauling and usually some means is provided so the ratio of drive between the engine and the rear wheels may be in- creased. On some tractors three changes of speed are provided, in addition to a reverse motion, combined in the gear set. Most of the tractors in general use, how- ever, have but two changes of speed, while man}- very practical machines have but one speed forward and reverse. Where the reverse gearing is incorporated in the change-speed gear set, but one ratio of drive is pos- sible when the reverse gears are engaged, whereas when a separate reversing mechanism is utilized in connection with a change-speed gearing, as many speeds backward as there are forward may be obtained. Action of Simple Change=speed Gears Outlined. — In order to explain the method of operation of a sim- ple change-speed gear set, the essential e ements of a mechanism of this character are shown at Fig. 105. A gear attached to the engine crank shaft A drives the cross -shaft B. This carries a pair of sliding-gear mem- bers, which are keyed to it so that they must turn at the same speed, but which may be shifted so they will engage the gears on the cross shaft C, which in turn drives the rear wheels by means of pinions which mesh with the large gears attached to the traction members. One of the gears attached to the differential casing is 24 inches in diameter, the other gear is 27 inches. The small sliding pinion which is adapted to engage with a 24-inch gear is 8 inches in diameter, while that which will mesh with the larger or 27-inch gear is but 5 inches in diameter. Obviously, these dimensions are presented only to make 268 Tin: Modern Gas Tractor A/y>v/7ee/. '*a/~/ny ^3 Dr/i//f} Three-point support is not difficult to obtain when the one-piece swinging front axle is utilized because a pivoted point is necessary to secure easy steering. When the Ackerman type axle is used, however, this being the form in which the wheels are carried by steering knuckles, it would not be necessary to supply the single pivotal point of support if it were not imperative to have the three-point method of suspension. Fig. 118 outlines the construction of a skeleton type movable spindle axle which is hinged at a central point to permit the front wheels to tilt as indicated in the illustration. The Modern Gas Tractor 12!) 1 PIVOT Fig. 118. — Showing Arrangement of Ackerman Front Axle to Obtain Three Point Support of Tractor Frame. Gas tractors, as a rule, are not mounted on springs because their speed of travel is slow and the large wheels employed reduce the need for springs which are so neces- sary with automobiles or horse-drawn vehicles. The front view of a Phoenix tractor outlined at Fig. 119 shows the method of utilizing a spring mounting for the front axle and at the same time obtaining the desired degree of flexibility essential to a practical three-point support running gear. Two springs are used, one at each side of 2!>° The Modern Gas Tractor £ *§?. W&Bx&Et Fig. 119. — Method of Mounting Front End of Phoenix Tractor Frame on Springs Designed to Permit Three Point Sus- pension Principle. the axle, and these carry a bearing at their center which rocks on a stud attached to the bottom of the curved The Modern Gas Tractor 293 front frame member. The construction is so clearly shown in illustration that further description is unneces- sary. Facts Concerning Tractor Wheels. — Gas tractor frames may be mounted on either three or four wheels. When a three-wheel construction is employed it is some- times the two front wheels that are used for steering with a single large driving member and in some cases the two front wheels serve as driving members while a single Fig. 120. — Showing Advantages of Large Wheels for Tractor Driving Members. rear wheel serves to steer the vehicle. The four-wheel construction is the most conventional, however, and the two front wheels are smaller in diameter and much lighter than the rear wheels and are used practically only for steering purposes as most of the tractor weight, in some cases 80 or 90 per cent, is carried over the rear or traction members. When a single rear driving wheel is employed no differential gear is needed, though most engineers prefer to use two traction members and obtain 2i>4 The Modern Gas Tractor a more effective contact area between driving members and the ground. The front wheels are generally of the same type and are a built-up structure composed of a hub from which circular section spokes of steel rod radiate to the steel rim. Generally a raised collar or flange is shrunk onto the smooth tire to prevent side slip. In some cases the wheels are made in one piece and have the rim, spokes and hub cast integral. The traction wheels vary from twenty to thirty-two inches wide and from six to eight feet in diameter. Most engineers favor a large wheel because this will bridge over irregularities of the field surface easier than the wheels of lesser diameter, have more area of contact with the ground and are much more efficient as driving mem- bers. The advantages when a large wheel is used com- pared to one of smaller diameter under similar condi- tions are clearly outlined at Fig. 120. In this case it is assumed that each wheel has sunk six inches into the ground. It will be noted that the area of contact of the 6-foot diameter wheel is but 5.8 square feet while that of the 8-foot diameter member is 7.75 square feet. In order to pull the tractor out of the rut the engine must exert as much power with a 6-foot wheel as would be necessary to pull it up a 66 per cent grade. With the 8-foot wheel the amount o angularity is reduced and the grade corresponds to but 55 per cent. It will be evident by study of diagram why the large wheel is superior to the member of less diameter. Methods of Construction. — The best driving wheel construction is known as the built-up type of wheel which is l'ghter than the cast wheel and which has ample strength when properly designed to do the work. There are two general methods of construction used in the built-up type of wheels. In one, spokes are The Modern Gas Tractor 295 GEAR WHEEL SPOKES ■ TRANSMISSION BAR EXTERNAL SPUR GEAR Fig. 121. — Tractor Driving Wheel Showing Method of Attach- ing External Spur Bull Gear to Wheel Hub and Rim. made of flat bars which are bent over and riveted to the rim of the driver. Each spoke is attached to the hub by rivets and the weight of the engine is carried by subjecting the spokes to a compress on stress, such as obtains on practically all types of horse-drawn vehicles. . The other and preferred construction is known as "the suspended type" of wheel. The spokes have round heads and pass completely through the rims and are attached to the hub in much the same manner as a wire spoke bicycle or automobile wheel. 29G The Modern Gas Tractor The weight of the tractor is therefore suspended by the spokes which are under tension instead of compres- sion. With this method of construction there are no rivets to shear off and get loose and the suspended type of wheel is not only considerably lighter than the flat spoke type but it has greater resiliency and is superior to either the cast or flat spoke type of wheels for this reason In order to make a large driving wheel practical when of the built-up type, it is desirable to remove all driving strains from the spokes, and in order to accomplish this the power that is applied to the large master gears is transmitted to the rim directly by con- necting the driving gear to the steel plate rim member by bars of flat or round stock. The rims of the wheels must be of sufficient strength to withstand hard usage and are nearly always reinforced to prevent crimping. This reinforcement may be angle iron or channel iron hoops riveted to the inner periphery of the wheel or the rims may be specially rolled so as to have an in- wardly projecting flange so that the rim will be suitably reinforced and at the same time retain the advantages of one piece construction. A typical traction whee of the suspension spoke type is shown at Fig. 121. The master driving gear or bull gear, as it is generally called, is centered from the wheel hub by means of five rods, spaced equidistantly around its circumference and provided with adjustable members which make for accurate gear location. The actual driving strains are taken from the gear rim by means of the four brackets of flat stock which are attached to the driving gear at one point and to the rim of the wheel at two points. The wheel at Fig. 122 is practically the same in construction, except that the The Modern Gas Tractor 297 driving gear is an internal spur form and has spokes cast with the gear rim. The casting emploj'ed for the hub is also shown. The holes in the outer periphery- are used to pass the spokes through while the series of slotted openings in the flanges of the hub permit the assembler to insert nuts which hold the spokes under tension and insure firm attachment to the hub. TRANSMISSION BAR TERNAL SPUR GEAR HUB CASTING Fig. 122. — Tractor Driving Wheel and Hub Casting. Note Internal Spur Drive Gear and Method of Attaching to Hub and Rim. On some forms of tractors it is considered desirable to reduce the shock of driving as much as possible by connecting the driving gear to the wheel rim by trans- mission rods and springs instead of the stiffer bars previously described. The wheel shown at Fig. 123 is a flat spoke form. The master driving gear is at- 298 The Modern Gas Tractor t ached to a series of five lugs which deliver their power to the wheel rim through the medium of transmission rods, which are joined to the movable lugs only by means of helical coil springs. The drive is thus directed to the wheel rim by yielding members and the wheel is not subjected to shocks which may result from irregu- lar or sudden power application to fixed gearing. This also permits the wheel to surmount obstacles without producing as much strain on the transmission gears FLAT SPOKE TRANSMISSION ROD LUG TO WHICH DRIVING GEAR 15 FASTENED Fig. 123.— Traction Wheel of Gas Tractor With Spring Mem- bers to Remove Shocks From Driving Gears. The Modern Gas Tractor 299 Fig. 124. — Driving Wheel of Tractor Utilizing Chain Drive. as would obtain if the bull gear was attached directly to the wheel rim by non-yielding transmission rods. The wheel depicted at Fig. 124 differs from those previously shown in that it is provided with a driving sprocket instead of a spur gear and must be operated through the medium of chains instead of by direct meshing of teeth, as is the case with either internal or external spur gear drive. 300 The Modern Gas Tractor A typical hub is shown in section at Fig. 125. This consists of a casting pierced with a number of holes through which the spokes extend to the rim. This hub is of steel and is lined with a bushing of bronze which is interposed between it and the steel shaft and well lubricated to take the wear. It is kept from end movement by means of a bronze thrust collar, which bears against the axle supporting bearing and the face of the hub flange. The hub is prevented from coming off by a dust collar which is pinned to the axle. Fig. 125. — Cross Section of Hart-Parr Rear Hub Showing Wheel Bearing and Method of Lubrication. In order to secure greater traction on soft ground than would be obtainable with a smooth steel tire the outer rims of the traction wheels are always provided with a series of projecting lugs or points which are called "grouters." These may be of pressed steel, steel castings, malleable or cast iron. They are some- times attached parallel to the axle and at other times at an angle to facilitate self-cleaning. When grouters The Modern Gas Tractor 301 are set at an angle they are generally placed so that the rear end of one comes opposite the front of the adjacent member so the circumference of the wheel is made more continuous and jolting is eliminated on hard surfaces. Pressed steel plates may be used to form a continuous succession of corrugations which Fig. 126. — Traction Wheel Rims Showing Cleats or Grouters of Various Types Utilized to Increase Frictional Adhesion With Ground. will extend entirely around the circumference of the wheel. It is claimed that this form of construction can pass over soft ground without tearing up the sur- face and at the same time it is as efficient under other conditions as the other types. Some tractor manu- 302 The Modern Gas Tractor facturers provide sharp conical pyramid shape spikes which may be removed if the tractor is to be operated over road surfaces that it is not desirable to tear up. Various forms of grouters are shown at Fig. 126. Those outlined at A are merely strips cut from T section iron bar riveted to the wheel rim. This is the form usually provided on English tractors and while these prove very efficient on good roads they are not as satis- factory as the more pronounced grouters or mud lugs Fig. 127. — Extension Rims Designed to be Attached to Regular Traction Wheels to Obtain Greater Contact Area When Used on Soft Ground. in general field work. The grouters shown at B are iron castings bolted to the rim. At C a combination of angularly placed grouters and external flanges to minimize lateral slip of the wheel is provided. It is sometimes desirable to provide a greater area of con- tact than is obtained with the regular width wheel when operating a tractor on soft ground. Extension rims, such as shown at Fig. 127, are provided in most The Modern Gas Tractor 303 cases for use in conjunction with the regular types of wheels. These extensions range from ten to fifteen inches in width and are designed so that they may be easily attached to the traction members when it is desired to increase the width of the wheels. Action and Advantages of the Caterpillar Tread. — It is a fact that will not be questioned that a heavier load can be hauled over a smooth road than over a rough or muddy one. The locomotive, a very efficient and powerful traction engine, travels on a smooth steel Fig. 128. — Showing Construction of Caterpillar Tread Traction Member of Holt Tractor. track. It would not be possible to lay tracks over our highways for tractors to operate on so one tractor manu- facturer obtains the advantages of the track principle and applies it to the agricultural and freighting industry by using what are known as "Caterpillar Traction Members." This tractor, which has been previously illustrated, automatically lays and travels on a smooth level steel track, strong, durable and flexible, over which it successfully negotiates ploughed fields, soft delta lands, prairies, country and mountain roads, and 304 The Modern Gas Tractor operates successfully over field and highway surfaces that are very difficult to negotiate with wheel traction engines. The Caterpillar Tread enables the engine to bridge ditches several feet in width, a feat that is not possible with the wheel forms. By means of the track distribution of weight is effected over an area of ground the equal of which is not cov- ered under any other than this track laying principle of construction. The increased area of contact between the traction members and the ground means better traction and increased drawbar horse-power. The side view of the Caterpillar Tractor shown at Fig. 16 indicates clearly the method of construction, while the illustration at Fig. 17 shows the tractor from another point of view. The construction of the Caterpillar trac- tion member itself is clearly shown at Fig. 128. The construction is simple and easily understood. The track shoes, which come in contact with the ground and take the place of a tire on the ordinary wheel, are drop forged from plough steel, and are practically indestructible. The track rails are made of steel cast- ings which have great strength and endurance. The spacing blocks which hold the pair of rails to the proper distance and with whicn the sprocket teeth engage to drive the track are made of manganese steel. The power is applied by steel sprocket wheels at the rear end of the machine which continually picks up the tracks, carrying them forward over the supporting rollers to blank sprockets which continually lay the tracks down and provide a path over which the engine moves. The ordinary wheel with a 24-inch base width in order to cover an area equal to that of one 24-inch Caterpillar track would have to be 120 feet in diameter and would weigh more than fifteen tons. Obviously, this is not The Modern Gas Tractor 305 a practical construction, so the advantage the Cater- pillar track offers in the matter of contact area in pro- portion to weight can be readily understood. Reference to the illustration at Fig. 129 serves to bring out these differences clearly, while the tabular comparison at Fig. 130 shows the claims of the manufacturers of this device and the comparison made by them between the Fig. 129. — Comparison Between Wheel and Caterpillar Tread Traction Members. 306 The Modern Gas Tractor Cor~v=>*>mson of C^TCFff^iuLf^ff f?rvo VJmetel. Tvf>£z Cfl TEfT P/i-L RFf Wm£-£TL. f?e///nO- FricttOrt Quite constant under Ordinary conditions Very h'ari eor/h Ground Slippoae. ( Proportiona/ fo area of O-notrnc/ contact, Wt. on driver^ One/ number of orovdmri try confacf v*/fh ground UOOO so. m. pr-our>d Surface area Dopendenf on conditio of pro-end . A/ ever *cee ds 3QO stf i n f7as>um inn we*n>fif on drivers the same /m%S&Q/bs or more / 26 rcisde r j / ood per so in ef around *urfBce-&S7bz f^aou/fy for Bridoiip uneven p/oces &Ood on account of /onp ground ConVo&f, \/Jo/pSrf on f'r-or, t Sfeer/'na Whee/s "Pr-acf/caffy con 9 fc/n f 7e>*refe>ncy fa poc^t ffre. **ar^A depend* ~f u^ort W/ per- 5a- /n. tjnofer- STS"fb9. per- Sa- f/ever mere then 3 ■40 fo 90 fbs Oepen den t en 7rac fi ve. e fforf and pr-ades 4o fo 90 /is p* a 9 . ,„ Confer of Serosa er&ow frr-Ouncf r^boutf *?€>' Fig. 130. — Tabular Comparison Between Caterpillar and Wheel Types of Traction Engines. Caterpillar Tread and the wheel form that they also manufacture. It is contended that the great bearing surface obtained by this construction ranges from 2,000 to 3,600 square inches, varying with the width of the track. Consequently the weight of the traction engine is so distributed that a pressure of but from four and one half to eight pounds per square inch is exerted against the ground which is much less than the pressure exerted by a horse. The distribution of the weight over such a great surface eliminates the possibility of the engine becoming The Modern Gas Tractor 308 The Modern Gas Tractor mired where the ground is wet and soft and the tractor cannot pack the soil and injure its fertility as much as other forms which concentrate a greater amount of weight on a lesser bearing surface. The wheel trucks are spring mounted and pivot on center in order to per- mit the tread or track to conform with the irregularities of the road bed. Thus the weight of the engine is carried on eight small truck wheels, four on each side, which are mounted on roller bearings to reduce the friction and which roll smoothly along on the track rails like the truck wheels of a railroad locomotive. The combined width of these rails is nine inches, which is equivalent to four ordinary sixty-pound railroad rails, two of which would have ample carrying power to support the entire weight of the Caterpi.lar tractor. Tractor Front Axles. — The function of the tractor front axle is more in directing the machine than in supporting much of the weight of the engine. Owing to the comparatively small diameter and width of the front wheels it is not desirable that they be called upon to take much weight. It is desirable to concentrate as much of the weight on the rear or traction members as is possible because the tractive efficiency depends upon the amount of force with which the driving mem- bers are held in contact with the ground. Then, again, if the front wheels of a tractor were called upon to carry much of the weight it would be difficult to control the engine when on soft ground. The type of front axle used will depend entirely upon the method of steering employed. It may be a one-piece axle like that of a carriage or wagon, supported by a ball and socket joint at the center which will permit it to swivel around when operated by the steering gear or move up and down under the influence of road irregularity. The Modern Gas Tractor 309 The front axles of many tractors follow automobile engineering principles and are built on the same plan as the Ackerman axle so widely used and practically universal on self-propelled road vehicles. -STEERING WHEEL F[G. 132.— Front View of L H. C. "Mogul" Gas Tractor Frame Showing Centrally Pivoted One Piece Axle. How Tractors are Steered. — The common methods of steering tractors when two front wheels are employed are clearly outlined at Fig. 131. At A the ordinary tight and loose chain and drum construction which has received wide application on road rollers and steam 310 The Modern Gas Tractor \ ACKERMAN TYPE FRONT AXLE. ELLIOT TYPE STEERING KNUCKLE Fig. 133. — Front View of I. H. C. Tractor Using Ackerman Type Front Axle With Elliot Pattern Steering Knuckles. traction engines is outlined. A drum is mounted across the two frame members and is operated by means of a worm and worm wheel. The chains, which run to the front axle pivoted at a central point, are so joined to the drum that when this is turned one chain winds The Modern Gas Tractor 311 up, while the other unwinds. Obviously the axle will be pulled along with the chain that is winding up and the axle and wheel assembly will assume a steering angle just as the front wheels of a horse-drawn vehicle do The method at B is by the Ackerman axle. The axle is a member fixed in one direction, i. e., it cannot swing around but can move only up and down or tip from side to side under the influence of hollows or mounds on the road or field surface. The wheels are mounted on small stub axles which are attached to steering knuckles adapted to swing in yokes carried at the extremities of the axle. Steering arms extend from each knuckle or steering spindle and are joined together by a tiebar so that one wheel cannot move without producing a corresponding movement of its neighbor. One of the steering knuckles is provided with two steering arms, one of which is attached to the tiebar, while the other is joined to the steering mechanism by a drag link. The reduction in practic- ally all cases between the handwheel and the steering members is by worm and sector gearing. The sector is fulcrumed so that it swings about a fixed point and the reciprocating motion of the steering arm the sector operates is transmitted to the steering knuckles by the drag link. The advantage of the type of steering gear shown at B is that it makes for more stable sup- port than the swinging front axle does and it is also operated more easily. The view at Fig. 132 is taken from the front end of a tractor running gear and clearly shows the appli- cation of the pivoted axle and the tight and loose chain steering gear. At Fig. 133 a heavy tractor front axle of the Ackerman type having Elliot pattern steering 312 The Modern Gas Tractor ^STEERING WHEEL STEERING , COLUMN DRAG LINK SINGLE WHEEL f0F? STEERING Fig. 134. — Front View of Three Wheel Hart-Parr Gas Tractor Frame Utilizing One Wheel for Steering Purposes. knuckles to which the wheels are attached is clearly depicted. In a number of cases the tractor frame is supported by three wheels, the member carried at The Modern Gas Tractor 313 Fig. 135.— Sectional View of Front Wheel of Hart-Parr Three Wheel Tractor Showiag Method of Supporting Steering Member. the front end being utilized for steering. A frame of this pattern is shown at Fig. 134, the wheel being op?rated through the usual form of steering wheel by means of reduction gearing and a drag link. 314 The Modern Gas Tractor The method of supporting a single front steering wheel is clearly shown at Fig. 135. The wheel has a large hub which is provided with a bearing surface on its inner periphery which runs on two bronze bushings carried by the steering knuckle. The wheel is supported by a cross member which is attached to a bearing in which the steering knuckle pivot pin is fastened. A steering arm is attached to the wheel core and moves the wheel to the angle desired for steering. Automatic Steering Arrangement. — In many cases it is desirable to provide means so that a tractor and plough outfit can be operated by one man without difficulty. This may be done in two ways. Either the steering or the operation of the machinery the tractor is hauling must be automatically arranged. In ploughing with the lever actuated types of engine ploughs the engine operator can attend to these if long furrows are being ploughed without difficulty if an automatic steering arrangement is used. A typical construction when applied to a tractor having a centrally pivoted one-piece axle is shown at Fig. 136, while another form, which is suitable for use when a front axle of the Ackerman type is utilized, is depicted at Fig. 136-A. The operation of these devices is not difficult to under- stand. As usually constructed a wheel is carried by a frame extending from the front axle which drops into the last furrow cut. If the furrow is moderately straight, this wheel will keep the tractor axle in proper position so that it can follow any slight deviations from a true course made in cutting the last furrow with- out any attention from the operator. At Fig. 136 it will be apparent that when a front wheel is carried at the extremity or apex of the triangu- lar support joining it to the axle, which forms the base, The Modern Gas Tractor 315 310 The Modern Gas Tractor any movement of the wheel will be transferred back to the front axle. An arrow carried at the end of a standard so that it can be conveniently glanced at by the operator from time to time serves as a direction indicator and a guide by which the course of the tractor or any deviation from a correct line of travel will be Fig. 136a. — The Cuddy Automatic Steering Device Applied to Aekerman Type Front Axle. readily ascertained. In the device shown at Fig. 136-A the action is somewhat similar to that previously de- scribed, except that two wheels are used and a system of leverage is employed to change the direction of The Modern Gas Tractor 317 Fig. 137. — Showing Important Members of Conventional Power Transmission System. 318 The Modern Gas Tractor movement of the main steering member on the front axle. Methods of Final Drive. — One of the important problems that the tractor designer is called upon to solve is that of power transmission from the motor to the rear wheels. It is imperative that this be ac- complished with as little loss of energy as possible because the power loss through friction of gearing is not available at the drawbar. Unfortunately, it is necessary to employ a large gear reduction between the engine and the tractor rear wheels and this can only be accomplished by using intermediate gearing, which is interposed between the bull gears on the wheels and the crankshaft of the motor. The efficiency of the transmission system depends largely upon the number of gears used, whether these are smoothly fin- ished or merely rough cast members and whether they are suitably protected from the abrading action of the dirt and grit present in field work. Well cut steel gearing, properly housed in a dust-proof and oil-tight casing can be kept lubricated and there- fore maintained to a high degree of efficiency. This is more easily accomplished with countershaft or in- termediate gearing than with the main bull pinions and gears. It is necessary in most constructions that these be exposed on account of the difficulty which obtains in incasing them properly. Several tractors are built, however, in which all gearing is protected from grit and kept running in a bath of lubricant Obviously the wear will be less on gearing of this nature. The Conventional Method. — The conventional ar- rangement of driving gearing with the various parts separated in order that their construction may be clearly ascertained is shown at Fig. 137. The power of the Tin: Modern Gas Tractor 319 engine is first directed to the cross shaft shown at A This is mounted on ball bearings of the annular pattern and carries at one extremity a large spur gear which meshes with a pinion on the engine crankshaft. A sliding member composed of two gears is adapted to be moved back and forth on this cross shaft by a Fig. 138. — Front View of Hackney Gas Tractor Which has Traction Members at Front End and Single Rear Wheel for Steering. gear shifting collar operated through a hand lever forming part of the control system. These sliding gears must turn with the cross shaft because they are kept from rotating ndependently of it by a substantial 320 The Modern Gas Tractor key which, however, does not limit their lateral motion. Immediately back of this cross shaft to which the power from the engine is first delivered, another countershaft assembly, which is depicted at B, is mounted. This is spaced in such a way that the sliding gears on the main shaft of the transmission may be moved to engage two gears bolted to the differential gear casing. When the largest gear on the cross shaft is in mesh with the smallest gear on the differential case a high speed is obtained while the engagement of the smaller gear on the cross shaft with the larger gear attached to the differential drum gives a reduction in speed. The ar- rangement of the differential gear interior is just the same as has been previously described, the balancing mechanism being of the bevel gear and pinion type. As is true of all differential cross shafts the right and left master pinions, which engage the bull gears on the rear wheels, are driven by independent shafts from the differential gears. The rear axle is of the usual dead pattern and is depicted at C. Large internal spur gears are attached to the wheel rims and are driven from the differential cross shaft by the master pinions. Use of Chains and Sprockets. — The driving method previously considered is that generally followed because with the large driving members used on gas tractors it is desirable to apply the power as near to the rim as possible. In some form of tractors the drive from the differential cross shaft to the traction members is by chains and sprockets such as are used widely in automobile engineering practice. This permits one to locate the differential gear cross shaft at any convenient point in the frame as the drive may be through chains of any length within reasonable limits. The view at Fig. 138 is that of the front end of the Hackney auto The Modern Gas Tractor 321 Fig. 139.— Rear View of Holt Caterpillar Tractor Showing Chain Drive to Traction Members From Cross Shaft. plough which is unconventional in construction inasmuch as the front wheels are employed as traction members while a single rear wheel is utilized for steering purposes. This method of drive makes it possible to place the engine directly over the wheels as shown at Fig. 13 (Chapter I) and carry the differential cross shaft at a point about mid-way on the frame. At Fig. 139 the driving chains which are utilized to take the power of the engine from the cross shaft mounted above the 322 The Modern Gas Tractor rear axle of the Holt Caterpillar Tractor to the track- laying sprockets are clearly outlined. Live Axle Forms. — One of the most popular types of axles used in automobile practice is termed "the full floating" live axle. In this construction the wheels are driven by means of shafts attached to them by some form of positive clutch while they themselves revolve on independent bearings carried by the housings which inclose the axle shaft. The differential gearing is always a part of an axle of this pattern and is mounted at the center in a case made to receive it and the shafts which drive the wheels are attached to the bevel dif- ferential gears in just the same manner as is employed on a differential cross shaft. This method of axle con- struction is not as satisfactory for tractor use as it is in its automobile applications, first, because it is difficult to obtain the desired gear reduction by the single pair of gears usually employed in driving the differential gear case, and second, because the power to turn the wheel is applied at its center instead of near the rim, which places severe torsional stresses or twisting strains on driving shafts when used in connection with large diameter wheels. A number of tractor manufacturers are experimenting with this form of axle but in order to use it have been forced to reduce the size of the driving members which makes this form of construction more suitable for combined motor trucks and tractors than for the regular pattern traction engines used generally in field work. The differential drum on the automobile live axle is usually driven by a pair of bevel gears, the desired reduction ratio of 23^ or 3 to 1 being easily obtained. In order to provide the low ratios of drive needed between the engine and the rear wheels of gas tractors The Modern Gas Tractor 323 it would not be possible to employ bevel gears carried directly in the differential housing. The use of worm gearing, however, enables the designer to employ but a single pair of reduction gears in the rear axle though a set of intermediate gearing is necessary to provide a partial reduction of speed before the power is directed to the worm gear of the axle. The construction of a worm gear driving assembly is clearly shown at Fig. 140. The worm gear is attached Single Row \Batl B ea ring \'\ :^XxN\ worm PTT. New Departure Double Row Ball Bearing Fig. 140. — Sectional View of Worm Drive Gearing Used in Connection With Live Rear Axle. to the differential casing and is revolved by means of the worm mounted above it and connected to the speed reducing cross shaft back of the engine. In order to reduce friction to a minimum the worm is mounted on New Departure ball bearings of the single and double row types. The end thrust of the worm is taken by a large double row bearing which is clamped to the shaft and housing in such a manner that it is restrained from lateral movement and is thus able to resist thrust in either direction and radially applied 324 The Modern Gas Tractor The Modern Gas Tractor 325 loads as well. The single row ball bearing of the con- ventional annular pattern has a floating outer race, i. e., that member can move back and forth to some extent should the worm shaft expand clue to heating while in operation. Gearing of this character is carried in an oil-tight container and as the differential casing may be filled with lubricant through the oil filler plug at the top of the case the gearing will run with minimum depreciation and maximum efficiency. The view at Fig. 141 is a section through half of a worm gear driven live axle. The differential assembly is mounted on large double row bearings which locate the worm gear accurately in the center of the driving worm, a condition necessary to secure efficient driving. The rear wheels are carried by two double row ball bearings the inner members of which are clamped to and supported by the tube or housing serving to inclose the driving alxe. The drive shaft turns the wheel by means of a positive clutch attached to the end of the axle shaft and fitting into suitable depressions in the interior periphery of the wheel hub. An advantage of this method of construction is that the differential gear and driving axles may be removed if necessary without taking off the wheels. Owing to the expense of building and the fact that this method of axle con- struction is not adapted for use with the extremely large diameter driving members ordinarily employed on gas tractors it is obvious that the systems of drive in which the power is applied to the rim of the wheel directly instead of through the medium of the spokes and hub will continue to be most popular and generally satis- factory. CHAPTER IX. DRIVING AND HOUSING THE TRACTION ENGINE. How to Start Traction Engines — How to Start Tractor — Typi- cal Tractor Control Systems — Advice on Tractor Opera- tion — Housing the Tractor — Combined Tractor House and Farm Workshop — Fuel Storage Methods — Tools and Equipment for Care of Tractor. How to Start Traction Engines. — As a rule before shipment from the factory, all of the reputable makes of gas tractors are thoroughly tested with and without load to make sure that all parts are functioning properly. This includes tests of the motor on the block, running the tractor on a special testing track around the works and after the machine has been in use for some time, determining the power capacity of the motor to ascertain if it approximates the standard established by means of a brake test and determining the tractive or pulling power by some form of dyna- mometer test. Therefore, the tractor purchaser receives a machine that has been carefully tested and that should start without difficulty if the proper steps are taken. The most important thing to do before endeavoring to start the engine is to see that the fuel and water containers are full and that all the electric wiring is properly connected. All mechanical oilers should be filled with the proper lubricant and if a constant level splash system is employed enough oil to insure thorough lubrication should be put into the crank case. The 326 The Modern Gas Tractor 327 open gears should be well covered with grease and all grease cups should be screwed down to make sure that all bearing surfaces fed by these members are receiving the proper supply of lubricant. Generally one or two quarts of oil will be sufficient in the crank case and nothing but the best cylinder oil should be used for this purpose. If there is too much oil in the engine, clouds of white smoke will issue from the exhaust pipe, so a certain amount can be drained from the engine case by means of petcock or drain plug provided for the purpose. In starting a new engine it would be well to remember that surplus oil will do no harm and that plenty of oil is much cheaper than repairs. When the engine is new and all bearing parts are still stiff, copious lubrication is one of the surest methods of obtaining a smooth running machine. Before attempting to start the engine one should become familiar with the various control levers pro- vided both for controlling the speed of the motor and for handling the various clutches. The first point to make sure about is that the master clutch handle is set in a neutral position, i. e., with the clutch released. This will disconnect the engine from the transmission and will permit the power plant to run independently of the rear wheels. The spark advance lever is placed in the full retarded or late position, the lever that con- trols the throttle of the carburetor is set so this member will open the throttle slightly and the engine may be primed by pouring a little gasoline in each of the cylin- ders through the priming cups or petcocks, if these are provided. The switch is placed on the side of the coil marked "battery" if a double ignition system is provided. The engine is turned over, either by means of a starting handle attached to the crankshaft or by 328 The Modern Gas Tractor rocking the flywheel on those types of tractors that are not provided with a starting crank. After the engine crankshaft has been turned over two or three times a sharp hiss will be heard at one of the priming cocks accompanied by a sheet of flame. The priming cocks are then closed and the engine crank- shaft is given a brisk turn until one of the pistons passes Fig. 142. — Side View of Morris Tractor Showing Operator's Platform and Control Levers. its compression and ignition point. The engine should start off at once if everything is right. After the power plant has started and is running at the proper speed, throw the switch lever to the side of the switch marked "magneto" but keep the throttle of the carburetor nearly closed until ready to start the tractor. This The Modern Gas Tractor 329 will prevent the engine from racing and the crankshaft will turn at a comparatively low speed. By referring to the view of the tractor shown at Fig. 142, the loca- tion of the operator's platform and control levers are easily determined. In this machine, it is necessary to start the engine by rocking the large flywheel or turn- ing it over until the pistons have drawn in a charge of gas and it has been compressed ready for ignition. Fig. 143. — Governors of the Centrifugal Type Form Important Part of