WILLIAM .sv/-;.i//-;.\'v, r.R.s. 383 



a heat not certainly superior to what would be produced 

 it -olid fuel had been burned there instead ; on the contrary, gas 

 of the description we are dealing with is a poorer fuel than solid 

 fir -I. and the heat produced in the furnace will, therefore, be very 

 m 'derate indeed. But the flame, after passing over the bed of the 

 furnace, does not go to the chimney direct, but has to pass through 

 two iTg'-Merative chambers, similar to those already described ; the 

 larger proportion of the heated products of combustion will pass 

 through the air regenerator chamber, simply because it is the 

 largest channel, and another portion will pass through the gas 

 regenerator. The products of combustion pass from these 

 chambers through the reversing valves, and are by them directed 

 into the passage leading to the chimney. 



The operation, therefore, is simply this, that the air and com- 

 bustible gas pass up into the furnace through the one pair of 

 chambers, and pass away, after combustion, towards the chimney 

 through the other pair. But in passing through the second pair, 

 the heat of the products of combustion is given up to the brick- 

 work. The upper portions of this brickwork take up the first, 

 and, therefore, the highest degree of heat, and, as the burnt gases 

 are passed downwards through the regenerators, they are, by 

 degrees, very completely deprived of their heat, and reach the 

 bottom of the chambers and the chimney comparatively cold. 

 After this action has been going on, say, for an hour, the reversing 

 valves are turned over. They are simple flaps, acting like a four- 

 way cock, and, by throwing over the levers which work them, the 

 direction of the currents is reversed. The gas and air will enter 

 now through the second pair of chambers, and the air passing up 

 one regenerator and the gas passing up the other, will take up heat 

 from the bricks previously heated by the descending current. The 

 gases so heated, say, to 1000 Fahr., will enter into combustion, 

 and if the heat produced at the former operation was 1000, it 

 ought this time to be 2000, because the initial point of temperature 

 is 1000 higher. The products of combustion will also escape at 

 2000, and passing through the chequer work of the first pair of 

 regenerators, its uppermost ranges will be heated to very nearly 

 2000. The temperature will diminish by degrees in descending 

 till the gaseous currents have again reached the bottom nearly 

 cold. Again reversing the process, after another hour or half-hour, 



