ON CONSUMPTION OP FUEL AND PREVENTION OF SMOKE. H3 



tensity of Iieat and greater brilliancy in its illuminating powers. Finding it 

 however impossible to separate the nitrogen from the oxygen of the air (for 

 general purposes), we must take the mixture as it is, and instead of using 

 1 atom of oxygen, we must take 2 of nitrogen along with it, and as 4; atoms of 

 oxygen and 8 of nitrogen are required for the saturation of 1 atom of car- 

 buretted hydrogen, it follows that four times the quantity of air in volume 

 and 144' of weight will be necessary for that purpose. Again, for the satu- 

 ration of 1 atom of bi-carburetted hydrogen, 6 atoms of oxygen and 12 of ni- 

 trogen, in weight 216, are wanted, which, added to the previous quantity in 

 combination with the carburetted hydrogen, the whole supply of air will there- 

 fore be 4 + 6 = 10 volumes of atmospheric air to one of coal-gas. Ten to one 

 is therefore the true proportion of atmospheric air required for attaining per- 

 fect combustion, and for reducing the gases to their ultimate products of car- 

 bonic acid and water. 



Having determined the conditions and relative proportions of the gases 

 and their supporters in a state of perfect combustion, it will be seen that in 

 order to ensure ceconomy and efiect in the combustion of fuel, a large 

 and copious supply of air must be admitted to the furnace, and that in the 

 ratio of 10 volumes of air to 1 of coal-gas. It is difficult to determine the 

 exact quantities evolved from every description of fuel, and probably equally 

 so to supply its equivalent of air; but in order to attain certainty in this 

 respect, let the openings be made sufficiently large, and by a little attention 

 to the quality of the fuel and quantity of air required for its combustion, 

 the apertures may be contracted till such time as a mean average and a close 

 approximation to the maximum effect are obtained. 



The concentration of heat is a consideration of much importance in the 

 ceconomy of the steam-engine and the industrial arts; and as much depends 

 upon its preservation, it may be useful in this place to direct attention to a 

 few self-evident facts, which if properly attended to will lead to considerable 

 saving in the use and application of heat. 



It cannot be doubted, that after having applied the rules, conditions and 

 proportions requisite for the creation of heat, the whole of our knowledge 

 may become obsolete unless the heat thus generated be closely preserved, 

 and if I may use the expression, kept xxiarm. It would be worse than useless 

 to study oeconomy in one department, so long as a lavish expenditure goes 

 on in another ; and having once acquired a given (juantity of heat, the next 

 thing to be done is to retain and prevent its escape. Caloric is a body which 

 radiates in all directions, and unless surrounded with warm clothing, or non- 

 conducting substances, it is sure to disappear ; and although tightly bottled 

 up, it sets at defiance the closest and hardest metals, and frequently escapes 

 through the pores of the thickest iron and steel. Unlike gases and fluids, 

 such as air and water, it is only kept within bounds by an envelope of soft 

 wool or pounded charcoal, and the highest temperature of heat may some- 

 times be retained by a solid compact mass of lime and baked clay. This is 

 strongly exemplified in the construction of ovens and furnaces, which, taken 

 as a rule, will establish the principle on which heat can be preserved without 

 diminution till it is used. For this purpose we should recommend the flues 

 and furnaces of boilers, and other fires, to be closely encased with good 

 building material adapted for the retention of heat, and all steam-boilers to 

 be well-covered and clothed, so as to prevent (as much as possible) the 

 escape of heat in that direction ; and for steam-engines, that all the steam 

 pipes, cylinders, &c. siiould he closely enveloped in a thick coating of felt, 

 canvas or wood, and afterwards well-painted. These precautions being taken, 

 the effects will soon become visible in a saving of 15 to 20 per cent, of fuel, 

 18-M. I 



