420 EXPERIMENT STATION RECORD. [Vol.35 



Meteorological Cooperation; Symons Memorial Medal. 1912; Dates of Opening 

 of Navigation through Lake Pepin, 1861-1916; and Snow Surveys in City 

 Creek Canyon, Utah, 1914-1916 (illus.), by A. H. Thiessen. 



Meteorological observations at the Massachusetts Agricultural Experi- 

 ment Station, J. E. Ostrander, D. Potter, and J. S. Sims (Massachusetts 8ta. 

 Met. Bills. S29-330 {1916), pp. 4 each). — Summaries of observations at Amherst, 

 Mass., on pressure, temperature, humidity, precipitation, wind, sunshine, cloudi- 

 ness, and casual phenomena during May and June, 1916, are presented. The 

 data are briefly discussed in general notes on the weather of each month. 



[Amount and composition of rainfall at Georgetown, Demerara, 1910— 

 1914], J. B. Harrison {Rpt. Dept. Sci. and Agr. Brit. Guiana, 1914-15, pp. 

 38-40, App. I, p. 6). — Monthly and annual averages of the amount and compo- 

 sition (chlorin, nitrogen as ammonia, and nitrogen as nitrates) of rainfall are 

 shown for 25 years— 1S90-1915. 



" In round figures the mean annual rainfall during the 25 years . . . was 

 98 in. The average rain water contained per liter of water at 84° F. 5.428 mg. 

 of chlorin, 0.0315 mg. of nitrogen in ammonia salts, and 0.0705 mg. of nitrogen 

 in nitrates. During the 25 years the monthly ranges of variation in the con- 

 stituents of the rain have been very wide, chlorin ranging from 1.77 to 42.552, 

 nitrogen in ammonia from to 1.275, and nitrogen in nitrates from to 0.823 

 mg. per liter of water at 84°." The average annual rainfall per acre during 

 the period was 97,611 tons, " containing chlorin equivalent to 203 lbs. of common 

 salt and 2.6 lbs. of combined nitrogen in the forms of nitrates and of ammonia." 



Atmospheric pollution, W. P. Wynne (Abs. in Rpt. Brit. Assoc. Adv. Sci., 

 1915, p. 388; Nature [London'], 96 (1915), No. 2401, pp. 442-444, figs. 3; Sci. 

 Ahs., Sect. A-Phys., 19 {1916), No. 218, p. 55; U. S. Mo. Weather Rev., 44 {1916), 

 No. 3, p. 114). — This is an abstract of a paper read at the Manchester meeting 

 of the British Association for the Advancement of Science, 1915, based upon 

 monthly results of chemical examinations of rain water collected at four 

 places in Shefliield. The records cover the period from July, 1914, to June, 

 1915. The results show certain discrepancies which lead to the conclusion 

 " that the method of measurement usually adopted does not afford a reliable 

 indication of the real degree of atmospheric pollution, and that better results 

 might be obtained if a feasible method could be devised for drawing air 

 continuously through water and measuring the amount of the impurities 

 extracted in this way." 



The character and extent of atmospheric pollution in English and Scotch 

 towns, J. B. C. Kershaw {Engineer [London], 120 {1915), No. 3125, pp. 473- 

 415, figs. 2; Metallurg. and Chem. Engin., IS {1915), No. 16, pp. 967-911, figs. 6; 

 abs. in Sci. Abs., Sect. A-Phys., 19 {1916), No. 211, p. 6; U. S. Mo. Weather 

 Rev., 44 {1916), No. 3, p. 114)- — This article summarizes and discusses the 

 results of observations on atmospheric pollution in ten English and six Scottish 

 towns during the winter months, October to March, of 1914-15. 



It is shown that the dust fall for the English towns during the six months 

 varied from 532 tons per square mile for Oldham to 32 lbs. per square mile 

 for Malvern. The dust deposits were found to consist chiefly of tar, solid 

 carbonaceous particles, and ash, the relative proportions of these not varying 

 widely in the different towns. In the Oldham dust the proportions were 1.5 

 per cent of tar, 29 of carbonaceous matter, and 69 of ash. As a general rule 

 the percentage of ash has been found to be highest and of tar and soot lowest 

 in manufacturing districts. The observations in the Scottish towns were less 

 complete and are not strictly comparable Muth those of the English towns. 

 It is claimed that Oldham with a winter soot- and dust-fall at the rate of 

 1,064 tons per square mile per annum is comparable with Pittsburgh, which 



