CHAPTER XXXVII.

=STEAM ENGINES.=

=Engine Cylinders= 372 to 374 The bores of 372 Sizes of 372 Wear of 372 Counterbore of 372 Clearance in 372 Lubrication of 373 The cocks of 373 Relief valves of 373 The steam ports of 373 Lagging 374 Jacketed cylinders 374 =Engine Pistons= 374 The speeds of 374 With releasing gears 374 With positive valve gears 374 The rings of 374 The follower 374 Testing the rings of 374 =Engine Piston Rods= 375 Methods of securing 375 Packing 375 Glands for 375 =Engine Cross Heads= 375 =Engine Guide Bars= 375 =Engine Connecting Rods= 375 Connecting rod keys 375 Angularity of 375 The lengths of 375 =Valves= 376 to 378 The D-valve 376 The point of cut off 376 Period of expansion of the steam 376 Point of release of the steam 376 Point of compression of the steam 376 Lead of 376 Point of admission of the steam 376 The lip 376 Exhaust lap 376 Steam lap 376 Tracing the action of 376 Double ported valves 377 The Allen valve 377 Webb's patent valve 377 Balanced valves 377 Circular valves 377 Piston valves 378 Separate cut off valves 378 Meyer's cut off valves 378 Gonzenback's cut off valve 378 =Eccentrics= 378 Shifting eccentrics 378 The action of 378 The angular advance of 378 =Designing Slide Valves= 380 =Valve Motions= 381 Diagram for designing 381 =Link Motion= 383 In full gear forward 383 In full gear backward 383 The action of 383 Setting the valves 383 =Governors= 384 Fly ball or throttling 384 Isochronal 384 Dancing 384 Speed of 384 Spring adjustment of 384 Sawyer's valve for 384 Speeder for 384 =Starting a Slide Valve Engine= 384 Crank position in 384 =Examination of an Engine= 385, 387 Adjusting connecting rod brasses 385 Adjusting main bearing 386 Taking a lead 386 Squaring a valve 386 Heating, to avoid 386 Setting a valve 386 Leaky throttle valves 386 Freezing an engine, prevention of 386, 387 =Pumps= 387, 388 Lift and force 387 Plunger 387 Rotary 387 Single-acting 387 Double-acting 387 Displacement of 387 Principles of action of 387, 388 Speed of 388 Capacity of 388 Air chamber of 388 Belt 388