An American Makes the First Workable Gas Engine.—And now we come to a gas engine that was the first really practical one ever built up to the beginning of the nineteenth century, and the credit of it is due to Robert Street, an American.
He was granted a patent in 1794 for a gas cylin der and piston engine to work a pump. In this en gine the bottom of the cylinder was heated and a few drops of turpentine were allowed to fall into it. When the turpentine evaporated it formed a vacuum in the cylinder and the atmospheric pressure on the piston forced it up.
An explosive mixture made by passing air over a sponge soaked in turpentine was admitted into the cylinder just before the piston moved up and the latter compressed it on its down stroke. A flame was then applied to the touchhole, which exploded the fuel mixture, as it is now called, and this drove the piston up. His engine is pictured in Fig. 8.
To Street is also due the credit of being the first to convert a liquid fuel into a gas and to make an explosive mixture by mixing it with air.
A Double Acting Gas Engine.—In the engines that have gone before you will have observed that the explosive force of the gas acted on one side of the piston only, and that is the way that all of the gas, gasoline, and oil engines are made to-day.
In 1797 a Frenchman named Lebon took out a patent for a double acting gas engine in which the explosive fuel mixture was compressed by a com pression pump and then admitted alternately on each side of the piston as steam is in an ordinary steam engine.
The piston rod was connected with a shaft and this worked the gas compressor pump. To fire the fuel mixture Lebon intended to use a spark set up by an electric machine which would also be driven by the shaft. Unfortunately the inventor was as sassinated in 1804 and so his engine came to naught.
The Gas Engine Competes With the Steam En first gas engine to be put to the prac tical test of pumping water was made by Samuel Brown, of London, in 1823. Like Hautefeuille's gas engine, his was of the vacuum type, and in the next ten years four of these engines were used in England for pumping water. Each engine could raise 300 gallons of water 15 feet high on 1 cubic foot of gas.
The Invention of an Improved Igniter. William. Barnett, also of England, got up in 1838 a double acting gas engine, but his fame rests on an ignition cock for firing the fuel mixture.
In this igniter, see Fig. 4, which was screwed to the head of the cylinder, two flames were used, one on the inside and the other on the outside of the cylinder; now when the force of the explosion put out the inside flame, a valve opened in the cock and it was again relit by the outside flame, which was always burning.
Then Came the Electric Spark.---It was Barsanti and Matteucci, of Italy, who first used the electric spark to ignite the fuel charge in the cylinder. This was in 1857, when electricity was getting pretty well out of its swaddling clothes. Their engine was also of special design, but it was not used afterward, and hence did not help along the state of the art. Fig. 5 shows their igniter.
The Advent of the Commercial Gas workers along the line of the gas engine were busy now everywhere, but Lenoir, of France, designed and built, in 1860, the first gas engine that was really a commercial success.
There was nothing new or original about this gas engine of Lenoir's, but what he did was to work out every single part of it so carefully that when he built the engine it worked efficiently. His engine was very like the steam engine as it is built today, but, of course, with the addition of valves to admit the fuel mixture, and others to let the burnt gases escape. It is shown in Fig. 6.
In 1860 two of Lenoir's engines were built in Paris, one of six and the other of twenty horse power. According to descriptions published at that time both of these engines ran as smoothly and as silently as the best steam engines then in use.
An American Gasoline and Oil 1873 George Brayton began to build in the United States gasoline and oil engines which were better than any that had yet been produced.
The outstanding feature of the design of his engines was that the fuel mixture burned at a constant pres sure instead of in a series of explosions.