Tractor Power Plant Control Svstem. While most tractor power plants are provided with automatic centrifugal governors, such as shown at Fig. 143, to keep the engine from racing even if the throttle lever is open, they are set so that the engine speed will be higher than is desirable when running light. These governors are made in two forms, the ?,:>() The Modern Gas Tractor type generally used being shown in illustration. The tractor power plant may be controlled by a throttling governor or by a hit and miss system which is employed when engines of the stationary type are utilized as power plants. The centrifugal governor is the most popular where the engine is supplied with gas by a carburetor provided with a throttle so that the amount of vapor supplied the cylinders may be regulated. The principle of the centrifuga governor is easily under- stood When the speed of the engine increases to a point where it is desirable to reduce it the weights attached to the governor arms fly out on account of centrifugal force and close the throttle, this slowing up the engine. The governor shown at A (Fig. 143) forms part of the mixing or vaporizing valve that supplies mixture to the cylinders. It is driven by means of a small, flat belt running from the engine crankshaft to a pulley on the governor. The power from the horizontal shaft is transmitted to the vertical revolving member that carries the governor weight and spring assembly by a pair of small miter gears. The governor shown at B is similar in construction, except that it is provided with a case, the cover of which is removed to outline construction of interior mechanism. The tendency of the weights to fly out is changed to a reciprocating motion of small plunger rod members which oscillate the shaft carried at the base of the casing to which the throttle lever is attached. This form of governor is driven directly by means of a bevel gearing carried inside of the engine base. In some tractors the control system is so arranged that the governor may be cut out at will and the power plant controlled solely by the throttle lever, if it is desired to augment the speed The Modern Gas Tractor 331 of the engine beyond that point to which the governor is set. As a rule it is not difficult to start a multiple cylinder engine by the hand starting crank provided, or by rocking the flywheel. In some cases where a one or two cylinder engine of large capacity is utilized it is difficult to start these by hand unless conditions are exceptionally favor- able. The difficulty usually encountered in setting in Fig. 144. — Small Engine Used to Start Large Power Plant of I. H. C. "Mogul" Tractor. motion a large engine, especially in cold weather, when the oil in the cylinder has congealed, is ingeniously overcome on the I. H. C. 45 horse-power Mogul tractor by providing a 1 horse-power engine of the air cooled type to turn the crankshaft of the power plant over. This little engine, which is illustrated at Fig. 144, relieves the operator of all labor of revolving the heavy fly- 332 The Modern Gas Tractor wheel by hand against partial compression that is neces- sary on some large tractors. This starting engine is a complete little power plant in itself and is equipped with its own gasoline tank and battery box. It is an air cooled motor of the four- cycle type with an inclosed crankcase. A jump spark ignition system composed of batteries and induction coil is provided while the gasoline tank holds one gallon and is mounted on brackets extending from the cylinder casting. A small friction wheel 43^ inches in diameter with a 5-inch face is keyed to the crankshaft extension. The engine crankcase is hinged on a shaft carried by a base casting while the cylinder is steadied by a rod attached to the engine base by an eccentric bearing. This can be operated by a hand lever so the cylinder may be tilted a short distance and the friction pulley brought to bear against the tractor engine flywheel outer periphery. The engine is clamped to the tractor frame with four quickly detachable fasteners and may be easily removed and used for other work around the farm if the tractor is not in use. When starting the larger engine, the first step is to throw in the compression relief cam of the main power plant so that the piston will be resisted by only partial compression. The small starting engine is put into operation and allowed to run free for a minute or two till it attains sufficient speed to develop full power. When this has been done, the lever rotating the eccentric bearing on the starting engine is pulled up till the friction pulley is pressed against the large engine fly- wheel. Owing to the difference in diameter between the flywheel and the small friction pulley the starting engine rotates the large crankshaft at sufficient speed for starting even if the large engine does not operate The Modern <1as Tractor :VM>> Fig. 145. — Rear View of I. H. C. Tractor Showing Control Levers and Operator's Platform. easily. When the large engine starts, the compression relief cam is thrown out so that the piston gets the benefit of full compression and the small starting engine is tilted back and stopped. How to Start Tractor. — After the engine has been started and has run long enough so that it is thoroughly warmed up and operating efficiently the next step is to start the traction engine itself. The type of trans- mission employed will determine the number of levers used to control the various speeds and forward and 334 The Modern Gas Tractor reverse motion. A one speed tractor will be much simpler to operate than a form having a two or three speed gear box. The control platform of a one speed tractor is shown at Fig. 145. It will be seen that there are two hand levers, a foot pedal and a hand wheel used to control the machine. One of the hand levers is used as a reverse member, while the other controls the master clutch. The hand wheel is utilized to move the front axle for steering purposes and the pedal applies the brake when it is desired to stop. If the tractor is to be run in a forward direction the reverse lever is set in the notch corresponding to the "go ahead" position. The master clutch has been dis- connected before the engine started and for this reason the reverse lever can be moved as desired without pro- ducing any movement of the tractor. The point should be emphasized that in no case should a reverse lever be moved without the master clutch being disengaged. When ready for the load, the throttle is opened and the spark lever is advanced, this allowing the engine to run at a speed where it will develop its power. The master clutch lever is then pushed forward or pulled back (depending upon the design) so the clutch is engaged very slowly and gradually. When the tractor has at- tained a certain amount of momentum, the clutch control lever may be pushed to its extreme "on" position after which it needs no further attention until it is desired to stop the tractor. The operator need only be con- cerned with directing the machine by means of the steering gear. If the machine is running too fast the engine speed may be reduced by closing the throttle, whereas if it is not running fast enough its speed may be augmented by opening the throttle and supplying more gas to the engine. The Modern Gas Tractor VSo To stop a tractor the first step is to close the throttle, throw out the clutch, retard the spark lever and apply the foot brake. If the stop is to be a lengthy one, the engine may be put out of operation by throwing off the ignition switch and closing the gasoline valve at the tank. The clutch lever should always be kept in the "off' position unless the reverse lever is provided Fig. 146. — Control Levers and Starting Crank of "Twin City 40" Gas Tractor. with a "neutral" notch, in which position it is not con- nected to either forward or reverse drive gears and then the master clutch may be let in if desired. It is not desirable to leave the clutch in if the tractor is to ::.".('» The Modern Gas Tractor make a stop of any moment because considerable strain may be present in the parts of the clutch actuating mechanism which had better be released. Typical Tractor Control Systems. — In order to enable the reader to understand the functions of the various control levers thoroughly a number of control systems of typical tractors are outlined at Figs. 146, 147 and 148. That at Fig. 146 forms part of the "Twin City 40" gas tractor. The lever A is used to set the gearing in either forward or reverse motion and when in the position shown is at a neutral point or between the two positions. The lever B is utilized to throw in and release the master clutch. The switch handle C is carried on the face of the induction coil and may be moved to the right or left to couple either battery or magneto to the ignition system. The throttle lever D is in the full open position when pulled back to the extreme limit of the quadrant. The spark lever E is in full retard position when thrown to the other ex- tremity of the quadrant, as indicated. A starting crank F is utilized to turn over the crankshaft of the motor. Steering is by hand wheel of the conventional pattern. The instructions given by the makers for operating this tractor follow: To Start Motor: 1. — Fill priming cups on top of motor with gasoline. Open petcocks and allow the gasoline to flow into the cylinders. If motor is very cold two or three injections of fuel may be required, while if motor is very warm, very little gasoline and often no priming is necessary. 2. — Close priming cocks and open relief cocks on side of motor. 3. — Referring to Fig. 146, use the following directions for starting motor and engaging traction: Place lever A The Modern Gas Tractor 337 in the central notch of the quadrant, throw in the clutch with lever B which is done by pushing it forward. Re- tard the ignition spark by throwing lever E forward as shown in the illustration. Open the throttle by moving lever D backward, as indicated. Throw the switch lever C in contact with point marked "B" for batteries. Turn over engine crankshaft with starting handle F. As soon as the motor starts close the relief cocks, throw out the clutch with lever B and stop the clutch shaft by bearing down on the brake pedal Q. Throw the switch lever C onto side of switch marked "M" which is the magneto side and advance the spark with lever E by pulling it backward. To Engage Traction: For traveling forward move the lever A into rear notch of the quadrant; for reverse motion push it forward into the other notch. Never move lever A when clutch is running at high speed. If this lever cannot be moved from neutral to either side readily, revolve the clutch shaft very slowly by barely engaging ever B and keep one foot on brake pedal Q to prevent rapid movement of clutch. Always engage lever B gradually, as engaging the master clutch too quickly will stall the motor or impose severe strains in the driving gears. A gas tractor is a heavy mass of metal and should be put in motion very slowly, the clutch being allowed to slip until sufficient momentum has been attained so that clutch may be fully engaged without shock. Control speed by spark and throttle levers. The control system outlined at Fig. 147 is utilized on the Holt Caterpillar tractor and the same instruc- tions for starting the engine previously given will apply in this case as well. The engine speed is regulated by the usual form of spark and throttle levers mounted 838 The Modern Gas Tractor on a quadrant, just forward of the steering wheel. Four clutch levers are provided. The one nearest the steering wheel is used to throw the master clutch in the engine flywheel on or off as desired. A reverse lever which can be set at either neutral position as indicated or for forward or reverse motion is provided Fig. 147. — Control System of Holt Caterpillar Tractor Showing Important Elements. convenient to the operator and back of the master clutch lever. The other two hand levers, which are placed alongside of the master clutch control lever, are utilized The Modern Gas Tractor 339 Speed change operating lever. Also disengages the traction Timer and throttle Clutch operating leuer. One only for threshing and field work. /Steering wheel. -Operator's seat. -Reverse lever. Draw bar, showing adjustable hook-up clamps. Fig. 148. — Operator's Cab of Pioneer Gas Tractor Wit It Important Parts of Control System Indicated. to operate clutches necessary for steering with a Cater- pillar Tread. Steering the tractor is accomplished by releasing the friction clutch which drives the caterpillar traction member that is on the inside of the circle when making 340 The Modern Gas Tractor a turn, in connection with the usual form of hand wheel. With this form of traction member, steering by the front wheel accomplishes but little unless the steering clutch is disengaged to correspond with the direction one wishes to turn. After disengaging the inside friction lever the degree of turning depends on the angle of the front wheel. The mode of procedure in steering around a corner is as follows: When about to make a turn, disengage the clutch lever that controls the friction clutch driving the traction member that is to be on the inside of the circle first, then turn the front wheel and as the curve is made straighten the front wheel and engage the friction clutch that has been released when the tractor is again headed in a straight line The control of this form of tractor is not radically different from the wheel form except that care must be taken to always release one of the steering clutches to provide a certain differential action as no differential gear is fitted. The control group, which is inside of the operator's cab of the Pioneer gas tractor, is outlined at Fig. 148. In this, the motor speed is regulated by the usual spark and throttle levers mounted on a quadrant forward of the steering wheel. Three hand levers are provided. One is the reverse lever, operating on a notched segment, so that it may be set either in neutral, forward or reverse positions. The other large lever provided with a latch is a clutch operating lever while the changes of speed are obtained by moving a third hand lever which shifts the sliding gears of the gearset. Steering is by the conventional form of hand wheel. This tractor is dis- tinctive in that the cab is entirely inclosed to protect the operator from the elements and that a comfortable upholstered seat is provided for him. The general The Modern Gas Tractor 341 rules that have been given for the control of other tractors apply just as well to this machine. Advice on Tractor Operation. — The operation of a gas tractor will not prove difficult to an engineer familiar with steam tractor operation or to one who is familiar with automobile driving. The main point to remember is that the tractor may be stopped im- mediately by disengaging the master clutch and applying the brakes. One who has never controlled a heavy machine of this character will first have to become familiar with operation of the steering mechanism. An automobile is provided with a steering gear that is quick to act and one and a half turns of the steering wheelis all that is necessary to turn the wheels from one extreme position to the other. This sensitiveness is necessary on account of the high speed automobiles are capable of. With a tractor conditions are different, the speed is low and considerable weight is supported by the front wheels. This means that a greater number of turns of the hand wheel will be required to steer a tractor than will be needed to direct a motor car. This is necessary because less effort is required from the operator on account of the lower ratio on the worm reduction gearing, and as the tractor is traveling at a compara- tively low speed the operator has ample time to turn the hand wheel any number of times that may be desired to insure movement of the front wheels. Most tractors are provided with a crank or small handle extending from the rim of the steering wheel so that this member may be revolved at a higher rate of speed than would be possible if it were grasped around the rim. The tractor operator should always be careful when operating on highways to avoid hollows or soft ground and mudholes should always be passed by making a 342 The Modern Gas Tractor detour instead of steering the heavy machine recklessly- through them. Care should be taken in passing over bridges to make sure that these are of ample strength as many flimsily built wooden structures have failed under the great weight of the tractor for which they were never designed. If the tractor becomes mired and the differential lock is not available pieces of plank, brush, straw or anything that will help traction may be put under the driving wheels. If one wheel is on dry land a tractor will often free itself provided that the differential gear is temporarily put out of commis- sion. This can easily be done on most tractors by bolt- ing a lever carried by the revolving axle shaft to the wheel hub that normally revolves free around it when the differential gear is in operation. This insures that both wheels will turn with the axle and the wheel that is on dry land will provide traction enough to move the machine under these conditions. If the differential gear were in operation the traction member that was in the mudhole and which had the least adhesion with the ground would just spin around, whereas the other member would remain stationary. On two and three speed tractors the operator should always use that ratio best suited for the work the tractor is doing. In getting from place to place over the roads and for hauling light loads the highest speed of a three speed tractor, which is about six miles an hour, can be used. For hauling heavier loads over the highways the medium speed, which is about three and one-half or four miles per hour, will give the best results. For drawbar work where considerable power is needed the lowest gear ratio, which is seldom over two miles per hour, should be used The tractor should not be operated on the low gear except when conditions demand The Modern Gas Tractor 348 it and if the load is light it is preferable to run on one of the higher gears and throttle the engine down than it is to run on a low gear ratio and run the engine at full speed. When operating a tractor over hard roads, especially those of the macadamized variety, the operator owes it to the public to remove the grouters, traction points or mud lugs from the rear wheels and run on the smooth steel tire. The use of grouters cuts up a road too much, whereas running with steel tires will offer enough ad- hesion to secure traction on a hard road and at the same time the road is benefited by the rolling action of the large wheels, rather than being cut up as is the case when the projections ordinarily fitted to increase trac- tion in the field are fitted. Housing the Tractor. — The average farmer is apt to be negligent in providing suitable quarters in which the various farm machines may be stored. It is a com- mon sight to travelers on trains leaving the East for the Middle West to find costly agricultural machinery out in the open fields alongside of the tracks. If this was confined to but one section of the country it would be reasonable to assume that the failing was not a common one, but the observant traveler, especially if he has economical instincts and is familiar with machinery, will note practically the same condition existing in all States through which he passes. In one field a mowing machine will be seen half mired in a swamp with its vital parts rusting away. In another case it may be only a plough or hay rake or a toothed harrow, but nevertheless, these less expensive machines are wholly without protection and are covered with rust. This sort of treatment means that machines which should have a normal working life of from five to ten years, 344 The Modern Gas Tractor depreciate so rapidly that a perpetual mortgage must be kept on the farm in an endeavor to supply the new machines which are needed very often. Exposure to the elements is not good for any form of machinery composed of wood and metal. The wood will rot while the metal portions oxidize away and all bearing points and moving parts become so clogged with rust that when the machine is put in service again considerable time is needed to place in a condition where it will be able to do any kind of work. In several cases the writer has observed traction engines hauled up alongside of some decrepit shed or out-house and covered with a tattered old piece of canvas or banked half way up in a snow drift. Of course, it is generally known that the running gear portions of a traction engine are not very sensitive but this does not mean that a tractor should not be given that protection from the elements that is so necessary to secure maximum service and minimum depreciation. Even the cheapest tractors represent an investment of $1,000 or more and it is not reasonable of the farmer to expect good service from a machine which he leaves exposed to all conditions of wind and weather. An old awning or tent cover or a lot of old bagging is not sufficient protection for a piece of machinery that is as costly as a tractor. Even the poorest farmer will take the proper steps to protect his live stock and in many cases these are housed in more pretentious quarters than he and his family share. It is not necessary that the tractor house should be an expensively constructed or ornate structure but it is imperative that it be sub- stantial and weather proof. Very satisfactory houses may be erected for a few hundred dollars that will insure adequate protection to the tractor. The Modern Gas Tractor 345 ~*l o If o sai/c/dng S-H- 34(5 The Modern Gas Tractor The farmer about to build a house for his tractor must choose between several different types of construction and in addition to local conditions he must be governed in this selection by proper consideration of cost, safety, durability and fire protection. The tractor house may be of simple frame construction, consisting of ordinary odds and ends of lumber and old planks from some demolished barn or shed as the cheapest example to the more expensive but substantial houses made of new lumber. The shed may be an all steel structure with studding composed of various light structural iron shapes, such as angles, tees, or channels covered with corrugated sheet iron. Of late there is considerable attention being paid to concrete construction and if the farmer has a gravel bank on his land this will make the most satis- factory form of building. In considering the cheaper types of frame construc- tion for tractor houses, these may be neglected as un- suitable for permanent installation because of lack of durability and an undesirable fire risk which should be given careful consideration if one intends to use the power plant of the tractor as stationary engine during the time that the tractor is not in use in the field. A steel construction, while very efficient and satisfactory, is usually so great in first cost that this will generally prohibit its use for the ordinary tractor house. Rein- forced concrete, through the reduction in price of first- class Portland cement and the development of very satisfactory and economical mixtures, has been receiving considerable attention because a very substantial build- ing may be erected at low cost and in a comparatively short space of time. A building of this nature is free from vibration, does not require repairs or renewal, and offers the maximum The Modern Gas Tractor 348 The Modern (J as Tractor fire protection. The exact cost of a building in any case is governed by local conditions. In considering wood construction one should remember that skilled laborers are required to do a really satisfactory job, though very substantial stiuctures have been erected by the farmer and his help without the assistance of a highly paid carpenter. In making a building of con- crete one must consider the price of cement, the cost of obtaining suitable sand, broken stone or gravel, the price of lumber for forms and the wages of laborers. As concrete is largely laid by the cheapest kind of labor the high rates necessary to pay for the skilled laborers needed with wood or steel construction can be eliminated. In designing the tractor house, assuming that one has to be built specially for it, one should make provision to build a structure enough larger than absolutely needed to shelter the tractor so a small work bench may be provided and also ample storage space for the various supplies and spare parts needed to insure continual operation of any piece of machinery. If buildings are already available one should be careful to select a struc- ture which has no cellar because the average floor of a barn or stable is not strong enough to support the great weight of a traction engine which ranges from four tons for a 12 horse-power type to fifteen tons for the 45 and 60 horse-power forms. Care should always be taken when a building with a basement is used that the floor is well shored up by additional posts and strengthened by additional heavy planking to bear the excess strain for which it was not originally calculated. The size of the building depends largely upon the size of the tractor that is to be housed. A traction engine will vary in width from 7 feet 6 inches to 10 feet, and as it is desirable to have space on all sides, The Modern 7 design, which should not prove costly, is shown at Fig. 152. In this the fuel is stored in a large tank buried underground outside of the garage or tractor house, while a hand operated pump of the suction type is inside the shelter and protected from the elements. At Fig. 152-A an underground gasoline storage outfit which can be installed at low cost and made by any one of average mechanical intelligence is outlined. This consists of an air-tight copper or steel tank, well coated with asphaltum paint, preferably, though a galvanized iron container can be used if desired. The construction should be such that the tank will resist air pressures up to 40 or 50 pounds per square inch. Three spuds are placed in the top of the tank, one to take two-inch standard iron pipe, the others to fit one-half and one-eighth gas pipe respectively. A two-inch pipe cap, to which a piece of one-half by one-quarter inch bar stock is attached by machine screws or rivets, is used for a filler cap at the end of the piece of large pipe. This is cut of sufficient length so that the tank can be buried underground below frost line and still leave four or five inches of pipe projecting above the surface after the hole in which the tank was placed is filled. A special reducing fitting is made to fit the spud, tapped one-half inch pipe size, this to take a piece of one-quarter inch pipe, which extends to about an inch from the bottom of the tank and projects above the surface of the reducing bushing. A standard ell is then screwed in place and the piping continued as shown in sketch. A piece of one-eighth gas pipe runs from the other spud to a T piece from which a branch extends to an air pressure gauge, and in which is placed a short piece of pipe having a ball check fitting 358 The Modern Gas Tractor or the usual universal tire valve. At the end of the one-quarter inch pipe, which runs up inside the motor house, is placed a ground shut-off fitting, to which a piece of rubber hose ten or twelve feet long is attached. It is advisable to make both the one-quarter and one- eighth inch pipe lines of brass, and to solder all joints Fig. 152b. — Bowser Underground Fuel Storage System for Automobiles or Tractors. as they are made, to insure absolute tightness at all points and eliminate all possibilities of leakage. The small petcock placed below the valve fitting is to be closed except when it is desired to take a gauge The Modern Gas Tractor 359 reading or when an ordinary foot pump is coupled to the valve to compress more air in the tank. This fitting when closed prevents leakage of air through the check valve, which might result if this was depended upon to retain the compressed air in the container. The handle on the filler cap is convenient in filling the container as it provides leverage and makes easy the removal of the cap from the pipe. This may be protected by a strong wooden box, with a hinged cover, provided with a hasp and padlock to prevent tampering with the contents. The tank may be of any desired capacity, but one holding about 200 gal- lons will answer the requirements of the average tractor operator. The filler cap should seat against a piece of soft packing to insure an air tight joint on the fill- ing pipe. The tank should be placed as close to the wall of the tractor house as possible to simplify piping. After the container is filled with fuel to about seven- eighths its capacity to leave an air space, an ordinary foot pump is coupled to the air valve in the pressure pipe and air supplied to the tank until the gauge indi- cates a pressure of 15 or 20 pounds a square inch on top of the liquid. In filling a tractor tank, it is merely necessary to place the end of the rubber hose in the tank opening and turn on the supply, and after suffi- cient fuel is drawn the shut-off fitting may be closed. As the supply of gasoline becomes less, more air should be forced into the main container. The installation is not costly, and the material needed, with the possible exception of the tank, can be obtained in almost any town or village, and its simplicity and utility will be appreciated by the practical farmer. All fittings are indicated in the drawing and there should be no diffi- culty in assembling the outfit. 3G0 The Modern Gas Tractor Tools and Equipment for Care of Tractor. — The farmer who intends to take care of this own tractor or one who has several of these machines will find need for a number of tools of a slightly different character from those generally used in repairing farm implements. A set of small tools most likely to be used should be carried on every tractor, as often repairs of a minor nature must be made in the field. In the illustration 'Fig. 153) a comprehensive outfit of small tools and devices that will be found especially valuable in making repairs for the tractor engines or transmission system are outlined. The tool roll contains an assortment of tools that are more generally used and is a modified form of the tool kit generally supplied for automobile repairing. The only difference between the tools is that these are larger and more substantial in order to handle the more rugged parts of the tractor mechanism. The tool roll shown contains all necessary wrenches, pliers, screw drivers, punches, drift pins, chisels and files, as well as miscellaneous supplies necessary to make ordinary repairs. r In addition to the tools outlined a small bench vise that can be attached to the step or tool box cover of the tractor will be found of considerable value. The large file assortment may be kept at the workshop for use in making more extended repairs. This is true also of the carbon scrapers, the valve spring lifter and the hand drill. The hacksaw, hand vise and tinner's snips occupy but little room and can be conveniently stored away in the tractor tool box. The blow torch will be found very desirable in providing a source of heat for the soldering iron and for loosening rusted on nuts and for many other purposes that will suggest themselves. Among the general supplies that should be included The Modern Gas Tractor 361 302 The Modern Gas Tractor in the equipment are spare spark plugs for the motor, a few feet of primary and secondary electric wire, ma- terial to make the various gaskets and packings used on the engine, a quantity of cotton waste or old rags, an emergency supply of cylinder oil for the lubricator and hard grease for the grease cups. The other sup- plies or spare parts needed will vary with the type of tractor and the distance it is to be operated from a base of supply. The writer has made mention of the fact that an out- fit of blacksmith's tools may be obtained at relatively small cost. As these enter largely into the care of the tractor and auxiliary appliances it may be pertinent to enumerate the contents of a complete blacksmith's outfit which is illustrated at Fig. 154 and which, can be purchased for $35 to $40. This consists of a 60- pound anvil with tool steel face; a 35-pound wrought iron blacksmith's vise; a portable lever forge, provided with a compact blower for supplying draft, and a two- speed self-feed post drill which takes up to half inch round shank drills and will drill to the center of a twelve- inch circle. The miscellaneous small tools include a die stock and dies, a set of standard taps, one hot cutter, one cold cutter, a hardie, a pair of flat-lip tongs, one pair of pincers, one farrier's knife, seven drill bits, one farrier's hammer, one hand hammer and a monkey wrench. A few other tools, such as a medium weight sledge hammer, a more complete assortment of tongs, two or three rasps, a set of heavy files, and an assortment of standard bolts and nuts, as well as blanks which may be threaded as required, will be found valuable. The stock needed may be purchased at small cost and will include various sizes of round, flat and square bar The Modern Gas Tractor 363 3(i4 The Modern Gas Tractor iron and steel. All the odds and ends of iron or steel, as well as cast-off bolts, tie-bars, turn buckles, iron hoops, etc., that ordinarily go to waste, may be picked up and put in a stock box with the assurance that they will be found useful at some future date. No workshop will be complete without a set of wood working tools and very fortunately a very practical outfit can be purchased at comparatively small cost. Fig. 155. — Complete Set of Carpenter's Tools a Useful Addi- tion to Farm Repair Shop Equipment. Wood working tools are not only necessary in the farm workshop but are of obvious utility in making repairs incidental to the upkeep of buildings, fences, and the erection of new structures. A very convenient outfit for use around the farm or shop is shown at Fig. 155 The Modern Gas Tractor :!i>.~> and can be purchased for .$12 to $15. It consists of the following tools: One 22" hand saw, one 6" try square, one 2' rule, one pair 5J^" combination pliers, one 10" bit brace, four auger bits, one each size ^", Vi' M"> and 1"; five gimlet bits, one steel hammer, one 8" draw knife, one double cutter spoke shave, one 5" steel blade screw driver, two socket chisels, one jack plane, one 5%" iron block plane and a carpenter's pencil. A plumb bob and chalk line, nail set, level and a large steel square can be purchased to complete this outfit at slight added expense. The hardware necessary, such as nails, screws, staples, locks, hinges, etc., can be purchased as required and soon enough of these supplies are left over when purchases are made from time to time so a very useful stock of miscellaneous small hard- ware accumulates without its cost being so apparent as would be the case if everything that was thought desirable was purchased outright. CHAPTER X. TRACTION ENGINE TROUBLES AND ELIMINATION. Location of Defects and Remedies — Loss of Power — Poor Compression — Carbon Deposits — Valve Grinding — Timing Valves — Care of Piston and Rings — Noisy Operation — Adjusting Bearings — Mixture Troubles — Ignition System Derangements — Cooling and Lubrication Group Faults — Running Gear Derangements— Tractor Hitches — Utility and Uses of Modern Gas Tractor — Homemade Gas Trac- tors — Auto Tractor Attachment — Future Possibilities. Location of Defects, and Remedies. — The de- rangements that interfere with satisfactory tractor opera- tion may exist in either the tractor power plant which includes the engine and auxiliary groups or in the running gear assembly in which the clutches, transmis- sion, driving and differential gearing, as well as frame, wheels and axles are included. The troubles with the power plant are the most difficult to detect because there are a number of different conditions that may produce the same symptoms. Running gear faults, as a rule, are easily located because they are usually due to some loose or damaged part that may be easily noticed on inspection. One who is familiar with mechanical construction and practical operation of tractors will have no difficulty in tracing common motor troubles to their source, but while the expert readily recognizes the symptoms which show derangement of the various power plant components 366 The Modern Gas Tractor 367 the average farmer or tractor operator is apt to waste a lot of time and energy in trying to locate trouble unless he does so by a systematic search for defects. The internal combustion motor or gas engine, which is utilized as a power plant on practically all gas tractors and which is clearly shown in Figs. 156 and 157, is composed of a number of distinct groups which have been previously described in detail. These various Fig. 156. — Power Plant of Phoenix Tractor Showing Water Pump. Governor Assembly and Ignition Magneto. auxiliary devices are closely related to each other and defective operation of any one of these may seriously affect the power plant or stop it altogether. The careful tractor driver will always inspect the motor and other points of the mechanism liable to de- 3GS The Modern Gas Tractor rangement before starting on a run of any consequence, and if inspection is carried out in a systematic manner and any loose nuts, wires or other fastenings are given attention it is seldom that irregular operation will be due to any broken parts. The natural wear and the depreciation which it causes occur slowly and when parts begin to deteriorate sufficient warning is always given Fig. 157.