38 WAVES OF SAND AND SNOW 



dividing the sum of all the lengths by the sum 

 of all the heights is 184. 



It was a matter of great interest to ascertain 

 if this were a constant ratio — i.e., if the average 

 steepness of the waves were always the same, or 

 if it were, on the other hand, dependent upon 

 circumstances. Passing over for the present other 

 observations made on 7th and 8th, I therefore 

 record here the measurement of a series of waves 

 made on the loth (near the series measured on the 

 8th), proceeding down wind as before. The total 

 length of the series of twenty-three waves was 

 656 feet, the average wave-length being there- 

 fore 28 feet 6 inches. The individual wave-lengths 

 were not measured, but the height of each wave 

 was taken, the average being i foot 8*5 inches. 

 The ratio of length to height was therefore 1 6* 7, 

 which only differs by about 10 per cent, from the 

 ratio obtained two days before. The significance 

 of this result was much increased by the circum- 

 stance that I already found the profile of the little 

 ripples made by wind in the surface layers of 

 loose sand upon the Dorsetshire coasts to have 

 this shape, the ratio of length to height being 

 1 8* 5 5. 1 In any group of these ripples the indi- 



^ " On the Formation of Sand Dunes," by Vaughan Cornish, 

 Geographical Journal, March, 1897. 



