94 DR MILLER ON THE METEOROLOGY OF 
TABLE XVII.—Derpuctions relative to the Humipity of the ATMOSPHERE at the 
Mountain STATIONS, in the year 1852. 
WEIGHT OF 
VAPouR. 
STATION. 
Wet Bulb. 
Dew Point 
of Air, 
Degree of Humidity, 
(complete Saturation 
1-000.) 
| In a cubic foot 
| Required for 
Saturationofa 
cubic ft, of Air. 
h. m. <s 5 Grains. 
Wastdale Head, 7-42 a.m., 247 above the Sea, : . 3-12 
Do. do. 4-50 p.m., : : 3 | 3-17 
Brant Rigg, : : 924 : . : 6 | 3-10 
Stye Head, : . 1448 : . : 2-95 
Lingmell, . = 5M ilcirhs) : : 2-90 
Sprinkling Tarn, . 1900 : : . 2:79 
Great Gabel, . aeee2o25 . : : 2-60 
Sea Fell Pike, . 5 S66: ‘| 2.40 
In addition to the above systematic readings, I find the following casual observations dispersed 
through the Registers :— 
September 5, 1845.—The thermometer on the summit of Skiddaw, at noon, stood at 41°; sky 
overcast, sun gleaming out at intervals. Temperature of a strong spring, about 2 miles from the 
summit, also 41°. Air at foot of mountain, 3" 30™ p.m., 58°. 
May 6, 1847.—Temperature of air at foot of Sca Fell, at 105 40™ a.m., 52°; on the summit of 
the Pike, at 1 p.m., 37°, and intensely cold. Extensive drifts of snow on the east side of the moun- 
tain. Temperature of a spring near Sprinkling Tarn, 37°. Between 4" and 5" 30™, p.m., whilst 
passing over Stye Head in the direction of Borrowdale, there occurred one of the most dreadful storms 
of thunder and lightning which it has been my lot to witness. The electric discharges were frequent 
and extremely dazzling, and many of them followed, almost instantaneously, by deafening peals 
of thunder reverberating from hill to hill. A large quantity of hail fell, (unaccompanied by rain,) 
quite sufficient to give me a thorough drenching. The storm was confined to the mountains, and the 
hail did not reach the valleys. I made two attempts to ascend the Gabel, and on both occasions was 
obliged to retreat before the fury of the elements. 
September 9, 1847.—Ascended Snowdon in Wales, and found the temperature at the Farm- 
House on the Beddgelert side, to be 56°-7 ; at the summit, 46°'8, a difference of only 9°-9 in 3571 
feet, or a descent of 1° in every 357 feet of elevation. We ascended Snowdon through an exceed- 
ingly dense mist, which enyeloped the mountain nearly to its base. The fine white vesicles composing 
the cloud settled upon our garments, and long before arriving at the summit, they appeared as if 
covered with minute particles of snow. I am inclined to think that the latent heat evolved by the 
vapour during its conversion into mist (Cirrostratus) tended to equalize the temperature between the 
top and bottom of the mountain, and that a much greater difference would be found in a clear, or 
even a moderately clear atmosphere. 
