CHEMICAL AND PHYSICAL NOTES. 169 
1 p.m. the following air temperatures were observed :—between 2.40 
and 2.46 p.m., 17°°5, 18°:0, 17°°5, 17°-0, 17°°3, 17°-1; mean, 
17°°4; and between 2.50 and 2.54 pm. 16°°5, 16°°5, 16°°7, 
and 16°°5; mean, 16°°55. The mean of the two sets is 17°°06. 
It must be repeated that each of these individual observations is a 
faithful indication of the average temperature of the air in which the 
thermometer was whirled, and in so far as its sensibility enabled it 
to assume the same temperature as the air. From this spot I de- 
scended to the glacier and went up it until I got to a position which, 
judging by the eye, was at the same height as the station just left 
on the mountain side, and about one kilometre distant from it in a 
straight line. The weather was rapidly getting colder, the sky being 
covered with the characteristic Féin cloud. The wind was fresh 
down the glacier, which made the exposure of the thermometer 
easy and good. The hot &éhn puffs were also very striking. The 
thermometer was first swung exposed to sun and wind, showing 
temperatures varying from 10°'5 to 11°°2, the mean being 10°°8 C. 
Swung in my own shadow, but exposed to the wind, the temperature 
was 9°°8. The wet bulb was 4°°7, showing a relative humidity of 
37. The thermometer was now exposed, both wet and dry, in a 
horizontal position with the bulb at a distance of about 2 cm. from 
the ice, on the top of one of the superficial ridges of the glacier, 
and fully exposed to the wind, though shaded from the sun. The 
observed temperatures were: dry, 6°°6 C.; wet, 3°°7; relative 
humidity, 58-5. The exposure of the thermometer was as good 
as could be desired, and, with the fresh breeze blowing, it was 
thoroughly ventilated. I was again much struck with the highness 
of the temperature of the air almost in actual contact with the ice. 
The observations at 1 m. and 2 cm. from the ice were repeated, 
giving substantially the same results—at 1 m., dry bulb 10°-2, wet, 
5°*1; at 2cm,, dry bulb 6°°8, and wet 3°°2. The hot Féhn puffs 
were more striking on the ice than on the land, owing to the greater 
difference between their temperature and that of the surrounding air. 
At 4pm. I left the ice and returned to the station of 1 o’clock on 
the hill-side, and took the temperature at 4.35 p.m.—dry bulb 16°:0, 
wet 8°°0, relative humidity 24°5. At the station in the valley 
‘below the glacier the temperature was at 5.45 p.m., dry bulb 
16°°4, wet 11°°8, and relative humidity 56. These observations, 
besides showing the remarkable conditions of the air over the glacier, 
indicate the fineness and warmth of the weather which prevailed. 
“On the 21st August another series of observations was made at 
the stations on the Jand and on the ice. The breeze on the ice was 