— Valve Side of Phoenix Four Cylinder Tractor Motor Showing Crankcase Inspection Plates, Inlet and Exhaust Manifolds and Carburetor. so that repairs may be made promptly, and thus serious derangement is prevented. The main troubles with the power plant are loss of power, irregular action, overheating, and noisy opera- tion. The first usually denotes some fault in the piston The Modern Gas Tractor 369 rings or valves of the engine and is due primarily to poor compression. Irregular operation, which is the condition that exists when cylinders do not fire regu- larly, is nearly always the result of defects in the gas supply system or the ignition appliances. Overheating invariably denotes inadequate lubrication or failure of the ccoling system. Noisy operation can always be accepted as a condition due to mechanical wear. Fig. 158. — Side View of Bates Gas Tractor Showing Accessi- bility of Power Plant When Automobile Type Motor Hood is Raised. Loss of Power. — While loss of power is usually a condition that can be ascribed to poor compression it will result indirectly if any of the other faults are evident. Obviously, if an engine is missing explosions and is not firing regularly its power will be reduced materially and thus the condition of ''skipping" or "missing fire" as it is called will produce loss of power indirectly. If 370 The Modern Gas Tractor the engine is overheated so the various parts are running with considerable friction there will be a loss of power because of the increased internal load in the motor itself. Overheating may be directly caused by failure of the oil supply in which case the coasequences are apt to be serious unless the motor is stopped as soon as this defect is apparent. Troubles with the cooling system are easily determined by the steam which issues from the radiator or cooling tank. Fig. 1.58 a. -^Showing Accessibility, of Power Plant on Holt Caterpillar Tractor. Tractor power plants are generally housed in an accessible manner, if they are under a hood or bonnet, as outlined at Fig. 158, or may be easily reached as ordinarily mounted in unprotected positions on the tractor frame. The power plant shown at Fig. 159 has been photographed in position on the frame with other parts removed in order to show clearly the method of placing a typical tractor motor and the auxiliary devices The Modern Gas Tractor 371 upon which its operation depends. The location and method of drive of the magneto which forms the igni- tion system and that of the mechanical oiler, which supplies the engine with lubricant, is clearly outlined. The valve springs are placed at the top of the cylinders and are easily reached when it is desired to relieve the valves of their tension so that these members may be ground. The centrifugal governor and the linkage by which it controls the throttle valve are also clearly outlined. Attention is called to the inspection plates on top of the engine base through which the interior portions of the crank case may be easily inspected. These plates are readily detachable by loosening a bolt that holds them in place by a clamp bar, the ends of which bear on the center portion of two plates. If it is desired to remove the cylinders, the first step is to take off the exhaust and intake manifolds, then the cylinder pair may be pulled off of the engine base by removing the nuts that hold it in place. The valves may be ground without removing the cylinders, and in fact all working parts of this motor may be reached without taking the lower portions of the crank case or engine bed from its position on the tractor frame. If adjustments are necessary to the bearings of thecrank shaft, the top half of the diagonally divided crank case may be removed without difficulty by loosening a few oil pipes and the connecting link between the governor and the throttle chamber. When this top plate is removed the entire interior of the crank case, including the cam shaft, is open for inspection. The point of accessibility is one that is given special prominence in the design of tractor power plants, much more so than is the case in the small gas engines used for automobile propulsion. This is on account of the 372 The Modern Gas Tractor large size cf the tractor engine parts and the difficulty which obtains in handling them without proper facili- ties. As an example of a construction that permits maxi- mum accessibility, the illustration at Fig. 160 is pre- sented. This shows a workman removing the piston from the interior of a gas tractor cylinder without removing the latter from the engine base or taking the engine bed from its position on the tractor frame. EXHAUST FIPE5 THROTTLE CilAMftEff MAGNETO i • ^ {jl/FLYBALL GOVERNOR 1 NT nnfflft MECHANICAL ' ** ^ B OILER INSPECTION PLATE Fig. 159. — Power Plant of "Twin City 25" Gas Tractor Show- ing Accessibility of Auxiliary Parts. Valves and Valve Springs and Crankcase Interior Inspection Plates. Most traction engine designers endeavor to have all parts accessible as this is one of the first things that the experienced tractioneer looks for when purchasing a new machine. A breakdown in the field is not always serious if the parts can be readily reached, but at the other hand, it The Modern Gas Tractor 373 may mean the expenditure of considerable time and money if the entire engine has to be dismantled every time the interior mechanism is out of order. There are some automobile engines where it is practically im- possible to reach the pistons without taking the cylinders off of the engine bed and where the entire engine must be taken apart to get at the main bearings of the crank- shaft or the bushings in the big ends of the connecting Fig. 160. — Showing How a Piston of Gas Traction "Big Four" Engine May be Removed From Cylinder to Inspect Rings and Remove Carbon Deposits From Piston Top. rods. This is not tolerated by the expert gas tractor operator, and the factor of accessibility of components alone may make or prevent the sale of a machine. Poor Compression. — If the engine is losing power and the power loss is not accompanied by skipping, 374 The Modern Gas Tractor overheating, or noisy operation, it is due to poor com- pression. This results from conditions inside or outside of the cylinders that will allow leakage of gas from the interior. Gas may escape through defective valve operation caused by the valves not seating properly or being out of time. If the valve system is all right the trouble is generally due to faulty piston rings or worn or scored cylinders. The method of testing for poor compression is simple, consisting of cranking the engine without the ignition system being turned on and with compression relief cocks closed. If the engine turns over easily and no appreciable resistance is felt, it is invariably due to a loss of gas from one or more of the cylinders. If it is a multiple cylinder engine the defective member may be easily determined by cranking over the motor with all of the compression cocks, except one, open. Each cylinder is tested in turn and the thing to remember is to keep the com- pression cock in the cylinder that is to be tested closed, while the others are left open so that the engine can be turned with minimum resistance. The cylinders that have good compression will offer a decided resistance to turning the crankshaft, while those in wh'ch compres- sion is weak will permit one to turn the crank very easily. If compression is poor the first thing to do is to inspect the external parts which may be easily reached. This means looking for a leak at valve chamber caps, spark plug gasket, or blown packing between cylinder and cylinder head, if that construction is employed. Other causes are broken valve springs, sticking or bent valve stems, valve plunger stuck in guide, loss of clearance between valve stem end and top of valve operating plunger (usually caused by loose adjusting screw which has worked up and kept the valve from seating) or a The Modern Gas Tractor 375 defective priming cock. Some of the defects of the internal parts which may be looked for are a broken valve, a warped valve head, dirt under valve head, which prevents valve from seating, burnt or pitted valve seat or valve head, cracked piston head or cylinder (rarely occurs), broken piston rings, piston ring slots in line, loss of piston ring elasticity or spring, or piston rings gummed in the piston grooves. The piston and cylinder walls may be badly scored by defective lubri- cation or a deep groove may have been cut in the cylin- der by a loose wrist pin which allows the gas to blow by very easily. Carbon Deposits. — One of the fertile causes of general motor inefficiency and one which often con- tributes to loss of power, as well as noisy operation, is the deposit of carbon that accumulates in the com- bustion chamber. These deposits result from burnt cylinder oil and sometimes from excessively rich mixture, and are more apt to exist on motors operating on low grade fuel such as kerosene or distillate, than in gasoline engines where combustion is more perfect. These deposits accumulate on the piston top and in the in- terior of the combustion head and valve chamber. They interfere with correct valve operation by gumming up the valves and prevent a full charge from reaching the motor, as well as retarding the prompt expulsion of burnt gases by building up around the valves. The deposits in the cylinder head may cause trouble owing to some projecting particle remaining incandes- cent from the heat of a previous explos'on and firing the fresh charge prematurely. Carbon deposits always produce loss of power, but their presence is usually clearly indicated by a pronounced knocking or pounding noise. The only remedy for this defective condition ;>7(i The Modern Gas Tractor is to remove them from the engine interior. This is done by scraping away the material with small hoe- form steel scrapers that may be Inserted through the holes left when the valve chamber caps are removed or by removing the cylinder head if the construction permits. This is one of the marked advantages of the detachable head design. The head may be removed without disturbing the rest of the motor and the de- posits of carbonaceous substance may be scraped from both cylinder head and piston. If the deposits are of long standing it wi'l be necessary to dismantle the motor in order to reach them and secure their positive removal. This accumulation may be prevented by careful super- vision of the amount of oil supplied the motor, making sure that it is never in excess of the actual requirements, using only the best grades of cylinder oil having a high fire test, and by careful regulation of the mixture to insure that the fuel and air proportions will be those that will burn without leaving a residue. These deposits may be reduced to some extent by injecting three or four tablespoonfulls of kerosene into the cylinders at the end of a day's run, through the priming cocks. This softens the deposit which has ac- cumulated during the day and when the engine is started up the next mormng the dissolved carbon will be ejected through the exhaust as it will be carried out by the burnt gases. The soft deposit is not difficult to cope with, and in fact, various chemical carbon removers are advertised quite extensively which will remove it without making it necessary to take the motor apart, provided the accumulations are not of too long stand- ing. The hard, thoroughly baked on carbon can only be removed by mechanical means. Valve Grinding. — The most common cause of lost The Modern Gas Tractor ::tt compression is leaky valves, and this condition material- izes on even the best constructed traction engine. This is one point that requires periodical attention, and as a rule the first thing done, if the engine lacks power, is to grind in the valves to a new seating. The inlet valves do not need grinding as often as the exhausts do, but they are generally refitted at the same time that the exhaust members are ground to a new seat. When a valve needs grinding the defective conditions that make this necessary are apparent at a glance. Fig. 161. — How Valve Spring and Valve May be Removed From Gas Tractor Engine Cylinder. The first step when valves are suspected is to remove them from the cylinder. The method of doing this is clearly outlined at Fig. 161. It is necessary to release the valve spring pressure sufficiently so the key which keeps the collar against the lower end of the valve spring- in place may be withdrawn from the valve stem. The method of doing this is shown at A. The first opera- tion is to remove the valve cap, then the manifolds may be taken from the motor. The valve head is then kept 378 The Modern Gas Tractor in place by pressing down on it with a screw driver and the valve spring is raised either by means of a special valve spring lifter or by using an end or S wrench or any other fork form tool that will raise the valve spring without touching the valve stem. After the pin or key is withdrawn from the valve stem, the valve may be easily lifted from the cylinder, as shown at Fig. 161-B. The method of valve grinding is simple and one way of accomp- lishing this is shown at Fig. 162. Befcre the valve is replaced in the cylinder the stem is thoroughly cleaned by means of emery cloth and all gummed oil is cleaned out of the valve stem guides. A light spring is placed between the valve head and the end of the valve stem guide in order to raise it from its seat when pressure on the grind- ing tool is relieved. VALVE SEAT MOTE. LIGHT SPRING. FOR LIFTING VALVE OFF SEAT WHEN 6,»IN0INC Fig. 162.— Method of Using Bit Brace and Screwdriver Bit in Grinding Valves. Special and somewhat costly valve grinding tools have been devised, and while these members are thoroughly practi- cal, a very efficient and satisfactory appliance, which is almost universally used, is the ordinary bit brace. A screwdriver bit is made to turn the valve, provided that the head is properly slotted to receive this form The Modern Gas Tractor :!7!) of tool. Sometimes the valve head is provided with two holes, and is then turned by a simple forked tool, which may be easily hammered up to shape so it will fit the bit stock. The faces of the valve and the valve seat are smeared with a mixture of emery and oil made into a thick paste. If the valve surfaces are deeply scored or pitted it will be necessary to start grinding with a medium grade emery. In grinding only sufficient pressure to keep the valve against the seat is used and this is relieved from time to time in order that the valve may be lifted from its seat by the coil spring beneath it. Valves are not ground with a continuous rotary motion. The oscillating motion that would result if the bit stock was turned nearly a complete revolution and then back around again is better, lifting the valve from the seat frequently to prevent the accumulation of little balls of emery which may score the seat quite badly. Too much pressure will also do more harm than good. The valve should be taken from the cylinder and the valve head and seat thoroughly cleaned with gasoline. New abrasive should be used each time the valve is replaced for grinding. After most of the roughness has been smoothed down and the valve head and seat begin to have an even ap- pearance which is an indication of a smooth surface, the mixture of medium grade emery and oil may be replaced by one of flour emery, crocus, or ground glass, which may be mixed with kerosene, instead of the heavier lubricating oil. These make fine mixtures for polishing valve seat. When the valve has been properly ground it will be smooth and have a bright ring all around its face. The valve seat will also show bright. An important precaution to observe when grinding valves, 380 The Modern Gas Tractor especially on horizontal motors, is that none of the abrasive reaches the interior of the engine cylinder. This is easily done by blocking the port or passage between the valve and combustion chamber with a wad of cloth, to which a string is attached so it may be withdrawn from the cylinder without trouble in case it should become dislodged from its position and fall in. Timing Valves. — When the grinding process is completed and the valve springs have been replaced, it will be well to see that the valves are timed properly before the manifolds are put back. An important point to observe is that the proper amount of clearance between the end of the valve stem and the plunger is retained. • During the process of grinding it may be possible to bed the valves down enough so that the stems will project farther down and bear against the valve plunger before the valve head seats in the valve chamber. After valves are ground it is good practice to go over the engine timing carefully and verify it. The flywheel of most tractor engines of the multiple cylinder form is usually marked with letters which indicate the points where the valves open and close. The crankshaft should be turned by the starting crank, and when the point on the flywheel that indicates valve opening is in line with the trammel or indicator that usually indicates the vertical center line of the engine, there should be no clearance between the valve stem and the plunger that operates it. When the other valve is open in the same cylinder, then there should be an appreciable clearance between the valve plunger and end of valve stem. This is given as 0.007" for the inlet valves and 0.01" for the exhaust valves. More clearance is provided between the exhaust valve The Modern (Ias Tractor 381 stems and plungers on account of the greater expansion of these members due to heat. If the engine timing has been disturbed, as is often the case when an engine is dismantled, care should be taken to replace the timing gears just as they were before the engine was taken apart. This is usually indicated by marks made by the manufacturer of the motor. If no marks are noticed, then the tractioneer should be careful to make some for himself in order that he will be sure to replace the timing gears correctly. The best way to do this is to bring one of the pistons, pre- ferably that in the front cylinder, to the top center and to see that both valves in that cylinder are closed. One tooth on the crankshaft gear is then marked with a center punch, or steel letter stamp or even with a cold chisel, if neither of the others is available. The teeth on the larger gear which drives the camshaft on either side of the marked tooth on the crankshaft gear are then marked for future identification in the same manner. In case the engine timing is lost and the gears or flywheel are not marked, the traction engine operator may approximate the proper timing as follows: The piston in either the front or rear cylinder is brought to the end of its upward stroke and the camshaft is rocked in such a manner that both valves are closed. The timing gears are then meshed and locked into place. The engine crankshaft is then turned about half a revo- lution and the exhaust valve is watched to see if it rises from its seat. If it rises from its seat when the piston is about three-quarters of the way down on its stroke, the engine may be considered timed approxi- mately correct and if nothing else has been disturbed, such as the cams on the shaft, etc., the rest of the 382 The Modern Gas Tractor cylinders will undoubtedly be timed correctly enough so the engine will start without difficulty. If the exhaust valve opens late the timing gear may be moved a few teeth and again meshed with the gear on the crank- shaft. The crankshaft is rotated again and the opening of the exhaust valve again noted. The closing point is next determined by continuing to turn the crank- shaft. The exhaust valve remains open during the next upstroke of the piston and does not close till after the piston starts on the intake stroke. Right after the exhaust valve closes, the intake valve should open and remain open during the next down stroke of the piston, at which time the cylinder should fill with gas. To facilitate timing it may be well to mark the fly- wheel at points to correspond to the position of the pis- ton in the first cylinder when it is at the top of its stroke and similarly when it is at the bottom of the cylinder. These marks may be made with a center punch or steel stamp and should come directly opposite each other. They are of greatest value on engines with inclosed crankcase, as when the crankshaft is exposed, it is easy to follow piston movements by the position of the crankpin and connecting rod. The exhaust valve generally opens about 30 degrees crankpin travel ahead of the mark corresponding to the bottom posi- tion of the piston on the down stroke following ignition. The valve remains open the remainder of that stroke and the entire next stroke, closing a few degrees after the piston has started, on the suction stroke. The inlet valve opens about 15 degrees late and closes about 10 degrees late. The exhaust valve thus remains open a period equal to about 220 degrees crankshaft travel, the inlet valve seldom remaining open more than 180 degrees. The ignition spark, with timing lever at center The Modern Gas Tractor 383 position on quadrant, should take place just when the piston reaches the end of the compression stroke. Care of Piston and Rings. — Very often poor com- pression is caused by a defective condition of the piston or piston rings. If lubrication has been neglected and the cylinder has seized at any time, both the piston and cylinder walls will be found scratched and scored. Even if lubrication has not been neglected, but poor oil or an insufficient quantity has been used, the same scratches will be apparent though not to so large a degree. The piston rings may break, which will allow the gas to escape through the division between the broken parts. They may become gummed in their grooves so they do not spring out as they should and gas can blow by them. In cases where the piston rings are not pinned the slots in the rings may work in line and permit gas to escape through the series of openings. Piston rings often lose their elasticity or spring, or they may wear to such an extent that they will not form an effective seal against the explosive pressure. In event of deterioration, the only method is to replace the rings with new members. If the piston rings do not work freely in the grooves, they should be removed from the piston and all burnt oil cleaned off. The car- bon deposits which have collected in the grooves should also be removed before the rings are replaced. If the piston and cylinder walls are badly scored the only remedy is to have the cylinder bore ground out to a new surface and use a new piston member made to fit the enlarged bore. This will mean that new rings must be fitted as well as a new piston. Many believe that the cheapest way in the end is to secure an entirely new piston and cylinder from the makers to replace the defective members. 384 The Modern Gas Tractor Noisy Operation. — A number of power plant de- rangements are readily noted because they give positive indication of trouble by noises easily distinguishable by the untrained ear. Knocking or rattling sounds are usually the result of wear in the connecting rods or main bearings, though often a very sharp knock, such as might be attributed to a loose bearing, is due to carbon deposits in the cylinder or combustion chamber, premature ignition due to advance spark lever or a loose flywheel. Dry bearings are invariably indicated by squeaking sounds and whenever this signal of dis- tress is heard the engine should be stopped immediately and oil applied to the parts which have indicated their dry condition. Leaks produce whistling or blowing sounds; a sharp, definite pitched whistle denotes the escape of gas under pressure and is usually produced by a defective pack- ing or gasket that is used between the cylinder and cylinder head or as a joint for the exhaust manifold. A blowing sound is caused by leaky packing in the crank case, worn main bearings or wear in the valve plunger guides. Grinding noises in the motor are usually caused by the timing gears and will be heard if these gears are dry or if they have become worn. Minor rattles often indicate nothing more serious than too great clearance between valve stem and their operating plungers, or wear in the valve plunger guides. Any loose driving connection anywhere on the engine will contribute its quota of noise and often a combination of sounds are produced that will be very annoying even if they do not indicate serious wear. Adjusting Bearings. — The most fertile source of noisy operation is wear in the main bearings of the engine or looseness in the connecting rod bearings. The Modern (Jas Tkactor 385 The points where deterioration produces the most noise are clearly indicated at Fig;. 163, which shows the bottom view of the top half of a four-cylinder engine crankcase. This shows clearly the five main bearings of the crank- shaft, two of these members, that on the rear and the one next to it, having the bearing cap removed in order to show the shaft journals. Under the influence of the explosions the bearings in time tend to become CRANKSHAFT UPPE R HALF CRANKCASE MAIN BEARING CAP BOLTS AIN BCARING CAP Fig. 163. — Bottom View of Crankcase With Bottom Half Removed to Expose Crankshaft and Main Bearings. hammered down a trifle and lost motion exists between the crankshaft and the bearing bushes. If the wear is comparatively slight it may be eliminated by removing some of the thin shims of sheet metal placed between the bearing caps and the lower portion of the box and replacing the caps. This will enable 380 The Modern Gas Tractor them to bed down closer to the crankshaft and the lost motion which produces the noise will not exist. If the bearings have worn to such an extent that removing the shims will not be sufficient, new brasses or bushings must be inserted in the boxes and scraped to fit the crankshaft. If the crankshaft is cut or scored, the journals should be smoothed with fine emery cloth before attempt is made to fit the bearings to the shaft. A typical connecting rod in a disassembled condition is shown at Fig. 164 with the various parts separated CONNECTING ROD CAP BOLTS ^CONNECTING ROD CAP WRISTP1N BUSHING CONNECTING ROD BUSHING5 Fig. 164. — Connecting Rod of Gas Tractor Power Plant Show- ing Removable Crankpin Brasses. in order that the construction may be clearly ascer- tained. It will be noticed that the small bushing which surrounds the wrist pin is a solid member pressed into the boss at the upper end of the connecting rod. If any wear exists at this point the old bushing should be forced out and replaced by a new member. The lower portion of the connecting rod which encircles the crank pin is provided with a split box composed of two white metal bushings that bed into the con_ The Modern Gas Tractor 387 necting rod and the connecting rod cap, respectively. The two halves of the connecting rod lower end are usually separated by thin shims or liners, such as used in main bearings, and if the connecting rod is not very loose, lost motion may be e iminated by removing enough of the thin shims and then joining the parts together se- curely. If the connecting rod bushings are worn too much to permit refitting, they can be easily replaced by new members secured from the maker. The average tractor operator is not apt to be a good enough mechanic to scrape in and refit a set of main bearings, but this process is not a difficult one to learn, the only requirements being that the workman shall Fig. 165.— Tools That Facilitate Refitting of Bearings. be reasonably careful, have the proper tools and be patient enough to fit the bearings properly The tools shown at Fig. 165 will considerably facilitate refitting of bearings. The set of three scrapers shown will prove adequate for all sizes of bushings while the socket wrench set will make the constant removal and replace- ment of the bearing cap nuts a less difficult task than if the ordinary form of monkey wrench is used. When refitting the main bearings the first precaution is to clean the crankshaft thoroughly. Only attempt to fit one box at a time, as if more than one bearing cap is tightened it will be hard to tell which one is too 388 The Modern Gas Tractor tight. After the shaft and boxes have been cleaned, the main journals of the crankshaft should be coated with a very light, thin film of Prussian blue pigment which may be obtained in a collapsible tube at any paint store. The crankshaft is then dropped in the boxes which are held by the engine base and revolved a number of times in order that all the high spots on the boxes will have a chance to run against the shaft. When the shaft is removed the high spots will be indicated by specks of blue on the brasses. Before again replacing the crankshaft, these high spots are scraped off by means of curved bearing scrapers. The shaft is again replaced and revolved so that it will indicate another set of high places. The scraping in process is continued on all of the lower boxes until the crankshaft has many points of bearings evenly dis- tributed at each box. The caps are the next to receive attention. The shaft is allowed to remain in place and one cap is fitted at a time. The crankshaft journals are kept covered with Prussian blue, a new film being put on with the finger each time a test for high places is to be made. The fitting is started with either the front or rear main bearing cap which is brought against the shaft by means of the retaining nuts, until it is difficult to turn the shaft. The nuts are slacked up a trifle and the crankshaft turned. Part of the Prus- sian blue will be scraped off by the high points in the bearing caps and these are removed by the scraper and the fitting process continued until the bearing cap shows an equal bearing by a uniform distribution of color. The cap is properly fitted when the crank- shaft does not turn unduly hard with the bearing cap retaining nuts bedded down firmly and the cap in firm contact with the engine base or the interposed Tn io Modern Gas Tractor 389 shims of metal. Each cap is fitted in turn, and if the work is carefully done it will be found possible to turn the crankshaft over without much difficulty when all the caps have been properly replaced and no lost motion will exist between the caps and crankshaft. The same instructions apply to fitting connecting rods, the test for high spots being made by the use of Prussian blue pigment and the trial to ascertain if the bearing clamps the shaft too tightly is made by rocking the connecting rods back and forth. The degree of resistance indicates the fit of the bearing. A con- necting rod is usually considered properly fitted if it is not loose and yet will drop over slowly due to the piston weight when placed in a vertical position. Care should be taken not to adjust bearings too tightly, as this may produce sufficient heating to burn out the white metal bushings or score the crankshaft journals badly when harder materials, such as bronze, are used. Before replacing either connecting rod or main bearing caps for the last time, it will be well to use liberal quantities of cylinder oil to insure that they will be properly lubricated when the power plant is first started after the refitting process is complete. Mixture Troubles. — Defective carburetion is usu- ally indicated by misfiring or irregular operation. The common derangements of the components of the fuel system and the best method for their location follow: The first thing to do is to see if the fuel is flowing to the carburetor from the tank. This is done by dis- connecting the feed pipe and seeing if the stream coming- out is the full size of the orifice. If it trickles out slowly it is an indication that either the pipe is clogged with dirt or that there is an accumulation of scale, rust or lint at the strainer screen usually placed in tank over 390 The Modern Gas Tractor the gasoline discharge coupling. This may also indicate that there is not enough liquid in the tank. Insufficient fuel supply is sometimes due to the shutoff valve between the tank and carburetor having jarred either partly or wholly closed because of vibration. If the stream of fuel from the tank indicates that it is reaching the carburetor all right, that device should be examined to see if there is any dirt or water in the float chamber. The float chamber of most carburetors may be drained by a petcock provided for the purpose. Dirt may constrict the passage between the flow chamber and the spray nozzle and very often the fine holes or spray openings in the latter may become blocked up by par- ticles of foreign matter. The float may be binding and the gasoline needle valve regulating the supply opening in the bowl may stick to its seat. Any of these condi- tions would reduce the supply of fuel and the engine would not receive sufficient quantities of properly pro- portioned gas. Some of the conditions that will produce poor mixture are: The air valve spring may be weak or broken, the gasoline or fuel adjusting needle may be loose and jar out of adjustment, the air valve spring adjusting nuts may be a poor fit on the valve stem and adjust- ments will not be retained, air may leak in through leaky joints of the inlet manifold or through holes of a porous casting; or the valve stem may have worn enough in the guides so air is drawn into the mixture through the worn inlet valve stem guide bushings. Any foreign matter in the fuel will cause irregular operation because the standpipe bore may be partially constricted and not allow enough fuel to reach the mixture. If clouds of black smoke are expelled from the exhaust pipe it indicates that the fuel supplied the mixture is The Modern Gas Tractor 391 excessive and the supply should be reduced by screwing down on the needle valve in carburetors where this method of regulation is provided. If no needle valve is used the fuel proportions may be reduced by altering the fuel level in the float bowl. A pronounced "popping" in the carburetor means that the mixture contains too much air. If this is not due to air leaking in through worn valve guides or leaky manifolds it may be over- come by screwing in the auxiliary air valve adjustment so the valve does not open so much or by slightly in- creasing the fuel supply by opening up the regulating needle. The exhaust gas will be free from any objec- tionable odor and will be clean if fuel is not burnt in excess. The character of the mixture may be judged by the color of the flame issuing from the exhaust pipe if the engine is run with an open throttle after dark. A red flame indicates too much gasoline, and a yellowish one shows an excess of air. A pronounced blue flame such as given by a gas stove or gasoline stove burner will indicate the properly proportioned mixture. Ignition System Derangements. — When a battery ignition system is provided and the engine does not run regularly the first thing to look for is to see if there is a spark at the spark plugs. These members are re- moved from the cylinders and are then again coupled up to the secondary wires. They are laid on the cylinder castings in such a way that the bushing intended to be screwed into the cylinder is in good metallic contact but the insulated terminal at the upper end out of contact. The engine is then turned over slowly by hand and the spark plugs watched to see if there is any spark between the points. If there is no indication of current flow the following may be looked for: A broken wire anywhere in the primary circuit, a defective 392 Tin: Modern Gas Tractor ground connection, loose battery terminals, broken battery connections, lack of current at the battery. The method of testing dry cells is extremely simple and is outlined at Fig. 166. Each cell is tested in turn by a small watch size testing instrument which indicates the available current strength in amperes. Any dry cells that read below six or seven should be rejected and, in fact, it will be well to replace dry cells unless they indicate at least eight amperes. Fig. 166.— Method of Testing Capacity of Dry Cell. If there is no spark at the plugs but the spark coil vibrators buzz properly this shows that the primary wiring is all right and that the fault must be looked for either in the wires comprising the secondary circuit or at the spark plugs themselves. Spark plugs may be rendered inoperative by cracked insulation or by deposits The Modern Gas Tractor 398 of carbon around the electrode. Secondary wires some- times break or may become oil soaked or have the insulation worn away, either of which permits the current to become grounded to some metal part of the motor. The electrodes of a spark plug may have burnt away enough so the gap is too great or the points may be too close together. If there is no vibration at the spark coil the trouble may be due to broken timer wires, burnt or pitted vibrator contact points, vibrator out of adjustment, or poor connections at the com- mutator or timer. If a low tension magneto is fitted as an auxiliary supply of current, about the only thing that will cause failure of current generation outside of slipping or broken driving connections is brush trouble. The commutator sometimes becomes covered with an oil glaze or the brush holders may become fouled with old oil. Either of these conditions interferes with the flow of the current. The brushes may become worn so they no longer bear on the commutator and the current generated by the armature cannot be collected and sent to the outer circuit. Obviously any derange- ment of the driving connections will interfere with current generation because the armature will not be turned sufficiently regular or at the proper speed. If a high tension magneto is fitted and no spark is produced at the plugs the following defective conditions should be looked for: Broken secondary wires, current collecting brushes or distributor brush not making con- tact, contact points of the make-and-break device may be out of adjustment or covered with oil; the wiring may be attached to wrong terminals; the dis- tributor filled with metallic particles, carbon dust or oil accumulations; the distributor contacts may not .">'.»4 The Modern Gas Tractor be making proper connections because of wear or a defective distributing brush or more serious derange- ment may exist, such as defective windings or conden- sers, which fortunately are of extremely rare occurrence. Cooling and Lubrication Group Faults. — Owing to the simplicity of the cooling systems ordinarily used on gas tractors they are not liable to give trouble if the radiator or tank is kept full of clean water and the circulation is not impeded. The most common troubles producing defective cooling are due to impeded water circulation. A radiator may become clogged with rust or sediment and the piping or water jackets some- times become filled with scale that tends to retard the flow of water. If the water pump or its driving means fail, circulation will not be positive and overheating will re- sult, as is also evident if the cooling fan belt breaks or slips. When rubber hose is used in the circulation system, this may deteriorate inside and the area of the inside passages become reduced due to particles of rubber hanging down. The cooling system is often apt to overheat after anti-freezing solutions of which calcium chloride forms a part have been used, as crystals of the salt may collect in the radiator, piping or water jackets. These crystals can only be dissolved by chemical means when in inaccessible places, but where the construction permits they may be removed by scraping. Over- heating is sometimes caused by rich mixture and some- times by defective lubrication. When the oiling group is not working properly the friction between the parts of the mechanism usually produces heat. Poor lubrication usually results from: Not enough oil in the engine crank case or mechanical oiler, oil of poor quality, broken or clogged oil pipes, broken oil pump or defective oil pump drive. The The Modern Gas Tractor 395 oil supply may be reduced by defective inlet or discharge check valves at a mechanical oiler or by worn pump- plungers in that device. A clogged oil passage or pipe leading to an important bearing point will result in loss of power and overheating because the oil cannot get between the working surfaces. Much of the trouble caused by defective oiling may be prevented by using only the best grades of lubricating oil, and lubricants *•*' _, VI JL I 23» ■ Fig. 167. — Assembly View of Reversing Gear, Main Drive and Differential Gearing of "Twin City 40" Gas Tractor. of poor quality will cause friction and overheating even if all parts of the oil system are working properly. If a mechanical oiler becomes inoperative or its driving means fail while the tractor is in the field, the engine may be kept in operation by putting enough oil in the :>!M; The Modern Gas Tractor crank case so the connecting rods will dip into it as the crank-shaft revolves. Running Gear Derangements. — Running gear trouble and its cause is usually apparent as soon as it happens. If a clutch refuses to hold or if a shifting gear will not engage it is obviously due to some mechani- cal derangement that can be fixed as soon as located. A typical transmission system is shown at Fig. 167, and in this various driving members and the bearings as well as clutch and gear shifting levers are clearly shown. There are some points about the running gear of a tractor where wear or loose parts may directly concern the safety of the driver. A defect in either the steering gear or the brakes might result disastrously to the operator in event of failure. One of the most important members of the transmis- sion system, which the writer will consider in connection with the running gear assembly, is the clutch, and de- rangements of this member will affect the efficiency of the entire assembly. The most common defects are failure to engage properly, slipping under load and "grabbing," which is the result of too sudden engage- ment. The former condition is usually the result of wear of the wood friction blocks, and may generally be easily compensated for by screwing out on the adjust- ment provided so the clutch blocks may be brought more forcibly into contact with the clutch-ring when the actuating lever is operated. Slipping may be caused by charred or broomed out friction blocks, and when this condition is evident the best remedy is to replace these members. If the clutch engages too suddenly it is generally due to the adjustment having been taken up to a point where the hand lever need only be moved a very small The Modern Gas Tractor :\ { .)7 amount to produce clutch engagement. This can be prevented by proper attention to the clutch adjust- ments. If a clutch shifting collar is worn too much, or the small pins in the yokes of the rods connecting the clutch operating bell crank with the hand lever are worn, it may take too much movement of the handle to set the clutch. This defect can be easily remedied by replacing the worn members. Not much trouble is produced by the gearing of a tractor until the gear teeth become worn. When shift- ing members are used to obtain changes of speed there may be some difficulty met with in sliding these into mesh if the edges of the teeth are burred over, and this often causes trouble on the teeth of the positive jaw clutches used in connection with reversing gears. Diffi- culty in clutch or gear shifting is sometimes due to binding of the control levers or operating rods because of accumulations of rust or dirt. Driving gears do not give much trouble, though when the teeth become worn or the bearings in which the shafts run become loose, there will be considerable noise and rattle while the gearing is in action. Where chains are used for driving, these for the most part are run without covering of any kind, and as the action of the dirt and gravel is to combine with the grease on the outside and form an abrasive, consider- able wear will result if the chains are not kept clean. To obtain proper results from driving chains, they must be kept in proper adjustment. A chain that runs too loose is apt to climb the teeth of a sprocket, whereas if it is adjusted too tightly they are liable to break, especially if the sprocket teeth are worn hook shape Not much trouble is caused by bearings if these are kept properly oiled. The same rules previously giver 398 The Modern Gas Tractor for fitting engine bearings apply just as well to the plain bearings used for supporting the differential cross shaft or the rear axle. In some tractors anti- friction bearings are used, these being of the ball or roller type. It is important that the oil used with bearings of this nature contains no acid, and care should be taken to prevent dirt or grit from entering the bearing housings. Fig. 168. — Driving Gears of "Twin City 25" Gas Tractor. Grinding sounds in gearing are usually produced by gears meshing too deeply, while worn gears usually manifest their defective condition by rattling. The wheels should be tested from time to time to see that their bearings are not worn unduly by jacking up the tractor frame and turning or shaking them after they Thk Modern Gas Tractor :!'