SPEECH OF SIR WILLIAM ARMSTRONG. 379 



the purpose of testing the practicability of preventing smoke in 

 the combustion of bituminous coal in steam-engine boilers, I can 

 state with perfect confidence that so far as the raising of steam is 

 concerned, the production of smoke is unnecessary and inexcusable. 

 The experiments to which I refer proved beyond a doubt that by 

 an easy method of firing, combined with a due admission of air 

 and a proper arrangement of fire-grate, not involving any complex- 

 ity, the emission of smoke might be perfectly avoided, and that 

 the prevention of smoke increased the economic value of the fuel 

 and the evaporative power of the boiler. As a rule, there is more 

 smoke evolved from the fires of steam-engines than from any others, 

 and it is in these fires that it may be most easily prevented. But 

 in the furnaces used for most manufacturing operations the pre- 

 vention of smoke is much more difficult, and will probably not be 

 effected until & radical change is made in the system of applying 

 fuel for such operations. Not less wasteful and extravagant is 

 our mode of applying coal for domestic purposes. It is computed 

 that the consumption of coal in dwelling-houses amounts, in this 

 country, to a ton per head per annum of the entire population ; so 

 that upwards of 29,000,000 tons are annually expended in Great 

 Britain alone for domestic use. If any one will consider that lib. 

 of coal applied to a well-constructed steam-engine boiler, evaporates 

 101b. or one gallon of water, and if he will compare this effect with 

 the insignificant quantity of water which can be boiled off in steam 

 by lib. of coal consumed in an ordinary kitchen fire, he will be 

 able to appreciate the enormous waste which takes place by the 

 common method of burning coal for culinary purposes. The sim- 

 plest arrangements to confine the heat and concentrate it upon the 

 operation to be performed would suffice to obviate this reprehensi- 

 ble waste. So also in warming houses, we consume in our open 

 fires about five times as much coal as will produce the same heat- 

 ing effect when burnt in a close and properly constructed stove. 

 Without sacrificing the luxury of a visible fire, it would be easy, 

 by attending to the principles of radiation and convection,, to ren- 

 der available the greater part of the heat which is now so improvi- 

 dently discharged into the chimney. These are homely considera- 

 tions — too much so, perhaps, for an assembly like this ; but I 

 trust that an abuse involving a useless expenditure, exceeding in 

 amount our income-tax, and capable of being rectified by attention 

 to scientific principles, may not be deemed unworthy of the notice 

 of some of those whom I have the honour of addressing. 

 ******* ***^c 



