247 



is subjected, at the rate of 8 inches a day ; which, if the action were 

 uniform at all seasons, would amount to 240 feet a year. 



The author also describes a system of remarkable bands of white 

 ice which he observed to sweep across the Glacier du Geant in the 

 same general direction as the "dirt-bands." He traced these bands 

 to the following origin. The streams which flow upon the glacier 

 in its upper portions, cut deep channels in the ice ; these channels, 

 during the winter, become gorged with snow, which is afterwards 

 compressed to a highly resistant white ice during the descent of the 

 glacier. Similar bands were also observed in a most remarkable po- 

 sition at the base of the Talefre cascade ; and here also he found the 

 glacier crumpled into a series of protuberances, one consequence 

 of the crumpling being the production of a " backward " as well as 

 a forward " dip " of the veined structure. A similar system of pro- 

 tuberances occurs on the Glacier du Geant ; and here also the author 

 found the same structure dipping backward as well as forward. The 

 cause of the crumpling is assigned in the paper. 



The physical quality in virtue of which ice is able to change its 

 form in the manner indicated by the observations is next inquired 

 into ; and it is shown by measurements carried out upon the glacier 

 itself, that no quality which could with propriety be called viscosity 

 is possessed by glacier ice. All the phenomena appear to be recon- 

 ciled by reference to the fragility of ice at a temperature of 32 F., 

 coupled with its power of regelation. The intestine motion of the 

 parts is no doubt aided to some extent by the partial liquefaction of 

 the ice by pressure ; a fact first publicly pointed out by Mr. James 

 Thomson, and proved experimentally by Prof. William Thomson 

 and the author. 



June 3, 1858. 

 The LORD WROTTESLEY, President, in the Chair. 



The Annual General Meeting for the Election of Fellows was held 

 this day, 



The Statutes respecting the election of Fellows having been read, 

 Sir George Back and Mr. Gwynn Jeffreys were, with the consent 

 of the Society, appointed Scrutators to assist the Secretaries in exa- 

 mining the lists. 