.>!» are relieved of the machine's weight. With a one piece front axle the important point to watch is the sup- porting pivot, and this should be kept clean and well oiled at all times. Steering chains should be examined frequently to make sure that no links have started to pull apart and that they are in proper condition. When an Ackerman type axle is used, the steering knuckles should be looked over to make sure that the spindle bolts are right and at the same time the various joints of the drag link and tiebar should be carefully examined for any lost motion. It will be well to encase all of the joints of a steering system in small leather bags packed with grease, because if these are kept well lubricated and protected from grit, very little wear will exist at these points. The brake should be always kept in proper adjust- ment. The means prov ded are available on inspection. If the brake fails to hold properly the friction facing should be examined to see that it has not become worn and the various portions of the operating levers should be inspected to see that there are no weak points or worn parts liable to give out at a critical time. A brake should not be adjusted too tightly, because if it bears on the brake drum when in released position it will cause friction and produce loss of power. At the other hand if the brake is not adjusted sufficiently tight a full movement of the operating lever will not apply the brake tight enough to stop the tractor. An important point to observe when the wheels are of the built-up construction is that the spokes are kept properly tightened, as one or more loose spokes in a wheel will seriously reduce the strength of the assembly. A typical built-up wheel, in which the spokes are screwed into the cast hub and held in place by 400 The Modern Gas Tractor The Modern Gas Tractor 401 lock nuts, is shown at Fig. 168, and to tighten these members the lock nuts must be slacked up and the threaded end of the spoke screwed into the hub more tightly with a Stilson or pipe wrench, then locked in place with the lock nut. Tractor Hitches. — The use to which the gas tractor has been more widely applied than any other is in furnishing power for pulling ploughs. The hitch required is relatively simple, as the gang of from six to twelve ploughshares is attached to the tractor drawbar as a compact unit. The only precaution to observe is that the chains by which the plough is pulled should be at- tached to the drawbar in such a way that an even draft will be obtained and the ploughs trail along directly back of the tractor. If a large number of bottoms are provided and the total width of the gang exceeds that of the tractor, the plough frame must be attached to the drawbar so that the ploughshare that is in the furrow last cut will be about on a line with the high tractor driving wheel outer edge. Under these conditions it is not possible to have the plough pull as evenly as when a lesser number of shares are used, because those which project beyond the tractor cannot fail to produce a side draft. Two common forms of the gang plough have been devised for use with the gas tractor. That at Fig. 172 shows a conventional five bottom gang with hand op- erated levers to control the depth of cut and the action of the ploughshares. Most power ploughs are provided with a wheel or colter which is placed just in advance of the plough point so it will be raised automatically over a stone or other impediment that might damage the plough. A platform of planks is placed over the forward portions of the frame so that a man can stand 402 The Modern Gas Tractor The Modern Gas Tractor 403 on the plough and control the levers as desired. As this means that two men must be employed in plough- ing, another form of gang plough which is known as the "self-lift" has been devised to make it possible for the engineer of the tractor to control the ploughs directly from his position on the tractor platform. Fig. 171. — Holt Caterpillar Tractor at Work Ploughing Deep Furrows. The Avery "self-lift" engine gang plough, having ten ploughshares, is shown at Fig. 173. At Fig. 174 the method of raising the ploughshares is clearly outlined. A special broad tread wheel having grouters to insure 404 The Modern Gas Tractor Fig. 172.— Typical Hand Lift Five Bottom Gang Plough Adapted for Use With Traction Engine. Fig. 173.— Avery "Self Lift" Ten Bottom Gang Plough Makes It Possible for Engineers to Control Ploughs Without Leaving Tractor Cab. The Modern Gas Tractor 405 positive drive is mounted beneath the plough frame and drives a cross shaft by means of chain and sprocket connection. A series of pivoted bellcrank arms to which the ploughshare beams are attached by chains are utilized in lifting them. The method of operation is simple. A trip lever is pulled in such a way that a clutch is engaged. This connects the driving sprocket to the short shaft on which the bevel pinion is mounted that meshes with the bevel gear driving the eccentric Fig. 174. — View Showing Mechanism of Avery "Self Lift" Plough. shaft. As the gears turn, the eccentrics pass under the rollers in the plough lifting cranks, and in this man- ner the ploughs are lifted directly by means of power instead of by the usual hand lever. Many traction engine operators, especially those who have to cultivate large areas, arrange to draw a number of machines at the same time and thus perform different operations on a certain strip of ground by going over 400 The Modern Gas Tractor r v "c is v kvvvvui'dii uvu u l PACKER i 3-3 EIGHT BOTTOM PLOW ^ U u u u TOOTH HARROWS TOOTH HARROWS Fig. 175. — Plan Views of Combination Hitches That Save Time and Labor. A — Plough, Packer and Toothed Harrow. B — Plough, Packer, Drill and Toothed Harrows. The Modern Gas Tractor 407 2 M ■5 V S o n S "S H a a a _a = H •a ° -2 si T3 a .9 Pu h — — CO — '5 I— Ih . 3 (fife - 3 a" !S .Eh a : .2 o go 40S The Modern (Ias Tractor it only once. At Fig. 175-A a hitch is shown in which an eight bottom gang plough is attached directly to the tractor drawbar. A packer is attached to the plough and tooth harrows are drawn in turn from the packer. By utilizing machines in this manner the ground is broken, packed, and harrowed at one time. Another hitch which is very similar is shown at B. In this a drill is interposed between the packer and the tooth harrows and thus a strip of ground may be Fig. 177. — Outfit of Berland and Lee, Brady, Mont., Ploughing With Disc Plough and Packing With Stone Drag. ploughed, packed, seeded, and harrowed in practically one operation. The illustration at Fig. 176 shows a practical application of a plough, packer, tooth harrow, and drill, actually in use in the field. That at Fig. 177 clearly demonstrates the utility of a disc harrow or plough and stone drag packer combination. The number of auxiliary machines that can be used in connection with the plough depends largely upon the power of the tractor available. Some of these have The Modern Gas Tractor 409 wMmmww Fig. 178.— Simple Three Drill Hitch Easily Made by Any Farmer. i = fc r . o i n c^?a a ^ e *p 1 Fig. 179.— Wrought Iron Pipe Drill Hitch for Three Drills. 410 The .Modern Gas Tractor ^~Vjfc Fig. 180. — Practical Application of Drill Hitch. just barely enough to haul a six or eight bottom gang plough without increasing the load by adding other machines. If the tractor has a wide margin of power it is, of course, possible to operate other farm imple- Fig. 181. — Hansmann Patent Five Drill Hitch Very Useful in Seeding Large Areas as It Covers a Strip Sixty Feet Wide. The Modern Gas Tractor 411 ments without straining the tractor. The ordinary eight-foot disc harrow, which weighs about six hundred pounds, requires four horses to draw it. This means that it will take approximately 600 pounds pull for a tractor to draw it. A twenty-foot drag harrow requires the same power as an eight-foot disc harrow and the same pull will also operate a ten-foot wide clod crusher. As three horses will usually handle a twelve-foot disc Fig. 182.— Avery Gas Tractor Outfit Owned by D. M. Circle, Kiowa, Kansas, Pulling a Double Disc and Lever Tooth Harrow. drill, which seeds a strip eight feet wide, a pull of 450 pounds will be needed for each drill hauled. An easily made and simple drill hitch is outlined at Fig. 178. The method of attaching the drill is so clearly shown that further comment is not necessary. The ingenious farmer is often able to make hitches for use in connection with a gas tractor by utilizing odds and ends that are found on any farm of any pretension?. 412 Tin: Modern Gas Tractor i> ,PCT»IL OF CLEVIS ^P Fig. 183.— Details of Easily Constructed Harrow Hitch for Four Ten Foot Disc Harrows. At Fig. 179 a method of utilizing wrought iron pipe and fittings so that three 12-foot drills will obtain equal draft from the tractor drawbar is outlined. An old wagon axle is cut in half and one wheel is attached at each end of the long four-inch pipe that forms the basis of the attachment. The practical application of a disc and drill combination is shown at Fig. 180. Fiu. 1S4. — Practical Application of 1. H. C. "Mogul" Tractor in Road Grading Work. The Modern Gas Tractor 413 When one considers the rapid growth of the gas tractor industry it is but natural to assume that a number of attachments would be devised for use with traction engines. That shown at Fig. 181 is the Hansmann five-drill hitch, which makes it possible for a tractor of sufficient power to pull five 12-foot drills and thus seed a strip 48 or 50 feet wide. An easily made harrow hitch, which will enable the tractor to pull four 10-foot disc harrows, is clearly depicted at Fig. 183. The draft Pig. 185. — Avery Gas Tractor Pulling Western Wagon Loader and Elevator Grader. bar of this device is composed of a length of 3" x 6" beam about 18 feet long. Four clevises are spaced along this evener bar. The bar is hauled by two 5-8" steel cables, secured to a ring at one end and to clevises attached to the beam at the others. The ring is at- tached to the center of the tractor drawbar or in the line of pull if the harrows are drawn by a gang plough or follow any other implement. The details of the 414 The Modern (J as Tractor device are clearly shown and should be easily followed by any one of average mechanical ability. Utility and Uses of Modern Gas Tractors. — The gas tractor offers many advantages in road construction and they are rapidly replacing the steam tractors formerly widely employed for this service. A con- vertible road roller-tractor combination is practically three machines in one, inasmuch as a simple change will convert the tractor to a road roller and vice versa and the machine can be used practically all the year round, as it can be utilized for hauling and belt work when not employed as a road roller. Economy is a strong point in favor of the gas operated road roller. As machines of this kind carry a supply of fuel and cooling water sufficient for practically a day's opera- tion, no water wagon or coal wagon is needed to act as a tender as is necessary with the steam tractor. A hitch by which a powerful enough gas tractor may be utilized to haul three road scrapers or graders at a time is clearly outlined at Fig. 186. This makes it possible to finish a large amount of work in one trip, as practically the entire width of the average roadway may be treated at the same time. The machine nearest the ditch line is attached directly to one end of the drawbar by means of a pole while the others are pulled by half-inch steel cables as indicated. The method by which the road scrapers are made to follow the tractor is also clearly shown. The same hitch as out- lined would be practical with any other machine of which a number must be hauled at the same time, such as harvesters, etc. The marked advantage of the gas tractor in road work is that the change speed gear feature found on most gas tractors enables them to do very heavy scrap- Tin: Modern Gas Tractor 415 ing. By operating on one of the lower speeds a scraper blade full can be handled both on the level and when ascend- ing hills, and it is never necessary to stop the machine and drop part of the load as is the case with a horse-drawn scraper when a heavier cut is taken than can be carried through by horses. When a tractor is used for road work the character of the work is always better than when horses are employed, because there are no irregular- ities in the cut as are invariably present when a scraper is drawn by animal power. The lower cost of op- erating a road scraper by tractor as compared with the cost of doing this work by horses is probably the greatest point in favor of the gasoline tractor. The road commissioners of a New York town 41G Thk Modern Gas Tractor owning and operating a gas tractor" state that the weekly expense when using six horses on the road machine has been $84.00 per week (including two-horse team hire at the rate of $4.00 each per day). They state that when operating the scraper by means of the tractor they accomplish one-third more work at a total weekly expense, including cost of gasoline, cylinder oil and operators, of $36.00, or a net saving of $48.00 per week plus one-third more work. To reduce this to the basis Fig. 187. — Special Wagon Adapted to be Used in Train Hauled by Gas Tractor. of the cost for an equal amount of work, the hire of one additional team should be added, in which case the saving effected by the tractor is $72.00 per week. These figures cover the total cost of the work based on actual working conditions throughout the season (but not including interest and depreciation on machin- The Moderx Gas Tractor 417 Fig. 188. — Combination Road Roller and Tractor, an Extremely Useful Machine for General Contractors or Municipal Use. A — Machine With Roller for Steering and Auxiliary Rims on Traction Members. B — Roller Removed From Front and Wheels Substituted, Making Practical Tractor for Road or Field Work. 418 The Modern Gas Tractor ery), the quality of the work being better than would be obtained by horse power. The tractor referred to has also been used by the town chiefly for hauling gravel and crushed stone and doing other work of this nature, but in this particular instance has, during the late fall and winter, been a source of revenue to them as it has been rented to private parties for operating machines by belt power and also for ditching. A tractor can be used successfully for hauling, and under average conditions on dirt or gravel roads, 20,000 Fig. 189. — Harvesting With Avery Gas Tractor in North Dakota. pounds, exclusive of the weight of the machine, can be hauled with a tractor of but 15 horse-power. On mac- adam roads, or good gravel roads, the hauling capacity is, of course, increased. As a rule, the character of the road surface greatly affects the hauling capacity. On a plank road but 100 pounds draft per ton hauled is neces- sary. Upon macadam road it will require from 150 to 225 pounds draft to haul one ton. The amount of power necessary increases to about 300 pounds per The Modern Gas Tractor 419 4iMi The Modern Gas Tractor ton on a gravel road and an average of about 400 pounds puJl per ton on a common dirt road. Wagons intended to be pulled by tractors are of special form and are made so they can be coupled up in a train. As the width of wheels has material bearing upon the hauling capacity, most wagons adapted for use on soft roads have wide wheels. Such a vehicle with a platform body is shown at Fig. 187. The construction of a combined gas tractor and road roller is clearly shown at Fig. 188. The view at A shows the roll in place under the front end of the machine and the auxiliary smooth steel tires attached over the grouters of the driving wheels. A tractor designed for use either as a road roller or tractor usually has a different method of front suspension than is commonly employed on tractors in order to use a roller of larger diameter than usually allowed for the front wheels. At B a one-piece axle carrying two wheels has been substituted for the roll assembly and the smooth steel tires have been removed from the traction members so that the grouters on the wheels again become effective. This makes possible the use of the machine as a tractor. The change from one to the other can be readily effected on the road, so the general contractor finds the combination machine a very good investment. With the development of the successful binder hitch, it has been found practical to use the gas tractor for power in harvesting. Six-foot binders require from three hundred to five hundred pounds draft to pull them at a speed high enough to do good work. Mowing machines without binder attachment and capable of taking a five or six-foot cut are usually operated with two horses and therefore require a draft of about 250 to 300 pounds when hauled by a tractor. This value may be increased The Modern Gas Tractor 421 422 The Modern Gas Tractor largely by dull knives, binding or tight boxes, or when cutting highly resistant grains or grass. Timothy is the hardest crop to cut and takes the most power. As almost all mowers run at speeds that are variable, it is difficult to give exact figures regarding the power consumption of mowing machines or binders. As a high speed must be maintained on a binder, it is common practice to use three horses, whereas two are sufficient for the mower. As the machines work to best advantage at a speed of about two and one-half miles per hour, Fig. 192. — Gas Tractor Not Only Cuts but Stores the Fodder. it will be apparent that the gas tractor is particularly well adapted for use in harvesting, as even the lower powered forms are capable of pulling three mowing machines at this speed. The views at Fig. 189 and Fig. 190 show the application of the gas tractor in harvesting work. The gas tractor is particularly suitable for threshing after the grain is harvested, owing to the ease with which it can be utilized as a stationary power plant for The Modern Gas Tractor 423 work with the belt. The advantages in threshing have been considered at length in one of the earlier chapters, so it is merely necessary in this instance to briefly enumerate its advantages. At Fig. 191 an entire thresh- ing outfit is shown ready for the road. The gas tractor can haul the threshing machine and the attendant train of wagons any distance, and when the scene of activities is reached it is but the work of a few moments to connect the tractor with the machine to be operated by means of a long driving belt as shown in the lower portion of the illustration. It will be apparent that the tractor is not only capable of hauling the imple- ments and wagons necessary to any point, but it can also be utilized successfully for driving the machinery when it reaches its destination. The power needed to operate various forms of machines under belt as given by the International Harvester Company follows: MACHINE. HORSE-POWER. 4-Roll Deering Husker and Shredder 12 6-Roll Deering Husker and Shredder 15 4-Roll McCormick Husker and Shredder 12 6-Roll McCormick Husker and Shredder 15 8-Roll McCormick Husker and Shredder 20 10-Roll Piano Husker and Shredder 20 24" x 40" Thresher 15 28" x 44" Thresher 20 28" x 48" Thresher 20 32" x 52" Thresher 25 36" x 56" Thresher 25 4-Hole Keystone Sheller 12 6-Hole Keystone Sheller 12 424 The Modern Gas Tractor As the ordinary tractor power plant will develop its full brake horse-power when used in belt work it will be apparent that even the lighter traction engines may be used successfully for operating the machinery that must be run by belt. The utility of the tractor for this purpose is clearly indicated at Fig. 192. Here the machine has been placed outside of the barn and convenient to the material to be cut and elevated into the loft. The tractor is run to where the work is to be done and a simple belt connection with any machine serves to drive it. Fig. 193. — Holt Caterpillar Tractor Demonstrates Its Worth In Swampy Ground. The tractor may often be used under conditions that on first consideration would seem impossible. At Fig. 193 the utility of the Caterpillar Tread Tractor in swampy ground is clearly demonstrated and it should be remembered that on land of this nature it is practi- cally impossible to work horses. The illustration at Fig. 194 shows another unusual application where the gas tractor has successfully replaced horses. The work of hauling logs over the snow covered and rough roads The Modern Gas Tractor 425 of the lumber regions is economically done by the gas traction engine and the train of wagons that it hauls. The view at Fig. 195 clearly demonstrates that a gas tractor can be operated in very deep snow, and when one considers the height of the driving wheels it will be apparent that a tractor can be used over roads that would seriously impede other forms of self-pro- pelled vehicles. Home=made Gas Tractors. — A discussion of gas tractor construct on would not be complete without Fig. 194. — The Modern Gas Tractor Makes Hauling of Heavy Logs a Commercial Proposition. reference to some of the ingenious outfits that have been built by farmers for their own use. The machine at Fig. 196 is a light construction in which a circular saw outfit has been made self-propelling Only one of the rear wheels is driven, this being operated by gearing which in turn receives the power of the engine through a leather belt. Tightening this belt serves to transmit the power from the engine to the counter- shaft and from thence to the driven wheel. When the belt tension is released, the engine may run free of the wheel. The vehicle is directed by a steering wheel 420 The Modern Gas Tractor which operates the independently pivoted front wheels which are joined by a tiebar in just the same manner as in the Ackerman axle. The circular saw is mounted at the front end of the machine and is adapted to be driven from the engine when the tractor has reached its destination. Another home-made tractor of substantial construc- tion in which a single cylinder stationary type engine Fig. 195. — An Aultman & Taylor Tractor Operating in Deep Snow, Shows That All the Year Round Service May be Obtained From the Modern Gas Tractor. is utilized for power, is shown at Fig. 197. The drive is by means of a belt from the engine pulley to a pulley placed on a countershaft mounted directly over the front axle. A sprocket is secured to this shaft between the two bearings, and this drives a larger sprocket The Modern Gas Tractor 427 attached to a differential gear of a cross shaft. The rear wheels are driven from this cross shaft by chain and sprocket connection. The front axle is a one-piece type and is operated by a chain steering gear and the usual form of hand wheel. It is not considered practical for the average farmer to attempt to build a tractor, and most of the machines constructed have not been as practical as those built Fig. 196. — Ingenious Home-made Light Tractor Saw Construct- ed bv F. J. Jantz of Hillsboro. Kansas. by experienced manufacturers with proper facilities. The machines illustrated are presented to show what may be accomplished by the handy man who is able to utilize odds and ends and old implement parts that ordinarily would be considered as junk and contrive a machine that is capable of doing useful work. Before the tractor had been developed to the point of per- 42S The Modern Gas Tractor fection that now obtains, many home-made machines were used for various purposes. With the advent of the improved gas tractors the farmer has been able to obtain machinery that would answer his purpose at a much lower cost than if he attempted to build a machine following his own ideas. Pig. 197. — Home-made Gas Tractor Outfit Built by John H. Sands, Cavalier, North Dakota. Auto Tractor Attachment. — The auto-tractor is an attachment of recent development, designed to be attached to the standard types of automobiles and to make it possible to use the self-propelled vehicles in performing the various kinds of farm work where mech- The Modern Gas Tractor 429 430 The Modern Gas Tractor anical power may be utilized. The general construction may be readily determined by examining Fig. 198, which shows the tractor attachment partly in place under the auto chassis. The illustration Fig. 199 shows a side view of an automobile to which this attachment has been fitted, while that at Fig. 200 is a rear view of the same machine showing the tractor hauling a three bottom gang plough. This device is of such form that it may be attached to any automobile of standard tread and utilizes the auto- mobile engine and driving system which can be made to do the work of either a stationary or traction engine. The power is transmitted to the tractor attachment by means of small pinions fastened to the rear hubs of the motor car. These mesh with a train of gears which gives a speed reduction and which multiplies the available drawbar horse-power of the automobile twelvefold. The machine uses its own power to load itself in that it draws the tractor attachment into place under the car. A pair of supporting members called "chairs" are at- tached to the axle which are designed to rest on the frame-members of the tractor so as to lift the wheels of the automobile from the ground. » It is claimed that from either the standpoint of initial investment or operating cost this machine is very eco- nomical. The owner of an automobile may secure many of the advantages offered by the gasoline tractor with an additional investment of about one-fourth what a gas- oline tractor would cost. The tractor attachment is light in weight and the wheels, which are six feet in di- ameter, make it possible to operate an automobile with a tractor attachment successfully on soft or wet ground. The rear wheels of the automobile are raised clear of the ground and it is stated that when in position on the The Modern Gas Tractor 431 tractor and in operation there is less strain on the automobile than when traveling over country roads. In operation, the automobile with tractor attachment is as easy to control as a one speed tractor because most of the driving is done entirely with the change speed lever in the high speed or direct drive position. The direct drive through the automobile gearing to the automobile rear wheels differs only in one respect from conditions present in regular road travel and that is Fig. 199. — Side View of Automobile, Equipped With Auto- tractor Attachment. that the power is applied at the face of the pinion secured to the hub instead of at the tire. The revolving rear wheels act as flywheels and make for smoother operation. The gearing is designed so that two speeds are available, one of two miles per hour and one of four miles per hour. As is true of the conventional form of tractor the lower speed is used when pulling ploughs or doing other work where the full capacity of the machine is needed. The high speed is utilized in moving wagon trains and similar road work. 432 The Modern Gas Tractor The gearing is so proportioned that when the tractor is moving at a speed of two miles per hour the automobile power plant is running at from 800 to 1000 revolutions per minute. This speed is the normal at which the aver- age motor can operate continuously without strain and at the same time deliver practically its full horse-power. The attachment will fit automobiles ranging from twenty to ninety horse-power and as it can be attached or detached in very few minutes it does not interfere with the ordin- ary use of the automobile. After a day's work in the field the large traction wheels may be uncoupled and the de- vice left in the field ready for the next day's work while the automobile conveys the workmen to their destination. The auto-tractor is provided with a pulley attachment which permits it to be used as a stationary power plant and will operate all kinds of farm machinery from a grindstone to a threshing machine. Among some of the refinements of detail that are apparent are an auxiliary cooling system on the tractor attachment which insures that the automobile motor will not overheat on account of the low vehicle speed. A fan, pump and radiator are placed on the tractor attachment and water is passed through the auxiliary radiator as well as that of the car by means of simple connections and the motor is thus properly cooled under all conditions of weather. A stor- age tank holding twenty-four gallons is connected into the cooling system and an all-day run without additional water is possible. The amount of work that can be done with the tractor attachment depends entirely upon the size of the engine in the automobile to which it is applied. The following table shows the relation between the horse-power rating of the automobile and the number of horses it will re- place in field work. The Modern Gas Tractor 433 Automobile Rating. Farm Horses Replaced. 20 Horse-power 4 to 6 30 " 6 to 9 40 " 10 to 14 50 " 14 to 18 60 " 18 to 22 75 " 22 to 30 90 " 30 to 36 As previously mentioned, the automobile is carried almost entirely by the steel frame of the tractor attach- ment on which the rear axle rests and which is fastened rigidly to the front axle so that the power exerted at the traction wheels is distributed evenly on the entire auto- mobile chassis. It is claimed that the device has been examined carefully by automobile manufacturers and engineering experts and that no criticism was offered after a close study of the principles of operation had been made. It is believed that this attachment will serve to still further promote the sales of automobiles to farmers. Future Possibilities. — The field of usefulness to which the tractor can be applied is enormous. Over ten million horses are in use in the big farming States or agricultural purposes.' If the farmers of these States would replace but one out of five horses or 20 per cent, it is claimed that there is a market for over sixty thousand tractors of the medium power class, not to mention the large sale and great market for the smaller machines designed to do the work of three or four horses on the small farm. The tractor has demonstrated its worth and is prac- tical in construction. It has demonstrated that it will cut the cost of production of all farm products and will reduce the cost of marketing as well because the road to market is shortened by mechanical power. 434 The Modern Gas Tractor Fig. 200. — Rear View of Automobile With Auto-tractor Attachment, Showing Practical Application in Ploughing. One authority says, "The tractor is at the dawn rather than at the twilight of its development." It has develop- ed from a monstrous, inefficient toy into a powerful and efficient servant. It is not only on the farm that the tractor can be The Modern Gas Tractor 435 used to advantage. In contracting and construction work its uses are unlimited. Many deposits of stone have been converted into surfacing material for high- ways by its aid. It has been used in building and main- taining roads, in digging irrigation canals, and filling drainage ditches. It has hauled machinery to the mines, brought the ore to the surface and carried it to the railroad or smelting plant. Enormous logs have been taken from forests where big teams of horses could not be handled. It has been used even in the field of modern amusement enterprises, and a number of the big tent shows are shifting their heavy trucks with a traction engine which also runs a dynamo and fur- nishes power for electrically lighting the tents during the evening exhibition. The performance of the tractor in the past is but a promise of what it may accomplish in the future. Much depends on the education of the farmer. It is not natural to assume that one who has been familiar with horses since childhood will be ready to replace these with mechanical power about which he knows compara- tively nothing. As the tendency of modern farming is to make it more scientific and an engineering proposi- tion, the farmer of the future will be trained in solving mechanical problems. While it is to the younger ele- ment that we must look for substantial progress and ready adoption of new methods, much will be accom- plished by even the conservative old-time farmer who will realize the advantages of mechanical traction, study the applications and forms of gas tractors best suited to his work and link the invaluable experience of the past with the progressive ideas of the future. CHAPTER XI. MISCELLANEOUS RULES AND FORMULA. A Collection of Useful Rules, Tables and Formulae That Will Prove of Value to the Student, Mechanic or Farmer, These Include Additional Rules for Figuring Horse-power, for Estimating the Capacity of Tanks, Strength of Mate- rials, U. S. and Foreign Conversion Tables ?nd Other Interesting Information of a Miscellaneous Nature. 437 USEFUL RULES, TABLES AND FORMULAE RULES FOR CALCULATING HORSE=POWER. To calculate the horse-power of any 4-cycle motor, the following general formula is always used, this giving the output of a single cylinder and must be multiplied by the number of cylinders for multiple cylinder engines. PLA R _ 33000x2 ~ H ' P ' In which P= pounds per square inch. L= length of stroke in feet. A = piston area in inches. R=the number of revolutions per minute. The pressure in any engine is assumed to be a mean effective pressure or average pressure throughout the stroke, and is written M. E. P. For gasoline engines of the usual 4-cycle automobile type this pressure can be assumed at between 75 and 100 pounds, it, of course, varying with the general design. The actual M. E. P. of an engine which has already been built can be deter- mined by the manograph, which records by means of a streak of light the outline of the indicator card, which, if desired, can be permanently retained by means of a photographic plate. It can also be determined at speeds under 500 R. P. M. by diagrams produced by ordinary steam engine indicators, but these are not accurate when used with high speed gasoline engines, the manograph being far superior. 439 440 The Modern Gas Tractor FORMULA FOR INDICATED HORSE=POWER. D 2 XLXnXM. E. P.XR. T TT „ gen/V w. ~ I- H - p - 4-eycle X Constant for 5o0,000 2-cyele engines, 275,000. D 2 =Bore of cylinders in inches squared. L = Stroke of piston in inches. R = Revolutions per minute of crankshaft. n = Number of cylinders. M. E. P. = Mean effective pressure. Mean Effective Pressure increases as the compression and decreases as the R. P. M. augment. The thermal efficiency of a motor is the ratio between the work done and the thermal energy contained in the fuel con- sumed and is between 15 to 30 per cent. The mechanical efficiency, by which is understood the ratio between the work actually done to the energy expended on the piston by the expanding gases, is approximately 85 per cent. MEAN EFFECTIVE PRESSURES OF TYPICAL AUTO MOTORS. Make. Cylinders. H. P. R. P. M. M. E. P. National. . . Four 5x5 11 /i6" j 64 j 54 1,400 1,055 81.1 90.9 Pierce Six 4x4%" j 44.5 ( 30.9 1,263 800 76.1 85.4 Rambler. . . Four 5x5 H" 43.5 1,091 73.1 Thomas. . . Six 4^x53^" 49 1,091 76.0 Thomas. . . Six 4Mx53^" 34 700 83.4 S. A. E. HORSE=POWER FORMULA. The formula adopted is 2 .5 ' and based on 1,000 feet per minute piston speed. D is the cylinder bore, N the number of cylinders, and 2.5 a constant, based on the average view of the Mechanical Branch as to a fair conservative rating. The Modern Gas Tractor 441 TABLE OF HORSE-POWER FOR USUAL SIZES OF MOTORS, BASED ON S. A. E. FORMULA. Bore. Horse -power. Inches. M M 1 Cyl. 2 Cyls. 4 Cyls. 6 Cyls. 2V 2 64 2H 5 10 15 1% 68 2% 5V 2 11 16^ 2% 70 3 6 127.o 187 5 2% 73 37,6 6M 13M 19J/ 8 3 76 3Vo 775 1475 21»/« 3K 79 3»/« 7"/,6 157s 237.6 3M 83 4M sy 2 167.o 257s 3^ 85 47.6 QVs 18M 277s 3H 89 47io 9 4 / 5 197s 297s Wz 92 5^ 103^ 20 H 317o 3% 95 5^ 11M 22 y 2 33^ Z 7 A 99 6 12 24 367.6 4 102 67s 127s 257s 387s ±Vs 105 6»/.6 13^ 27}4 407,o 4J4 108 7H 14^ 287.o 437s 4H 111 7^ 157.6 30^ 4517.6 4H 114 8V10 167s 3275 487 5 4^ 118 87.6 173^ 3434 517s 4^ 121 9 18 367.0 547,0 ±H 124 9V 2 19 38 57 5 127 10 20 40 60 5K 130 10 y 2 21 42 63 5J4 133 11 22 447 10 667s 5^ 137 117.6 23 46 697.0 442 The Modern Gas Tractor Bore. Horse- Dower. Inches. M/M 1 Cyl. 2 Cyls. 4 Cyls. 6 Cyls. sy 2 140 lZVxo 24V 5 48V, 72V, 5 5 A 143 12 V 8 25V.6 50^ 75"/,, 5% 146 13^ 2&y 2 53 79 K 5V S 149 13»A, w y 8 55^ 82Vio 6 152 14V, 28 4 / 5 57»/, 867, To simplify reading of the above, the horse-power figures are approximate, but correct within one-six- teenth. A SIMPLE HORSE=POWER FORMULA. H. P. = PLD 2 R with three decimal places pointed off. In which P=Mean effective pressure. L= Stroke in inches. D= Diameter in inches. R= Number of cylinders. The M. E. P. can be assumed or taken from tables. A speed of 1,000 R. P. M. is the only assumption made, and the formula takes into consideration pressure, bore and stroke, and is the simplest form to which the writer has yet been able to reduce the H. P. formula, still re- taining all the essentials. WELL=KNOWN CLUB AND ASSOCIATION HORSE=POWER FORMULAE. For easy comparison of one car with another and for facilitating handicapping at hill climbs and race meets, the following formulae have been given out by clubs and associations. For the sake of uniformity, let: D 2 = Square of piston diameter in inches. L = Stroke in inches. R = Revolutions per minute. N = Number of cylinders. The Modern Gas Tractor 443 HORSE=POWER FORMULA, 4=CYCLE ENGINES. D 2 N A. L. A. M. Formula, H. P.= Roberts Formula, H. P.= Royal Auto Club, H. P.= 2.5 D 2 LNR " 1800 (D+L) 2 N 9.92 Fig. 201.— Plan of Easily Constructed Prony Brake for Making Power Tests. 4-U Tiik Modern Gas Tractor TABLE FOR CALCULATING B. H. P. OF AN ENGINE. KNOWING THE BRAKE ARM LENGTH, SPEED AND PULL ON THE SCALES. (c. T. SWART.) B. H. P. = 2X3.1416XRXPXN 33,000 R= Brake arm in feet. P=Pull on scales in pounds. N = Revolutions per minute. Values in table = 2X3.1416X100XRXP 33,000 The figures in this table are for a speed of 100 revo- lutions per minute; therefore when readings are taken for any other speed, the answer found in the table must be multiplied by the actual speed divided by 100. Pull in Arm in Feet. Pounds 1 1M iy 2 m 2 2M 2H 2H 3 5 0.095 0.119 0.142 0.166 0.190 0.214 0.238 0.2610.285 10 0.190 0.238 0.285 0.332 0.381 0.428 0.475 0.5220.570 15 0.285 0.357 0.428 0.498 0.570 0.642 0.713 0.7830.785 20 0.380 0.476 0.570 0.666 0.760 0.856 0.950 0.14 1.15 25 0.475 0.595 0.713 0.830 0.950 1.07 1.19 1.31 1.43 30 0.570 0.713 0.885 0.996 1.15 1.28 1.43 1.57 1.71 35 0.665 0.833 1.00 1.16 1.33 1.49 1.66 1.83 2.00 40 0.760 0.952 1.14 1.33 1.52 1.71 1.91 2.09 2.28 45 0.855 1.07 1.28 1.49 1.71 1.93 2.14 2.35 2.56 50 0.950 1.19 1.43 1.66 1.90 2.14 2.38 2.61 2.85 55 1.05 1.31 1.57 1.83 2.09 2.35 2.61 2.87 3.14 60 1.15 1.43 1.71 2.00 2.28 2.57 2.85 3.13 3.42 Table concluded on next page. The Modern Gas Tractor 445 Pull in Arm i;i Feet. Pounds 1 IX \ i a I 1% 2 2H 2V 2 2?4 3 65 1.24 1.55 1.85 2.16 2.47 2.78 3.09 3.39 3.71 70 1.33 1.66 2.00 2.33 2.66 3.00 3.33 3.66 4.00 75 1.43 1.78 2.14 2.49 2.85 3.21 3.57 3.92 4.27 80 1.52 1.90 2.28 i2.66 3.04 3.42 3.80 4.18 4.56 85 1.62 2.02 2.42 12.83 3.23 3.64 4.04 4.44 4.85 90 1.71 2.14 2.56 2.99 3.42 3.85 4.28 4.70 5.14 95 1.81 2.26 2.71 3.16 3.61 4.06 4.52 4.96 5.42 100 1.90 2.38 2.85 3.32 3.80 4.27 4.75 5.22 5.71 105 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 110 2.10 2.62 3.14 3.65 4.18 4.70 5.23 5 . 