;j98 KEPOKT— 1901, 



Terrestrial Surface Waves. — First Beport of the Committee, consisting 

 of Br. J. Scott Keltie (Chairman), Lieut.-Col. Bailey, late R.E., 

 i)r. Vaughan Coknish, Mr. A. Eoope Hunt, F.G.S., Mr. W. H. 

 Wheeler, M.lnst.C.E., and Mr. E. A. FLoyER. (Drawn up by 

 Dr. Vaughan Cornish.) 



The following papers have been published by Dr. Vaughan Cornish since 

 the Bradford Meeting, viz. — On the Formation of Wave Surfaces in 

 Sand, ' Scottish Geographical Journal,' January 1901 ; On Sand-waves in 

 Tidal Currents, 'Geographical Journal,' August 1901. 



On December 4, 1900, Dr. Cornish left for Canada to study the surface 

 forms of snow, returning to England March 16. During the voyage out, 

 Liverpool to Boston, much heavy weather was encountered, and observa- 

 tions, with some measurements and photogiaphs, were obtained of deep- 

 sea storm-waves. On the return voyage, New York to Southampton, 

 some good observations were obtained of the conditions obtaining in a 

 heavy swell. A paper on ocean waves, embodying results obtained by 

 Dr. Cornish during several years, is in preparation. 



Canada was snow-covered during the whole of the expedition. The 

 country was traversed from Monti'eal to Vancouver and back by the 

 Canadian Pacific Railway. Special facilities were most kindly accorded 

 by this railway company in the interest of pure science. The principal 

 places of observation were Montreal, Winnipeg (Manitoba), and Glacier 

 House (British Columbia), which afforded good opportunities for the study 

 of the three principal kinds of snow surface which were encountered. 

 The observations appear to divide themselves naturally under two heads : 

 (1) snow-waves and ripples ; (2) snow-drifts and snow-caps ; and the 

 results of the expedition are now being worked up under these heads. 



The most striking point with reference to the trains of moving waves 

 of cold, dry, drifting snow is that the place most favourable to their 

 formation is an extensive level surface free from inequalities or obstruc- 

 tions, such as a frozen lake. Here most readily occur those local S2tr- 

 charges of snow which originate the long trains of waves. At first these 

 travel freely, but their march and growth do not continue so long as is 

 the case v/ith the homologous waves of sand, because the snow readily 

 sets into a coherent, though friable, mass. The height of tliese waves was 

 "•enerally not more than six inches. They are flatter than the homologous 

 jeolian sand-waves, the wave-lengths being often forty or fifty times as 

 great as the amplitude. 



Ripples, perfectly homologous with the ieolian sand-ripples, are pro- 

 duced in the granular snow-stuff formed by erosion of consolidated snow. 

 Their wave-lengths are similar to those of the sand-ripples, but their 

 amplitude is less. There are also regularly undulating surfaces carved by 

 the wind in more coherent snow, particularly when it is well stratified. 

 The ridges retreat before the Avind, keeping their steeper slope on the 

 weather side. The material has an internal arrangement not imposed by 

 the wave motion, and, so long as it is a part of the waved structure, is itself 

 stationary. It is therefore fitting that these surfaces, which are frequent 

 and regular, should have a distinguishing name, and it is proposed to call 

 them undulates. The ratio of height to length in the undulates is greater 

 than in the normal waves and normal ripples. 



