276 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



[1900. 



no measurements were got. Earth currents about mid- 

 night. 



Nov. 10. — Thermometer box changed after ll 11 , put 

 on ladder stand. Height of bulbs above snow = 53 inches. 



Nov. 12. — Snow fell during the day, but turned to rain 

 at 17 u . Silver thaw at 17 h , 19 h , and 20 h . 



Nov. 14. — Fog or mist to-day till 13 h , when it cleared 

 away, leaving a cloudless sky. Fog lay below and hung 

 about the summit all day, so that the atmosphere was 

 saturated. The fog rose and again covered the summit 

 at 19' 1 . A fog-bow was seen at 14 h and 15 h . Ther- 

 mometer box changed after 13 h . Height of bulbs above 

 snow = 44 inches. Silver thaw at 5 h . 



Nov. 15. — At 23'' the Dry and Wet bulb thermometers 

 were changed. 



Nov. 17. — Thermometers changed after 12 h . 



Nov. 18. — Thermometers changed after 12 h . To-day a 

 raven was seen at N.E. cliff. 



Nov. 19. — Summit clear all day, with fog below. 

 Earth shadow seen at 1 6 h . 



Nov. 22. — After 3 h changed the thermometers. 



Nov. 23. — Raven seen to-day near the bucket stage. 



Nov. 27. — The thermometer box was changed after 18 h . 

 Height of bulbs above snow = 42 inches. 



Nov. 28. — Strong, squally S.E. winds all day, and at 17 h 

 it blew a gale, which continued till midnight. The Tower 

 Thermometer was used at 17 h as the observer was unable 

 to read the outside thermometers owing to the drift. 

 Barometer pumping heavily in the evening. Clear fog 

 crystals forming rapidly to-day. 



Nov. 30. — Thermometer box changed after 4 h . 



Dec. 3. — Fog till 14 h , clear with foggy intervals since. 

 Thermometer box changed after 15 h . Lunar corona at 



23 h , but too fleeting to measure. Lunar halo at 24 h , radius 

 22° 56'. 



Dec. 4. — Lunar corona at l h , too faint to measure. A 

 very distinct lunar halo was seen at the same hour, the 

 radius being 23° 27'. Another lunar halo was seen at 

 21 h , and 22 h but it was not distinct enough to measure. 



Dec. 7. — Thermometer box changed after 8 h . 



Dec. 8. — Barometer pumping at times all day. 



Dec. 12. — Six ptarmigan seen flying over the Obser- 

 vatory to-day. 



Dec. 13. — Lightning and earth currents noted in 

 early morning. Lunar corona at 4 h , no measurement 

 obtained. Fog crystals were forming rapidly during 

 the day. The Dry and Wet thermometers at 4 1 ' were read 

 at 4 h 10 m owing to observer's lamp being blown out. 



Dec. 15. — Earth currents in early morning and after- 

 noon. 



Dec. 21. — At 3 h the door of the Stevenson screen was 

 frozen so hard that it had to be opened with a chisel ; in 

 consequence the temperature was not read till 3 h 12 m . 



Dec. 27.— Thermometers were changed at 2 h 15™. 

 Feathery fog crystals forming rapidly to-day. 



Dec. 28. — Heavy wreaths of snow surround the Obser- 

 vatory, almost level with the roof. Depth of snow at 

 snow post = 28 inches. 



Dec. 29. — The fog showed signs of lifting early in the 

 morning, but it was not till 16 h that it finally cleared. 

 Cumulus and cirrus types thereafter till midnight, when 

 fog set in again. Fleeting lunar corona at 17 h ou cir.-cum. 

 cloud. Thermometers changed after 14 h . 



Dec. 30. — Fog all day. At midnight it cleared away, 

 leaving a cloudless sky, but persisted below in a thick bank. 



Dec. 31. — Changed thermometers after 2 h 20 m . 