75 6.27 115 2.19 2.74 3.28 3.82 4.37 4.92 5.47 6.01 6.66 120 2.28 2.86 3.42 3.98 4.56 5.14 5.71 6.27 6.85 ANTI=FREEZING SOLUTIONS FOR COOLING SYSTEM. There are three principal agents used as the basis for anti-freezing solutions in the cooling systems of water-cooled tractor engines — calcium chloride, gly- cerine and alcohol. The alcohol solution is usually pre- ferred, especially since the tariff has been removed on denatured alcohol, because it does not damage the metal of the water jackets, radiator or connections, and has no fault except that it evaporates. The other solutions each have advantages, and users may consult their own preferences as to which agency they prefer. Calcium chloride (CaCL) is a very effective cooling agent but unless the chemically pure article is used there is danger of corrosion of the metal with which it comes in contact. A solution of 5 pounds of calcium chloride to each gallon of water will not freeze at any temperature above 35 degrees below zero. A more convenient way to prepare the solution is to first make 446 The Modern Gas Tractor a "saturated solution" of the calcium chloride and water, that is mix with a quantity of water warmed to 60 deg. Fahr. all the calcium chloride the water will completely dissolve, and use equal parts of this saturated solution and pure water in the cooling system of the motor. If chemically pure calcium chloride is used no trouble will result. Chloride of lime (CaOCL) should be avoided. Crude calcium chloride retails at about 8 cents or 10 cents a pound, while the chemically pure article is worth about 25 cents in small quantities. Glycerine is an effective cooling agent and as it will not crystalize in the water jacket it is preferable in this respect to calcium chloride and it has the further merit of not requiring any renewal during the season as it does not evaporate. It is therefore only necessary to add pure water to replace that which has evaporated. The main fault ascribed to gtycerine is its tendency to soften hose connections. Equal parts of glycerine and water are used. In using a glycerine solution care should be taken to thoroughly cleanse the jackets of any residue of crystals from calcium solutions previously used as this residue will thicken and cloud the glycerine solution. Alcohol can be used in either small or large quantities. The freezing point of various ethyl alcohol mixtures taken from "Physikalisch-Chemische Tabellen" are as follows : Percentage of alcohol in water . . 2.418 5.014 8.105 17. '.Hi Freezing temperature, deg. F. . .30.264 28.418 26.213 18.52 Percentage of alcohol in water . .36.43 51.06 86.22 Freezing temperature, deg. F . . . 3.20 - -10.48 - -29.02 In addition to these straight mixtures of water and one anti-freezing element there are several combina- The Moderx Gas Tractor 447 tions of three or more elements such as 1-5 alcohol, 1-5 glycerine and 3-5 water; 4 parts water, 3 parts carbonate potash and 2 parts glycerine, etc. A saturated solution of common salt can also be used. It does not affect the metal of the system and remains fluid down to deg. Fahr. An incrustation, however, occurs as the water evaporates. Water must be added to make up for evaporation when glycerine, calcium chloride or salt is used. Fig. 202. — A Simple Method of Determining Grade Percentages Without a Qradometer. HOW TO ASCERTAIN THE GRADE WITHOUT A QRADOMETER. A method of determining the percentage of a grade on any road without any special instruments is here given and illustrated. All that is required is to measure off ten feet on any convenient stick and rest one end as shown in the sketch above, upon the surface of the road, being careful to keep the stick horizontal. This can be done by using a spirit level or an ordinary bottle filled with water allowing a bubble in the well-known mariner. Measure from the end of the stick to the road 448 The Modern Gas Tractor surface and multiply by 10, which will give the per cent of the grade. The average of several such measure- ments will give fairly accurate results. TO REMOVE RUST. Rust may be removed from iron by immersing the piece for several clays, or until the rust has entirely disappeared, in water to which a little sulphuric acid has been added with a piece of zinc firmly attached to the iron so that it makes a good contact. The iron is not attacked as long as the zinc remains in contact with it. Iron or steel may be cleaned of rust by the use of the following: 100 parts stannic chloride dissolved in 1,000 parts water. Add to a solution containing 2 parts tartaric acid dissolved in 1,000 parts water. Add to the mixture 20 cubic centimeters indigo solution diluted with 2,000 parts of water. Clean the metal parts of all grease, apply the solution to the stained portions for a few seconds, rub clean with a moist cloth, then with a dry cloth, and if desired then use any good metal polish. Old rust may be removed in some cases by rubbing with a paste consisting of equal parts of fine tripoli and flowers of sulphur thoroughly mixed with olive oil. Powdered alum in strong vinegar, oil of tartar, or fine emery is also used to remove rust. Kerosene or turpentine if left on the stained or rusted portions over night, will sufficiently soften the rust so that it may be removed by the use of fine emery cloth followed by a polishing powder. Rust spots on nickel can be treated with grease, and after several days rubbed with a rag saturated with a few drops of hydrochloric acid in ammonia. Parts should be thoroughly rinsed, dried and polished. The Modern Gas Tractor 44! I RUST PREVENTIVE. The following is a good rust preventive for steel: 16 parts turpentine, and 1 part caoutchouc dissolved by a gentle heat. To this add 8 parts boiled oil, stir and at the same time bring to the boiling point. Apply with a brush after the manner of varnishing. This coating can be removed by the use of turpentine if desired. ■ — TABLE OF COMPOSITION OF COMMON ALLOYS. White Bearing Metal 2 Bronze 90 Bronze for bushings 130 Bearing Bronze (for motors) 110 Phosphor Bronze (for gears) 90 Bronze for flanges, etc., to be brazed 32 Babbitt metal 2 Brass for light parts 2 * Phosphor tin. MELTING POINTS OF VARIOUS METALS. Aluminum Bronze Cast Iron (Cray). Cast Iron (White) Copper Lead Steel Tin Wrought Iron .... Degrees F. 1,157 1,692 2,012 to 2,228 1,922 to 2,075 1,929 to 1,996 608 to 61S 2,372 to 2,532 442 to 446 2,732 to 2,912 451) The Modern Gas Tractor ROAD SIGNS. American Motor League "Caution Signs." Back- ground and posts white, symbols black. No. 1 indicates approach to a steep descent; No. 2, approach to a railroad crossing; No. 3, approach to a branch road (to right) ; No. 4, approach to a branch road (to left); No. 5, approach to cross roads; No. 6, approach to a ditch or abrupt depression in the road; No. 7, approach to a hummock or "thank you, ma'am;" No. 8, approach to a city, village or other collection of inhabited dwellings; No. 9, is a general caution signal indicating the proximity of any danger or obstruc- tion not scheduled above, or any other condition requir- ing caution. No. 9 (not shown in cut) is a plain white sign and can be improvised in emergency cases by using a sheet of white cloth fastened upon a board of proper shape. "Each sign is placed at a distance of not less than 200, nor more than 300 yards from the point to which it refers. Fig. 203. — Road Signs of American Motor League That Give Warnings of Interest to Tractor Operators or Motorists. The Modern (Jas Tractor 431 TABLE OF HORSE=PO\VER COSTS. I Rate of Fuel Motive Power Consumption. Gas Engine on In pounds per Producer Gas. HP. Hour. Cost of Fuel per Brake Test Horse-power 1 Hour. Cost of Coal per 2.000 Pounds. 1.00 1.25 1.50 S3 . 00 84.00 $5.00 .0012 .0015 .0019 .0023 .0016 .0020 . 0025 .0030 .0020 .0025 .0031 .0037 $6 .00 $7 . 00 .0024 ! .0028 . 0030 . 0035 .0037 .0044 .0044 .0053 Gas Engine on Natural Gas. In Cubic Feet per H.P. Hour 9 10 I 1 12 Cost of Natural Gas. 1,000 Cubic Feet. $0.15 .0014 .0015 .0017 0018 SO . 20 .0018 .0020 .0022 .0024 $0.25 .0023 .0025 .0028 .0030 $0.30 .0027 .0030 .0033 .0036 Gas Engine on Illuminating Gas In Cubic Feet per H.P. Hour. Cost of Gas per 1,000 Cubic Feet. $0.60 SO. 70 $0 . 80 $0 . 90 $1.00 15 17 20 .0090 .0102 .0120 .0105 .0119 .0140 .0120 .0136 .0160 .0135 .0150 .0153 .0170 .0180 .0200 Gasoline Engine In Pints per Brake H.P. Hour. Cost of Gasol|ne per Gallon. SO. 10 $0. 12 $0. 14 $0.16 $0.18 0.80 1.00 1.10 .0100 .0125 .0137 .0120 .0150 .0165 .0140 .0175 .0192 .0160 .0200 .0220 .0180 .0247 Table concluded on next page. 4.">2 The Modern (Jas Tractor TABLE OF HORSE=POWER COSTS===Continued. Electric Motor 85% Efficiency In Kilowatts per H.P. Hour Cost of Electricity per Kilowatt Hour. of Wiring. $0 . 02 $0 . 03 SO . 04 SO . 05 ■SO . 07 0.878 .0175 .0263 1 0351 .0439 1 .0614 Steam Engine on Coal. In Pounds per H.P. Hour. Cost of Coal per 2,000 Pounds. $3 . 00 $4.00 $5 . 00 $6 . 00 $7 . 00 4 6 8 10 .0060 .0090 .0120 .0150 .0080 .0120 .0160 .0200 .0100 .0150 .0200 .0250 .0120 .0180 .0240 .0300 .0140 .0210 .0280 . 0350 CAPACITY OF CYLINDERS. NUMBER OF GALLONS FOR ONE FOOT DEPTH. When diameter is given in feet = (square of diameter)x5.873 When diameter is given in inches = (square of diameter)x0.0408 TABLE OF CAPACITIES OF CYLINDRICAL TANKS IN LIQUID GALLONS (APPROXIMATE). Gals. 1 2 3 4 5 6 7 8 9 10 Gallons per inch 6x12 6x18 6x24 6x36 6x42 6" dia. . 122 7x12 7x18 7x24 7x30 7x36 7x42 7x48 7" " .165 8x15 8x18 8x24 8x30 8x36 8x42 8x45 8x48 8" " .217 9x12 9x15 9x18 9x24 9x30 9x34 9x36 9x40 9" ' .275 10x20 10x24 10x26 10x28 10x32 10" " .340 12x16 12x18 12x20 12x24 12" " .486 Gals 10 15 20 25 30 35 40 45 50 Gallons per inch 10x32 10x48 10" dia. .340 12x24 12x34 12x42 12x50 12x60 12" " .486 14x18 14x24 14x30 14x38 14x44 14x52 14x60 14" " .666 1 fix is 16x24 16x30 16x36 16x42 16x48 16x54 16x60 16" " .870 The Modern (Jas Tractok 4..:; RULE FOR CAPACITY OF SQUARE OR RECT= ANGULAR TANKS. Multiply height in inches by width in inches and the product by length in inches, then divide by 231, which will give answer in gallons. For small tanks, divide by 57.75, and you will obtain capacity in quarts. TRACTIVE EFFORT ON VARIOUS SURFACES. Pounds per Ton. On rails or plates 5 . 16 Asphalt or hardwood 12 . 24 Macadam 30 . 60 Loose gravel 140 to 200 Sand 400 . REVOLUTIONS OF WHEELS OF VARYING DIAMETER PER MILE. Dia. Circum. in in Inches. Feet. „ , . For R.P.M. Revolutions multiply per Miles per Mlle - Hour by For R.P.S. multiply Miles per Hour by 48 12.57 420.0 7.00 0.1166 50 13.00 403.4 6.72 0.1120 52 13.61 387.9 6.46 0.1073 54 14.14 373.4 6.22 . 1033 56 14.66 360.2 6.00 . 1000 58 15 . 18 347.8 5.79 0.0965 60 15.71 336.1 5.60 0.0933 62 16.23 325.3 5.42 0.0903 64 16.75 315.2 5.25 0.0875 66 17.28 305.5 5.09 0.0848 68 17.80 296 . C) 4.94 0.0823 70 18.36 288.1 4.80 0.0798 72 18.85 280.1 4.67 0.0778 78 20.42 258.6 4.31 0.0718 84 21.99 240.1 4.00 0.0666 90 23.56 224.1 3.73 0.0622 96 25.16 210.1 3.50 0.0586 454 The Modern Gas Tractor STRENGTH OF AUTOMOBILE STEELS. SUMMARY OF TENSILE TESTS Made with 2-inch Test Specimens of Carpenter Steel Company's Auto Steels in Accordance with the Standard Specifications of the American Society for Testing Materials. Grade "On .-. ,r. a .2 §8 Z'-r.C 5 c OJhH e Condition. 43 O c3 2, o& g>0 3« % % Chrome-Nickel Auto-Steel No. 5-317 65,650 91,200 27.0 64.3 Natural " 210.000 315.000 5.0 19.0 Tempered " 185,400 269,200 6.0 20.2 " " 140,000 225,200 8.0 30.2 " " " 114,000 130,500 19.0 60.0 Toughened Chrome-Nickel Auto- Steel No. 3-317 70.000 106,000 18.0 45.0 Natural 135,000 197,000] 9.0 37.0 Tempered " 90,000 110,000 25.0 55.0 Toughened Dynamic Auto-Steel No. L3-14 103,800 121,39020.0 60.0 Special Nickel Steel No. 575 80,000 99,000 21.0 58.2 " " No. 575 87,000 102,000 21.0 62.0 Crucible Auto-Steel No. L-521 160,000 175,000] 7.0 30.0 Tempered Special Auto-Steel No. 506 70,000 113,950 22.0 49.0 Natural No. 506 71,200 105,600 24.0 49.3 " Weldable Auto-Steel No. 492 49,050 93.000 21.5 35.0 " " No. 492 50,000 93,000 22.0 37.0 Auto-Steel No. 478 48,300 74,500 29.0 43.0 No. 478 46,500 77,500 28.0 1 45.0 No. 5-317. Suitable for transmission gears, counter-shafts and parts used for transmission of power. No. 3-317. Mild-temper suitable for ease hardened gears. No. L 3-14. Axle-steel, to withstand alternating stresses and dynamic strains. No. 575. Contains 3 H per cent, nickel and is manufactured to meet the U. S. Navy specification known as "High Grade." No. L-521. Crucible gear-steel (moderate price) gears can be tempered and do not require hardening. No. 506. Manganese steel for shafts, bolts, etc., not sub- jected to excessive alternating or recurrent stresses. No. 492. Special straight-carbon crucible steel, with a The Modern Gas Tractor 455 fairly high tensile strength, suitable for axles and other parts that have to be welded. No. 478. Special high-grade open-hearth steel, which is particularly adapted to such parts as are not subjected to unusual strains. It is suitable for axles, axle-journals, and various small parts of automobiles. USEFUL CONVERSION TABLES AND RULES. TO CHANGE COMMON FRACTIONS INTO A DECIMAL To convert a common fraction into a decimal : Divide the numerator by the denominator, adding to the numerator as many ciphers prefixed by a decimal point as are necessary to give the number of decimal places desired in the result. % = 2.0000 + 3 = 0.6666 + DECIMAL EQUIVALENTS OF FRACTION ONE INCH. OF ADVANCING BY 64TH. 1-64 0.015625 17-64 . 265625 33-64 0.515625 49-64 0.765625 1-32 0.03125 9-32 0.28125 17-32 0.53125 25-32 0.78125 3-64 0.046875 19-64 . 296875 35-64 . 546875 51-64 . 796875 1-16 0.0625 5-16 0.3125 9-16 . 5625 13-16 0.8125 5-64 0.078125 21-64 0.328125 37-64 0.578125 53-64 0.828125 3-32 0.09375 11-32 0.34375 19-32 . 59375 27-32 0.84375 7-64 0.109375 23-64 0.359375 39-64 0.609375 55-64 . 859375 1- 8 0.125 3- 8 . 375 5- 8 0.625 7- 8 0.875 9-64 0.140625 25-64 0.390625 41-04 . 640625 57-64 . 890625 5-32 0.15625 13-32 0.40625 21-32 . 65625 29-32 0.90625 11-64 0.171875 27-64 0.421875 43-64 0.671875 59-64 0.921875 3-16 0.1875 7-16 . 4375 11-16 0.6875 15-16 . 9375 13-64 0.203125 29-64 0.453125 45-64 0.703125 61-64 0.953125 7-32 0.21875 15-32 . 46875 23-32 0.71875 ' 31-32 1) '.His;:. 15-64 0.234375 31-64 484375 47-64 0.734375 63-64 9S4375 1- 4 q 25 1- 2 0.50 3- 4 0.75 1 1. 4r><; Thk Modern Gas Tractor MONEY CONVERSION TABLES. English. U. S. 1 Farthing $0.0051 1 Farthing $0.0051 1 Penny 0203 6 Pence 0.1217 1 Shilling 0.2433 20 Shillings 4.8665 1 Pound 4.8665 5 Pounds 24.3325 U. S. English. $0.01 1 . 96 Farthings $0.01 1.96 Farthings 0.01 0.492 Pence 0.25 12.3 0.25 1.0275 Shillings 1.00 4.11 1.00 0.2055 Pounds 5.00 1.0275 " French. U. S. 1 Centime $0.00193 10 Centimes 0.0193 100 " 0.193 1 Franc 0.193 10 Francs 1.93 U. S. French. $0.01 5 . 1813Centimes 0.10 51.813 1.00 5. 1813 Francs 10.00 51.813 " German U. S. 1 Pfennig $0.00238 25 Pfennigs 0.0595 100 " 0.238 1 Mark 0.238 10 Marks 2 . 38 U. S. German. $0.01 4.201 Pfennigs 0.25 1.05025 Marks 1.00 4.201 10.00 42.01 THERMOMETER SCALE CONVERSIONS. One Fahrenheit degree = 5-9 degree Centigrade = 4-9 degree Reaumur. In the following conversion formulae: F = Degrees Fahrenheit. C = Degrees Centigrade. R = Degrees Reaumur. Readings above freezing point, 32 degrees F., zero C, zero R., are positive ( +), readings below are treated as negative ( — ). F = — + 32; F = ^ + 32; C = R = 4(F — 32) Freezing point F = 32 degrees = zero C = zero R. Boiling point = 212 degrees F = 100 degrees C = 80 degrees R. The Modern 500 900-1,800 0.525 8 6 750 1,800-3,000 1 . 35 10 8 1,200 ::.000-4,000 1.80 12 10 L.725 4,000-5,000 2 40 14 12 2,200 4»;l> The Modern Gas Tractor WHAT MAY BE ACCOMPLISHED BY PUMPS OF VARY ING CAPACITY IN IRRIGATION WORK. Acres Irrigated in 10 Hours. Gallons Pumped 1-in. 2-in. 3-in. 4-in. 5-in. 6-in. per Minute. deep. deep. deep. deep. deep. deep. 600 13.2 6.6 4.4 3.3 2.6 2.2 824 18.2 9.1 6.0 4.5 3.6 3.0 944 20.8 10.4 6.9 5.2 4.1 3.4 988 21.8 10.9 7.2 5.4 4.3 3.6 1,000 22.1 11.0 7.3 5.5 4.4 3.7 1,200 26.5 13.2 8.8 6.6 6.3 4.4 1,500 33.1 16.5 11.0 8.2 6.6 5.5 2,000 44.2 22.1 14.7 11.0 8.8 7.3 Acres Irrigated in 24 Hours. Gallons Pumped 1-in. 2-in. 3-in. 4-in. 5-in. 6-in. per Minute. deep. deep. deep. deep. deep. deep. 600 31.8 15.9 10.6 7.9 6.3 5.3 824 43.7 21.8 14.5 10.9 8.7 7.3 944 50.0 25.0 16.7 12.5 10.0 8.3 988 52.4 26.2 17.4 13.1 10.4 8.7 1,000 53.0 26.5 17.6 13.2 10.6 8.8 1,200 63.6 31.8 21.2 15.9 12.7 10.6 1,500 79.5 39.7 26.5 19.9 15.9 13.2 2,000 106.0 53.0 35.3 20.5 21.2 17.6 INDEX Aekerman Axle, Parts of, 311. Ackerman Front Axle, Con- struction of, 311. Action of Automatic Carbure- tors, 167 Action of Change Speed Gear, 267. Action of Clutch Described, 248. Action of Float Feed Carbu- retor, 164. Action of Friction Roll Clut- ches, 256. Action of Gas Motors, 101. Action of Kerosene Vaporizer, 177. Action of Magneto Ignition Systems, 214. Action of Self-Lift Gang Plough, 403. Action of Simple Mixing Valve, 161. Action of Valves, 129. Actual Power of Horse, 41. Advantages of Concentric Float, 168. Advantages of Large Wheels, 294. Advantages of One Cylinder Motors, 110. Advantages of Power Trac- tion, 37. Adjusting Bearings, How to. 384. Adjustment of Brakes, 399. Advice on Tractor Operation, 341. Agriculture, Application of Mechanical Power, 35. Air, Composition of, 160 Air Valves, Auxiliary, 171. Air, Weight of, 161. Alcohol, Facts About, 158. Analysis of Requirements of Tractor, 53. Animals Used in Ploughing, 35, Anti-freezing Solutions, 445. Automatic Carburetors, 167. Automatic Steering Arrange- ment, 314. Automobile Steels, Strength of, 454. Automobile Type Power Plants, 125. Auto - Tractor Attachment. 428. Auto Tractor Attachment, Capacity of, 433. Auxiliary Air Valves, 171. Auxiliary Engine to Start Power Plant, 332. Axle, Ackerman, 311. Axle, One Piece Front, 308. Axle, Worm Drive for Tractor, 325. 463 464 Index B Balance of Two Cylinder Motors, 119. Battery Ignition Methods, 209. Bearings, Fitting, 388. Bearings, How to Scrape, 388. Baume Test, Method of Mak- ing, 158. Belt Operated Machines, Power Needed for, 423. Blacksmith Tools for Farm Use, 362. Block Type Clutches, 254. Brake Horse-power, Calculat- ing, 444. Brake Test, Meaning of, 94. Brake Test, Method of Mak- ing, 94. Brakes, Adjustment of, 399. Breaking, Cost of Tractor Power, 48. C Cam Shaft Drives, 139. Capacity of Auto Tractor At- tachment, 433. Capacity of Centrifugal Pumps 461. Capacity of Cylinders, 452. Carbon Deposits, How to Reduce, 376. Carbon Deposits, Symptoms Denoting, 375. Carbon Deposits, Troubles Due to, 375. Carburetion, Causes of De- fective, 389. Carburetion, Elements of, 160. Carburetor Air Valves, 171. Carburetor, Concentric Float Type, 168. Carburetor Float Construc- tion, 171. v arburetor Spray Nozzles, 169. Carburetors, Advantage of Float Feed, 165. Carburetors, Automatic, Ac- tion of, 167. Carburetors, Parts of, 168. Care of Piston, 383. Care of Piston Rings., 383. Caterpillar Tread, Action of, 304. Caterpillar Tread Tractors, 88. Cause of Poor Compression, 373. Causes of Mixture Troubles, 389. Causes of Noisy Operation, 384. Centrifugal Governors, 329. Centrifugal Pump Construc- tion, 226. Centrifugal Pump, Power Needed to Operate, 461. Chains, Defects of Driving, 397. Change Speed Gearing, I. H. C, 276. Change Speed Gearing. Morris, 270. Clutch, Action of Simple Type Described, 248. Clutch, Holt Tractor, 250. Clutch, Three Plate, 250. Clutch, Troubles of, 393. Clutch, Why Needed, 245. Clutches, B-ioek Type, 254. Clutches, Friction Disc, 254. Index 465 Clutches, Friction Roll, 256. Clutches, Requirements of, 248. Clutches, Typical Tractor, 250. Coil Vibrator, Action of, 194. Combined Farm Truck and Tractor, 91. Combined Gas Tractor and Road Roller, 420. Comparing Two and Four Stroke Motors, 99. Comparing Work of Horse and Tractor, 39. Composition of Common Al- loys, 449. Compression, Cause of Poor, 373. Compression of Gas, Value of, 105. Concentric Float Carburetor. Advantages, 168. Connecting Rod Bushings, How to Replace, 386. Connecting Rod Design, 142. Connecting Rod Types, 142. Constant Level Splash System. 242. Construction of Ackerman Axle, 311. Construction of Centrifugal Pump, 226. Construction of Cylinders, 139. ( Jonstruction of Induction Coil, 193. Construction of Tractor Frames, 282. Construction of Wheels, 294. Conventional Drive Gearing. 318. Cooling Fan, Action of, 227. Cooling Fan Drive, 227. Cooling System Faults, 394. Cooling System Forced Cir- culation, 222. Cooling System, Thermo Syphon, 222. Cooling Systems, Oil, 224. Cooling Systems, Pump Types, 225. Cost of Tractor Ploughing, 47. Cost of Tractor Power in Various Work, 51. Crankcase, Design of Four Cylinder, 152. Crankcase, Single Cylinder, 150. Crankshaft Design, 144. Crankshafts, Four Cylinder, 146. Crankshaft, One Cylinder, 145. Crankshaft, Two Cylinder. 145. Current Production. Methods of, 189. Cylinder Construction, 139. Cylinder Design, 133. Cylinder With Detachable Head, 133. Cylinders, How to Remove, 371. I) Decimal Equivalents Table, 455. Deep Ploughing, Value of, 77. Defective Carburetion, Causes of, 389. Defects of Driving Chains, 397. 466 Index Design of Connecting Rods, 142. Design of Crankshafts, 144. Design of Cylinders, 133. Design of Float Chambers, 170. Design of Pistons, 140. Detachable Head Cylinder, 133. Diagram of Four Cylinder Ignition System, 212. Differential, Bevel Pinion, 280. Differential Gear Action, 278. Differential Gear Lock, Utility of, 281. Differential Gear, Why Used, 276. Differential Pinions, Action of, 279. Disadvantages of Steam Trac- tors, 58. Distinctive Designs of Trac- tors, 87. Draft for Wagons, Table of, 71. Draft, Meaning of, 42. Draft of Tractors, 57. Draft of Wagons, 71. Draft, Traction Dynamometer for Measuring, 96. Drawbar Pull, How Deter- mined, 96. Dry Batteries, Action of, 189. Dry Battery, Capacity of, 190. K Economical Aspect of Power Traction, 44. Efficiency of Steam and Gas Power, 56. Efficiency, Thermal, of Horse, 40. Electrical Ignition, Advantages of, 188. Electric Spark, How Produced in Cylinders, 196. Elements in Carburetion, 160. Elements of Tractor Design, 61. Engine Base Design, 149. Extension Rims, Why Used, 302. F Fall Ploughing, Value of, 45. Faults in Running Gear, 396. Faults of Cooling Systems, 394. Faults of Ignition Systems, 391. Faults of Oiling Systems, 394. First Steam Ploughing Engine, 37. First User of Ploughs, 37. Fitting Bearings, 388. Float Chamber Design, 170. Float Construction, 171. Float Feed Carburetors, 165. Float Feed Carburetor, Action of, 166. Flywheel Construction, 146. Flywheel Marks, Relation to Valve Timing, 382. Flywheel Retention, 148. Flywheels, Safe Speed of, 148. Flywheels, Weight of, 147. Flywheel, Utility of, 146. Forced Circulation Cooling System, 222. Formulae for Horse-power, 443. Formula for Indicated Horse- power, 440. Index 46: Four-Cycle Engines, Operation of, 99. Four Cylinder Ignition System, 213. Frames, Cast, 285. Frames, Materials of Con- struction, 283. Frames, Tractor, 282. Frames, Typical Tractor, 2s;;. Frames, Use of Springs, 291. Friction Disc Clutch, 254. Friction Roll Clutches, 256. Front Axles, Tractor, 308. Front Wheel Drive, 320. Fuel Injection System, 181. Fuel Storage Methods, 354. Functions of Induction Coil, 193. Future Possibilities of Gas Tractor, 433. G Gang Plough, Self-Lift, 403. Gang Ploughs for Tractor Use, 401. Gang Ploughs, Types of, 401. Gas Motor, Medium and Heavy Duty, 113. Gas Motors, Action of, 101. Gas Motors, Automobile Type, 125. Gas Motors, How Gas is Exploded, 187. Gas Motors, Multiple Cy- linder Types, 113. Gas Motors, One Cylinder, 110. Gas Motors, Reason for Cool- ing, 219. Gas Motors, Speed, of, 62. Gas Motors, Two Cylinder Types, 119. Gas Motors, Types of, 07. Gas Motors, Valve System of, 136. Gas Motors, Vertical Cylinder. Advantages, 117. Gas Motors, Why Oiled, 231. Gasoline, Amount Used in Threshing, 51. Gasoline, Chemical Composi- tion of, 160. Gasoline, Facts About, 154. Gasoline Storage Outfit, Home Made, 357. Gas Power, Efficiency of, 56. Gas Power Plant Group, 62. Gas Tractor, Future Pos- sibilities of, 433. Gas Tractor, Power Delivery by Belt, 68. Gas Tractor, Thermal Ef- ficiency of, 56. Gas Tractor, Weight Distribu- tion, 68. Gas Tractors, Home Made, 425. Gas Tractors, Sizes of, 59. Gas Tractors, Types of, 74. Gas Tractors, Why Most Popular, 57. Gear Ratios for Various Work, 342. Gearing, Troubles With, 397. Gearing, Worm Drive, 32."). Gears, Action of Change Speed, 267. Gears, Construction of Drive, 318. Gears, Differential, 276. Gears, Reversing, 263. 468 Index Gears, Speed Changing, 266. Gears, Wheel Driving, Attach- ment of, 296. Governors, Construction of Centrifugal, 330. Governors, Engine Speed, 329. Grades, Influence on Traction, 70. Grades, Power Needed to Overcome, 70. Gradients, Table of, 74. Grouters, Types of, 300. Grouters, Why Used, 300. H Hauling, Power Needed for, 65. Hauling, Power Needed for Wagons, 71. Heavy Duty Engines, 113. Heider Friction Disc Clutch, 254. High Tension Ignition, Four Cylinder System, 212. High Tension Magneto, 205. High Tension Magneto, Ac- tion of, 207. High Tension Magneto, Dis- tributor Arrangement, 206. High Tension Magneto, Speed of Rotation, 206. High Tension Magneto Troubles, 393. High Tension Spark Plug, 197. Hitches for Gas Tractors, 401. Hitch for Road Scrapers, 414. Hitch, Harrow, 416. Hitch, Simple Drill, 411. Home Made Gasoline Storage Outfit, 357. Home Made Gas Tractors, 425. Horse, Actual Power of, 41. Horse, Compared With Work of Tractor, 39. Horse, Draft of, 42. Horse Equivalent Power Rat- ing of Tractor, 97. Horse-power Belts Will Trans- mit, 460. Horse-power Formulae, 443. Horse-power of Shafts, 458. Horse-power, Rules for Cal- culating, 439. Horse-power, S. A. E. Formulae for, 440. Horse-power Table, 441. Horse-power, Table of Costs, 451. Horse, Thermal Efficiency of, 40. Housing the Tractor, 343. How Gas Is Supplied Cylinder, 103. How to Start Engines, 326. How to Adjust Bearings, 384. How to Adjust Main Bearings, 385. How to Ascertain Grade, 447. How to Remove Cylinders, 371. How to Remove Rust, 448. Hub Construction for Tractor Wheels, 300. I Igniter Plate Construction, 195. Ignition System Faults, 391. Indicated Horse-power De- fined, 92. Index 4(H) Indicated Horse-power, For- mula for, 440. Induction Coil, Construction of, 193. Induction Coil, Functions of, 193. Influence of Grades on Trac- tion, 70. Influence of Mechanical Power on the Arts, 33. Influence of Road or Field Surface on Traction, 71. Influence of Weight on Trac- tion, 69. Inspection of Mechanism, Value of, 368. Irrigation Tables, 462. K Kerosene Carburetor, Action of, 179. Kerosene, Facts About, 156. Kerosene Vaporizer, Action of, 177. L Large Capacity Tractors, 82. Large Wheels, Advantages of, 294. Liquid Fuels, Advantages of, 153. Liquid Fuels, Alcohol, 158. Liquid Fuels, Gasoline, 154. Liquid Fuels, Kerosene, 156. Live Axle Forms for Tractor Use, 322. Location of Traction Engine Troubles, 366. Location of Tractor Power Plants, 370. Lock for Differential Gear, 281. Loss of Power, Causes of, 369. Low Tension Igniter Plate, 195. Low Tension Ignition System, Action of, 208. Low Tension Magneto Troubles, 393. Lubricants, Requirements of, 232. Lubricants, Solid, 234. Lubricants, Supply to Main Bearings, 244. Lubricants, Why Used, 232. Lubricating Mediums, 233. Lubricating Systems, Gravity, 235. Lubrication by Splash, 239. Lubrication, Mechanical Oil- ing, 237. M Main Bearings, How to Ad- just, 385. Magneto Action Explained, 200. Magneto Governor, Action of, 203. Magneto, High Tension Type, 205. Magneto Troubles, High Ten- sion, 393. Magneto Troubles, Low Ten- sion, 393. Magneto With Revolving Armature, 202. Magnetos, Oscillating Arma- ture Forms, 201. Magnetos, Types of, 199. Mean Effective Pressures of Auto Motors, 440. 470 Index Mechanical Generators, Ad- vantages of, 198. Mechanical Oiling Systems, 237. Mechanical Power, Applica- tion to Agriculture, 35. Mechanical Power, Influence on Arts, 33. Medium Duty Engines, 113. Melting Point of Metals, 449. Method of Removing Valves, 377. Method of Valve Grinding, 377. Method of Valve Timing, 3S0. Methods of Current Produc- tion, 189. Methods of Exploding Charge- 187. Methods of Final Drive, 318. Methods of Fuel Storage, 354. Methods of Testing Batteries, 392. Metric Conversion Tables, 457. Mixture Troubles, Causes of, 389. Money Conversion Tables, 45G. Mowers and Binders, Tractor Operating, 422. Multiple Cylinder Motors, 113. Multiple Cylinder Motors, Power Delivery of, 112. N Noisy Operation, Causes of, 384. O Ohio Friction Roll Clutch, 256. Oil Cooling System, 224. Oiling System Defects, 394. One Cylinder Motors, Ad- vantages of, 110. Operating Principles of Four Cycle Engine, 99. Operating Principle of Two Cycle Engine, 106. Orchard Tractors, 75. Parts of Carburetors, 168. Parts of Gas Power Plant, 62. Parts of Tractor Engines, 127. Parts of Typical Tractors Outlined, 83. Petroleum Products, 156. Piston and Rings, Troubles With, 383. Piston, Care of, 383. Piston Design, 140. Piston Rings, Defects of, 383. Piston Rings, Function of, 141. Piston Rings, Types of, 141. Piston Types, 140. Plough Horse, Pulling Power of, 42. Ploughing, Animals Used in, 35. Ploughing by Tractor, Cost of, 47. Ploughing, Definite Time for, 45. Ploughing, Effect of Soil on Power Needed, 66. Ploughing, First Engine for, 37. Ploughing, Power Needed for, 66. Ploughing, Self Contained Tractors for 82. Ploughing, Test for Power Needed, 67. Index 471 Ploughing, Value of Deep, It. Ploughing, Value of Fall, 45. Ploughs, First Use of, 37. Poor Compression, Causes of, 373. Poor Compression, Locating Weak Cylinder, 374. Power, Actual, of Horse, 41. Power Delivery of Multiple Cylinder Motors, 112. Power Delivery Under Belt, 68. Power, Experiments of Watt, 41. Power for Ploughing, Tests to Determine, 67. Power Needed for Belt Oper- ated Machines, 423. Power Needed for Hauling. 65. Power Needed for Ploughing, 66. Power Needed to Overcome Grades, 70. Power Plant, Auxiliary for Starting, 332. Power Plant Group, What It Is, 62. Power Plant, How to Start. 326. Power Plant, Parts and Func- tions of, 128. Power Plants, How Housed, 370. Power Plants, Multiple Cylin- der, 113. Power Plants, Selection of, 64. Power Plants, Three Cylinder, 121. Power Plants, Two Cylinder, 119. Power Rating Basi.- of Trac- tors, 92. Power Rating, Brake Horse- power, 94. Power Rating, Drawbar Horse- power, 95. Power Rating, Horse Equiv- alent, 97. Power Rating, Indicated Horse-power, 92. Power Traction, Advantages of, 37. Power Traction, Economical Aspect of, 44. Practical Prime Movers for Tractors, 55. Prime Movers for Tractors, Practical, 55. Prime Movers, Steam and Gas Compared, 55. Prime Movers, Thermal Ef- ficiency of, 56. Producing Spark in Cylinders, 196. R Radiator Construction, 228. Radiator, Functions of, 228. Reason for Cooling Gas Engine, 219. Replacing Connecting Rod Bushings, 386. Requirements of Clutches, 248. Requirements of Tractor, Analysis of, 53. Reversing Gear. Holt, 265. Reversing Gear, Why Needed, 262. Reversing Mechanism, Typical 263. 472 Index Revolutions of Wheels Per Mile, 453. Revolving Armature Magneto, 202. Road Scrapers, Hitch for Hauling, 414. Road Signs, Meaning of, 454. Road Surface, Influence on Traction, 71. Rule for Figuring Tank Ca- pacity, 453. Rule for Pulley Speeds, 458. Rules for Calculating Horse- power, 939. Running Gear Faults, 396. Rust, How to Prevent, 449. Rust, How to Remove, 448. Scraping Bearings, Methods of, 388. Secor-Higgins Kerosene Car- buretor, 181. Secor-Higgins Kerosene Car- buretor, Action of, 186. Self-Contained Tractors for Ploughing, 82. Selection of Power Plants, 64. Simple Drill Hitch, 411. Simple Harrow Hitch, 416. Simple Mixing Valve, Con- struction, 161. Sizes of Gas Tractors, 59. Sizes of Tractor Wheels, 294. Sizes of Valves, 137. Small Farm Tractors, 76. Soils, Effect on Power for Ploughing, 66. Spark Plug, High Tension, 197. Spark Timing, 217. Splash System, Constant Level, 242. Speed Changing Gear, Ohio, 261. Speed Changing Gears, Why Needed, 266. Speed of Fly Wheels, Safe, 148. Speed of Magneto Armatures, 206. Spray Nozzles of Carburetors, 169. Starting Large Motor, Engine for, 332. Starting Power Plant, Small Engine for, 332. Starting Tractor Power Plant, 326. Starting "Twin City" Motor, 336. Steam Power, Efficiency of, 56. Steam Tractors, Disadvantages of, 58. Steering, Automatic, 314. Steering Caterpillar Tread Tractor, 339. Steering Gear, Chain and Drum, 310. Steering Tractor by One Wheel, 314. Steering Tractors, How Ac- complished, 309. Storage Battery, Construction of, 101. Strength of Automobile Steels, 454. Suspension Spoke Wheel, 290. Table for Calculating Brake Horse-power, 444. Index 473 Table of Draft for Wagons, 71. Table of Gradients, 74. Table of Horse-power, 441. Table of Horse-power Costs, 451. Testing Batteries, Methods of, 392. Thermal Efficiency, Meaning of, 40. Thermal Efficiency of Gas Tractor, 56. Thermal Efficiency of Horse, 40. Thermal Efficiency of Steam Tractor, 56. Thermometer Scale Conver- sions, 456. Thermo-Syphon Cooling Sys- tem, 222. Three Cylinder Power Plants, 121. Three Plate Clutch, 250. Three Point Support, How Obtained, 288. Three Point Support, With Swinging Axle, 290. Three Point Tractor Support, Why Used, 287. Threshing, Cost of Tractor Power, 49. Timing the Spark, 217. To Change Common Fractions to Decimal, 455. Tools, Blacksmithing, 362. Tools for Care of Tractor, 360. Tools, Woodworking, 365. Traction Dynamometer, Con- struction of, 96. Traction Engines, How to Start, 326. Traction Engines, Main Power Plant Troubles, 368. Traction Engine Troubles, Location of, 366. Traction Gearing, How to Engage, 337. Traction, Influence of Weight on, 69. Traction Member, Caterpillar Tread, 304. Tractive Effort Table, 453. Tractor Attachment for Autos, 428. Tractor Care, Tools for, 360. Tractor, Comparing With Work of Horse, 39. Tractor Control, Holt Cater- pillar, 337. Tractor Control Methods, 334. Tractor Control, Pioneer Sys- tem, 340. Tractor Control,Twin City, 3:W. Tractor Control, Typical Sys- tems, 336. Tractor Designs, Elements of, 61. Tractors, Distinctive Designs of, 87. Tractors, Draft of, 57. Tractor Drive by Chains and Sprockets, 320. Tractor Drive, Conventional, 318. Tractor Drive, Front Wheel, 320. Tractor Engines, Four Cyl- inder, 113. Tractor Engines, Parts of and Functions, 127. Tractor Engines, Three Cyl- inder, 121. 474 Index Tractor Engines, Two ( !yl- inder, 119. Tractor Frame, Typical, 285. Tractor Frames, Construction of, 285. Tractor Front Axles, 308. Tractor Hitches, 401. Tractor House and Workshop. 350. Tractor Houses, Suggestions for, 353. Tractor Houses, Types of, 346. Tractor Housing, Why Neces- sary, 343. Tractor, How to Start, 333. Tractor, How to Stop, 335. Tractor, Many Applications of, 43. Tractor Mechanism, Inspec- tion of, 368. Tractor Motors, Speeds of, 62. Tractor Motors, Various Types Compared, 62. Tractor Operation, Advice on, 341. Tractor Power for Workshop, 353. Tractor Power Plants, Main Troubles of, 368. Tractor Suspension on Springs. 29 1. Tractor, Three Wheel Support, 312. Tractor Troubles, Loss of Power, 369. Tractor Wheels, Construction of, 293. Tractor Wheels, Front, 294. Tractor Wheels, Reinforce- ment of Rim, 296. Tractor Wheels, Sizes of, 294. Tractor Wheel, Suspension Spoke Type, 296. Tractors, Caterpillar Tread Type, 88. Tractors, Drawbar Horse- power of, 95. Tractors, Farm Truck Type, 91. Tractors for Ploughing, Sell- Contained, 82. Tractors for Small Farms, 76. Tractors, Large Capacity, 82. Tractors, Orchard Type, 75. Tractors, Parts of, Outlined, 83. Tractors, Power Rating Basis of, 92. Tractors, Prime Movers for, 55. Tractors, Steam and Gas Com- pared, 55. Troubles Due to Carbon De- posits, 375. Troubles With Clutches, 396. Troubles With Gearing, 397. Troubles With Piston and Rings, 383. Two-Cycle Engines, Operating Principle of, 106. Two Cylinder Gas Motors, 119. Two Cylinder Ignition System, 211. Two Cylinder Motors, Balance of, 119. Two Cylinder Motors, How They Fire, 119. Types of Gas Engines, 97. Typical Tractor Clutches, 250. U Utility of Clutch, 245. Index 475 Utility of Modern Gas Tractor, 414. V Value of Deep Ploughing, 77. Valve Action of Gas Motors, 129. Valve Grinding, Method of, 377. Valve Removal, Method of. 377. Valve Sizes, 137. Valve System of Gas Motors, 136. Valve Timing by Fly Wheel Marks, 382. Valve Timing, Method of, 380. Valves, How Operated, 139. Vaporizer, Ellis Two-Cycle Type, 176. Vertical Cylinder Motors, Ad- vantages of, 117. W Wagons, Power Needed for Hauling, 71. Water Cooling Systems, Anti- freezing Solutions, 445. Water, Use of With Kerosene Mixtures, 184. Watt, Experiments of, 41. Weight Distribution m Gas Tractors, 68. Weight of Air, 161. Weight of Flywheels, 147. Wheel Drive by Sprocket, 299. Wheel, Hub for, 300. Wheel, One for Steering, 314. Wheel, Spring Buffer Drive, 298. Wheel, Suspension Spoke, 296. Wheels, Extension Rims for, 302. Wheels for Tractors, 293. Wheels, Grouters for, 300. Wheels, Methods of Construc- tion, 294. Wheels, Sizes of, 294. Why Differential Gear Is Used. 276. Why Engines Are Oiled, 231. Why Gas Is Compressed Be- fore Ignition, 105. Why Gas Tractors Are Pop- ular, 57. Wood Working Tools for Farm Use, 365. Work of Tractor, Cost of. 51. Worm Drive Gearing, 325. ^T*V PRACTICAL SCIENTIFIC TECHNICAL — — «^**;^*— — EACH BOOK IN THIS CATALOGUE IS WRITTEN BY AN EXPERT AND IS WRITTEN SO YOU CAN UNDERSTAND IT THE NORMAN t HENLEY PUBLISHING COMPANY Publishers of Scientific and Practical Books 132 Nassau Street New York, U.S. A. Any book in this Catalogue sent prepaid on receipt of price. SUBJECT INDEX PAGE Accidents 18 Air Brakes 17, 19 Arithmetics 20 Automobiles 3 Balloons 3 Bevel Gears 14 Boilers 22 Brazing 3 Cams 15 Car Charts 4 Change Gear 14 Charts 3, 4, 22 Chemistry 23 Coal Mining 23 Coke 4 Compressed Air 5 Concrete 5 Cyclopedia 4, 20 Dictionaries 7 Dies 7 Drawing 8, 24 Drop Forging 7 Dynamo 9, 10, 11 Electricity 9, 10, 11, 12 Engines and Boilers 22 Factory Management 12 Flying Machines 3 Fuel 13 Gas Manufacturing 14 Gas Engines 13, 14 Gears 14 Heating, Electric 9 Hot Water Heating 27 Horse-Power Chart 4 Hydraulics 15 Ice Making 15 India Rubber 25 Interchangeable Manufacturing 20 Inventions 15 Knots 15 Lathe Work 16 Lighting (Electric) 9 Link Motion 17 Liquid Air 16 Locomotive Boilers 18 Locomotive Engineering 17, 18, 19 Machinist's Books 20, 21, 22 PAGE Manual Training 22 Marine Engines 22 Marine Steam Turbines 29 Mechanical Movements 20, 21 Metal Turning 16 Milling Machines 21 Mining 22, 23 Oil Engines 13 Patents 15 Pattern Making 23 Perfumery 23 Pipes 28 Plumbing 24 Producer Gas 13 Punches 7 Railroad Accidents 18 Receipt Book 23, 25 Refrigeration 15 Rope Work 15 Rubber Stamps 25 Saws 26 Sheet Metal Working Shop Tools Shop Construction Shop Management Sketching Paper Smoke Prevention Soldering Splices Steam Engineering 26, Steam Heating Steam Pipes Steel Superheated Steam Switchboards 9, Tapers Telephone Threads Tools 20, Turbines Ventilation Valve Gear Valve Setting Walschaert Valve Gear Watchmaking Wiring 9, 11, Wireless Telephones and Telegraphy. . . . 