This article is reprinted from the November 26, 1892 issue of Scientific American.
It has generally been supposed that gas engine were necessarily limited to 30 horse power and under, and that where larger engines are required they must necessarily be made by compounding smaller ones. Our engraving, however, shows a large gas engine made by H. W. Caldwell & Son Company, Chicago, Ill., and used in the large grain elevator of Taylor Brothers, at Cooper's Point, Camden, N.J.
This engine is rated at 100 horse power. It is operated by carbureted air, consisting of a mixture of common air and gasoline vapor. This provides a fuel which is not only invariable in quality, but is quite inexpensive. In large quantities the gasoline costs six cents per gallon in large cities, and as this engine is operated by one gallon of 74 gravity gasoline per horse in ten hours, it will be seen that the cost of fuel is very light compared with the power yielded. As the engine is working at present it is developing 62 horse power actual. The cylinder has a bore of 16 inches and the stroke is 24 inches. The crank shaft has a speed of 150 revolutions per minute. The gasoline is drawn directly from a tank considerably lower than the engine, and its vapor is mingled with the air without any special carbureting device. The governor limits the number of charges admitted to the cylinder by controlling an air gate over one of a pair of air tubes shown at the rear of the engine. The air gate has two ports and allows air to be drawn through either tube according to the action of the governor.
In one tube there is a nozzle leading upward from a reservoir containing less than a pint of gasoline, and when the port above this tube is opened, the engine takes in an explosive charge. The charges are ignited by an incandescent tube encased in a large tube lined with asbestos.
Heretofore, one objection to large gas engines has been the use of tube timers. In this engine they are entirely dispensed with. Another objection to large gas engines has been the difficulty in starting. In some cases, small auxiliary engines have been used for this purpose. All this is obviated in this engine by the use of a novel self-starter, which consists of a hand pump used for forcing the charge into the cylinder and a detonator for exploding the charge after it has been introduced. This device gives the engine its first impulse, after which it continues to operate steadily with its automatic gear.
As this engine requires no fireman or skilled engineer, and as it uses cheap fuel which leaves no residue, it is apparent that this engine has great advantages over the steam engine. The credit of the invention of this engine is due to Mr. James A. Charter, who has long been known in the gas engine business.