August 30, 1919] 



SCIENCE 



211 



would be interesting to know if others have 

 observed anything like it in other localities. 



About four inches of light dry snow fell dur- 

 ing the afternoon and night of March 2. 

 Towards the end of the storm the flakes were 

 very large and the wind blew at a considerable 

 velocity. This high wind continued most of the 

 day of March 3. After the sun had been shin- 

 ing on the snow for three or four hours and 

 had probably formed a thin layer of moist 

 snow on top, the wind would catch up a por- 

 tion of this moist snow and roll it over and 

 over, forming a snowball of increasing size 

 until the gust of wind had spent its energy, or 

 the ball had become too large to be rolled any 

 farther. Some people who saw this process 

 taking place said that the fields were literally 

 alive with moving snowballs. This peculiar 

 phenomenon continued until about noon and 

 the fields around Orono and Bangor were left 

 with countless snowballs everywhere. Back of 

 each snowball could be seen the triangular 

 shaped path, from which the snow had been 

 rolled up. In one instance this triangle was 

 found to be approximately thirty-six feet in 

 length, but that was for an unusually large 

 snowball. The snowballs were of all sizes, 

 from two or three inches in diameter up to 

 nearly two feet. Of course the largest ones 

 were formed where the ground sloped so that 

 the ball rolled down hill, but even on the level 

 some of the balls were a foot or more in diam- 

 eter. One ball in particular, on which meas- 

 urements were taken and recorded, was ellip- 

 tical in shape, the horizontal diameter being 

 twenty inches and the vertical diameter being 

 fourteen inches. LEO^f Elmer Woodman 



TJnivebsity of Maine, 

 Orono, Maine 



on measuring the density of the 

 "17-year locust" population 



To THE Editor of Science : According to 

 the Bulletin of the Department of Agriculture 

 ISTo. 127, on the " 17-year locust" of 1919 there 

 was to be expected a very dense population of 

 locusts this summer in the eastern and south- 

 ern states. Brood 10 of the " 17-year locust " 

 and brood 18 of the " 13-year locusts " are co- 

 incident this year. One of the items of inter- 



est in the periodicity of these insects is the 

 number of individuals appearing from time 

 to time. 



I wish to suggest a means of measuring the 

 numbers of them, in a manner that will make 

 it easy to compare the density of them from 

 year to year. 



Wherever these cicadas are there is pro- 

 duced an incessant screech. The intensity of 

 this " screechy " sound is dependent upon the 

 density of " locust " population. A measure- 

 ment of the intensity of this sound may be 

 referred to the density of the population in 

 the environment where the intensity of the 

 sound is produced. This is applying " sound 

 ranging." The proper environment would 

 have to be chosen. 



This means would at least afford an excel- 

 lent way to record the activity of the cicada 

 during any one season; and might be devel- 

 oped to give relative seasonal activity also. 

 Enoch Karrer 



BuKEAU OP Standards 



SCIENTIFIC BOOKS 



World-Power and Evolution. By Ellsworth 

 Huntington. New Haven, Tale University 

 Press, 287 pp., 30 figures. 1919. 

 This is a far-reaching book, written in an 

 interesting style, and is suggestive of thought 

 along new lines, not only to students of evolu- 

 tion (especially those interested in the ac- 

 cepted laws of heredity), but to biologists, 

 paleontologists, physicians and statesmen as 

 well. The underlying thesis of the study is 

 organic change, largely brought about by the 

 cha.nging environment, chiefly climate, which 

 affects the well being and health of organisms. 

 " Training, heredity and physical environment 

 are like food, drink and air." They are nec- 

 essary materials and conditions that are at 

 the basis of all life. Humanity " does not yet 

 realize that the human species must be bred 

 as carefully as race horses," and even when 

 people inherit perfect constitutions their 

 health must receive much care. That climate 

 largely underlies himaan health, this book 

 abundantly demonstrates, and that it is a 

 changing climate that develops the strongest 