7 21 20 20 1 8 i:5 3 15 27 27 28 28 17 11 16 12 ■22 22 29 27 19 I 17 19 29 j 12 12 ! |^= ANY OF THESE BOOKS PROMPTLY SENT PREPAID TO ANY ADDRESS IN - THE WORLD ON RECEIPT OF PRICE. XSt^How to Remit. — By Postal Money Order, Express Money Order, Bank Draft or Registered Letter. CATALOGUE OF GOOD, PRACTICAL BOOKS AUTOMOBILE THE MODERN GASOLINE AUTOMOBILE— ITS DESIGN, CONSTRUCTION, MAINTENANCE AND REPAIR. By Victor W. Page, M. E. The latest and most complete treatise on the Gasoline Automobile ever issued. Written in simple language by a recognized authority, familiar with every branch of the automobile industry. Free from technical terms. Everything is explained so simply that anyone of average intelligence may gain a comprehensive knowledge of the gasoline automobile. The information is up-to-date and includes, in addition to an exposition of principles of construction and description of all types of automobiles and their components, valuable money-saving hints on the care and operation of motor cars propelled by internal combus- tion engines. Among some of the subjects treated might be mentioned: Torpedo and other symmetrical body forms designed to reduce air resistance; sleeve valve, rotary valve and other tvpes of silent motors; increasing tendency to favor worm-gear power-transmission; univers'al application of magneto ignition; development of automobile electric-lighting systems; block motors; underslung chassis; application of practical self-starters; long stroke and offset cylinder motors; latest automatic lubrication systems; silent chains for valve operation and change-speed gearing; the use of front wheel brakes and many other detail refinements. By a careful study of the pages of this book one can gain practical knowledge of automobile construction that will save time, money and worry. The book tells you just what to do, how and when to do it. Nothing has been omitted, no detail has been slighted. Every part of the automobile, its equipment, accessories, tools, supplies, spare parts necessary, etc., have been discussed comprehensively. If you are or intend to become a motorist, or are in any way interested in the modern Gasoline Automobile, this is a book you cannot afford to be without. Nearly 600 6x9 pages — and more than 500 new and specially made detail il- lustrations, as well as many full page and double page plates, showing all parts of the automobile. Including nine large folding plates. Price $2.50 BALLOONS AND FLYING MAGHINES MODEL BALLOONS AND FLYING MACHINES. WITH A SHORT ACCOUNT OF THE PROGRESS OF AVIATION. By J. H. Alexander. This book has been written with a view to assist those who desire to construct a model airship or flying machine. It contains five folding plates of working drawings, each sheet containing a different sized machine. Much instruction and amusement can be obtained from the making and flying of these models. A short account of the progress of aviation is included, which will render the book of greater interest. Several illustrations of full sized airship and flying machines of the latest types are scattered throughout the text. This practical work gives data, working drawings, and details which will assist materially those interested in the problems of flight. 127 pages, 45 illustra- tions, 5 folding plates. Price $1.50 BRAZING AND SOLDERING BRAZING AND SOLDERING. By James F. Hobart. The only book that shows you just how to handle any job of brazing or soldering that comes {ilong; tells you what mixture to use, how to make a furnace if you need one. Full of valuable kinks. The fifth edition of this book has just been published, and to it much new matter and a large number of tested formulas for all kinds of solders and fluxes have been added. Illustrated 25 cents CHARTS MODERN SUBMARINE CHART— WITH 200 PARTS NUMBERED AND NAMED. A cross-section view, showing clearly and distinctly all the interior of a Submarine of the latest type. You get more information from this chart, about the construction and opera- tion of a Submarine, than in any other way. No details omitted — everything is accurate and to scale. It is absolutely correct in every detail, having been approved by Naval Engineers. All the machinery and devices fitted in a modern Submarine Boat are shown, and to make the engraving more readily understood all the features are shown in operative form, with Officers and Men in the act of performing the duties assigned to them in service con- ditions. This CHART IS REALLY AN ENCYCLOPEDIA OF A SUBMARINE. It *s educational and worth many times its cost. Mailed in a Tube for 25 cents CATALOGUE OF GOOD, PRACTICAL BOOKS ■ BOX CAR CHART. A chart showing the anatomy of a box car, having every part of the car numbered and its proper name given in a reference list 20 cents GONDOLA CAR CHART. A chart showing the anatomy of a gondola car, having every part of the car numbered and its proper reference name given in a reference list 20 cents PASSENGER CAR CHART. A chart showing the anatomy of a passenger car, having every part of the car numbered and its proper name given in a reference list 20 cents WESTINGHOUSE AIR-BRAKE CHARTS. Chart I. — Shows (in colors) the most modern Westinghouse High Speed and Signal Equip- ment used on Passenger Engines, Passenger Engine Tenders, and Passenger Cars. Chart II. — -Shows (in colors) the Standard Westinghouse Equipment for Freight and Switch En- gines, Freight and Switch Engine Tenders, and Freight Cars. Price for the set . 50 cents TRACTIVE POWER CHART. A chart whereby you can find the tractive power or drawbar pull of any locomotive, without making a figure. Shows what cylinders are equal, how driving wheels and steam pressure affect the power. What sized engine you need to exert a given drawbar pull or anything you desire in this line 50 cents HORSE POWER CHART. Shows the horse power of any stationary engine without calculation. No matter what the cylinder diameter of stroke; the steam pressure or cut-off; the revolutions, or whether con- densing or non-condensing, it's all there. Easy to use, accurate, and saves time and calcu- lations. Especially useful to engineers and designers ... 50 cents BOILER ROOM CHART. By Geo. L. Fowler. A Chart — size 14 x 28 inches — showing in isometric perspective the mechanisms belonging in a modern boiler room. Water tube boilers, ordinary grates and mechanical stokers, feed water heaters and pumps comprise the equipment. The various parts are shown broken or removed, so that the internal construction is fully illustrated. Each part is given a reference number, and these, with the corresponding name, are given in a glossary printed at the sides. This chart is really a dictionary of the boiler room — the names of more than 200 parts being given. It is educational — worth many times its cost 25 cents CIVIL ENGINEERING HENLEY'S ENCYCLOPEDIA OF PRACTICAL ENGINEERING AND ALLIED TRADES. Edited by Joseph G. Horner, A. M. I. E. M. This set of five volumes contains about 2,500 pages with thousands of illustrations, including diagrammatic and sectional drawings with full explanatory details. This work covers the entire practice of Civil and Mechanical Engineering. The best known experts in all branches of engineering have contributed to these volumes. The Cyclopedia is admirably well adapted to the needs of the beginner and the self-taught practical man, as well as the mechanical en- gineer, designer, draftsman, shop superintendent, foreman, and machinist. The work will be found a means of advancement to any progressive man. It is encyclopedic in scope, thorough and practical in its treatment of technical subjects, simple and clear in its descriptive matter, and without unnecessary technicalities or formulae. The articles are as brief as may be and yet give a reasonably clear and explicit statement of the subject, and are written by men who have had ample practical experience in the matters of which they write. It tells you all you want to know about engineering and tells it so simply, so clearly, so concisely, that one cannot help but understand. As a work of reference it is without a peer. $6.00 per single volume. For complete set of five volumes, price $25.00 COKE COKE— MODERN COKING PRACTICE; INCLUDING THE ANALYSIS OF MATERIALS AND PRODUCTS. By T. H. Byrom and J. E. Christopher. A handbook for those engaged in Coke manufacture and the recovery of By-products. Fully illustrated with folding plates. It has been the aim of the authors, in preparing this book, to produce one which shall be of use and benefit to those who are associated with, or inter- ested in, the modern developments of the industry. Contents: I. Introductory. II. Gen- 4 CATALOGUE OF GOOD, PRACTICAL BOOKS eral Classification of Fuels. III. Coal Washing. IV. The Sampling and Valuation of Coal, Coke, etc. V. The Calorific Power of Coal and Coke. VI. Coke Ovens. VII. Coke Ovens, continued. VIII. Coke Ovens, continued. IX. Charging and Discharging of Coke Ovens, X. Cooling and Condensing Plant. XI. Gas Exhausters. XII. Composition and Analysis of Ammoniacal Liquor. XIII. Working-up of Ammoniacal Liquor. XIV. Treatment of Waste Gases from Sulphate Plants. XV. Valuation of Ammonium Sulphate. XVI. Direct Recoverv of Ammonia from Coke Oven Gases. XVII. Surplus Gas from Coke Oven. Use- ful Tables. Very fully illustrated. Price S3. 50 net COMPRESSED AIR COMPRESSED AIR IN ALL ITS APPLICATIONS. By Gardner D. Hiscox. This is the most complete book on the subject of Air that has ever been issued, and its thirty- five chapters include about every phase of the subject one can think of. It may be called an encyclopedia of compressed air. It is written by an expert, who. in its 665 pages, has dealt with the subject in a comprehensive manner, no phase of it being omitted. Includes the physical properties of air from a vacuum to its highest pressure, its thermodynamics, com- pression, transmission and uses as a motive power; in the Operation of Stationary and Port- able Machinery, in Mining. Air Tools, Air Lifts, Pumping of Water, Acids, and Oils; the Air Blast for Cleaning and Painting, the Sand Blast and its Work, and the Numerous Appli- ances in which Compressed Air is a Most Convenient and Economical Transmitter of Power for Mechanical Work. Railway Propulsion. Refrigeration, and the Various Uses to which Compressed Air has been applied. Includes forty-four tables of the physical properties of air. its compression, expansion, and volumes required for various kinds of work, and a list of patents on compressed air from 1875 to date. Over 500 illustrations, 5th Edition, revised and enlarged. Cloth bound, $5.00. Half Morocco, price $6.50 CONCRETE ORNAMENTAL CONCRETE WITHOUT MOLDS. By A. A. Houghton. The process for making ornamental concrete without molds has long been held as a secret, and now, for the first time, this process is given to the public. The book reveals the secret and is the only book published which explains a simple, practical method whereby the concrete worker is enabled, by employing wood and metal templates of different designs' to mold or model in concrete any Cornice, Archivolt, Column, Pedestal, Base Cap, Urn or Pier in a monolithic form — right upon the job. These may be molded in units or blocks, and then built up to suit the specifications demanded. This work is fully illustrated, with detailed engravings. Price $2.00 CONCRETE FROM SAND MOLDS. By A. A. Houghton. A Practical Work treating on a process which has heretofore been held as a trade secret by the few who possessed it, and which will successfully mold every and any class of ornamental concrete work. The process of molding concrete with sand molds is of the utmost practical value, possessing the manifold advantages of a low cost of molds, the ease and rapidity of operation, perfect details to all ornamental designs, density, and increased strength of the concrete, perfect curing of the work without attention and the easv removal of the molds re- gardless of any undercutting the design may have. 192 pages. Fully illustrated. Price $2.00 CONCRETE WALL FORMS. By A. A. Houghton. A new automatic wall clamp is illustrated with working drawings. Other tvpes of wall forms, clamps, separators, etc., are also illustrated and explained " 50 cents CONCRETE FLOORS AND SIDEWALKS. By A. A. Houghton. The molds for molding squares, hexagonal and many other styles of mosaic floor and side- walk blocks are fully illustrated and explained 50 cents PRACTICAL CONCRETE SILO CONSTRUCTION. By A. A. Houghton. Complete working drawings and specifications are given for several styles of concrete silos with illustrations of molds for monolithic and block silos. The tables, data and information presented in this book are of the utmost value in planning and constructing all forms of concrete silos 50 cents MOLDING CONCRETE CHIMNEYS, SLATE AND ROOF TILES. Bv A. A. Houghton. The manufacture of all types of concrete slate and roof tile is fullv treated. Valuable data on all forms of reinforced concrete roofs are contained within its pages. The construction of concrete chimneys by block and monolithic systems is fullv illustrated and described. A number of ornamental designs of chimney construction with molds are shown in this valu- able treatise 50 cent* CATALOGUE OF GOOD, PRACTICAL BOOKS MOLDING AND CURING ORNAMENTAL CONCRETE. By A. A. Houghton. The proper proportions of cement and aggregates for various finishes, also the methods of thoroughly mixing and placing in the molds, are fully treated. An exhaustive treatise on this s ibject that every concrete worker will find of daily use and value 50 cents CONCRETE MONUMENTS, MAUSOLEUMS AND BURIAL VAULTS. By A. A. Houghton. The molding of concrete monuments to imitate the most expensive cut stone is explained in this treatise, with working drawings of easily built molds. Cutting inscriptions and designs is also fully treated .50 cents MOLDING CONCRETE BATH TUBS, AQUARIUMS AND NATATORIUMS. By A. A. Houghton. Simple molds and instruction are given for molding many styles of concrete bath tubs, swimming pools, etc. These molds are easily built and permit rapid and successful work 50 cents CONCRETE BRIDGES, CULVERTS AND SEWERS. By A. A. Houghton. A number of ornamental concrete bridges with illustrations of molds are given. A collapsible center or core for bridges, culverts and sewers is fully illustrated with detailed instructions for building . . . . . 50 cents CONSTRUCTING CONCRETE PORCHES. By A. A. Houghton. A number of designs with working drawings of molds are fully explained so anyone can easily construct different styles of ornamental concrete porches without the purchase of expensive molds , 50 cents MOLDING CONCRETE FLOWER POTS, BOXES, JARDINIERES, ETC. By A. A. Houghton. The molds for producing many original designs of flower pots, urns, flower boxes, jardinieres, etc., are fully illustrated and explained, so the worker can easily construct and operate same 50 cents MOLDING CONCRETE FOUNTAINS AND LAWN ORNAMENTS. By A. A. Houghton. The molding of a number of designs of lawn seats, curbing, hitching posts, pergolas, sun dials and other forms of ornamental concrete for the ornamentation of lawns and gardens, is fully illustrated and described 50 cents .CONCRETE FOR THE FARM AND SHOP. By A. A. Houghton. The molding of drain tile, tanks, cisterns, fence posts, stable floors, hog and poultry houses and all the purposes for which concrete is an invaluable aid to the farmer are numbered among the contents of this handy volume , 50 cents POPULAR HANDBOOK FOR CEMENT AND CONCRETE USERS. By Myron H. Lewis, This is a concise treatise of the principles and methods employed in the manufacture and use of cement in all classes of modern works. The author has brought together in this work all the salient matter of interest to the user of concrete and its many diversified products. The matter is presented in logical and systematic order, clearly written, fully illustrated and free from involved mathematics. Everything of value to the concrete user is given including kinds of cement employed in construction, concrete architecture, inspection and testing, water- proofing, coloring and painting, rules, tables, working, and cost data. The book comprises thirty-three chapters, as follows: Introductory. Kinds of Cements and How They are Made. Properties, Testing and Requirements of Hydraidic Cement. Concrete and its Properties. Sand, Broken Stone and Gravel for Concrete. How to Proportion the Materials. How to Mix and Place Concrete. Forms for Concrete Construction. The Architectural and Artistic Possibilities of Concrete. Concrete Residences. Mortars. Plasters and Stucco and How to Use Them. The Artistic Treatment of Concrete Surfaces. Concrete Building Blocks. The Making of Ornamental Concrete. Concrete Pipes. Fences, Posts, Etc. Essential Features and Advantages of Reen- forced Concrete. How to Design Reenforced Concrete Beams, Slabs and Columns. Ex- planations of the Methods and Principles in Designing Reenforced Concrete Beams and Slabs. Systems of Reenforcement Employed. Reenforced Concrete in Factory and General CATALOGUE OF GOOD, PRACTICAL BOOKS Building Construction. Concrete in Foundation Work. Concrete Retaining Walls, Abut- ments, and Bulkheads. Concrete Arches and Arch Bridges. Concrete Beam and Girder Bridges. Concrete in Sewerage and Drainage Works. Concrete Tanks, Dams and Reser- voirs. Concrete Sidewalks. Curbs and Pavements. Concrete in Railroad Constructions. The Utility of Concrete on the Farm. The Waterproofing of Concrete Structure. Grout or Liquid Concrete and Its Use. Inspection of Concrete Work. Cost of Concrete Work. Some of the special features of the book are: 1. The Attention Paid to the Artistic and Architectural Side of Concrete Work. 2. The Authoritative Treatment of the Problem of Waterproofing Concrete. 3. An Excellent Summary of the Rules to be Followed in Concrete Construction. 4. The Valuable Cost Data and Useful Tables given. A valuable Addition to the Library of Every Cement and Concrete User. Price $2.50 WATERPROOFING CONCRETE. By Myron H. Lewis. Modern Methods of Waterproofing Concrete and Other Structures. A condensed statement of the Principles, Rules, and Precautions to be Observed in Waterproofing and Damp- proofing Structures and Structural Materials. Paper binding. Illustrated. Price. .50 cents DICTIONARIES STANDARD ELECTRICAL DICTIONARY. By T. O'Conor Sloane. An indispensable work to all interested in electrical science. Suitable alike for the student and professional. A practical hand-book of reference containing definitions of about 5,000 distinct words, terms and phrases. The definitions are terse and concise and include every term used in electrical science. Recently issued. An entirely new edition. Should be in the possession of all who desire to keep abreast with the progress of this branch of science. Complete, concise and convenient. 682 pages. 393 illustrations. Price .... $3.00 DIES— METAL WORK DIES: THEIR CONSTRUCTION AND USE FOR THE MODERN WORKING OF SHEET METALS. ' By J. V. Woodworth. A most useful book, and- one which should be in the hands of all engaged in the press working of metals; treating on the Designing, Constructing, and Use of Tools, Fixtures and Devices, together with the manner in which they should be used in the Power Press, for the cheap and rapid production of the great variety of sheet metal articles now in use. .It is designed as a guide to the production of sheet metal parts at the minimum of cost with the maximum of output. The hardening and tempering of Press tools and the classes of work which may be produced to the best advantage by the use of dies in the power press are fully treated. Its 505 illustrations show dies, press fixtures and sheet metal working devices, the descriptions of which are so clear and practical that all metal-working mechanics will be able to understand how to design, construct and use them. Many of the dies and press fixtures treated were either constructed by the author or under his supervision. Others were built by skilful mechanics and are in use in large sheet metal establishments and machine shops. Price $3.00 PUNCHES, DIES AND TOOLS FOR MANUFACTURING IN PRESSES. By J. V. Woodworth. This work is a companion volume to the author's elementary work entitled "Dies, Their Construction and Use." It does not go into the details of die making to the extent of the author's previous book, but gives a comprehensive review of the field of operations carried on by presses. A large part of the information given has been drawn from the author's personal experience. It might well be termed an Encyclopedia of Die Making, Punch Making, Die Sinking. Sheet Metal Working, and Making of Special Tools, Sub-presses, Devices and Mechani- cal Combinations for Punching, Cutting, Bending, Forming, Piercing, Drawing, Compressing and Assembling Sheet Metal Parts, and also Articles of other Materials in Machine Tools. 2d Edition. Price $4.00 DROP FORGING, DIE SINKING AND MACHINE FORMING OF STEEL. By J. V. Woodworth. This is a practical treatise on Modern Shop Practice. Processes, Methods. Machines, Tools, and Details, treating on the Hot and Cold Machine- Forming of Steel and Iron Into Finished shapes; Together with Tools, Dies,- and Machinery involved in the manufacture of Duplicate CATALOGUE OF GOOD, PRACTICAL BOOKS Forgings and Interchangeable Hot and Cold Pressed Parts from Bar and Sheet Metal. This book fills a demand of long standing for information regarding drop forging, die-sinking and machine forming of steel and the shop practice involved, as it actually exists in the modern drop forging shop. The processes of die-sinking and force-making, which are thor- oughly described and illustrated in this admirable work, are rarely to be found explained in such a clear and concise manner as is here set forth. The process of die-sinking relates to the engraving or sinking of the female or lower dies, such as are used for drop forgings. hot and cold machine forging, swedging and the press working of metals. The process of force- making relates to the engraving or raising of the male or upper dies used in producing the lower dies for the press-forming and machine-forging of duplicate parts of metal. In addition to the arts above mentioned the book contains explicit information regarding the drop forging and hardening plants, designs, conditions, equipment, drop hammers, forging machines, etc.. machine forging, hydraulic forging, autogenous welding and shop practice. The book contains eleven chapters, and the information contained in these chapters is just what will prove most valuable to the forged metal worker. All operations described in the work are thoroughly illustrated by means of perspective half-tones and outline sketches of the machinery employed. 300 detailed illustrations. Price $2.50 DRAWING— SKETCHING PAPER LINEAR PERSPECTIVE SELF-TAUGHT. By Herman T. C. Kraus. This work gives the theory and practice of linear perspective, as used in architectural, engi- neering, and mechanical drawings. Persons taking up the study of the subject by themselves will be able by the use of the instruction given to readily grasp the subject, and by reason- able practice become good perspective draftsmen. The arrangement of the book is good ; the plate is on the left-hand, while the descriptive text follows on the opposite page, so as to be readily referred to. The drawings are on sufficiently large scale to show the work clearly and are plainly figured. The whole work makes a very complete course on perspective draw- ing, and will be found of great value to architects, civil and mechanical engineers, patent attorneys, art designers, engravers, and draftsmen $2.50 PRACTICAL PERSPECTIVE. By Richards and Colvin. Shows just how to make all kinds of mechanical drawings in the only practical perspective isometric. Makes everything plain so that any mechanic can understand a sketch or drawing in this way. Saves time in the drawing room, and mistakes in the shops. Contains practical examples of various classes of work. 3rd Edition 50 cents SELF-TAUGHT MECHANICAL DRAWING AND ELEMENTARY MACHINE DESIGN. By F- L. Sylvester, M.E., Draftsman, with additions by Erik Oberg, associate editor of "Machinery." This is a practical treatise on Mechanical Drawing and Machine Design, comprising the first principles of geometric and mechanical drawing, workshop mathematics, mechanics, strength of materials and the calculations and design of machine details. The author's aim has been to adapt this treatise to the requirements of the practical mechanic and young draftsman and to present the matter in as clear and concise a manner as possible. To meet the demands of this class of students, practically all the important elements of machine design have been dealt with, and in addition algebraic formulas have been explained, and the elements of trigonometry treated in the manner best suited to the needs of the prac- tical man. The book is divided into 20 chapters, and in arranging the material, mechan- ical drawing, pure and simple, has been taken up first, as a thorough understanding of the principles of representing objects facilitates the further study of mechanical subjects. This is followed by the mathematics necessary for the solution of the problems in machine de- sign which are presented later, and a practical introduction to theoretical mechanics and the strength of materials. The various elements entering into machine design, such as cams, gears, sprocket wheels, cone pulleys, bolts, screws, couplings, clutches, shafting and fly- wheels have been treated in such a way as to make possible the use of the work as a text- book for a continuous course of study. It is easily comprehended and assimilated even by students of limited previous training. 330 pages, 215 engravings. Price. . . . $2.00 A NEW SKETCHING PAPER. A new specially ruled paper to enable you to make sketches or drawings in isometric perspective without any figuring or fussing. It is being used for shop details as well as for assembly drawings, as it makes one sketch do the work of three, and no workman can help seeing just what is wanted. Pads of 40 sheets, 6x9 inches, 25 cents. Pads of 40 sheets, 9x12 inche6. 50 cents; 40 sheets, 12x18, Price $1.00 8 CATALOGUE OF GOOD, PRACTICAL BOOKS ELECTRICITY ARITHMETIC OF ELECTRICITY. By Prof. T. O'Conor Sloaxe. A practical treatise on electrical calculations of all kinds reduced to a series of rules, all of the simplest forms, and involving only ordinary arithmetic; each rule illustrated by one or more practical problems, with detailed solution of each one. This book is classed among the most useful works published on the science of electricity covering as it does the mathematics of electricity in a manner that will attract the attention of those who are not familiar with alge- braical formulas. 20th Edition. 160 pages. Price $1.00 COMMUTATOR CONSTRUCTION. By Wm. Baxter, Jr. The business end of any dynamo or motor of the direct current type is the commutator. This book goes into the designing, building, and maintenance of commutators, shows how to locate troubles and how to remedy them; everyone who fusses with dynamos needs this. 25 cents DYNAMO BUILDING FOR AMATEURS, OR HOW TO CONSTRUCT A FIFTY- WATT DYNAMO. By Arthur J. Weed, Member of N. Y. Electrical Society. A practical treatise showing in detail the construction of a small dynamo or motor, the entire machine work of which can be done on a small foot lathe. Dimensioned working drawings are given for each piece of machine work and each operation is clearly described. This machine, when used as a dynamo, has an output of fifty watts; when used as a motor it will drive a small drill press or lathe. It can be used to drive a sewing machine on any and all ordinary work. The book is illustrated with more than sixty original engravings showing the actual construction of the different parts. Among the contents are chapters on 1. Fifty Watt Dynamo. 2. Side Bearing Rods. 3. Field Punchings. 4. Bearings. 5. Commu- tator. 6. Pulley. 7. Brush Holders. 8. Connection Board. 9. Armature Shaft. 10. Armature. 11. Armature Winding. 12. Field Winding. 13. Connecting and Starting. Price, paper, 50 cents. Cloth $1.00 ELECTRIC FURNACES AND THEIR INDUSTRIAL APPLICATIONS. By J. Wright This is a book which will prove of interest to many classes of people; the manufacturer who desires to know what product can be manufactured successfully in the electric furnace, the chemist who wishes to post himself on the electro-chemistry, and the student of science who merely looks into the subject from curiosity. The book is not so scientific as to be of use only to the technologist, nor so unscientific as to suit only the tyro in electro-chemistry; it is a practical treatise of what has been done, and of what is being done, both experimentally and commercially with the electric furnace. In important processes not only are the chemical equations given, but complete thermal data are set forth and both the efficiency of the furnace and the cost of the product are worked out , thus giving the work a solid commercial value aside from its efficacy as a work of reference. The practical features of furnace building are given the space that the' subject deserves. The forms and refractory materials used in the linings, the arrangement of the connections to the electrodes, and other important details are explained. 288 pages. New Revised Edition. Fully illustrated. Price $3.00 ELECTRIC LIGHTING AND HEATING POCKET BOOK. By Sydney F. Walker. This book puts in convenient form useful information regarding the apparatus which is likely to be attached to the mains of an electrical company. Tables of units and equivalents are included and useful electrical laws and formulas are stated. One section is devoted to dynamos, motors, transformers and accessory apparatus; another to accumulators, another to switchboards and related equipment, a fourth to a description of various systems of distribution, a fifth section to a discussion of instruments, both fur portable use and switchboards; another section deals with electric lamps of various types and accessory appliances, and the concluding section is given up to electric heating apparatus. In each section a large number of commercial types are described, frequent tables of dimen- sions being included. A great deal of detail information of each line of apparatus is given and the illustrations shown give a good idea of the gt-ru-ral appearance of the apparatus under discussion. The book also contains much valuable information for the central station engi- neer. 438 pages. 300 engravings. Bound in leather pocket book form. Price . $3.00 ELECTRIC WIRING, DIAGRAMS AND SWITCHBOARDS. By Newtox Harrisox. \ thoroughly practical treatise covering the subject of Electric Wiring in all its branches, including explanations and diagrams which are thoroughly explicit and greatly simplify the subject. Practical every-day problems in wiring are presented and the method of obtaining intelligent results clearly shown. Only arithmetic is used. Ohm's law is given CATALOGUE OF GOOD, PRACTICAL BOOKS a simple explanation with reference to wiring for direct and alternating currents. The funda- mental principle of drop of potential in circuits is shown with its various applications. The simple circuit is developed with the position of mains, feeders and branches; their treat- ment as a part of a wiring plan and their employment in house-wiring clearly illustrated. Some simple facts about testing are included in connection with the wiring. Molding and conduit work are given careful consideration; and switchboards are systematically treated, built up and illustrated, showing the purpose they serve, for connection with the circuits, and to shunt and compound wound machines. The simple principles of switchboard construction, the development of the switchboard, the connections of the various instru- ments including the lightning arrester, are also plainly set forth. Alternating current wiring is treated, with explanations of the power factor, conditions calling for various sizes of wire and a simple way of obtaining the sizes for single-phase, two- phase and three-phase circuits. This is the only complete work issued showing and telling you what you should know about direct and alternating current wiring. It is a ready refer- ence. The work is free from advanced technicalities and mathematics, arithmetic being used throughout. It is in every respect a handy, well-written, instructive, comprehensive volume on wiring for the wireman, foreman, contractor, or electrician. 272 pages; 105 illus- trations. Price $1.50 ELECTRIC TOY MAKING, DYNAMO BUILDING, AND ELECTR T C MOTOR CON- STRUCTION. By Prof. T. O'Conor Sloane. This work treats of the making at home of electrical toys, electrical apparatus, motors, dynamos and instruments in general, and is designed to bring within the reach of young and old the manufacture of genuine and useful electrical appliances. The work is especially designed for amateurs and young folks. Thousands of our young people are daily experimenting, and busily engaged in making electrical toys and apparatus of various kinds. The present work is just what is wanted to give the much needed information in a plain, practical manner, with illustrations to make easy the carrying out of the work. 19th Edition. Price $1.00 ELECTRICIAN'S HANDY BOOK. By Prof. T. O'Conor Sloane. This work of 768 pages is intended for the practical electrician who has to make things go. The entire field of electricity is covered within its pages. Among some of the subjects treated are: The Theory of the Electric Current and Circuit, Electro-Chemistry, Primary Batteries, Storage Batteries, Generation and Utilization of Electric Powers, Alternating Current, Arma- ture Winding, Dynamos and Motors, Motor Generators, Operation of the Central Station Switchboards, Safety Appliances, Distribution of Electric Light and Power, Street Mains, Transformers, Arc and Incandescent Lighting, Electric Measurements, Photometry, Electric Railways, Telephony, Bell-Wiring, Electro-Plating, Electric Heating, Wireless Telegraphy, etc. It contains no useless theory; everything is to the point. It teaches you just what you want to know about electricity. It is the standard work published on the subject. Forty-one chapters, 610 engravings, handsomely bound in red leather with title and edges in gold. Price: $3.50 ELECTRICITY IN FACTORIES AND WORKSHOPS, ITS COST AND CONVENIENCE. By Arthur P. Haslam. A practical book for power producers and power users showing what a convenience the electric motor, in its various forms, has become to the modern manufacturer. It also deals with the conditions which determine the cost of electric driving, and compares this with other methods of producing and utilizing power. Among the chapters contained in the book are: The Direct Current Motor; The Alternating Current Motor; The Starting and Speed Regulation of Electric Motors; The Rating and Efficiency of Electric Motors; The Cost of Energy as Affected by Conditions of Working, The Question for the Small Power User; Independent Generating Plants; Oil and Gas Engine Plants; Steam Plants; Power Station Tariffs; The Use of Electric Power in Textile Factories; Electric Power in Printing Works; The Use of Electric Power in Engineering Workshops Miscellaneous Application of Electric Power; The Installation of Electric Motors; The Lighting of Industrial Establishments. 312 pages. Very fully illustrated. Price .... $2.50 ELECTRICITY SIMPLIFIED. By Prof. T. O'Conor Sloane. The object of "Electricity Simplified" is to make the subject as plain as possible and to show what the modern conception of electricity is; to show how two plates of different metals immersed in acid can send a message around the globe; to explain how a bundle of copper wire rotated by a steam engine can be the agent in lighting our streets, to tell what the volt, ohm and ampere are, and what high and low tension mean; and to answer the questions that perpetually arise in the mind in this age of electricity. 172 pages. Illustrate. Price $ 1.00 IO CATALOGUE OF GOOD, PRACTICAL BOOKS HOUSE WIRING. By Thomas W. Poppe. This work describes and illustrates the actual installation of Electric Light Wiring, the manner in which the work should be done, and the method of doing it. The book can be conveniently carried in the pocket. It is intended for the Electrician, Helper and Apprentice. It solves all Wiring Problems, and contains nothing that conflicts with the rulings of the Nation- al Board of Fire Underwriters. It gives just the information essential to the Successful Wiring of a Building. Among the subjects treated are: Locating the Meter. Panel Boards. Switches. Plug Receptacles. Brackets. Ceiling Fixtures. The Meter Connections. The Feed Wires. The Steel Armored Cable System. The Flexible Steel Conduit System. The Ridig Conduit System. A digest of the Xational Board of Fire Underwriters' rules relating to metallic wiring systems. Various switching arrangements explained and diagrammed. The easiest method of testing the Three and Four-way circuits explained. The grounding of all metallic wiring systems and the reason for doing so shown and explained. The in- sulation of the metal parts of lamp fixtures and the reason for the same described and illustrated. 125 pages. Fully illustrated. Flexible cloth. Price 50 cents HOW TO BECOME A SUCCESSFUL ELECTRICIAN- By Prof. T. O 'Conor Sloan e. Every young man who wishes to become a successful electrician should read this book. It tel's in simple language the surest and easiest way to become a successful electrician. The studies to be followed, methods of work, field of operation and the requirements of the successful electrician are pointed out and fully explained. Every young engineer will find this an ex- cellent stepping-stone to more advanced works on electricity which he must master before success can be attained. Many young men become discouraged at the very outstart by attempting to read and study books that are far beyond their comprehension. This book serves as the connecting link between the rudiments taught in the public schools and the real studv of electricity. It is interesting from cover to cover. Fifteenth edition. 202 pages. Illustrated. Price $1.00 MANAGEMENT OF DYNAMOS. By Lummis-Paterson. A handbook of theory and practice. This work is arranged in three parts. The first part covers the elementary theory of the dynamo. The second part, the construction and action of the different classes of dynamos in common use are described; while the third part relates to such matters as affect the practical management and working of dynamos and motors. The following chapters are contained in the book: Electrical Units: Magnetic Principles; Theory of the Dynamo; Armature; Armature in Practice; Field Magnets; Field Magnets in Practice; Regulating Dynamos: Coupling Dynamos; Installation, Running, and Maintenance of Dynamos; Faults in Dyn-mos; Faults in Armatures; Motors. 292 pages. 117 illustra- tions'. Price $1.50 STANDARD ELECTRICAL DICTIONARY. By T. O'Conor Sloane. An indispensable work to all interested in electrical science. Suitable alike for the student and professional. A practical hand-book of reference containing definitions of about 5,000 distinct words, terms and phrases. The definitions are terse and concise and include every term used in electrical science. Recently issued. An entirely new edition. Should be in the possession of all who desire to keep abreast with the progesss of this branch of science. In its arrangement and typography the book is very convenient. The word or term defined is printed in black-faced* type which readily catches the eye, while the body of the page is in smaller but distinct type. The definitions are well worded, and so as to be understood by the non-technical reader. The general plan seems to be to give an exact, concise definition, and then amplify and explain in a more popular way. Synonyms are also given, and refer- ences to other words and phrases are made. A very complete and accurate index of fifty pages is at the end of the volume; and as this index contains all synonyms, and as all phrases are indexed in every reasonable combination of words, reference to the proper place in the body of the book is readily made. It is difficult to decide how far a book of this character is to keep the dictionary form, and to what extent it may assume the encyclopedia form. For some purposes, concise, exactly worded definitions are needed; for other purposes, more extended descriptions are required. This book seeks to satisfy both demands, and does it with considerable success. Complete, concise, and convenient. 682 pages. 393 illustra- tions. Twelfth edition. Price $3.00 SWITCHBOARDS. By William Baxter, Jr. This book appeals to every engineer and electrician who wants to know the practical side of things. It takes up all sorts and conditions of dynamos, connections and circuits and shows by diagram and illustration just how the switchboard should be connected. Includes direct and alternating current boards, also those for arc lighting, incandescent, and power circuits. Special treatment on high voltage boards for power transmission. 2d Edition. 