110 WAVES OF SAND AND SNOW 



The rate of snowfall was about half an inch per 

 hour, but footprints were filled up by fall and 

 drift at the rate of i inch in fifteen minutes, so 

 that the accumulation by drifting over the icy sur- 

 face was nearly eight times as rapid as the rate of 

 deposition by snowfall. After half an hour of 

 snowfall and snowdrift, viz., at 1 1 a.m., numerous 

 patches of fresh snow had formed. Their number 

 and size increased, but up to 12.30 p.m., when I 

 adjourned for luncheon, they remained irregular. 

 Returning at 2.30 p.m., i.e., after snowfall and 

 snowdrift had lasted four hours, I found that the 

 irregular patches had become ridges transverse to 

 the direction of the wind, with the steeper faces to 

 leeward. The distances between the ridges of a 

 series were 6, i 2, 6, 8, and 7 feet. A boarded, or 

 " plank " path at the side of a road near by was still 

 uncovered by snow at 4.12 p.m. — i.e., after nearly 

 six hours of snowfall, when enough had fallen to 

 have covered it to a depth of nearly three inches if 

 there had been no wind. Under the actual cir- 

 cumstances of fall and drift the path could never 

 be covered except by submergence by a travelling 

 wave of snow. 



The snow-waves as they roll on leave behind a 

 shallow deposit of partially consolidated snow on 

 which fresh snow drifts but slowly. Erom what I 



