1846.] WEATHER AT CHAMOUNI DURING THE OBSERVATIONS. 133 



WEATHER AT CHAMOUNI. 



1844. October. A good deal of rain during the month, 

 which, on the 10th and 16th, fell as snow on the hills (nine 

 inches at Montanvert), and subsequently to the latter day the 

 glacier at the Montanvert was not clear of snow during the 

 winter. 14th. Source of the Arveiron diminished to one-fourth 

 (of the summer volume.) Ice-vault more than half closed. 



November. Till 14th much rain and snow ; fine with frost 

 after. 20th. Source of the Arveiron very low ; has not shifted 

 its usual position. 



December. Weather generally fine throughout ; cold most 

 severe from 7th to 12th. 



1845. January. The weather continued splendid till the 

 20th ; greatest cold from 2 to 5 Eeaumur. 19th. The 

 vault has disappeared at the source of the Arveiron. 20th, 

 The first snow fell which lay at Chamouni, and continued from 

 this day, attaining a depth of 1 J foot in February. Up to this 

 time all the secondary heights, even the Breven and Flegere, 

 were clear of snow, and the weather suitable for chamois hunt- 

 ing. Occasional snow till the end of the month. 



February. Snow at intervals all the month. 13th. 

 Greatest cold of the season ; thermometer 15 Reaum. fol- 

 lowed by fine weather. 20th. Snow lies 2-^ feet deep at the 

 upper stations on the glaciers ; 1 J foot at Chamouni. The arch 

 of the source of the Arveiron has wholly disappeared, but the 

 water issues at the usual places as in summer. The water is 

 reduced to a small amount and may easily be stepped across. 

 It is still ichitish and dirty, though less so than in summer ; 

 except when a change -of weather is threatened (when it is as 

 dirty as in summer.)* Same date. The glacier of Bossons has 

 extended itself much. " On ne s'y reconnait presque plus." It 

 is advancing towards the moraine of 1818 ; and the lower end 

 is at least seventy feet high. 



* This important remark proves that in the middle of winter a temporary ? 

 rise of temperature of the air over the higher glacier regions (which is the precursor 

 of bad weather) not only produces a thaw there, but finds the usual channels still 

 open for transmitting the accumulated snow water. 