190 pages. Illustrated. Price $1.50 II CATALOGUE OF GOOD, PRACTICAL BOOKS TELEPHONE CONSTRUCTION, INSTALLATION, WIRING, OPERATION AND MAINTENANCE. By W. H. Radcliffe and H. C. Cushing. This book gives the principles of construction gnd operation of both the Bell and Independent instruments; approved methods of installing and wiring them; the means of protecting them from lightning and abnormal currents; their connection together for operation as series or bridging stations; and rules for their inspection and maintenance. Line wiring and the wir- ing and operation of special telephone systems are also treated. Intricate mathematics are avoided, and all apparatus, circuits and systems are thoroughly described. The appendix contains definitions of units and terms used in the text. Selectee- wiring tables, which are very helpful, are also included. Among the subjects treated are Construction, Operation, and installation of Telephone Instruments, Inspection and Main- tenance of Telephone Instruments; Telephone Line Wiring; Testing Telephone Line Wires and Cables; W T iring and Operation of Special Telephone Systems, etc. 100 pages, 125 illus- trations $1.00 WIRELESS TELEGRAPHY AND TELEPHONY SIMPLY EXPLAINED. By Alfred P. Morgan. This is undoubtedly one of the most complete and comprehensible treatises on the subject ever published, and a close study of its pages will enable one to master all the details of the wireless transmission of messages. The author has filled a long felt want and has succeeded in furnishing a lucid, comprehensible explanation in simple language of the theory and practice of wireless telegraphy and telephony. Among the contents are: Introductory; Wireless Transmission and Receptiorv — The Aerial System. Earth Connections — The Transmitting Apparatus, Spark Coils and Trans- formers. Condensers, Helixes, Spark Gaps, Anchor Gaps, Aerial Switches — The Receiving Apparatus, Detectors, etc. — Tuning and Coupling, Tuning Coils, Loose Couplers, Variable Condensers, Directive Wave Systems — Miscellaneous Apparatus, Telephone Receivers, Range of Stations, Static, Interference — Wireless Telephones, Sound and Sound Waves, The Vocal Cords and Ear — Wireless Telephones, How Sounds are changed into Electric Waves — Wireless Telephones, The Apparatus — Summary. 200 pages. 150 engravings. Price $1.00 WIRELESS TELEPHONES AND HOW THEY WORK. By James Erskine-Murray. This work is free from elaborate details and aims at giving a clear survey of the way in which Wireless Telephones work. It is intended for amateur workers and for those whose knowledge of electricity is slight. Chapters contained: How We Hear; Historical; The Conversion of Sound into Electric Waves; Wireless Transmission; The Production of Alternating Currents of High Frequency; How the Electric Waves are Radiated and Received; The Receiving Instruments; Detectors; Achievements and Expectations; Glossary of Technical Words, Cloth. Price $1.00 WIRING A HOUSE. By Herbert Pratt. Shows a house already built; tells just how to start about wiring it; where to begin; what wire to use; how to run it according to Insurance Rules; in fact just the information you need. Directions apply equally to a shop. Fourth edition 25 cents FACTORY MANAGEMENT, ETC. MODERN MACHINE SHOP CONSTRUCTION, EQUIPMENT AND MANAGEMENT. By O. E. Perrigo, M.E. The only work published that describes the modern machine shop or manufacturing plant from the time the grass is growing on the site intended for it until the finished product is shipped. By a careful study of its thirty-two chapters the practical man may economically build, efficiently equip, and successfully manage the modern machine shop or manufacturing estab- ishment. Just the book needed by those contemplating the erection of modern shop buildings, the re-building and re-organization of old ones, or the introduction of modern shop methods, time and cost system. It is a book written and illustrated by a practical shop man for practical shop men who are too busy to read theories and want facts. It is the most complete all around book of its kind ever published. It is a practical book for practical men, from the apprentice in the shop to the president in the office. It minutely describes and illustrates the most simple and yet the most efficient time and cost system yet devised. Price $5.00 12 CATALOGUE OF GOOD, PRACTICAL BOOKS FUEL COMBUSTION OF COAL AND THE PREVENTION OF SMOKE. By Wm. M. Barr. This book has been prepared with special reference to the generation of heat by the combus- tion of the common fuels found in the United States, and deals particularly with the condi- tions necessary to the economic and smokeless combustion of bituminous coals in Stationary and Locomotive Steam Boilers. The presentation of this important subject is systematic and progressive. The arrangement of the book is in a series of practical questions to which are appended accurate answers, which describe in language, free from technicalities, the several processes involved in the furnace combustion of American fuels; it clearly states the essential requisites for perfect combustion, and points out the best methods for furnace construction for obtaining the great- est quantity of heat from any given quality of coal. Nearly 350 pages, fully illustrated. Price 12 $1.00 SMOKE PREVENTION AND FUEL ECONOMY. By Booth and Kershaw. A complete treatise for all interested in smoke prevention and combustion, being based on the German work of Ernst Schmatolla, but it is more than a mere translation of the German treatise, much being added. The authors show as briefly as possible the principles of fuel combustion, the methods which have been and are at present in use, as well as the proper scientific methods for obtaining all the energy in the coal and burning it without smoke. Considerable space is also given to the examination of the waste gases, and several of the representative English and American mechanical stoker and similar appliances are described. The losses carried away in the waste gases are thoroughly analyzed and discussed in the Ap- Eendix, and abstracts are also here given of various patents on combustion apparatus. The ook is complete and contains much of value to all who have charge of large plants. 194 pages. Illustrated. Price $2.50 GAS ENGINES AND GAS GASOLINE ENGINES : THEIR OPERATION, USE AND CARE. By A. Hyatt Verrill. The Simplest, Latest and Most Comprehensive popular work published on Gasoline Engines describing what the Gasoline engine is; its construction and operation; how to install it; how to select it; how to use it and how to remedy troubles encountered. Intended for owners. Operators and Users of Gasoline Motors of all kinds. This work fully describes and illus- trates the various types of Gasoline engines used in Motor Boats. Motor Vehicles and Stationary Work. The parts, accessories and Appliances are described, with chapters on ignition, fuel, lubrication, operation and engine troubles. Special attention is given to the care, operation and repair of motors with useful hints and suggestions on emergency re- pairs and make-shifts. A complete glossary of technical terms and an alphabetically ar- ranged table of troubles and their symptoms form most valuable and unique features of this manual. Nearly every illustration in the book is original, having been made by the author. Every page is full of interest and value. A book which you cannot afford to be without. 320 pages. Nearly 150 specially made engravings. Price $1.50 GAS, GASOLINE, AND OIL ENGINES. By Gardner D. Hiscox. Just issued, 20th revised and enlarged edition. Every user of a gas engine needs this book. Simple, instructive, and right up-to-date. The only complete work on the subject. Tells all about the running and management of gas, gasoline and oil engines, as designed and manu- factured in the United States. Explosive motors for stationary, marine and vehicle power are fully treated, together with illustrations of their parts and tabulated sizes, also their care and running are included. Electric ignition by induction coil and jump spark are fully explained and illustrated, including valuable information on the testing for economy and power and the erection of power plants. The rules and regulations of the Board of Fire Underwriters in regard to the installation and management of gasoline motors is given in full, suggesting the safe installation of explosive motor power.' A list of United States Patents issued on gas, gasoline, and oil engines and their adjuncts from 1875 to date is included. 484 pages. 410 engravings Price . . . $3.50 MODERN GAS ENGINES AND PRODUCER GAS PLANTS. By R. E. Mathot, M.E. A guide for the gas engine designer, user, and engineer in the construction, selection, purchase installation, operation, and maintenance of gas engines. More than one book on gas engines has been written, but not one has thus far even encroached on the field covered by this book. Above all Mr. Mat hot's work is a practical guide. Recognizing the need of a volume that i3 CATALOGUE OF GOOD, PRACTICAL BOOKS would assist the gas engine user in understanding thoroughly the motor upon which he depends for power, the author has discussed his subject without the help of any mathematics and without elaborate theoretical explanations. Every part of the gas engine is described in detail, tersely, clearly, with a thorough understanding of the requirements of the mechanic. Helpful suggestions as to the purchase of an engine, its installation, care, and operation form a most valuable feature of the work. 320 pages. 175 detailed illustrations. Price . . . $2.50 GAS ENGINE CONSTRUCTION, OR HOW TO BUILD A HALF-HORSE-POWER GAS ENGINE. By Parsell and Weed. A practical treatise of 300 pages describing the theory and principles of the action of Gas Engines of various types and the design and construction of a half-horse power Gas Engim-. with illustrations of the work in actual progress, together with the dimensioned working drawings giving clearly the sizes of the various details; for the student, the scientific investigator and the amateur mechanic. Tnis book treats of the subject more from the standpoint of practice than that of theory. The principles of operation of Gas Engines are clearly and simply described and then the actual construction of a half-horse power engine is taken up, step by step, showing in detail the making of the Gas Engine. 3d Edition. 300 pages. Price $2.50 THE GASOLINE ENGINE ON THE FARM: ITS OPERATION, REPAIR AND USES. By Xeno W. Putnam. This is a practical treatise on the Gasoline and Kerosene engine intended for the man who wants to know just how to manage his engine and how to apply it to all kinds of farm work to the best advantage. The book includes selecting the most suitable engine for farm work, its most convenient and efficient installation, with chapters on troubles, their remedies and how to avoid them. The care and management of the farm tractor in plowing, harrowing, harvesting and road grading are fully covered; also plain directions are given for handling the tractor on the road. Special attention is given to relieving farm life of its drudgery by applying power to the disagreeable small tasks which must otherwise be done by hand. Many homemade con- trivances for cutting wood, supplying kitchen: garden and barn with water, loading, hauling and unloading hay. delivering grain to the bins or the feed trough are included; also full directions for making the engine milk the cows, churn, wash, sweep the house and clean the windows, etc. Very fully illustrated with drawings of working parts and cuts showing Stationary. Portable and Tractor Engines doing all kinds of farm work. 300 pages. Nearly 150 engravings. 12mo. Price $1.50 CHEMISTRY OF GAS MANUFACTURE. By H. M. Royles. This book covers points likely to arise in the ordinary course of the duties of the engineer or manager of a gas works not large enough to necessitate the employment of a separate chemical staff. It treats of the testing of the raw materials employed in the manufacture of illuminat- ing coal gas, and of the gas produced. The preparation of standard solutions is given as well as the chemical and physical examination of gas coal including among its contents — Prepa- rations of Standard Solutions, Coal, Furnaces, Testing and Regulation. Products of Car- bonization. Analysis of Crude Coal Gas. Analysis of Lime. Ammonia. Analysis of Oxide of Iron. Naphthalene. Analysis of Fire-Bricks and Fire-Clay. Weldom and Spent Oxide. Photometry and Gas Testing. Carburetted Water Gas. Metropolis Gas. Miscellaneous Extracts. Useful Tables $4.50 GEARING AND CAMS BEVEL GEAR TABLES. By D. Ac. Engstrom. A book that will at once commend itself to mechanics and draftsmen. Does away with all the trigonometry and fancy figuring on bevel gears and makes it easy for anyone to lay them out or make them just right. There are 36 full-page tables that show every necessary dimen- sion for all sizes or combinations you're apt to need. No puzzling figuring or guessing. Gives placing distance, all the angles (including cutting angles), and the correct cutter to use. A copy of this prepares you for anything in the bevel gear line. 66 pages. . $1.00 CHANGE GEAR DEVICES. By Oscar E. Perrigo. A practical book for every designer, draftsman, and mechanic interested in the invention and development of the devices formfeed changes on the different machines requiring such mechan- ism. All the necessary information on this subject is taken up, analyzed, classified, sifted, and concentrated for the use of busy men who have not the time to go through the masses of irrelevant matter with which such a subject is usually encumbered and select such infor- mation as will be useful to them. It shows just what has been done, how it has been done, when it was done, and who did it. It saves time in hunting up patent records and re-inventing old ideas. 88 pages. $1.00 14 CATALOGUE OF GOOD, PRACTICAL BOOKS DRAFTING OF CAMS. By Louis Rotjillion. The laying out of cams is a serious problem unless you know how to go at it right. This puts you on the right road for practically any kind of cam you are likely to run up against. 25 cents HYDRAULICS HYDRAULIC ENGINEERING. By Gardner D. Hiscox. A treatise on the properties, power, and resources of water for all purposes. Including the measurement of streams, the flow of water in pipes or conduits; the horse-power of falling water; turbine and impact water-wheels, wave motors, centrifugal, reciprocating, and air- lift pumps. With 300 figures and diagrams and 36 practical tables. All who are interested in water-works development will find this book a useful one, because it is an entirely practical treatise upon a subject of present importance, and cannot fail in having a far-reaching influence, and for this reason should have a place in the working library of every engineer. Among the subjects treated are: Historical — Hydraulics, Properties of Water; Measurement of the flow of Streams; Flow from Subsurface orifices and nozzles; Flow of water in Pipes; Siphons of various kinds; Dams and Great Storage Reservoirs; City and Town Water Supply; Wells and their reenforcement ; Air lift methods of raising water: artesian wells; Irrigation of Arid districts: Water Power. Water Wheels; Pumps and Pumping Machinery; Reciprocating Pumps; Hydraulic Power Transmission; Hydraulic Mining; Canals; Ditches: Conduits and Pipe Lines; Marine Hydraulics; Tidal and Sea Wave power, etc. 320 pages. Price $4.00 ICE AND REFRIGERATION POCKET BOOK OF REFRIGERATION AND ICE MAKING. By A. J. Wallis- Taylor. This is one of the latest and most comprehensive reference books published on the subject of refrigeration and cold storage. It explains the properties and refrigerating effect of the different fluids in use, the management of refrigerating machinery and the construction and insulation of cold rooms with their required pipe surface for different degrees of cold; freezing mixtures and non-freezing brines, temperatures of cold rooms for all kinds of provisions, cold storage charges for all classes of goods, ice making and storage of ice, data and memoranda for constant reference by refrigerating engineers, with nearly one hundred tables containing valuable references to every fact and condition required in the installment and operation of a refrigerat- ing plant. Illustrated. (5th Edition, revised.) Price $1.50 INVENTIONS— PATENTS INVENTOR'S MANUAL, HOW TO MAKE A PATENT PAY. This is a book designed as a guide to inventors in perfecting their inventions, taking out their patents and disposing of them. It is not in any sense a Patent Solicitor's Circular, nor a Patent Broker's Advertisement. No advertisements of any description appear in the work. It is a book containing a quarter of a century's experience of a successful inventor, together with notes based upon the experience of many other inventors. Among the subjects treated in this work are: How to Invent. How to Secure a Good Patent. Value of Good Invention. How to exhibit an Invention. How to Interest Capital. How to Estimate the Value of a Patent. Value of Design Patents. Value of Foreign Patents. Value of Small Inventions. Advice on Selling Patents. Advice on the Formation of Stock Companies. Advice on the Formation of Limited Liability Companies. Advice on Disposing of Old Patents. Advice as to Patent Attorneys. Advice as to Selling Agents. Forms of Assignments. License and Contracts. State Laws Concerning Patent Rights. 1900 Census of the United States by counties of over 10,000 population. Revised editurn. 120 pages. Price $1.00 KNOTS KNOTS, SPLICES AND ROPE WORK. By A. Hyatt Verrill. This is a practical book giving complete and simple directions for making all the most use- ful and ornamental knots in common use. with chapters on Splicing, Pointing, Seizing, CATALOGUE OF GOOD, PRACTICAL BOOKS Serving, etc. This book is fully illustrated with one hundred and fifty original engravings, which show how each knot, tie or splice is formed and its appearance when finished. The book will be found of the greatest value to Campers, Yachtsmen, Travelers, Boy Scouts, in fact to anyone having occasion to use or handle rope or knots for any purpose. The book is thoroughly reliable and practical and is not only a guide but a teacher. It is the standard work on the subject. Among the contents are: 1. Cordage, Kinds of Rope. Construction of Rope, Parts of Rope Cable and Bolt Rope. Strength of Rope, Weight of Rope. 2. Sim- ple knots and Bends. Terms used in Handling Rope. Seizing Rope. 3. Ties and Hitches. 4. Noose. Loops and Mooring Knots. 5. Shortenings. Grommets and Selvages. 6. Lash- ings. Seizings and Splices. 7. Fancy Knots and Rope Work. 128 pages. 150 original engravings. Price 60 cents LATHE WORK MODERN AMERICAN LATHE PRACTICE. By Oscar E. Perrigo. This is a new book from cover to cover, and the only complete American work on the subject written by a man who knows not only how work ought to be done, but who also knows how to do it, and how to convey this knowledge to others. It is strictly up-to-date in its descriptions and illustrations, which represent the very latest practice in lathe and boring mill operations as well as the construction of and latest developments in the manufacture of these important classes of machine tools. Lathe history and the relations of the Lathe to manufacturing are given; also a description of the various devices for Feeds and Thread Cutting mechanisms from early efforts in this direction to the present time. Lathe design is thoroughly discussed, including Back Gearing, Driving Cones, Thread Cutting Gears, and all the essential elements of the modern Lathe. The classification of Lathes is taken up, giving the essential differences of the several types of Lathes, including, as is usually understood, Engine Lathes. Bench Lathes, Speed Lathes, Forge Lathes, Gap Lathes, Pulley Lathes, Forming Lathes, Multiple Spindle Lathes, Rapid Reduction Lathes, Precision Lathes, Turret Lathes, Special Lathes, Electrically Driven Lathes, etc. 424 pages. 314 illustrations. Price ...... $2.50 PRACTICAL METAL TURNING. By Joseph G. Horner. This important and practical subject is treated in a full and exhaustive manner and nothing of importance is omitted. The principles and practice and all the different branches of Turn- ing are considered and well illustrated. All the different kinds of Chucks of usual forms, as well as some unusual kinds, are shown. A feature of the book is the important section de- voted to modern Turret practice; Boring is another subject which is treated fully; and the chapter on Tool Holders illustrates a large number of representative types. Thread Cutting is treated at reasonable length; and the last chapter contains a good deal of information relating to the High-Speed Steels and their work. The numerous tools used by machinists are illustrated, and also the aujuncts of the lathe. In fact, the entire subject is treated in such a thorough manner as to make this book the standard one on ihe subject. It is indis- pensable to the manager, engineer, and machinist as well as to the student, amateur, and experimental, man who desires to keep up-to-date. 400 pages, fully illustiated. Price $3.50 TURNING AND BORING TAPERS. By Fred H. Colvin. There are two ways to turn tapers; the right way and one other. This treatise has to do with the right way; it tells you how to start the work properly, how to set the lathe, what tools to use and how to use them, and forty and one other little things that y >u should know. Fourth edition 25 cent9 LIQUID AIR LIQUID AIR AND THE LIQUEFACTION OF GASES. By T. O'Conor Sloane. This book gives the history of the theory, discovery, and manufacture of Liquid Air, and contains an illustrated description of all the experiments that have excited the wonder of audiences all over the country. It shows how liquid air, like water, is carried hundreds of miles and is handled in open buckets. It tells what may be expected from it in the near future. A book that renders simple one of the most perplexing chemical problems of the century. Startling developments illustrated by actual experiments. It is not only a work of scientific interest and authority, but is intended for the general reader, oeing written in a popular style — easily understood by every one. Second edition. 365 pages. Price $2.00 16 CATALOGUE OF GOOD, PRACTICAL BOOKS LOCOMOTIVE ENGINEERING AIR-BRAKE CATECHISM. By Robert H. Blackall. This book is a standard text book. It covers the Westinghouse Air-Brake Equipment, in- cluding the No. 5 and the No. 6 E. T Locomotive Brake Equipment; the K (Quick-Service) Triple Valve for Freight Service; and the Cross-Compound Pump. The operation of all parts of the apparatus is explained in detail, and a practical way of finding their peculiarities and defects, with a proper remedy, is given. It contains 2,000 questions with their answers, which will enable any railroad man to pass any examination on the subject of Air Brakes. Endorsed and used by air-brake instructors and examiners on nearly every railroad in the United States. 25th Edition. 350 pages, fully illustrated with folding plates and dia- grams $2.00 AMERICAN COMPOUND LOCOMOTIVES. By Fred. H. Colvin. The only book on compounds for the engineman or shopman that shows in a plain, practical way the various features of compound locomotives in use. Shows how they are made, what to do when they break down or balk. Contains sections as follows: — A Bit of History. The- ory of Compounding Steam Cylinders. Baldwin Two-Cylinder Compound. Pittsburg Two- Cylinder Compound. Rhode Island Compound. Richmond Compound. Rogers Compound. Schenectady Two-Cylinder Compound. Vauclain Compound. Tandem Compounds. Bald- win Tandem. The Colvin- Wight man Tandem. Schenectady Tandem. Balanced Loco- motives. Baldwin Balanced Compound. Plans for Balancing. Locating Blows. Break- downs. Reducing Valves. Drifting. Valve Motion. Disconnecting. Power of Compound Locomotives. Practical Notes. Fully illustrated 'and containing ten special "Duotone" inserts on heavy Plate Paper, show- ing different types of Compounds. 142 pages. Price $1.00 APPLICATION OF HIGHLY SUPERHEATED STEAM TO LOCOMOTIVES. By Robert Garbe. A practical book. Contains special chapters on Generation of Highly Superheated Steam; Superheated Steam and the Two-Cylinder Simple Engine; Compounding and Superheating; Designs ofj Locomotive Superheaters; Constructive Details of Locomotives using Highly Superheated Steam; Experimental and Working Results. Illustrated with folding plates and tables. Price $2.50 COMBUSTION OF COAL AND THE PREVENTION OF SMOKE. By Wm. M. Barr. This book has been prepared with special reference to the generation of heat by the combus- tion of the common fuels found in the United States, and deals particularly with the condi- tions necessary to the economic and smokeless combustion of bituminous coal in Stationary and Locomotive Steam Boilers. The presentation of this important subject is systematic and progressive. The arrangement of the book is in a series of practical questions to which are appended accurate answers, which describe in language, free from technicalities, the several processes involved in the furnace combustion of American fuels; it clearly states the essential requisites for perfect combustion, and points out the best methods of furnace construction for obtaining the greatest quantity of heat from any given quality of coal. Nearly 350 pages, fully illustrated. Price $1.00 DIARY OF A ROUND HOUSE FOREMAN. By T. S. Reilly . This is the greatest book of railroad experiences ever published. Containing a fund of infor- mation and suggestions along the line of handling men, organizing, etc., that one cannot afford to miss. 176 pages. Price $1.00 LINK MOTIONS, VALVES AND VALVE SETTING. By Fred H. Colvin, Associate Editor of "American Machinist." A handy book for the engineer or machinist that clears up the mysteries of valve setting. Shows the different valve gears in use, how they work, and why. Piston and slide valves of different types are illustrated and explained. A book that every railroad man in the mo- tive power department ought to have. Contains chapters on Locomotive Link Motion, Valve Movements, Setting Slide Valves, Analysis by Diagrams, Modern Practice, Slip of Block, Slide Valves, Piston Valves, Setting Piston Valves, Joy-Allen Valve Gear, Walschaert Valve Gear, Gooch Valve Gear, Alfree-Hubbell Valve Gear, etc., etc. Fully illustrated. Price . . . 50 cents 17 CATALOGUE OF GOOD, PRACTICAL BOOKS LOCOMOTIVE BOILER CONSTRUCTION. By Frank A. Kleinhans. The construction of boilers in general is treated, and following this, the locomotive boiler is taken up in the order in which its various parts go through the shop. Shows all types of boilers used; gives details of construction; practical facts, such as life of riveting, punches and dies; work done per day, allowance for bending and flanging sheets, and other data. Locomotive boilers present more difficulty in laying out and building than any other type, and for this reason the author uses them as examples. Anyone who. can handle them can tackle anything. Contains chapters on Laying Out Work; Flanging and Forging; Punching; Shearing; Plate Planing; General Tables; Finishing Parts; Bending; Machinery Parts; Riveting; Boiler Details; Smoke Box Details; Assembling and Calking; Boiler Shop Machinery, etc., etc. There isn't a man who has anything to do with boiler work, either new or repair work, who doesn't need this book. The manufacturer, superintendent, foreman, and boiler worker — all need it. No matter what the type of boiler, you'll find a mint of information that you wouldn't be without. Over 400 pages, five large folding plates. Price $3.00 LOCOMOTIVE BREAKDOWNS AND THEIR REMEDIES. By Geo. L. Fowler. Revised by Wm. W. Wood, Air-Brake Instructor. Just issued. Revised pocket edition. It is out of the question to try and tell you about every subject that is covered in this pocket edition of Locomotive Breakdowns. Just imagine all the common troubles that an engineer may expect to happen some time, and then add all of the unexpected ones, troubles that could occur, but that you had never thought about, and you will find that they are all treated with the very best methods of repair. Walschaert Locomotive Valve Gear Troubles, Electric Headlight Troubles, as well as Questions and Answers on the Air Brake are all included. 294 pages. 7th Revised Edition. Fully illustrated $1.00 LOCOMOTIVE CATECHISM. By Robert Grimshaw. The revised edition of "Locomotive Catechism," by Robert Grimshaw, is a New Book from Cover to Cover. It contains twice as many pages and double the number of illustrations of previous editions. Includes the greatest amount of practical information ever published on the construction and management of modern locomotives. Specially Prepared Chapters on the Walschaert Locomotive Valve Gear, the Air Brake Equipment and the Electric Head Light are given. It commends itself at once to every Engineer and Fireman, and to all who are going in for examination or promotion. In plain language, with full complete answers, not only all the questions asked by the examining engineer are given, but those which the young and less experienced would ask the veteran, and which old hands ask as "stickers." It is a veritable Encyclopedia of the Locomotive, is entirely free from mathematics, easily understood and thoroughly up-to-date. Contains over 4,000 Examination Questions with their Answers. 825 pages, 437 illustrations and three folding plates. 28th Revised Edition. . . $2.50 PRACTICAL INSTRUCTOR AND REFERENCE BOOK FOR LOCOMOTIVE FIREMEN AND ENGINEERS. By Chas. F. Lockhart. An entirely new book on the Locomotive. It appeals to every railroad man, as it tells him how things are done and the right way to do them. Written by a man who has had years of practical experience in locomotive shops and on the road firing and running. The infor- mation given in this book cannot be found in any other similar treatise. Eight hundred and fifty-one questions with their answers are included, which will prove specially helpful to those preparing for examination. Practical information on: The Construction and Opera- tion of Locomotives. Breakdowns and their Remedies; Air Brakes and Valve Gears. Rules and Signals are handled in a thorough manner. As a book of reference it cannot be excelled. The book is divided into six parts, as follows: 1. The Fireman's Duties. 2. General description of the Locomotive. 3. Breakdowns and their Remedies. 4. Air Brakes. 5. Extracts from Standard Rules. 6. Questions for examination. The 851 questions have been carefully selected and arranged. These cover the examinations required by the different railroads. 368 pages. 88 illustrations. Price $1.50 PREVENTION OF RAILROAD ACCIDENTS, OR SAFETY IN RAILROADING. By George Bradshaw. This book is a heart-to-heart talk with Railroad Employees, dealing with facts, not theories, and showing the men in the ranks, from every-day experience, how accidents occur and how they may be avoided. The book is illustrated with seventy original photographs and draw- ings showing the safe and unsafe methods of work. No visionary schemes, no ideal pictures. Just plain facts and Practical Suggestions are given. Every railroad employee who reads the 18 CATALOGUE OF GOOD, PRACTICAL BOOKS book is a better and safer man to have in railroad service. It gives just the information which will be the means of preventing many injuries and deaths. All railroad employees should procure a copy, read it. and do your part in preventing accidents. 169 pages. Pocket Size. Fully illustrated. Price 50 cents TRAIN RULE EXAMINATIONS MADE EASY. By G. E. Colling wood. This is the only practical work on train-rules in print. Every detail is covered, and puzzling points are explained in simple, comprehensive language, making it a practical treatise for the Train Dispatcher, Engineman. Trainman, and all others who ha'e to do with the move- ments of trains. Contains complete and reliable information of the Standard Code of Train Rules for single track. Shows Signals in Colors, as used on the different roads. Explains fully the practical application of train orders, giving a clear and definite understanding of all orders which may be used. The meaning and necessity for certain rules are explained in such a manner that the student may know beyond a doubt the rights conferred under any orders he may receive or the action required by certain rules. As nearly all roads require trainmen to pass regular examinations, a complete set of examina- tion questions, with their answers, are included. These will enable the student to pass the required examinations with credit to himself and the road for which he works. 256 pages.. Fully illustrated with Train Signals in colors. Price $1.26 TRAIN- RULES AND DESPATCHING. By H. A. Dalby. Every railroad man, no matter what department he's in, needs a copy of this book. It gives, the standard rules for both single and double track, shows all the signals, with colors wher- ever necessary, and has a list of towns where time changes, with a map showing the whole country. The rules are explained wherever there is any doubt about their meaning or where they are modified by different railroads. It's the only practical book on train rules in print. Over 220 pages. Leather cover. Price $1.50 THE WALSCHAERT AND OTHER MODERN RADIAL VALVE GEARS FOR LOCOMOTIVES. By Wm. W. Wood. If you would thoroughly understand the Walschaert Valve Gear you should possess a copy of this book, as the author takes the plainest form of a steam engine — a stationary engine in the rough, that will only turn its crank in one direction — and from it builds up — with the reader's help — a modern locomotive equipped with the Walschaert Valve Gear, complete. The points discussed are clearly illustrated: two large folding plates that show the positions of the valves of both inside or outside admission type, as well as the links and other parts of the gear when the crank is at nine different points in its revolution, are especially valuable in making the movement clear. These employ sliding cardboard models which are contained in a pocket in the cover. The book is divided into five general divisions, as follows: I. Analysis of the gear. II. De- signing and erecting the gear. III. Advantages of the gear. IV. Questions and answers relating to the Walschaert Valve Gear. V. Setting valves with the Walschaert Valve Gear; the three primary types of locomotive valve motion; modern radial valve gears other than the Walschaert; the Hobart All-free valve and valve gear, with questions and answers on breakdowns: the Baker-Pilliocl valve gear; the Improved Baker-Pilliod Valve Gear, with questions and answers on breakdowns. The questions with full answers given will be especially valuable to firemen and engineers in preparing for an examination for promotion. 24.5 pages. Third Revised Edition. - p rice $1.50 WESTINGHOUSE E— T AIR-BRAKE INSTRUCTION POCKET BOOK. By Wm. W. Wood, Air-Brake Instructor. Here is a book for the railroad man, and the man who aims to be one. It is without doubt the only complete work published on the Westinghouse E-T Locomotive Brake Equipment. Written by an Air Brake Instructor who knows just what is needed. It covers the subject thoroughly. Everything about the New Westinghouse Engine and Tender Brake Equip- ment, including the Standard No. 5 and the Perfected No. 6 Style of brake, is treated in de- tail. W ritten in plain English and profusely illustrated with Colored Plates, which enable one to trace the flow of pressures throughout the entire equipment. The best book ever published on the Air Brake. Equally good for the beginner and the advanced engineer. \\ ill pass any one through any examination. It informs and enlightens you on every point. Indispensable to every engineman and trainman. Contains examination questions and answers on the E-T equipment. Covering what the E-T Brake is. How it should be operated. What to do when defective. Not a question can be asked of the engineman up for promotion on either the No. 5 or the No. 6 E-T equipment that is not asked and answered in the book. If you want to thoroughly understand the E-T equipment get a copy of this book. It covers every detail. Makes Air Brake troubles and examinations easy. Price $1.60 «9 CATALOGUE OF GOOD, PRACTICAL BOOKS MACHINE SHOP PRACTICE AMERICAN TOOL MAKING AND INTERCHANGEABLE MANUFACTURING. By J. V. WOODWOHTH. A "shoppy" book, containing no theorizing, no problematical or experimental devices, there are no badly proportioned and impossible diagrams, no catalogue cuts, but a valuable collec- tion of drawings and descriptions of devices, the rich fruits of the author's own experience. In its 500-odd pages the one subject only, Tool Making, and whatever relates thereto, is dealt with. The work stands without a rival. It is a complete practical treatise on the art of American Tool Making and system of interchangeable manufacturing as carried on to-day in the United States. In it are described and illustrated all of the different types and classes of small tools, fixtures, devices, and special appliances which are in general use in all machine manufacturing and metal working establishments where economy, capacity, and interchangeability in the production of machined metal parts are imperative. The science of jig making is exhaustively discussed, and particular attention is paid to drill jigs, boring, profiling and milling fixtures and other devices in which the parts to be machined are located and fastened within the contrivances. All of the tools, fixtures, and devices illustrated and described have been or are used for the actual production of work, such as parts of drill presses, lathes, patented machinery, typewriters, electrical apparatus, mechan- ical appliances, brass goods, composition parts, mould products, sheet metal articles, drop forgings, jewelry, watches, medals, coins, etc. 531 pages. Price $4.00 HENLEY'S ENCYCLOPEDIA OF PRACTICAL ENGINEERING AND ALLIED TRADES. Edited by Joseph G. Horner, A.M. I., M.E. This set of five volumes contains about 2,500 pages with thousands of illustrations, including diagrammatic and sectional drawings with full explanatory details. This work covers the entire practice of Civil and Mechanical Engineering. The best known expert in all branches of engineering have contributed to these volumes. The Cyclopedia is admirably well adapted to the needs of the beginner and the self-taught practical man, as well as the mechanical en- gineer, designer, draftsman, shop superintendent, foreman, and machinist. The work will be found a means of advancement to any progressive man. It is encyclopedic in scope, thorough and practical in its treatment of technical subjects, simple and clear in its descriptive matter, and without unnecessary technicalities or formulae. The articles are as brief as may be and yet give a reasonably clear and explicit statement of the subject, and are written by men who have had ample practical experience in the matters of which they write. It tells you all you want to know about engineering and tells it so simply, so clearly, so concisely, that one cannot help but understand. As a work of reference it is without a peer. $6.00 per volume. For complete set of five volumes, price $25.00 MACHINE SHOP ARITHMETIC. By Colvin-Cheney. This is an arithmetic of the things you have to do with daily. It tells you plainly about: how to find areas of figures; how to find surface or volume of balls or spheres; handy ways for calculating; about compound gearing; cutting screw threads on any lathe; drilling for taps; speeds of drills, taps, emery wheels, grindstones, milling cutters, etc.; all about the Metric system with conversion tables; properties of metals; strength of bolts and nuts; decimal equivalent of an inch. All sorts of machine shop figuring and 1,001 other things, any one of Y/hich ought to be worth more than the price of this book to you, and it saves you the trouble of bothering the boss. 6th Edition. 131 pages. Price 50 cents MODERN MACHINE SHOP CONSTRUCTION, EQUIPMENT AND MANAGEMENT. By Oscar E. Perrigo. The only work published that describes the Modern Machine Shop or Manufacturing Plant from the time the grass is growing on the site intended for it until the finished product is shipped. Just the book needed by those contemplating the erection of modern shop buildings, the re- building and reorganization of old ones, or the introduction of Modern Shop Methods, time and cost systems. It is a book written and illustrated by a practical shop man for practical shop men who are too busy to read theories and want facts. It is the most complete all-around book of its kind ever published. 