March 25, 1904.] 



SCIENCE. 



491 



was practically no drop in pressure and no 

 perceptible cheeking of the combustion. 



Unskilled and underpaid firemen are re- 

 sponsible for a great deal of the poor econ- 

 omy and the black smoke of our boiler 

 furnaces. 



Of the efficiency of mechanical stokers 

 in preventing black smoke there can be no 

 doubt in the mind of any one who has seen 

 them in operation side by side with the old 

 type of hand-fired flat grates. 



Their economy can be estimated from 

 the following figures, which are the result 

 not of isolated tests, but of a careful ob- 

 servation covering a period of years. The 

 average rate of evaporation with hand- 

 fired Ohio or Pittsburg bituminous slack is 

 from five to six pounds of water per pound 

 of coal under actual conditions. With 

 mechanical stokers the average rate is from 

 seven to eight pounds of water per pound 

 of coal, and more than this has been ob- 

 tained under test conditions. 



A saving of from 15 to 30 per cent, may 

 be expected from the use of mechanical 

 stokers, and if the cost of steam to run the 

 machine be estimated at 5 per cent, (a lib- 

 eral allowance) there is left a very com- 

 fortable margin. 



As the writer is no longer connected with 

 any city government and can not be ac- 

 cused of any M^arping of judgment, he has 

 no hesitation in saying that he considers 

 the chain grate, as made by the Babcock 

 & Wilcox Co., the Green Engineering Co. 

 and others, as being the most successful 

 solution of the problem of burning soft 

 coal economically and without smoke, so 

 far presented. 



The uniform thickness of fire, the steady 

 feed under the boiler and the automatic 

 cleaning are the salient features in an ap- 

 paratus which is much better than any 

 stoker yet invented. 



If one could have a picture of Newburg, 

 that smoky suburb of Cleveland, as it was 



five years ago, and then again as it is to- 

 day and as it will be a year from now, 

 when the transition from hand firing to 

 chain grates shall have been entirely com- 

 pleted, there would be no need of any argu- 

 ment on this score. 



There is more than one phase in the 

 science of smoke prevention. So far we 

 have considered the strictly mechanical 

 side. There are also the ethical and the 

 legal sides to be considered. Grant that 

 smoke can be prevented, how shall we in- 

 sure that it will be, without trenching on 

 those rights which every American citizen 

 claims a-s his ? Ethically considered, every 

 one has a right to as much smoke as he 

 wants, so long as he does not incommode or 

 injure his neighbors. 



The damage to propei-ty and to health 

 from soft-coal smoke is now so generally 

 conceded that no argument on this point is 

 necessary. In other words, the man who 

 allows black smoke to issue from his chim- 

 ney is guilty of maintaining a nuisance as 

 much as he who allows garbage or foul 

 water to accumulate on his premises. 



To quote from the ordinances of the city 

 of Cleveland: 



Sec. 2. That the owner, agent, lessee or occu- 

 pant of any building or structure of any descrip- 

 tion from the smoke-staek or chimney of wliieh 

 there shall issue or be emitted such dense or black 

 or gray smoke within the corporate limits of the 

 city of Cleveland, shall be deemed and held to be 

 guilty of creating a public nuisance, and of vio- 

 lating the provisions of this ordinance. 



The fact once established by law and 

 precedent that smoke production is a nui- 

 sance and that smoke producers may be 

 fined like other law-breakers, it would seem 

 to be a comparatively easy matter to con- 

 trol the evil. Experience has shown that 

 this is not the case and that very few con- 

 victions have been made under the law. 



The first step that should be taken to- 

 regulate smoke production is to make it 



