Fig. 59-Sectional View of Modern Concentric Float Auto-
matic Carburetor
Fig. 60 Showing Forms of Spraying Nozzles Used in
Gasoline Carburetors

167

169

Fig. 61-Float Chambers Used in Carburetors to Maintain
Constant Level at the Jet.

170

171

172

Fig. 62-Types of Automatic Valves to Admit Auxiliary Air
to Mixture

Fig. 63-Automatic Carburetor Used on Holt Tractor
Fig. 64-Carburetor and Governor of Hart-Parr Design
Fig. 65-Practical Method of Supplying Fuel to Ellis Two-
Cycle Engine

Fig. 66-Action of Carburetor Used in Gas Traction
Company's "Big 4-30" Power Plant When Using
Kerosene

174

175

178

180

Fig. 67-How Injected Kerosene is Ignited by Heat in
Combustion Chamber. Sectional View of Muncie
Two-Cycle Oil Engine
Fig. 67a-Views of Secor-Higgins Carburetor, Used on
Rumely "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 . 185
Fig. 68-Induction Coil Used in Connection With Batteries

to Produce Electric Spark in Gas Engine Cylinder 194
Fig. 69-Devices for Producing Spark in Engine Cylinder.
A-Low Tension Igniter Plate. B-High Tension
Spark Plug

195

200

Fig. 70-Oscillating Armature Low Tension Magneto and
Integral Igniter Plate, a Complete Ignition System
Fig. 71-Revolving Armature Magneto Delivering Low
Tension Current. Used in Connection With Induction
Coil, Timer and Spark Plug to Form Complete Ignition
System

202

Fig. 72-Sectional View of Bosch High Tension Magneto, a Complete Current Producer for Four Cylinder Engine Ignition

Fig. 73-Typical Four Cylinder Low Tension Ignition.
System

208

Fig. 74-Simple Ignition System for One Cylinder Engine
Using Battery and Magneto

209

Fig. 75-Two Cylinder Battery and Coil Ignition System . 210
Fig. 76-Four Cylinder Ignition System Utilizing Battery
Current

Fig. 77-Diagram Explaining Action of Four Cylinder
Magneto Ignition System Used on "Big 4-30" Gas
Tractor.

212

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

Fig. 82-Forced Water Circulation Method of Cooling
Engine Cylinders

222

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
Fig. 864-Radiator Used on Holt Tractors Has Detachable
Cooling Sections

229

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
Fig. 89-Method of Supplying Oil Troughs of Holt Tractor
Motor Crankcase

237

.

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
Fig. 93-Method of Lubricating Main Bearings from Oil
Reservoirs Integral With Crankcase

242

243

Fig. 94—Side View of I. H. C. Mogul Tractor, Showing

Location of Clutch

246

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, Outlining 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. 111-Sectional View of Typical Countershaft With
Differential Gear in Place

Fig. 112-The Differential Spider With Bevel Pinions and
Spur Drive Gear Attached

279

Fig. 113-Countershaft With Differential Spider Outlined at
Fig. 112 Removed

280

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

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

Fig. 116-Rear End of I. H. C. Tractor Frame, Showing
Substantial Cast Members Serving to Support Counter-
shaft and Rear Axle Bearings.
Fig. 117-How Pivoted Solid Front Axle Permits Frame
Movement Without Distortion by the Three Point
Support. A-On Level Ground. B-Rear Wheel
Surmounting an Obstacle.

286

287

288

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

Fig. 120-Showing Advantages of Large Wheels for Tractor
Driving Members

Fig. 121-Tractor Driving Wheel Showing Method of
Attaching External Spur Bull Gear to Wheel Hub
and Rim

Fig. 122-Tractor Driving Wheel and Hub Casting. Note
Internal Spur Drive Gear and Method of Attaching to
Hub and Rim

292

293

. 295

297

Fig. 123-Traction Wheel of Gas Tractor With Spring Members to Remove Shocks from Driving Gears . 298 Fig. 124-Driving Wheel of Tractor Utilizing Chain

Drive

Fig. 125-Cross Section of Hart-Parr Rear Hub Showing
Wheel Bearing and Method of Lubrication
Fig. 126-Traction Wheel Rims Showing Cleats or Grouters
of Various Types Utilized to Increase Frictional
Adhesion With Ground

Fig. 127-Extension Rims Designed to be Attached to
Regular Traction Wheels to Obtain Greater Contact
Area When Used on Soft Ground

299

300

301

302

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
Engines. A-Tight and Loose Chain
B-Worm and Sector Gear and Ackerman

Traction
Method.

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

Fig. 135-Sectional View of Front Wheel of Hart-Parr
Three Wheel Tractor Showing Method of Supporting
Steering Member

312

'. 313

Fig. 136-Outlining Application of Automatic Steering
Arrangement to "Big 4-30" Gas Tractor

315

Fig. 136A-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
Fig. 140-Sectional View of Worm Drive Gearing Used in
Connection With Live Rear Axle
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

321

323

328

Fig. 143-Governors of the Centrifugal Type Form Important 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