WATER AS FUEL. 657 



strong brick cupola-furnace with an iron shell, as gas-generator ; this 

 connected by a flue with a secondary chamber as superheater, filled 

 with loose fire-brick nearly to the top. The gases generated from an 

 anthracite fire in the furnace are driven by the air-blast through the 

 connecting flue into the secondary or superheating chamber, at the bot- 

 tom ; here they meet a second air-blast, which urges them to a blaze 

 of intense and complete combustion ; and in this superheated condi- 

 tion they are forced up through the labyrinthine interstices of the fire- 

 brick with which the interior of the chamber is piled. 



So effective are these simple arrangements that, in the few minutes 

 required to kindle the mass of coals in the furnace to a cherry-red, the 

 mass of fire-brick in the superheater becomes white-hot and ready for 

 use. This result is the work of carbonic oxide and other products of 

 imperfect combustion usually passed off in the smoke of our domestic 

 chimneys, and finely illustrates the main point of advantage in gaseous 

 fuel — its more complete utilization. If any of us could see the regular 

 gaseous waste from our kitchen-stoves kindled up in the chimney to a 

 pitch of heat sufiicient to melt iron there, it would be a convincing 

 proof of the estimated loss of ninety-five per cent, of our fuel, and 

 would resemble faintly what is done outside the fire-chamber of the 

 Lowe or Strong furnace, and in what answers to the chimneys of our 

 dwellings. 



At this point (to return) the air-blast is shut off ; the outlet of the 

 chimney is tightly closed ; and a cock is turned which lets a jet of 

 steam from a boiler into the bottom of the furnace and up through 

 the mass of glowing coals. Instantly the process of combustion 

 ceases (as between the coal and atmospheric oxygen), and the genera- 

 tion of water-gas begins ; in other words, the coal now takes oxygen 

 in combustion from the steam which has been substituted for air, and 

 leaves the water hydrogen free. The hydrogen, lightest and thinnest 

 of gases, which had been pent in the form and consistency of water, 

 is now itself again, expanding to vast volume, like the ethereal genie 

 let out of the casket by the Arabian fisherman, and ready to do the 

 bidding of its liberator. At the same time a valve is opened in the 

 upper part of the furnace, which lets fall a steady shower of crude 

 petroleum on the fire. The pungent and fuliginous vapor in which 

 the oil rebounds from the burning coals is a heavy solution, so to 

 speak, of carbon in hydrogen. Into this thick mixture the free water 

 hydrogen, rushing up from the decomposition of steam below, freely 

 enters, diluting it to proper proportions for burning completely and 

 cleanly, without smoke, in the open air. Another ingredient, rolling 

 up from the fiery laboratory, also mingles in the tempest of hot gases, 

 and still further heightens the calorific and consuming powers of the 

 compound. This is carbonic oxide, the great value of which, either in 

 a fuel or illuminating gas, and its spontaneous development in place 

 of incombustible carbonic acid, are among the advantages which have 



VOL. XTI. — 42 



