24 ILLUSTRATIONS 



Plate 



No. 



Page 

 103 



III 



115 

 119 



13. Drifting waves of dry snow near Winnipeg . 



14. Drifting waves of dry snow at Winnipeg 



15. Ripples in granular snow 



16. Ripples in coarse granular snow 



17. Granular snow rippled, and a drift of fresh snow unrippled . 123 



18. Ripple-like ledges formed by drifting snow-particles falling 



on the lee face of a drift . . . . .127 



19. Erosion-ripples in the surface layers of snow . . .131 



20. Erosion-ripples in compact snow, showing its stratification . 135 



21. Erosion structures intermediate between the transverse and 



longitudinal, showing the stratification of the snow . 139 



22. Longitudinal structures formed by erosion of snow . . 143 



23. Longitudinal ridges of snow to leeward of obstructions . 146 



24. Beginnings of a snowdrift on the lee side of railings, near 



Montreal ....... 149 



25. Snowdrift near Grantown-on-Spey, showing curve of the 



upward current of the wind-eddy on the lee side . 152 



26. Snowdrift near Winnipeg, showing overhanging cornice on 



lee side ....... 155 



27. Snowdrift near Winnipeg, with small longitudinal ridge on 



lee side formed between the currents which converge 

 from right and left, taken looking up-wind . . 159 



28. The snowdrift with small longitudinal ridge on lee side, 



transverse view ...... 162 



29. Snowdrift near Winnipeg, with large longitudinal structure 



on the lee side ...... 165 



30. Bank of snow collected between currents converging on 



lee side of house (whilst the snow was drifting it 

 ascended like smoke from the pointed summit) . 169 



31. Snowdrift round a house on the prairie, enclosing a space 



swept bare by the wind . . . . '173 



32. Hollow kept clear of snow by the wind round an outhouse . 177 



33. Bank of drifted snow against the lee side of a house at 



Winnipeg ....... 181 



34. Space near a tree kept free from snow by the wind . . 185 



