270 PEOPESSOE TYNDALL’S OBSBEVATIONS ON THE MEE DE GLACE, 
nexion with the point, and I think one result of such ohservations would be the es.a- 
observation of the kmd. me la ,„v+incil T ren nested "Mr. Hiest 
near the Tacul, was about 140 feet in herght,^^^d neariy This 
to place two stakes one at t e ‘°P tl^e stake at the top 
was done “ that at the bottom showed an advance of 6 inches 
had moved through iig rpsnlt on account of the danger 
rr fc "' "‘t 
u. .. — — 
could be effected. vind with a shade of uncer- 
I f I fixed myself two stakes, one 
::rand t‘hV:ther at the bottom of the precipice, and « 
with ^importance of ascertaining the 7*'<>y';X -^rp^xed “ 
bottom, I cut steps in ^/'’C^^o'it Until Monday the 17th of August I was unable 
auger, and drove a stake dense fog and snow to the 
to reach the place again. On y P n j.-no- hnt the two lower ones were 
Tacul, and found the highest of the three ^^akes stm ,, 
buried in a heap of snow which ky at t e ase ^ Tuesday the 20tli of 
the perilous process above described ha to ® twenty-four hours, the motion 
August the displacements were measured. Eeduce 
of the three stakes was found to be as follows ;— ^ 
Top stake tn . ' b 
Middle stake 4*59 ^ ^ 
Bottom stake 
The distance from the top of the ice-wall to its base 
rope, to be UO-SS feet, but it was not of one 4 feet, 
height of the middle stake from the gioun w ’unttom of the ice-wall at the 
It fs therefore proved by these measurements t^ia ^"deportment of 
Tacul moves with less than half the veloctiy of the — ’ j’" kds. 
the intermediate stake shows how the velocity incieases loi 
