56 SEVENTH LETTER ON GLACIERS. [1844. 



to the point h. But, supposing G to be the bottom v of the 

 glacier, it will be seen how insignificant may be expected to be 



7 



Fig. 10. 



the variation of velocity between A, the surface, and B, one- 

 sixth of the depth, during the short period of a few weeks, or 

 even months. 



VIII. SEVENTH LETTER on GLACIERS.* ON THE 



VEINED STRUCTURE OF THE ICE. Addressed to the Rev. 

 Dr. WHEWELL, Master of Trinity College, Cambridge. 



Mechanical Considerations tending to explain the Forms of the Veined Structure 

 under different Conditions. 



SALERNO, May 18, 1844. 

 ****** * 



You object that the shells produced by the rupture of the parts 

 of the ice caused by excessive friction should be all parallel to 

 the sides and bottom of the trough of the glacier, instead of being 

 inclined from the sides inwards and forwards towards the centre, 

 as in fig. 11, and from the bottom upwards and forwards, as in 



Fig. 12. 



Fig. 11. 



fig. 12. You will find that I have endeavoured to explain this 



* Edinburgh New Philosophical Journal, October 1844. 



