Waves of sand and snow and the eddies which make them . w exhibited two kinds of ridges—one with theirfaces towards the wind, the other facing to lee-ward : the former with a surface grooved andscarped, the latter with a surface generallysmoother and more rounded. The appearance tothe novice is a mere confusion of forms, but whenI had learnt the secret of the two kinds of wavedsurface produced in loose and compact snowrespectively I could always recognize the two setsof forrns, and detect order where all at first hadseemed chaotic. I have now described two occasions upon whichthe formation of
Waves of sand and snow and the eddies which make them . w exhibited two kinds of ridges—one with theirfaces towards the wind, the other facing to lee-ward : the former with a surface grooved andscarped, the latter with a surface generallysmoother and more rounded. The appearance tothe novice is a mere confusion of forms, but whenI had learnt the secret of the two kinds of wavedsurface produced in loose and compact snowrespectively I could always recognize the two setsof forrns, and detect order where all at first hadseemed chaotic. I have now described two occasions upon whichthe formation of travelling waves occurred whenwind was removing a level deposit of loose another day I saw the formation of such wavesduring the covering of the ground by a fresh snow-fall accompanied by wind. The surface was hardand glazed, being that of old snow which hadthawed and been afterwards frozen. The snowfallbegan at , at about the time I arrivedupon the ground, and continued throughout theday, accompanied by a light to moderate 110 WAVES OF SAND AND SNOW The rate of snowfall was about half an inch perhour, but footprints were filled up by fall anddrift at the rate of i inch in fifteen minutes, sothat the accumulation by drifting over the icy sur-face was nearly eight times as rapid as the rate ofdeposition by snowfall. After half an hour ofsnowfall and snowdrift, viz., at 11 , numerouspatches of fresh snow had formed. Their numberand size increased, but up to , when Iadjourned for luncheon, they remained at , , after snowfall andsnowdrift had lasted four hours, I found that theirregular patches had become ridges transverse tothe direction of the wind, with the steeper faces toleeward. The distances between the ridges of aseries were 6, i 2, 6, 8, and 7 feet. A boarded, or plank path at the side of a road near by was stilluncovered by snow at —, after nearlysix hours of snowfall, when enough h
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Keywords: ., bookcentury1900, bookdecade1910, bookidwavesofs, booksubjectwaves
