Baltimore 26,466 58.7 1440 1018 142 2458 Boston 25,877 56.8 1398 1003 98 2401 Buffalo 23,200 49.7 1713 1324 157 3037 Chicago 26,442 57.9 1238 1282 116 2520 Cincinnati 26,758 58.6 1356 1202 81 2588 Cleveland 22,394 47.8 1584 1187 67 2771 Denver 29,355 65.9 645 1500 45 2145 Detroit 23,201 50.3 1477 1165 133 2642 Los Angeles 31,521 70.9 743 1404 258 2147 Louisville 25,715 56.8 1284 1094 233 2378 New Orleans 26,091 58.6 1045 1365 162 2410 New York 28,762 57.6 1279 1182 120 2461 Philadelphia 25,249 56.6 1369 1071 127 2440 Pittsburgh 22,573 49.0 1385 1294 185 2679 Portland, Me. 26,914 59.4 1321 1040 303 2361 San Francisco 25,453 56.3 900 1136 241 2036 St. Louis 24,957 58.7 1185 1019 42 2204 Washington D. C. 25,078 55.8 1088 1135 115 2223 It is observable that all the cities which have become notorious in the matter of smoke pollution show a very low percentage of sunshine, the worst conditions obtaining in the two cities having the most unsavory reputation for smoke, viz., Cleveland and Pittsburgh. These two cities consistently have the worst records for sunshine, for percentage of possible sunshine and for cloudy and partly cloudy days (combined totals). Unfortunately no meteorological data are available from stations situated in non-smoke-producing centers whose geographical conditions are similar to those obtaining in smoke-producing cities like Pittsburgh, Cleveland, Detroit, Cincinnati and St. Louis. The above data only enable us to compare the atmospheric conditions of one smoky city with another smoky city or with cities whose geographical surroundings are so different as to render the data useless for comparative purposes. However, the data recently collected by the Smoke Investigation of the University of Pittsburgh show, in complete accordance with similar English findings, that the lessened amount of sunshine in Pittsburgh is due to the smoke factor. Figures based on the number of tons of coal consumed in Pittsburgh from 1905 to 1911 show a fair degree of parallelism between the quantity of coal consumed and the number of smoky days. During the years in which an increasing amount of coal has been burned (owing to the heightened cost of gas) the hours of sunshine have fallen from about 2800 to 2200. Likewise the days on which the United States Weather Bureau has observed light or dark smoke in Pittsburgh, have increased as follows for the