CONTENTS 17 



wind — Recede by erosion of wind-facing cliff — During 

 lulls travel up- wind — Mode of erosion of partially con- 

 solidated snow : first, transverse ; finally, longitudinal 

 ridges, with a transition stage between — Stratification 

 shown by erosion. 



Waves in Dry Drifting Snow. 

 Formed near Montreal at minus 8° Fahrenheit — Length 

 and height — Flatter than sand-waves — Movement 

 visible and more rapid than that of sand — Surface un- 

 rippled — Measurements of snow-waves in Manitoba, 

 formed during removal of snow — Waves formed during 

 snowfall — Their formation upon a plane surface free 

 from obstructions. 



Crescentic Snow-Waves or Snow-Barchans, 



Formed in patches of loose snow travelling on a hard 

 surface — Finer lines than sand-barchans both in profile 

 and plan — Formation of crust on surface of snow and 

 its effect in arresting growth and movement of snow- 

 waves — Explained as due to sublimation — Increase in 

 density of snow which has been drifted by wind — 

 Compared with increase of density due to pressure. 



Ripples in Snow-Sand. 



Mode of formation of granular snow or " snow-sand " 

 — Rate of movement — Growth and movement more 

 rapid than those of sand-ripples — Measurements of 

 length and height — Obliteration in lee of larger ridge. 



Forms produced by Wind-erosion in Compact Snow {Studies 

 in Canada.) 

 Measurements of transverse ridges, facing up-wind — 

 Shape of pits — Longitudinal structures — Note on the 

 longitudinal sand-dunes of the great Indian Desert. 



