Inventors at Work, with Chapters on Discovery

by George Iles

Steam Engines.

An experimental quadruple-expansion steam engine at Sibley College, Cornell University, has consumed but 9.27 pounds of steam of 500 pounds pressure per indicated horse-power, with a mechanical efficiency of 86.88 per cent. An Allis-Chalmers compound engine, tested December, 1905, at the Subway Power-house, New York, developed 7,300 horse-power from steam at 175 pounds pressure with a consumption of 11.96 pounds of steam per indicated horse-power. The cylinders were not steam jacketed and no reheaters were used. This engine has two horizontal high pressure cylinders, 42 inches in diameter; and two vertical low pressure cylinders, 86 inches in diameter; all of 60 inch stroke. The four cylinders work on the same crank pin, with the effect of two cranks at right angles to each other in superseded designs. A [similar engine], less powerful, is shown opposite this page.

5000 HORSE-POWER ALLIS-CHALMERS STEAM ENGINE,
St. Louis Exposition, 1904.
Horizontal and vertical cylinders united to the same crank pin.