SMOKE AND DUST ABATEMENT— COTTEELL. 655 



ill the CtibB of the individual householder, a similar procedure appears 

 well-nigh hopeless. 



The most promising solution for the household smoke problem 

 appears to lie in the* use (enforced if necessary) of essentially non- 

 smoking fuels. New York City, with its municipal hard-coal regu- 

 lation, and Pittsburgh, w^ith its natural-gas supply, are good ex- 

 amples of what may be accomplished in this direction. In the case 

 of cities less favorably situated as regards such natural resources we 

 nmst probably look to the by-products coke oven and other forms of 

 gas producer to separate for us the difficultly manageable soft coals 

 into permanent gaseous and solid products, both of which are essen- 

 tially fool proof as far as smoke making is concerned, even when 

 placed in the hands of the untrained public. It is interesting here 

 to note that over half a century ago Sir WiUiam Siemens predicted 

 from economic considerations that the time would come wdien all 

 soft coal would first be coked and gasified before use. While this 

 development in our subsequent fuel technique may have been slow 

 and ramified into many forms not at once recognizable, the principles 

 Siemens had before him have certainly underlain a great part of the 

 progi'ess made since his time, and with the widespread interest now 

 being manifested in improved methods of combustion this line of 

 attack bids fair to take a position of ever-increasing prominence. 



Another important type of centralized smoke control which has not 

 yet been developed to its full possibilities is that of the central steam- 

 heating plant. A very serious offender as regards smoke in many 

 cities is the moderate-sized steam-heating plant, such as is found 

 in apartment houses and smaller ofiice buildings. The number of 

 these and the amount of smoke which each can produce under care- 

 less handling make them a serious item and far more difficult to 

 supervise and control than if consolidated into larger groups with 

 a single furnace plant for each group. Steam distribution with its 

 attendant condensed-water return meets, of course, with sharper 

 limitations than that of either gas or electricity, but even from the 

 economic standpoint, aside from the smoke question, it deserves more 

 serious consideration than it has yet had in municipal engineering. 



The ever-widening applications of electricity, especially in power 

 and heating, are also doing much to solve the smoke problem. Even 

 where the electricity has first to be generated from coal, a tremendous 

 advantage is gained by the centralization of furnaces in a few large 

 plants where the highest type of technical skill can be economically 

 devoted to securing perfect combustion. 



'The small isolated steam-power plant is rapidly disappearing and 

 giving way to the electric motor, primarily for economic reasons, 



