SMOKE ABATEMENT 



345 



injury caused by it is due, chiefly if not entirely, to the ash, tar, 

 and gases which it contains. 



In connection with the Pittsburg investigation, measurements 

 were commenced in April 1912 of the soot and dust fall in 

 various parts of the city by a method of observation somewhat 

 similar in principle to that now being used by the English 

 Committee for the Investigation of Atmospheric Pollution. 

 Twelve stations were selected, and samples of the soot fall were 

 obtained by exposing glass jars measuring 4 in. x 10 in., for a 

 month at a time, on the roofs of buildings, situated in the selected 

 areas. Table III. gives the results obtained in these observa- 

 tions, which extended over twelve months, and the figures 

 certainly seem to justify Pittsburg's claim to be considered the 

 dirtiest and smokiest city in the world. 



Table III. Soot-Fall in Tons per Square Mile per Year in 

 Pittsburg, U.S.A. (Bremner.) 



From article by John O'Connor, Jr., in Metallurgical and Chemical Engineer- 

 ing, April 1914. 



It is interesting to note that at the Convention of the 

 International Association for the Prevention of Smoke, held in 

 Pittsburg in September 191 3, a committee was appointed, on 

 the suggestion of Bailie Smith, of Glasgow, to co-operate with 

 the English committee in the introduction of the standard 

 method of soot and dust measurement into America. One may 

 endorse the hope expressed by Mr. O'Connor, that this com- 

 mittee will be successful in its work, and will obtain the co- 



