194 THE ADDRESSES, LECTURES, ETC., OF 



otherwise be lost by radiation into the atmosphere, and thus 

 enriches the gas by the addition of hydrogen and the formation of 

 carbonic oxide free from nitrogen. This mixture of gases passes 

 up a brick stack, H, and is then carried through a horizontal 

 "elevated cooling tube," J, wherein a certain amount of the 

 energy of sensible heat is transformed into that of pressure, in 

 which form it is required for two reasons : firstly, that there may 

 be no leakage of air into the gas flue ; and, secondly, that the gas 

 may be delivered with a slight outward pressure at the furnace. 

 The furnace consists of the regenerators, valves, and heating 

 chamber. The regenerators are four chambers, C, E, Fig. 2, 

 Plate 3, containing fire-bricks so arranged as to allow air or 

 gas to pass through them : these fire-bricks will be heated by 

 hot gas. and will heat cool air or gas passing through the 

 chambers. The regenerators are divided into pairs of two, which 

 are connected with special reversing valves, so arranged that the 

 gas-regenerator of the admission pair is connected with the gas- 

 producer, and the air-regenerator with the atmosphere, while the 

 products of combustion pass through the exit regenerators to the 

 chimney. The reversing valves are arranged like four-way cocks, 

 so that by throwing over the flaps the admission regenerators may 

 become exit regenerators, and vice -versa. The heating chamber, 

 D, is placed above the regenerators, and there are two sets of 

 ports leading from it to the two pairs of regenerators. 



When the furnace is in action, and at a certain high tempera- 

 ture, air enters the air-regenerator from the atmosphere, and gas 

 the gas-regenerator from the producer ; these currents are heated 

 as they traverse the brickwork of their respective regenerators, 

 and finally combine in the furnace, adding the heat of the brick- 

 work through which they have passed to that of chemical com- 

 bination or combustion. The flame produced having done its 

 work in the heating chamber, the products of combustion pass 

 down the exit regenerators, which they heat to a high temperature. 



After a certain time, generally half an hour, the direction of 

 the cui'rents is reversed by means of the reversing valves, the exit 

 regenerators becoming those of admission ; and thus each pair of 

 regenerators is alternately employed to heat the entering air and 

 gas, and to cool the products of combustion, which finally leave 

 the chimney at a comparatively low temperature. 





