Nov. 1848. TEMPERATURE, &c, OF WALLANCHOON. 219 



dismal promise for my chance of exploring lofty unin- 

 habited regions. All annual and deciduous vegetation had 

 long past, and the lofty Himalayas are very poor in 

 mosses and lichens, as compared with the European Alps, 

 and arctic regions in general. The temperature fluctuated 

 from 22° at sunrise, to 50° at 10 a.m. ; the mean being 

 35°;* one night it fell to 6J°. Throughout the clay, a 

 south wind blew strong and cold up the valley, and at 

 sunset was replaced by a keen north blast, searching 

 every corner, and piercing through tent and blankets. 

 Though the sun's rays were hot for an hour or two in 

 the morning, its genial influence was never felt in the 

 wind. The air was never very dry, the wet-bulb ther- 

 mometer standing during the day 3f ° below the dry, thus 

 giving a mean dew-point of 30J°. A thermometer sunk 

 two feet stood at 44°, fully 9° above the mean temperature 

 of the air ; one exposed to the clear sky, stood, during 

 the day, several degrees below the air in shade, and at 

 night, from 9° to 14f° lower. The black-bulb ther- 

 mometer, in the sun, rose to 65f° above the air, indicating 

 upwards of 90° difference at nearly the warmest part of the 

 day, between contiguous shaded and sunny exposures. The 

 sky, when cloudless, was generally a cold blue or steel-grey 

 colour, but at night the stars were large, and twinkled 

 gloriously. The black-glass photometer indicated 10' 521 

 inchesf as the maximum intensity of sunlight; the tempe- 

 rature of the river close by fell to 32° during the night, 

 and rose to 37° in the day. In my tent, the temperature 



* This gives 1° Fahr. for every 309 feet of elevation, using contemporaneous 

 observations at Calcutta, and correcting for latitude, &c. 



f On three mornings the maxima occurred at between 9 and 10 a.m. They 

 were, Nov. 24th, 10-509, Nov. 25th, 10'521. On the 25th, at Tuquoroma, I 

 recorded 10-510. The maximum effect observed at Dorjiling (7340 feet) was 10'328, 

 and on the plains of India 10350. The maximum I ever recorded was in Yaugma 

 valley (15,186 feet), 10-572 at 1 p.m. 



