118 



VISCOUS THEORY OF GLACIER MOTION. 



[1845. 



1' 30" exactly), and the fifth on the 17th, when the visual line 

 was in azimuth 89 47i'. 



TABLE showing the variable azimuths (observed) of the transverse 

 stations with the longitudinal direction Q q. 



EDINBURGH, July 1845. 



[As the concluding paragraph of this paper contained a slight 

 numerical mistake, it has been omitted.] 



[On reviewing these pages, after a lapse of thirteen years, I 

 feel afresh the interest of the experimental enquiry above 

 recorded, which, to the best of my knowledge, has not yet 

 been repeated. I ana impressed with the belief that it is well 

 worthy of repetition under more favourable circumstances. The 

 locality was by no means the best that might be found, although 

 it was probably the best amongst the glaciers of Chamouni. 

 The very level and almost uncrevassed portions of the glaciers 

 of the Aar and Aletch, and of others besides, present favourable 

 points for observing experimentally the plastic accommodation 

 of a definite portion of ice to the conditions of its motion. But 

 in the experiment of 1844 the drawback arising from the weather 

 was infinitely greater than that arising from the imperfect com- 

 pactness in the area of ice under observation. It is not too 

 much to say, that the state of the weather during my observa- 

 tions (to which I have referred at p. 113) could not possibly 

 have been more annoying and unfavourable. I hope that some 

 of the present race of active glacialists will resume the interest- 

 ing enquiry. Nov. 1858.] 



