Variation of Motion at different Seasons. 



333 



Bois II. On the Glacier des Bois near its lowest extremity, be- 

 hind the Cote du Piget^ and near its centre. 



BossoNS I. Upper station on the Glacier des Bossons, some way 

 above the plateau where the glacier is usually crossed ; on the west 

 side, near the moraine. 



Bossons II. Near the lowest extremity on the Glacier of Bos- 

 sons, where free from the moraine, on the western side. 



These four sets of observations are projected in Plate V., where 

 the four lower zigzag curves represent the gradation of diurnal ve- 

 locity by periods, according to the method adopted in projecting 

 my own observations in my Travels, p. 141. The general accord- 

 ance is sufficiently manifest, and the effect of the season of the year 

 is beautifully shewn, the following being the minimum and maxi- 

 mum values : — 



Daily motioB in inches, 

 Glacier des Bois, No. I., minimum in December, . . 11*5 

 Glacier des Bois, No. I., maximum in July, . . . 52*1 



Ratio of maximum to minimum, 



H:X 



