1856.] Nm Motors. 67 



by its inventor in tlie Crystal Palace, as noticed by us on previous 

 occasions. After many failures, causing no small amount of mortifi- 

 cation to himself, and disappointment to great numbers of curious 

 spectators, from far and near, the inventor at last, just as the Fair closed, 

 discovered that the cause of his ill luck was owing to a deficient supply 

 of gas. Having remedied the defect, we were invited, on the 20th inst., 

 to visit the Crystal Palace once more, and see it operate for a certainty. 

 We accepted the invitation, and did see it work freely and powerfully 

 for a considerable period, at the rate of sixty revolutions per minute. 



" The motive agent of this engine is carburetted hydrogen, — the gas 

 used in our streets and houses for illumination — and a mixture of 

 atmospheric air. It is well known that when this gas is saturated with 

 oxygen, it becomes an explosive mixture, which, when ignited, suddenly 

 explodes with great violence, like gunpowder. Many attempts have been 

 made to construct gunpowder and explosive gas engines, but Dr. Drake 

 is the first inventor who has succeeded in harnessing this mighty agent, 

 and making it submissive to his will in driving machinery ; for this he 

 deserves great praise. He commenced his experiments in 1837, and by 

 perseverance and ingenuity, has brought his gas engine to its present 

 operative condition. 



" In external appearance. Dr. Drake's machine bears a close resem- 

 blance to a horizontal engine. It has a piston ^nd cylinder, but in its 

 other parts a number of new devices are involved that arc not required 

 for steam. Motion is produced by exploding gas in the cylinder, first 

 behind and then in front of the piston, just the same in efi"ect as steam is 

 employed. At every stroke of the piston nine times more atmospheric 

 air than gas is admitted to the cylinder ; this is done by a peculiar 

 valve, which takes in the proper quantity of air from the atmosphere, 

 while the exact quantity of gas is being admitted through a pipe from 

 the supply reservoir. The heat generated by the explosion of the gas is 

 very great ; the piston is, therefore, made hollow, while the cylinder is 

 surrounded with a jacket, through which a stream of cold water circu- 

 lates for refrigeration. Two red hot igniting capsules are placed 

 through the side of the cylinder, one at each end. After the mixed gas 

 is admitted, it comes in contact with the hot iron, ignites, and instantly 

 expands, giving motion to the piston. Valves of the puppet kind, 

 operated by toes and springs, are used alternately to cover and uncover 

 the igniting irons, as well as to open and cut off the gas supply. The 

 mixed gas being composed of nitrogen, oxygen, and carburetted hydrogen, 

 these, when ignited, unite chemically in the cylinder — suddenly forming 

 carbonic acid gas, a little steam, and nitrogen. The amount of expansion 



