364 A. N. WincJiell— Great Dustfall of 1920. 



Table VIII. — Quantity of dust in storm of March, 1920. 



Weight of dust in Weight of dust in 



Sample Grams per square meter. Short tons per square mile. 



Madison No. 1 7.87 22.4 



Madison No. 2 10.30 29.3 



Madison No. 3 9.56 27.1 



La Crosse, Wis 5.03 14.3 



Dubuque, Iowa 4.53 12.9 



Charles City, la 8.34 23.7 



Carlisle, Pa 4.61 13.1 



About twenty more samples of this dustfall from vari- 

 ous parts of the country were sent to us, but the preceding 

 table includes all those which are sufficiently pure to make 

 exact records of value. The amounts may be compared 

 with the dustfalls at other times and places as follows : 



Table IX. — Quantity of dust in other storms. 



Weight of dust in Weight of dust in 



Place. Grams per square meter. Short tons per square mile. 



Madison, 1918 4.8 13.6 



Naples, 1901 11. 31.3 



Gorz, Austria, 1901 11.2 31.8 



Schemnitz, Hungary, 1901 1.9 5.4 



Hamburg, 1901 1.67 4.7 



Taormina, Sicily, 1901 2.7 7.7 



Except for Madison, the data are from Hellmann and 

 Meinardus, loc. cit. 



It is evident that the quantity of dust in the storm of 

 1920 is entirely comparable with that of the European 

 fall of 1901 in all cases measured. The area of the latter 

 was about 160,000 square miles while the area covered 

 by the American dustfall of 1920 was at least as great 

 and probably several times greater. The total dustfall 

 in Europe in 1901 was at least 1,782,200 metric tons or 

 1,964,000 short tons ; so far as the evidence goes it indi- 

 cates that the American dustfall of 1920 involved at least 

 as great a total, and probably several times as great a 

 total amount of material transported. 



Madison, Wisconsin, January 1, 1922. 





