WATHM AS FUJSZ, 659 



The first stage of the process invented by Mr. Strong is so nearly 

 the same with that ah-eady described that a repetition is unnecessary, 

 the furnace being fired up until the loose brick contents of the second- 

 ary chamber or superheater are at a white-heat, when, as before, gas- 

 making is commenced. But here the current of the process, so to 

 speak, is reversed. Instead of letting the jet of steam in at the bot- 

 tom of the furnace, we let on steam at the other end of the system, 

 L e., at the top of the superheater, and pass it directly downward 

 through the mass of white-hot fire-brick. This raises the steam to a 

 perfectly invisible gas, hotter than devouring flame, as it rushes from 

 the superheater, through an extra flue, into the upper part of the fur- 

 nace. There it meets a shower of anthracite coal-dust instead of pe- 

 troleum, sifted down into the furnace from above, and literally burns 

 it up with intense combustion — precisely as coal-dust would be de- 

 voured in the fierce flame of the blast-furnace seven times heated, 

 except that the oxygen of this combustion is supplied entirely by a 

 steam- instead of an air-blast. In other words, the steam furnishes 

 both heat and oxygen for the instant conversion of the coal-dust to 

 carbonic acid, with the consequent release of its own prodigious vol- 

 ume of hydrogen. Under their own increased pressure, the gases con- 

 tinue without pausing, down though the mass of glowing coals. In 

 making this passage, the carbonic acid takes up a double portion of 

 carbon from the hot coals and becomes carbonic oxide — the powerful 

 heating gas so often seen burning in a lambent violet flame on the sur- 

 face of anthracite fires when the air is let in on them. As there is no 

 access of atmospheric oxygen to the furnace, there is no opportunity 

 for the combustion either of this gas or of the freed hydrogen, and 

 accordingly both pass out together at the bottom of the furnace, 

 through a pipe which conducts to the gas-holder. 



The product of this process, before purification, has been rigorously 

 analyzed by the several methods, by Professor Gideon E. Moore, Ph. 

 D., and proves to be 52*76 per cent, pure hydrogen, 35"88 per cent, car- 

 bonic oxide, and 4*11 per cent, marsh-gas, making nearly ninety-three 

 per cent, of the whole volume in these powerful calorific agents, leav- 

 ing only six to seven per cent, of incombustible waste (carbonic acid 

 and nitrogen). Wurtz also gives substantially the same proportions, 

 in Johnson's " Cyclopgedia." 



The purity of this fuel is a consideration nearly sufficient of itself 

 to revolutionize the manufacture of iron, and especially of steel, for 

 which, in its perfection, few if any mineral coals are sufficiently free 

 from such troublesome ingredients as sulphur, phosphorus, etc. ; but of 

 this further on. 



With respect to comparative calorific values, Professor Moore's re- 

 port shows, by rigorous calculation, that the Strong fuel-gas will pro- 

 duce 2'78 times the practical effect of the amount of coal consumed in 

 its manufacture, supposing the same coal were burned directly by the 



