56 



SCIENCE. 



[N. S. Vol. IX. No. 211. 



given the subject by the muuicipal govern- 

 ment for years, nothing had been accom- 

 plislied, and it was, in this instance, proposed 

 to organize a technical commission to con- 

 duct competitive tests of various methods 

 and apparatus having for tlieir object the 

 suppression of smoke from boiler-furnaces. 

 The above-named commission was accord- 

 ingly formed and was assigned a credit of 

 8,050 francs for expenses. The commission 

 was to select acceptable forms of furnace 

 and report to the city government for their 

 license and use. One hundred and ten 

 competitors appeared, their schemes includ- 

 ing the following : 



GENERAL PLAN OF PROCEDURE. 



(1) Mechanical feed and methodical combustion. 16 



(2) Supplementary injection of air, hot or cold. . 20 



(3) Injection of steam, with or without air 5 



(4) Stirring the gases 7 



(5) Gas producers and heating the gases 7 



(6) Combustion of dust fuel 2 



(7) Washing the smoke 16 



( 8) Various other systems 37 



110 



Of the total, three-fourths were French 

 devices, one-fifth English, 3 American, and 

 the others of various European nation- 

 alities. A preliminary study led to the 

 careful test of ten. These were tested to 

 ascertain whether th-ey were capable of 

 burning ordinary fuels without smoke and 

 whether they were suitable for use in steam- 

 making. 



They were tested with rapid and with 

 slow combustion, with operatives supplied 

 by the makers and with firemen furnished 

 by the commission, under the direction of 

 first the one and then the other. The in- 

 tensity of the smoke was observed and 

 noted on a scale of five points. The usual 

 standard methods of determining the effi- 

 ciency of the apparatus were employed. 

 The corps of observation was detailed from 



ment de la Seine, Ville de Paris, Rcpublique Fran- 

 jaise — Liberty, Egalitu, Fraternitu." n. d. 



the offices of the city administration, or- 

 ganized and directed by the commission. 



The history of legislation, as given, traces 

 the progress of the subject in England from 

 the time of Charles II., who, two hundred 

 years ago, inaugurated repressive measures. 

 In France this form of legislation began 

 with an imperial decree in 1810. Both 

 countries now have well-considered laws 

 for suppression of smoke in cities. The 

 technical history, curiously enough, begins 

 with plans by Denis Papin. The next in- 

 ventor to follow this illustrious man of 

 science was James "Watt, with his inverted 

 draught and later arrangement of ' dead- 

 plate.' The ' automatic stokers,' ' tresusites 

 en Amerique, ' are referred to and their inci- 

 dental but none the less efiective, smoke 

 reductions are described. Legislation now 

 exists in all civilized countries, and many 

 more or less effective devices and methods 

 are in use for suppression of smoke. 



A commission of distinguished engineers 

 and scientific men was organized by the 

 German government, in 1892, which, after 

 prolonged experimental investigation, con- 

 cluded that success had not been attained, 

 but that the way to success was clearly in- 

 dicated. This commission, in computing 

 the heating power of combustibles from 

 analyses, adopted the formula ; 8000 C + 

 29000 (^"-0/8)4- 2500 /S- 600 W; where 

 IF is moisture. 



The outcome of the work of the French 

 Commission was the refusal to assign a first 

 prize, the awarding of two second prizes, of 

 two first mentions and of one second men- 

 tion. The conclusions formulated indicate 

 that the Commission is not satisfied that a 

 real success has been achieved, but never- 

 theless the researches were not without 

 value. Like the German Commission of 

 1892-4, it is concluded that "The work of 

 the Commission should be considered only 

 as a contribution to the study of ' fumivo- 

 rite,' and it is to be hoped that these re- 



