MECHANICS AND USEFUL ARTS. 83 



greater or less intensity of the heat to which it is exposed. London 

 Patent Journal. 



The London Times describes an exhibition given at Vauxhall Gar- 

 dens, with a view of testing the discoveries of M. Gillard. It says, 

 " The process for the manufacture of the gas consists in the decompo- 

 sition of water by passing a jet of steam over a bed of incandescent 

 charcoal in a retort, the gaseous products of which are hydrogen and 

 carbonic acid gas. The latter being separated by the action of quick- 

 lime in a purifier, the hydrogen in a state of comparative purity is in- 

 ducted to a gas-holder for use. Pure hydrogen, however, possesses 

 but little illuminating power, burning with an unsteady flame, and 

 emitting great heat. To remedy this, M. Gillard has invented an ap- 

 paratus of platinum wire, which is fitted by a brass frame to the burner, 

 by which the flame is converted into a column of intensely white light, 

 and, by the application of a brass chimney, a steady light is produced 

 without the emission of a particular smell or smoke. The experi- 

 ments were made at Vauxhall under disadvantageous circumstances, 

 but they were completely successful. The works, which had not 

 been used for years, were out of order, but after a time they were 

 brought into action, and a clear, powerful, and pure light was pro- 

 duced. It was stated that the hydrogen could be manufactured for 4d. 

 the thousand feet, and that the cost of the platinum would make but a 

 very inconsiderable addition to the charge." 



GAS FROM WATER. 



THE New York Post says that a means of procuring gas for illumi- 

 nation from water has been recently applied in that city. The propri- 

 etors of the Astor House have been using this gas for the last four 

 months. The light, they inform us, is much superior to that obtained 

 from the common gas, with which the whole city is supplied, while 

 the expense is less than one half. The apparatus, which is set up in a 

 small building at the rear of the hotel, is very simple in its construc- 

 tion, requiring only the attendance of two men, who, in seven hours, 

 can turn off sufficient gas for twenty-four hours' consumption. The 

 following is, as near as we could ascertain, the process by which the 

 gas is produced. The water used in its manufacture is discharged 

 from a can, in limited quantities, into a pipe passing through the re- 

 tort. This retort is kept constantly supplied with iron and charcoal, 

 the intense heat from which converts the water, in its passage through 

 the pipe, into steam. The steam thus formed is amalgamated with 

 liquid rosin, of which there is always a large supply kept in a boiler 

 placed immediately over the retort, so that the gas is obtained simply 

 from the combination of steam generated in the manner described, and 

 the liquid rosin. The volatile oil produced during the manufacturing 

 process is discharged through a separate pipe into receiving vessels. 

 This oil is disposed of at half a dollar per barrel. 



A company for the manufacture of this gas (which, we believe, is 

 that used in the Clipper office in Baltimore, and known as Brown's), 

 has been formed in Jersey City, with a capital of $ 500,000. They 



