114 REl'ORT 1844. 



On the Prevention of Smoke. — The ultimatum of this inquiry is twofold; 

 first the combustion of fuel, and secondly the prevention of smoke. In the 

 preceding investigation we have endeavoured to establish the laws which 

 regulate and govern the combustion of fuel, and in that attempt we have also 

 endeavoured to show the difference between perfect and imperfect combustion. 

 Now perfect combustion is the prevention of smoke, and whenever smoke 

 makes its appearance we may reasonably infer that imperfect combustion, 

 and probably want of attention to a few simple rules is the cause. We have 

 already inculcated these rules, and shown from well-known chemical facts, 

 that 1 atom of coal-gas requires 10 atoms of atmospheric air for its complete 

 combustion ; when that quantity is at its maximum or in excess there is no smoke, 

 ivhcn it is dyferent smoke is invariably present. It therefore follows, that in 

 order to render the residue of the products of combustion transparent, or 

 " smokeless," a supply of air amounting to ten times that of the gases evolved 

 must be admitted. Should it exceed that quantity the effect will not be 

 smoke, but an additional expenditure of fuel to supply the loss of heat which 

 this excess of air would require for absorption, rarefaction, &c. Hence the 

 necessity which exists for power to regulate the admission, if not the exact, 

 at least an approximate quantity of air. On the other hand, should the supply 

 be deficient in quantity (which is often the case), a dense volume of smoke is 

 then visible, accompanied with all the defects and annoyances of imperfect 

 combustion. 



The variable changes which accompany perfect and imperfect combustion 

 are not only visible, but may be proved by experiment. Let any person 

 apply his hand to the tube of an Argand gas-burner, and he will find that the 

 instant the aperture is partially closed the flame immediately becomes elon- 

 gated; and instead of a clear brilliant light, a dull red flame, with a dark 

 volume of smoke, is the result. This shows the effect of a diminished supply 

 of air ; and the same may be applied to a steam-engine furnace, when imper- 

 fectly supplied with oxygen, when the gases pass off in opake volumes un- 

 consumed, and where a considerable portion of heat is entirely lost from that 

 cause. It has been stated that we cannot have fire without smoke ; but this 

 is not the case in steam-boilers, as a well-constructed furnace properly ma- 

 naged furnishes many examples where bituminous coal is consumed in large 

 quantities and with little if any appearance of smoke. If coal were double 

 the price, it is more than probable that a great improvement would shortly 

 present itself, and that not exclusively in the suppression of the smoke nui- 

 sance, but in a further extension of those duties wherein ceconomy becomes 

 a leading feature in the attainment of these objects. It is therefore futile to 

 urge difficulties which have already been overcome, and where in many in- 

 stances " the prevention of smoke " is accomplished with perfect ease, and 

 with great benefit to the parties concerned. In attempting the total sup- 

 pression of this nuisance, two important considerations require to be attended 

 to as essential ; the first of which is abundance of boiler space, and the second 

 a siifficient supply of air. For the last of these we have already given suffi- 

 cient instructions for its admission; and for the first we could not furnish a 

 better rule for the capacity and power of boilers than that which applies to 

 the steam-engine, namely that of raising 33,000lbs. one foot high in a minute. 

 For example, suppose a steam-engine of 50 horse nominal power to be 

 worked according to the indicator up to 80 horse, which taken at 3;:),000 lbs. one 

 foot high in a minute, we have then to calculate, from data already given, the 

 size of boilers required. Using these precautions, and never loading the steam- 

 engine beyond its nominal power without enlarging the boilers in proportion, 

 the effects will be an almost total suppression of smoke and a saving of fuel. 



