The Cheap Power.

Progress, Volume I, Issue 8, 1 June 1906, Page 193

The Cheap Power.

Gardner D. Hiscox, the well-known American engineer, says — '' There is probably no more important mechanical industry, involving the production of motive power for all purposes within the age of steam, than that of the explosive motor and its far-reaching effect in the promotion of industry by a cheap helping-hand." The history of the gas engine itself goes back a long way, and the available records of the internal combustion

engine proper further still. Although the French initiated, m 1678, the long experimental era that indicated the coming of the cheap power, it was not until John Barber, in 1791, took out a patent for the production of force by the combustion of hydrocarbon in air that any advancement was made. This latter patent, curiously enough, comprised a very primitive form of rotary engine. Barber's idea was to turn coal, oil, or other combustible matter into gas by external firing, and then to mix the gases so produced with air in a vessel called the exploder. This mixture was then ignited as it issued from the vessel, and the ensuing flash caused a paddle-wheel to rotate. The records also show that an object of the inventor was to inject a little water into the exploder, in order to strengthen the force of the flash. In the middle " sixties " the consumption of gas had been reduced from 150 cubic feet per horse-power hour, m Barber's time, to 87.5 cubic ft. ; and m 1867 an atmospheric engine, invented by Otto and Langdon, appeared. In this engine a free piston was used m a vertical cylinder, the former being thrown up by the force of the explosion. The only work done on the up-stroke was that to overcome the weight of the piston and piston rod, and the latter, being made in the form of a rack, engaged with a toothed wheel on the axle as the piston descended, causing the fly-wheel to rotate Quite 4,000 engines of this make came into use, but it was not until 1876 that Otto carried into practical effect the principles which make his name figure so prominently in modern gas engineering. These principles, now known as the Otto cycle, were in reality embodied m the patent of a French engineer named Beau de Rocha, and are as follows :—: — (1). Largest possible cylinder volume contained by a minimum of surface. (2). The highest possible speed of working. (3). Maximum expansion. (4) Maximum pressure at beginning of expansion. The advance of the modern gas engine and its accompanying economy-worker, the producer plant, is truly remarkable. So quickly has this new power expanded to almost universal usefulness as a labour-saving element in the lesser industries, that literature on the subject has become exceedingly scarce ; indeed, the available text books cannot be reckoned on the fingers of one hand. In the current issue of Progress a complete report of a recent gas-producer trial appears, and from time to time it is our intention to devote a considerable amount of space to the important subjects of internal combustion engines and gas-producer plants