233 REPORT — 1872. 



that is being burnt. Suppose that -we could reduce the total consumption both in 

 summer and in winter by 50 per cent., what an enormous boon that would be even 

 in the one matter of a pure atmosphere ! 



The other way in which we use coal is for purposes of manufacture ; and this, 

 again, may be divided into two branches at least — namely, the coal that is employed 

 for obtaining power and tlie coal that is employed in metallurgical and otlier 

 operations not immediately connected with the production of power. To treat of 

 these latter cases first, they are far too numerous to be dealt with in detail, and a 

 few of the principal therefore only must be considered. Take the siibject of coke- 

 making. How much coal is heated in clamps and in kilns to be converted into 

 coke, and in how few instances is any use made of the whole of the heat residing 

 in the gaseous parts of the coal which are driven off. This heat frequently amounts 

 to 30 per cent, of the whole of that which is iu the coal. 



We come next to the smelting of iron. Take the preliminary process of calcining 

 the ore. In those cases where the ore is " black band," the ore so common in 

 Scotland, the calcining is done by the combustion of the carbonaceous matter 

 mixed with the ore. Far more than the quantity of fuel requisite for the calci- 

 nation is associated with this ore ; but the whole of it is burnt o% and no effort 

 whatever is made to utilize the surplus heat. Then, with regard to the blast- 

 furnaces for smelting iron. Hero still, almost universally in Scotland, that large 

 seat of the iron manufacture, and to a considerable extent in England, the waste 

 gases are suffered to issue from the furnace-top, illuminating the country for miles 

 round, and bearing testimonj' to the indifference of the owner of the furnaces to a 

 waste of our store of fuel. ITpwards of GO years ago, viz. in 1811, the utilization 

 of these gases was suggested in France ; but not much was done for 30 years. 

 About 1840, however, their use becanae not infrequent in that country, and their 

 manufacturers and chemists taught ns that the gas thus recklessly wasted might be 

 collected and utilized, and made to replace the fuel expended in heating the hot 

 blast-stoves and in raising steam for the blowing-engines. But, for the cause which 

 has been and will be alluded to, the adoption of this plan was very slow indeed in 

 England. It has now been in use, however, for many years in our best conducted 

 works ; but, as a proof of the slowness of its introduction, the furnaces of Scotlnnd, 

 as I have already said, are even to this day almost universally worked upon the 

 wickedly wasteful principle of allowing these gases to burn idly away. 



Take, again, the melting of steel in crucibles, where the heat issues from the 

 furnace of necessity hotter than the heat of the melted steel (for were it not so it 

 would cool it) ; and of this issuing heat, as a rule, no use whatever is made. 



Take, again, the heating-furnace and puddling-furnace of our ironworks ; very 

 commonly from these heat at a greater temperature than that of welding iron escapes 

 up the chimneys disregarded, as though it had cost nothing for its generation. 



In many works, it is true, a portion of this heat is utilized for generating steam ; 

 but far more steam can be obtained than is required, even with the most umieces- 

 sary and lavish consumption of it, and thus in great ironworks boilers in which tlie 

 steam is generated by the waste heat of the furnaces may be seen constantly blow- 

 ing off large volumes of steam at the valves ; and many furnaces are iu use to which 

 no boilers are applied, for the simple reason that they would be absolutely super- 

 fluous. This waste of heat in steel-melting and in furnaces for iron and for other 

 metallurgical operations is by no means necessary, although it might be urged that 

 it is ; and it might be said that if a furnace is to heat a body to 3000 degrees, you 

 must of necessity allow the heat to escape at that temperature, or rather at some- 

 thing above it, or else in lieu of heating the body you will be cooling it, and tlurt 

 you can no more trap escaping heat than you can trap a sunbeam. But one of my 

 predecessors in this Chair, Mr. Siemens, has, as we know, shown us that you can 

 trap the heat, and that you can so lay hold of it and store it up that the gases as 

 they pass into the chimney from the furnace in which there is, say, even melting 

 steel shaU be lowered in tlieir temperature down to that which will not char a 

 piece of wood ; and he has shown us how this stored up heat may be communicated 

 to the separate streams of incoming air and gas of his gas-furnaces, so that tliey 

 shall enter the furnace at a high temperature, that temperature to bo increased by 

 their union and combustion iu the furnace. So beautifully can this trapping of 



