WILLIAM SIEMENS, F.R.S. 183 



filled with coal through a large hopper at the top ; this iron casing 

 is covered on the interior with a lining of refractory material, and 

 in this lining passages are arranged all round for the exit of the 

 ; a large opening at the bottom admits of the removal of ashes 

 and clinkers that may be formed in the combustion of the fuel, 

 and a blast, which by preference should be heated, is directed 

 riirlit into the very heart of the mass of fuel. The result is a very 

 high temperature in the centre of the mass, and no heat is lost at 

 that point, which loss would interfere with the due conversion 

 back into carbonic oxide. At the same time, water, which is 

 admitted by a continual streamlet into a pan near the bottom, is 

 evaporated, and currents of steam are directed or drawn into the 

 apparatus, passing through the zone of highest temperature 

 towards the centre of the mass. They there become converted 

 by contact with the incandescent fuel into carbonic oxide, and 

 hydrogen gas, which add greatly to the calorific effect of the gas 

 produced. 



Much has been said of late years of water-gas, and one has 

 sn 'ii statements in the papers calling attention to the enormous 

 store of fuel we possess in the ocean ; but a very little considera- 

 tion will show the utter fallacy of such a proposition, as getting 

 actual heat energy from water, which is already the product of 

 complete combustion. Water can only usefully assist in the 

 operation of gas production if you have spare heat to expend. 

 If in the gas-producer no water at all were admitted, you would 

 obtain a current of carbonic oxide, mixed with the other products 

 of distillation of the raw fuel that enters the apparatus ; and the 

 heat that would result from this combustion, even after a portion 

 of it had been expended in the backward reconversion of the 

 carbonic acid into carbonic oxide, and in the work of distillation 

 of the raw coal into hydro-carbons, would be sufficient to impart 

 to the gas at the point of exit a temperature of about 1,000 

 F., or a little more. This heat must be considered as a loss, 

 because if the gas had to be carried to any reasonable distance, 

 this free heat would be dispersed before it reached the furnace, 

 and it is with the view of utilising this heat, which would other- 

 wise be lost, that water can be had recourse to advantageously. 

 But it must be administered in judicious proportions. If too 

 much water is admitted the chemical action which is intended to 



