CHAPTER XLII.

=MARINE ENGINES.=

=Various Kinds of Marine Engines= 434 to 451 High pressure engines 434 Compound condensing engines 434, 435 Triple expansion engines 436 Donkey engines 442 Trunk engines 446 Oscillating engines 446 Geared engine 446 Compound engine of the steamship _Poplar_ 447, 450, 451 =Arrangement of Marine Engine Pumps= 436 =Boilers of Marine Engines, Arrangement of= 436, 437 =Various Parts of Marine Engines, etc.= 438 to 449 Valve for intermediate cylinder of triple expansion engines 438 Link motions for triple expansion engines 438 Auxiliary or by-pass valve 438, 439 Oiling apparatus 439, 440 Surface condensers 440 Circulating pumps 440 The snifting valve 440 The blow-through valve 440 Air pumps 441 The air chamber 441 Feed escape or feed relief valve 441 Bilge injections for marine engines 441, 442 Surface condensing, advantages of 442 Valves of the surface condensing engine 442 Case hardening 442 Link motion for marine engines 443 The separate expansion valve 443 Friction of slide valves 443 Double beat valves 443 The siphon 443 Steam lubricators 444 Marine engine valves that are worked by hand 444 Vacuum gauge 444 Condenser, to find the total pressure in the 444 Paddle wheels 444, 445 Screw propeller 445 The thrust bearing 445 Marine engine, the principal parts of 445 Lagging marine engines 446 Propeller cylinders 446 Fuel required 446 Freezing of pipes 446 Failure of engine to start, causes of 446, 447 Defective vacuum, causes of 447 Heating, causes of 447 Construction of a triple expansion engine 447 to 449