108 



VISCOUS THEORY OF GLACIER MOTION. 



[1845. 



[Omitting the details of the corrections, the following table 

 presents the results of the observations for three periods, 

 Aug. 9-26, Aug. 14-26, and Aug. 17-26.] 



This Table shows, first, in a striking point of view, the 

 regularity of action of the law by which the variable motion of 

 the different transversal points in the glacier is governed, since 

 the movement in the different intervals bears so near a propor- 

 tion, that when estimated in terms of the actual motion of the 

 glacier at the place, the relative motion of the parts scarcely 

 differs by unity in the second place of decimals, and is generally 

 much under it. Taking into account the inevitable errors of 

 observation and the extraordinarily unfavourable circumstances 

 of the weather, it is in the very highest degree improbable that 

 this law of continuity of the partial motions can be accounted 

 for by any casual justling or sliding of one finite portion of the 

 ice past another, which would inevitably have left some of the 

 points relatively at rest during some one of the many intervals 

 of observation, and given to others evidence of a starting motion 

 until friction had established a fresh position of repose amongst 

 the struggling masses. 



Secondly, This Table enables us to establish not only the 

 continuity of motion of any one point, but the continuity of the 

 relation which connects the points (1), (2), (3), etc. For 

 instance, the relative motions of (1) being 

 59 -56 -56. 



* The true sum ought to be about four inches greater. The difference arises 

 from the impossibility of estimating the correct velocities for the fractional intervals. 



