28 ILLUSTRATIONS 



Fig. 



Na Page 



11. Erosion form analogous to a barchan, wind from the left, 



from a photograph ..... 141 



12. Fence and completed snowdrift .... 148 



13. Stages of growth of snowdrift formed by a fence . . 148 



14. Snowdrift on both sides of a fence, on the right completed, 



on the left incomplete, from a photograph . . 153 



15. The fundamental curve of snowdrifts .... 154 



16. Plan of snowdrift caused by clump of bushes, wind from the 



left 158 



17. Profile (dotted) and central longitudinal section of the same 



drift ........ 163 



18. Section across the dotted line of Fig. 16 . . . 163 



19. Plan of the principal snowdrift around a house on the prairie, 



near Winnipeg, wind from the left . . . 164 



20. Profile and central longitudinal section of same snowdrift . 167 



21. Transverse section of snowdrift on lee side of an outhouse 



on the prairie ...... 167 



22. Plan of hollow round a tree, wind from the left . . 168 



23. Longitudinal section of the same . . . -171 



24. Cross section of the same, lee side . . . -171 



25. Hollow, etc., cut by wind, from left, around a stone, from a 



photograph taken in Scotland, February, 1900 . . 172 



26. Hollow cut by wind, from left, around a heap of manure on 



a field, from a photograph . . . • -175 



27. Longitudinal growth on lee side of a travelling snowdrift . 176 



28. Snow mushroom with hollow beneath, from a photograph . 215 



29. Current-mark on road after a thunderstorm . . . 285 



30. Plan of five ridges showing positions on four succeeding 



days, Dovey estuary, scale i"=i6'. . . . 321 