400 large quarto pages. 225 original and specially-made illustrations. Price $5.00 MECHANICAL APPLIANCES, MECHANICAL MOVEMENTS AND NOVELTIES OF CONSTRUCTION. By Gardner D. Hiscox. This is a supplementary volume to the one jpon mechanical movements. Unlike the first volume, which is more elementary in character, this volume contains illustrations and descrip- tions of many combinations of motions and of mechanical devices and appliances found in different lines of machinery. Each device being shown bv a line drawing with a description CATALOGUE OF GOOD, PRACTICAL BOOKS showing its working parts and the method of operation. From the multitude of devices de- scribed, and illustrated, might be mentioned, in passing, such items as conveyors and elevators, Prony brakes, thermometers,) various types of boilers, solar engines, oil-fuel burners, condensers, evaporators, Corliss and other valve gears, governors, gas engines, water motors of various descriptions, air ships, motors and dynamos, automobile and motor bicycles, railway block signals, car couplers, link and gear motions, ball bearings, breech block mechanism for heavy guns, and a large accumulation of others of equal importance. 1,000 specially made engrav- ings. 396 octavo pages. Price $2.50 MECHANICAL MOVEMENTS, POWERS, AND DEVICES. By Gardner D. Hiscox. This is a collection of 1,890 engravings of different mechanical motions and appliances, accom- panied by appropriate text, making it a book of great value to the inventor, the draftsman, and to all readers with mechanical tastes. The book is divided into eighteen sections or chapters in which the subject matter is classified under the following heads: Mechanical Powers; Transmission of Power; Measurement of Power, Steam Power; Air Power Appliances; Electric Power and Construction, Navigation and Roads; Gearing; Motion and Devices; Controlling Motion; Horological; Mining; Mill and Factory Appliances; Construction and Devices; Drafting Devices: Miscellaneous Devices, etc. 12th edition. 400 octavo pages. Price $2.50 MACHINE SHOP TOOLS AND SHOP PRACTICE. By W. H. Vandervoort. A work of 555 pages and 673 illustrations, describing in every detail the construction, operation, and manipulation of both hand and machine tools. Includes chapters on filing, fitting, and scraping surfaces; on drills, reamers, taps, and dies; the lathe and its tools; planers, shapers, and their tools: milling machines and cutters; gear cutters and gear cutting; drilling machines and drill work; grinding machines and their work; hardening and tempering; gearing, belting and transmission machinery: useful data and tables. 6th edition. Price .... $3.00 THE MODERN MACHINIST. By John T. Usher. This is a book showing, by plain description and by profuse engravings, made expressly for the work, all that is best, most advanced, and of the highest efficiency in modern machine shop practice, tools, and implements, showing the way by which and through which, as Mr. Maxim says, "American machinists have become and are "the finest mechanics in the world." Indicating as it does, in every line, the familiarity of the author with every detail of daily experience in the shop, it cannot fail to be of service to any man practically -connected with the shaping or finishing of metals. There is nothing experimental or visionary about the book, all devices being in actual use and giving good results. It might be called a compendium of shop methods, showing a vari- ety of special tools and appliances which will give new ideas to many mechanics, from the superintendent down to the man at the bench. It will be found a valuable addition to any machinist's library, and should be consulted whenever a new or difficult job is to be done, whether it is boring, milling, turning, or planing, as they are all treated in a practical manner. Fifth Edition. 320 pages. 250 illustrations. Price ... $2.50 MODERN MILLING MACHINES: THEIR DESIGN, CONSTRUCTION AND OPERA- TION. By Joseph G. Horner. This book describes-and illustrates the Milling Machine and its work in such a plain, clear, and forceful manner, and illustrates the subject so clearly and completely, that the up-to-date machinist, student, or mechanical engineer cannot afford to do without the valuable infor- mation which it contains. It describes not only the early machines of this class, but notes their gradual development into the splendid machines of the present day, giving the design and construction of the various types, forms, and special features produced by prominent manufacturers, American and foreign. Milling cutters in all their development and modernized forms are illustrated and described, and the operations they are capable of producing upon different classes of work are carefully described in detail, and the speeds and feeds necessary are discussed, and valuable and useful data given for determining these usually perplexing problems. The book is the most compre- hensive work published on the subject. 304 pages. 300 illustrations. Price . . $4.00 " SHOP KINKS." By Robert Grimshaw. A book of 400 pages and 222 illustrations, being entirely different frorn any other book on machine shop practice. Departing from conventional style, the author avoids universal or common shop usage and limits his work to showing special ways of doing things better, more cheaply and more rapidly than usual. As a result the advanced methods of representative establishments of the world are placed at the disposal of the reader. This book shows the proprietor where large savings are possible, and how products may be improved. To the employee it holds out suggestions that, properly applied, will hasten his advancement. No shop can afford to be without it. It bristles with valuable wrinkles and helpful suggestions. It will benefit all, from apprentice to proprietor. Every machinist, at any age. should study its pages. Fifth Edition. Price $2.50 21 CATALOGUE OF GOOD, PRACTICAL BOOKS THREADS AND THREAD CUTTING. By Colvin and Stabel. This clears up many of the mysteries of thread-cutting, such as double and triple threads, internal threads, catching threads, use of hobs, etc. Contains a lot of useful hints and several tables. 3rd Edition. Price 35 cents TOOLS FOR MACHINISTS AND WOOD WORKERS, INCLUDING INSTRUMENTS OF MEASUREMENT. By Joseph G. Horner. The principles upon which cutting tools for wood, metal, and other substances are made are identical, whether used by the machinist, the carpenter, or by any other skilled mechanic in their daily work, and the object of this book is to give a correct and practical description of these tools as they are commonly designed, constructed, and used. 340 pages, fully illustrated. Price $3.50 MANUAL TRAINING ECONOMICS OF MANUAL TRAINING. By Louis Rouillion. The only book published that gives just the information needed by all interested in .Manual Training, regarding Buildings, Equipment, and Supplies. Shows exactly what is needed for all grades of the work from the Kindergarten to the High and Normal School. Gives item- ized lists of everything used in Manual Training Work and tells just what it ought to cost. Also shows where to buy supplies, etc. Contains 174 pages, and is fully illustrated. 2nd Edition. Price $1.50 MARINE ENGINEERING MARINE ENGINES AND BOILERS, THEIR DESIGN AND CONSTRUCTION. By Dr. G. Bauer, Leslie S. Robertson, and S. Bryan Donkin. in the words of Dr. Bauer, the present work owes its origin to an oft felt want of a Condensed Treatise, embodying the Theoretical and Practical Rules used in Designing Marine Engines and Boilers. The need for such a work has been felt by most engineers engaged in the con- struction and working of Marine Engines, not only by the younger men, but also by those of greater experience. The fact that the original German work was written by the chief engineer of the famous Vulcan Works, Stettin, is in itself a guarantee that this book is in all respects thoroughly up-to-date, and that it embodies all the information which is necessary for the design and construction of the highest types of marine engines and boilers. It may be said, that the motive power which Dr. Bauer has placed in the fast German liners that have been turned out of late years from the Stettin Works, represent the very best practice in marine engineering of the present day. This work is clearly written, thoroughly systematic, theoretically sound; while the character of its plans, drawings, tables, and statistics is without reproach. The illustrations are care- ful reproductions from actual working drawings, with some well-executed photographic views of completed engines and boilers. 744 pages. 550 illustrations and numerous, tables. $9.00 net MODERN SUBMARINE CHART. A cross-section view, showing clearly and distinctly all the interior of a Submarine of the latest type. You get more information from this chart, about the construction and operation of a Submarine, than in any other way. No Details omitted — everything is accurate and to scale. It is absolutely correct in every detail, having been approved by Naval Engineers. All the machinery and devices fitted in a modern Submarine Boat are shown and to make the engraving more readily understood all the features are shown in operative form with Officers and Men in the act of performing the duties assigned to them in service conditions. This CHART IS REALLY AN ENCYCLOPEDIA OP A SUBMARINE. It is educational and worth many times its cost. Mailed in a Tube for 25 cents MINING ORE DEPOSITS, WITH A CHAPTER ON HINTS TO PROSPECTORS. By J. P. Johnson This book gives a condensed account of the ore-deposits at present known in South Africa. It is also intended as a guide to the prospector. Only an elementary knowledge of geology and some mining experience are necessary in order to understand this work. With these qualifications, it will materially assist one in his search for metalliferous mineral occurrences 22 CATALOGUE OF GOOD, PRACTICAL BOOKS and, so far as simple- ores are concerned, should enable one to form some idea of the possi- bilities of any he may find. Among the chapters given are: Titaniferous and Chromiferous Iron Oxides — Nickel — Cop- per — Cobalt — Tin — Molybdenum — Tungsten — Lead — Mercury — Antimony — Iron — Hints to Prospectors $2.00 PHYSICS AND CHEMISTRY OF MINING. By T. H. Byrom. A practical work for the use of all preparing for examinations in mining or qualifying for colliery managers' certificates. The aim of the author in this excellent book is to place clearly before the reader useful and authoritative data which will render him valuable assistance in his studies. The only work of its kind published. The information incorporated in it will prove of the greatest practical utility to students, mining engineers, collierv managers and all others who are specially interested in the present-day treatment of mining problems. Among its contents are chapters on: The Atmosphere; Laws Relating to the Behavior of Gases; The Diffusion of Gases; Composition of the Atmosphere: Sundrv Constituents of the Atmosphere; Water; Carbon; Fire-Damp; Combustion; Coal Dust and Its Action; Ex- plosives; Composition of Various Coals and Fuels; Methods of Analysis of Coal; Strata Ad- joining the Coal Measures; Magnetism and Electricity; Appendix; Useful Tables, etc ; Miscellaneous Questions. 160 pages. Illustrated $2.00 PRACTICAL COAL MINING. By T. H. Cockix. An important work, containing 428 pages and 213 illustrations, complete with practical de- tails, which will intuitively impart to the reader, not only a general knowledge of the princi- ples of coal mining, but also considerable insight into allied subjects. This treatise is posi- tively up to date in every instance, and should be in the hands of every colliery engineer geologist, mine operator, superintendent, foreman, and all others who are interested in or connected with the industry. 2nd Edition $2.50 PATTERN MAKING PRACTICAL PATTERN MAKING. By F. W. Barrows. This is a very complete and entirely practical treatise on the subject of pattern making, illus- trating pattern work in wood and metal. From its pages you are taught just what you should know about pattern making. It contains a detailed description of the materials used by pattern makers, also the tools, both those for hand use. and the more interesting machine tools; having complete chapters on the band saw. The Buzz Saw. and the Lathe. Individual patterns of many different kinds are fully illustrated and described, and the mounting of metal patterns on plates for molding machines is included. Rules, Formulas and Tables are included, containing simple and original methods for finding the weight of castings, both from the pattern itself and from the drawings. This section contains some new and practical formulas, which will be found very useful in estimating weights, with the accuracy required for quotations to prospective customers. All of these rules are simple, and can be put to practical use by the ordinary, every-day man, and they have been proved by years of actual use. Plain rules for keeping down the cost of patterns, with a complete system for checking the cost of and marking the patterns, and a card record showing what the pattern is, material used, where located in safe, with its cost and date of production, is included. The book closes with an original and practical method for the inventory and valuation of patterns. Con- taining 326 pages and 150 detailed illustrations. Price $2.00 PERFUMERY HENLEY'S TWENTIETH CENTURY BOOK OF RECEIPTS, FORMULAS AND PRO- CESSES. Edited by G. D. Hiscox. The most valuable Techno-chemical Receipt Book published. Contains over 10,000 practical receipts, many of which will prove of special value to the perfumer, a mine of information, up- to-date in every respect. Price, Cloth, $3.00; half morocco $4.00 PERFUMES AND THEIR PREPARATION. By G. W. Askinson, Perfumer. A comprehensive treatise, in which there has been nothing omitted that could be of value to the Perfumer. Complete directions for making handkerchief perfumes, smelling-salts, sachets, fumigating pastilles: preparations for the care of the skin, the mouth, the hair, cos- metics, hair dyes and other toilet articles are given, also a detailed description of aromatic substances: their nature, tests of purity, and wholesale manufacture. A book of general, as well as professional interest, meeting the wants not only of the druggist and perfume man- ufacturer, but also of the general public. Third edition 312 pages. Illustrated. . $3.00 23 CATALOGUE OF GOOD, PRACTICAL BOOKS PLUMBING MECHANICAL DRAWING FOR PLUMBERS. By R. M. Starbuck. A concise, comprehensive and practical treatise on the subject of mechanical drawing in its various modern applications to the work of all who are in any way connected with *he plumbing trade. Nothing will so help the plumber in estimating and in explaining work to customers and workmen as a knowledge of drawing, and to the workman it is of inestimable value if he is to rise above his position to positions of greater responsibility. Among the chapters contained are: 1. Value to plumber of knowledge of drawing; tools required and their use; common views needed in mechanical drawing. 2. Perspective versus mechan- ical drawing in showing plumbing construction. 3. Correct and incorrect methods in plumbing drawing; plan and elevation explained. 3. Floor and cellar plans and elevation; scale drawings; use of triangles. 5. Use of triangles; drawing of fittings, traps, etc. 6. Drawing plumbing elevations and fittings. 7. Instructions in drawing plumbing elevations. 8. The drawing of plumbing fixtures; scale drawings. 9. Drawing of fixtures and fittings. 10. Inking of drawings. 11. Shading of drawings. 12. Shading of drawings. 13. Sec- tional drawings; drawing of threads. 14. Plumbing elevations from architect's plan. 15. Elevations of separate parts of the plumbing system. 16. Elevations from architect'? plans. 17. Drawing of detail plumbing connections. 18. Architect's plans and plumbing elevations of residence. 19. Plumbing elevations of residence (continued) ; plumbing plans for cottage. 20. Plumbing elevations; roof connections. 21. Plans and plumbing eleva- tions for six-flat building. 22. Drawing of various parts of the plumbing system; use of scales. 23. Use of architect's scales. 24. Special features in the illustrations of country plumbing. 25. Drawing of wrought iron piping, valves, radiators, coils, etc. 26. Drawing of piping to illustrate heating systems. 150 illustrations. Price $1.50 MODERN PLUMBING ILLUSTRATED. By R. M. Starbuck. This book represents the highest standard of plumbing work. It has been adopted and used as a reference book by the United States Government, in its sanitary work in Cuba, Porto Rico, and the Philippines, and by the principal Boards of Health of the United States and Canada. It gives connections, sizes and working data for all fixtures and groups of fixtures. It is helpful to the master plumber in demonstrating to his customers and in figuring work. It gives the mechanic and student quick and easy access to the best modern plumbing practice. Suggestions for estimating plumbing construction are contained in its pages. This book represents, in a word, the latest and best up-to-date practice, and should be in the hands of every architect, sanitary engineer and plumber who wishes to keep himself up to the minute on this important feature of construction. Contains following chapters, each illustrated with a full-page plate: Kitchen sink, laundry tubs, vegetable wash sink; lavatories, pantry sinks, contents of marble slabs; bath tub, foot and sitz bath, shower bath; water closets, venting of water closets ; low-down water closets, water closets operated by flush valves, water closet range; slop sink, urinals, the bidet; hotel and restaurant sink, grease trap; refrigerators, safe wastes, laundry waste; lines of refrigerators, bar sinks, soda foun- tain sinks; horse stall, frost-proof water closets; connections for S traps, venting; con- nections for drum traps; soil pipe connections; supporting of soil pipe; main trap and fresh air inlet; floor drains and cellar drains, subsoil drainage; water closets and floor connections ; local venting ; connections for bath rooms ; connections for bath rooms, con- tinued; connections for bath rooms, continued; connections for bath rooms, continued; examples of poor practice; roughing-work ready for test; testing of plumbing system; method of continuous venting ; continuous venting for two-floor work ; continuous venting for two lines of fixtures on three or more floors ; continuous venting of water closets ; plumb- ing for cottage house; construction for cellar piping; plumbing for residence, use of special fittings; plumbing for two-flat house; plumbing for apartment building: plumbing for double apartment building; plumbing for office building; plumbing for public toilet rooms; plumbing for public toilet rooms, continued; plumbing for bath establishment ; plumbing for engine house, factory plumbing ; automatic flushing for schools, factories, etc. ; use of flushing valves; urinals for public toilet rooms; the Durham system, the destruction of pipes by electrolysis; construction of work without use of lead; Automatic sewage lift, automatic sump tank ; country plumbing ; construction of cesspools ; septic tank and auto- matic sewage siphon; country plumbing; water supply for country house; thawing of water mains and service by electricity; double boilers; hot water supply of large build- ings ; automatic control of hot water tank ; suggestions for estimating plumbing construc- tion. 400 octavo pages, fully illustrated by 55 full-page engravings. Price . $4.00 STANDARD PRACTICAL PLUMBING. By R. M. Starbuck. A complete practical treatise of 450 pages covering the subject of Modern Plumbing in all its branches, a large amount of space being devoted to a very complete and practical treatment of the subject of Hot Water Supply and Circulation and Range Boiler Work. Its thirty chapters include about every phase of the subject one can think of, making it 24- CATALOGUE OF GOOD, PRACTICAL BOOKS an indispensable work to the master plumber, the journeyman plumber, and the apprentice plumber, containing chapters on: the plumber's tools; wiping solder, composition and use; joint wiping; lead work; traps; siphonage of traps; venting; continuous venting; house sewer and sewer connections; house drain; soil piping, roughing; main trap and fresh air inlet; floor, yard, cellar drains, rain leaders, etc. ; fixture wastes: water closets ; ventilation; improved plumbing connections; residence plumbing; plumbing for hotels, schools, fac- tories, stables, etc.; modern country plumbing; filtration of sewage and water supply; hot and cold supply; range boilers; circulation; circulating pipes; range boiler problems; hot water for large buildings; water lift and its use; multiple connections for hot water boilers; heating of radiation by supply system; theory for the plumber; drawing for the plumber. Fully illustrated by 347 engravings. Price $3.00 RECEIPT BOOK HENLEY'S TWENTIETH CENTURY BOOK OF RECEIPTS, FORMULAS AND PRO- CESSES. Edited by Gardner D. Hiscox. The most valuable Techno-chemical Receipt Book published, including over 10,000 selected scientific, chemical, technological, and practical receipts and processes. This is the most complete Book of Receipts ever published, giving thousands of receipts for the manufacturer of valuable articles for everyday use. Hints, Helps, Practical Ideas, and Secret Processes are revealed within its pages. It covers every branch of the useful arts and tells thousands of ways of making money and is just the book everyone should have at his command. Modern in its treatment of every subject that properly falls within its scope, the book may truthfully be said to present the very latest formulas to be found in the arts and industries and to retain those processes which long experience has proven worthy of a permanent record. To present here even a limited number of the subjects which find a place in this valuable work would be difficult. Suffice to say that in its pages will be found matter of intense in- terest and immeasurable practical value to the scientific amateur and to him who wishes to obtain a knowledge of the many processes used in the arts, trades and manufactures, a knowledge which will render his pursuits more instructive and remunerative. Serving as a reference book to the small and large manufacturer and suppplying intelligent seekers with the information necessary to conduct a process, the work will be foimd of inestimable worth to the Metallurgist, the Photographer, the Perfumer, the Painter, the Manufacturer of Glues, Pastes, Cements, and Mucilages, the Compounder of Alloys, the Cook, the Physician, the Druggist, the Electrician, the Brewer, the Engineer, the Foundryman. the Machinist, the Potter, the Tanner, the Confectioner, the Chiropodist, the Manicure. *he Manufacturer of Chemical Novelties and Toilet Preparations, the Dyer, the Electroplater, the Enameler, the Engraver, the Provisioner. the Glass 'Vorker, the Goldbeater, the Watchmaker, the Jew- eler, the Hat Maker, the Ink Manufacturer, the Optician, the Farmer, the Dairyman, the Paper Maker, the Wood and Metal Worker, the Chandler and Soap Maker, the Veterinary Surgeon, and the Technologist in general. A mine of information, and up-to-date in every respect. A book which will prove of value to EVERYONE, as it covers every branch of the Useful Arts. S00 pages. Price $3.00 WHAT IS SAID OF THIS BOOK: " Your Twentieth Century Book of Receipts, Formulas and Processes duly received. I am glad to have a copy of it, and if I could not replace it money couldn't buy it. It is the best thing of the sort I ever saw." (Signed) M. E. Trux. Sparta. Wis. 'There are few persons who would not be able to find in the book some single formula that would repay several times the cost of. the book." — Merchant's Record and Show Window. RUBBER RUBBER HAND STAMPS AND THE MANIPULATION OF INDIA RUBBER. By T. O'Conor Sloane. This book gives full details on all points, treating in a concise and simple manner the elements of nearly everything it is necessary to understand for a commencement in anv branch of the India Rubber Manufacture. The making of all kinds of Rubber Hand Stamps. Small Articles of India Rubber, U. S. Government Composition, Dating Hand Stamps, the Manipulation of Sheet Rubber, Toy Balloons. India Rubber Solutions, Cements, Blackings, Renovating 2 5 CATALOGUE OF GOOD, PRACTICAL BOOKS Varnish, and Treatment for India Rubber Shoes, etc.; the Hektograph Stamp Inks, and Miscellaneous Notes, with a Short Account of the Discovery, Collection, and Manufacture of India Rubber are set forth in a manner designed to be readily understood, the explanations being plain and simple. Including a chapter on Rubber Tire Making and Vulcanizing; also u chapter on the uses of rubber in Surgery and Dentistry. Third revised and enlarged edition 175 pages. Illustrated $1.00 SAWS SAW FILINGS AND MANAGEMENT OF SAWS. By Robert Grimshaw. A practical hand book on filing, gumming, swaging, hammering, and the brazing of band saws, the speed, work, and power to run circular saws, etc. A handy book for those who have charge of saws, or for those mechanics who do their own filing, as it deals with the proper shape and pitches of saw teeth of all kinds and gives many useful hints and rules for gumming, yetting, and filing, and is a practical aid to those who use saws for any purpose. New edition, revised and enlarged. Illustrated. Price $1.00 STEAM ENGINEERING AMERICAN STATIONARY ENGINEERING. By W. E. Crane. This book begins at the boiler room and takes in the whole power plant. A plain talk on every-day work about engines, boilers, and their accessories. It is not intended to be scien- tific or mathematical. All formulas are in simple form so that any one imderstanding plain arithmetic can readily understand any of them. The author has made this the most prac- tical book in print ; has given the results of his years of experience, and has included about all that has to do with an engine room or a power plant. You are not left to guess at a single point. You are shown clearly what to expect under the various conditions ; how to secure the best results; ways of preventing "shut downs" and repairs; in short, all that goes to make up the requirements of a good engineer, capable of taking charge of a plant. It's plain enough for practical men and yet of value to those high in the profession. \ partial list of contents is: The boiler room, cleaning boilers, firing, feeding; pumps; jispection and repair; chimneys, sizes and cost; piping; mason work: foundations; testing cement; pile driving; engines, slow and high speed; valves; valve setting; Corliss engines, setting valves, single and double eccentric; air pumps and condensers; different types of condensers; water needed; lining up; pounds; pins not square in crosshead or crank; engineers' tools; pistons and piston rings ; bearing metal; hardened copper ; drip pipes from cylinder jackets; belts, how made, care of; oils; greases; testing lubricants; rules and tables, including steam tables; areas of segments; squares and square root; cubes and cube root; areas and circumferences of circles. Notes on: Brick work; explosions; pumps; pump valves; beaters, economizers; safety valves ; lap. lead, and clearance. Has a complete examination for a license, etc., etc. Second edition. 285 pages, Illustrated. Price . $2.00 EMINENT ENGINEERS. By Dwight Goddard. Everyone who appreciates the effect of such great inventions as the Steam Engine, Steamboat, Locomotive, Sewing Machine, Steel Working, and other fundamental discoveries, is interested in knowing a little about the men who made them and their achievements. Mr. Goddard has selected thirty-two of the world's engineers who have contributed most largely to the advancement of our civilization by mechanical means, giving only such facts as are of general interest and in a way which appeals to all, whether mechanics or not. 280 pages. 35 illustrations. Price $1.50 ENGINE RUNNER'S CATECHISM. By Robert Grimshaw. A practical treatise for the stationary engineer, telling how to erect, adjust and run the prin- cipal steam engines in use in the United States. Describing the principal features of various special and well-known makes of engines: Temper Cut-off, Shipping and Receiving Founda- tions, Erecting and Starting, Valve Setting, Care and Use, Emergencies, Erecting and Ad- justing Special Engines. The questions asked throughout the catechism are plain and to the point, and the answers are given in such simple language as to be readily understood by anyone. All the instructions given are complete and up-to-date; and they are written in a popular style, without any technicalities or mathematical formula. The'work is of a handy size for the pocket, clearly and well printed, nicely bound, and profusely illustrated. To young engineers this catechism 26 CATALOGUE OF GOOD, PRACTICAL BOOKS will be of great value especially to those whu may be preparing to go forward to be examined for certificates of competency; and to engineers generally it will be of no little service, as they will find in this volume more really practical and useful information than is to be found any- where else within a like compass. 387 pages. Seventh edition. Price .... $2.00 ENGINE TESTS AND BOILER EFFICIENCIES. By J. Buchetti. This work fully describes and illustrates the method of testing the power of steam engines, turbines and explosive motors. The properties of steam and the evaporative power of fuels. Combustion of fuel and chimney draft; with formulas explained or practically computed 255 pages, 179 illustrations $3.00 HORSEPOWER CHART. Shows the horsepower of any stationary engine without calculation. No matter what the cylinder diameter of stroke; the steam pressure or cut off; the revolutions, or whether con- densing or non-condensing, it's all there. Easy to use, accurate, and saves time and calcu- lations. Especially useful to engineers and designers. 50 cents MODERN STEAM ENGINEERING IN THEORY AND PRACTICE. By Gardner D. Hiscox. This is a complete and practical work issued for Stationary Engineers and firemen dealing with the care and management of boilers, engines, pumps, superheated steam, refrigerating machinery, dynamos, motors, elevators, air compressors, and all other branches with which the modern engineer must be familiar. Nearly 200 questions with their answers on steam and electrical engineering, likely to be asked by the Examining Board, are included. Among the chapters are: Historical; steam and its properties; appliances for the genera- tion of steam; types of boilers: chimney and its work; heat economy of the feed water; steam pumps and their work: incrustation and its work; steam above atmospheric pressure; flow of steam from nozzles: superheated steam and its work; adiabatic expansion of steam; indicator and its work; steam engine proportions; slide valve engines and valve motion; Corliss engine and its valve gear; compound engine and its theory; triple and multiple expansion engine, steam turbine; refrigeration; elevators and their management; cost of power; steam engine troubles; electric power and electric plants. 487 pages. 405 en- gravings. Price $3.00 STEAM ENGINE CATECHISM. By Robert Grimshaw. This unique volume of 413 pages is not only a catechism on the question and answer princi- ple; but it contains formulas and worked-oiA answers for all the Steam problems that apper- tain to the operation and management of the Steam Engine. Illustrations of various valves and valve gear with their principles of operation are given. Thirty-four Tables that are indispensable to every engineer and fireman that wishes to be progressive and is ambitious to become master of his calling are within its pages. It is a most valuable instructor in the service of Steam Engineering. Leading engineers have recommended it as a valuable educa- tor for the beginner as well as a reference book for the engineer. It is thoroughly indexed for every detail.' Every essential question on the Steam Engine with its answer is contained in this valuable work. Sixteenth edition. Price $2.00 STEAM ENGINEER'S ARITHMETIC. By Colvin-Cheney. A practical pocket book for the steam engineer. Shows how to work the problems of the engine room and shows "why." Tells how to figure horse-power of engines and boilers; area of boilers; has tables of areas and circumferences; steam tables; has a dictionary of engineering terms. Puts you on to all all of the little kinks in figuring whatever there is to figure around a power plant. Tells you about the heat unit; absolute zero; adiabatic expansion; duty of engines; factor of safety; and 1,001 other things; and everything is plain and simple — not the hardest way to figure, but the easiest. 2nd Edition 50 cents STEAM HEATING AND VENTILATION PRACTICAL STEAM, HOT-WATER HEATING AND VENTILATION. Bv A. G. King. This book is the standard and latest work published on the subject and has been prepared for the use of all engaged in the business of steam, hot water heating, and ventilation. It is an original and exhaustive work. Tells how to get heating contracts, how to install heating and ventilating apparatus, the best business methods to be used, with "Tricks of the Trade" for CATALOGUE OF GOOD, PRACTICAL BOOKS shoo use. Rules and data for estimating radiation and cost and such tables and information as make it an indispensable work for everyone interested in steam, hot water heating, and venti- lation. It describes all the principal systems of steam, hot water, vacuum, vapor, and vacuum- vapor heating, together with the new accelerated systems of hot water circulation, including chapters on up-to-date methods of ventilation and the fan or blower system of heating and ventilation. Containing chapters on: I. Introduction. II. Heat. III. Evolution of artificial heating apparatus. IV. Boiler surface and settings. V. The chimney flue. VI. Pipe and fittings. VII. Valves, various kinds. VIII. Forms of radiating surfaces. IX. Locating of radiating surfaces. X. Estimating radiation. XI. Steam-heating apparatus. XII. Exhaust-steam heating. XIII. Hot-water heating. XIV. Pressure systems of hot- water work. XV. Hot-water appliances. XVI. Greenhouse heating. XVII. Vacuum vapor and vacuum exhaust heating. XVIII. Miscellaneous heating. XIX. Radiator and pipe connections. XX. Ventilation. XXI. Mechanical ventilation and hot-blast heating. XXII. Steam appliances. XXIII. District heating. XXIV. Pipe and boiler covering. XXV. Temperature regulation and heat control. XXVI. Business methods. XXVII. Miscellaneous. XXVIII. Rules, tables and useful information. 367 pages. 300 detailed engravings. Price $3.00 STEAM PIPES STEAM PIPES.: THEIR DESIGN AND CONSTRUCTION. By Wm. H. Booth. The work is well illustrated in regard to pipe joints, expansion offsets, flexible joints, and self-contained sliding joints for taking up the expansion of long pipes. In fact, the chapters on the flow of steam and expansion of pipes are most valuable to all steam fitters and users. The pressure strength of pipes and method of hanging them are well treated and illustrated. Valves and by-passes are fully illustrated and described, as are also flange joints and their proper proportions, exhaust heads and separators. One of the most valuable chapters is that on superheated steam and the saving of steam by insulation with the various kinds of felt- ing and other materials with comparison tables of the loss of heat in thermal units from naked and felted steam pipes. Contains 187 pages. Price . . . ". $2.00 STEEL AMERICAN STEEL WORKER. By E. R. Markham. This book tells how to select, and how to work, temper, harden, and anneal steel for everything on earth. It doesn't tell how to temper one class of tools and then leave the treatment of another kind of tool to your imagination and judgment, but it gives careful instructions for every detail of every tool, whether it be a tap, a reamer or just a screw-driver. It tells about the tempering of small watch springs, the hardening of cutlery, and the annealing of dies. In fact there isn't a thing that a steel worker would want to know that isn't included. It is the standard book on selecting, hardening, and tempering all grades of steel. Among the chapter headings might be mentioned the following subjects: Introduction: the workman; steel; methods of heating; heating tool steel; forging; annealing; hardening baths; baths for hardening: hardening steel; drawing the temper after hardening; examples of hard- ening; pack hardening; case hardening; spring tempering; making tools of machine steel; special steels: steel for various tools; causes of trouble; high speed steels, etc. 366 pages. Very fully illustrated. 3rd Edition. Price $2.50 HARDENING, TEMPERING, ANNEALING, AND FORGING OF STEEL. By J. V. WOODWORTH. A new work treating in a clear, concise manner all modern processes for the heating, annealing forging, welding, hardening, and tempering of steel, making it a book of great practical value to the metal-working mechanic in general, with special directions for the successful hardening and tempering of all steel tools used in the arts, including milling cutters, taps, thread dies, reamers, both solid and shell, hollow mills, punches and dies, and all kinds of sheet metal working tools, shear blades, saws, fine cutlery, and metal cutting tools of all description, as well as for all implements of steel both large and small. In this work the simplest and most satisfactory hardening and tempering processes are given. The uses to which the leading brands of steel may be adapted are concisely presented, and their treatment for working under different conditions explained, also the special methods for the hardening and tempering of special brands. A chapter devoted to the different processes for Case-hardening is also included, and special reference made to the adoption of machinery steel for tools of various kinds. 4th Edition, 288 pages. 201 Illustrations. Price $2.50 28 CATALOGUE OF GOOD, PRACTICAL BOOKS TURBINES MARINE STEAM TURBINES. By Dr. G. Bauer and 0. Lasche, Assisted by E. Ludwig and H. Vogel. Translated from the German and edited by M. G. S. Swallow. This work forms a supplementary volume to the book entitled "Marine Engines and Boilers." The authors of this book. Dr. G. Bauer and O. Lasche. may be regarded as the leading authorities on turbine construction. The book is essentially practical and discusses turbines in -which the full expansion of steam passes through a number of separate turbines arranged for driving two or more shafts, as in the Parsons system, and turbines in which the complete expansion of steam from inlet to exhaust pressure occurs in a turbine on one shaft, as in the case of the Curtis machines. It will enable a designer to carry out all the ordinary calculations necessary for the con- struction of steam turbines, hence it fills a want which is hardly met by larger and more theoretical works. Numerous tables, curves and diagrams will be found, which explain with remarkable lucidity the reason why turbine blades are designed as they are, the course which steam takes through turbines of various types, the thermodynamics of steam turbine calculation, the influence of vacuum on steam consumption of steam turbines, etc. In a word, the very information which a designer and builder of steam turbines most requires. The book is divided into parts as follows: 1. Introduction. 2. General remarks on the design of a turbine installa- tion. 3. The calculation of steam turbines. 4. Turbine design. 5. Shafting and pro- pellers. 6. Condensing plant. 7. Arrangement of turbines. 8. General remarks on the arrangement of steam turbines in steamers. 9. Turbine-driven auxiliaries. 10. Tables. Large octavo. 214 pages. Fully illustrated and containing 18 tables. Including an entropy chart. Price, net $3.50 WATCH MAKING WATCHMAKER'S HANDBOOK. By Claudius Sauxier. This famous work has now reached its seventh edition and there is no work issued that can compare to it for clearness and completeness. It contains 498 pages and is intended as a workshop companion for those engaged in Watch-making and allied Mechanical Arts. Nearly 250 engravings and fourteen plates are included. Price ... .... $3.00 7?; University of California SOUTHERN REGIONAL LIBRARY FACILITY 405 Hilgard Avenue, Los Angeles, CA 90024-1388 Return this material to the library from which it was borrowed. win* Series 9482 ^ ooo