1884.] 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



325 



wood-work of the tower. It seems to have been due 

 either to earthquake or to the tower settling a little. 



Nov. 26.— Thermometer box shifted at 17 h . At 23 h 

 the snow post near rain-gauge (A) was found to be 

 thickened by snow crystals to a size of about 20 inches by 

 12. [The size of the post is 7 inches by 3.] 



Nov. 29. — At 2 h small corona seen. Very yellow look- 

 ing, inside red, with blue margin outside. Radius of red 

 1° 55'. At 16 h fog all over northern hills, but visibility 

 to southward. Sky faintly red to S.S.W., yellow and 

 pale green to S.W., and dark to E., which might be earth 

 shadow. No afterglow. At 17 h moon was shining 

 brightly, with under it a reddish-brown haze. At 18 b 

 faint blue corona round moon. At 22 h corona with blue 

 margin, colours inside red, not distinct. Radius of red, 

 1° 55'. The outer blue not always seen. At midnight 

 very faint halo. 



Nov. 30. — At l b faint halo, no colours, inside radius 

 roughly 18° 20' by stephanome — probably halo of 22° 

 radius. White snow crystals forming rapidly all after- 

 noon. 



Dec. 1. — Corona with red outside, but blue margin, 

 formed on scud passing over hill. Radius of red, 4° ; space 

 inside red blue looking. When the scud clears off, this 

 corona disappears, but the moon is seen surrounded by 

 a very much smaller one, very yellow looking inside the red. 

 At 3 h misty corona formed on scud. Red outside. Radius 

 of red, 2° 52'. 



Dec. 4. — At l h corona. Red outside. Radius of red 

 2°. Blue margin seen at times. 



Dec. 5. — At noon sky watery-looking round sun, and 

 red and yellow in colour under it. Horizon dark blue to 

 N.W. At 15 h thermometer box shifted. 



Dec. 11. — The snow post at Wragge's hut, after being 

 covered with snow crystals, got glazed over by rain falling 

 while the temperature was below 32°. The top was 

 covered by an umbrella of snow about 15 inches thick by 

 40 to 50 inches across. The diameter of the shaft was 

 about 20 inches, and the height 100 inches; the post 

 itself measures only about 6 inches by 1\. 



Dec. 17. — The snow near the Observatory was observed 

 to be lying in waves with some 50 or 60 inches between 

 the crest, the line of crests running perpendicular to the 

 wind. 



Dec. 20. — At 3 b thermometer box shifted. 



Dec. 21. — At 16 b a heavy bank of cumulus hid the 

 afterglow, but some cirrus clouds to N.E. had a pale red 

 glow on them. At 16 h 25 m the cumulus cloud was almost 

 gone, and a glow visible, extending downwards till it met 

 the ordinary sunset colours. The moon was pale green in 

 colour. The glow lasted till shortly after 17 b . 



Dec. 22. — Fine sunrise. At 7 h a pale green band ap- 

 peared just above S.E. horizon. At 8 h sky to W. purple, 

 with dirty sea-green under it, while to E. and S.E. it 

 showed bright red, yellow, and purplish pink. After 8 h 

 this red and yellow extended in both directions, forming 

 a coloured horizon all round ; above this the sky was 

 whitish green, and above that again was a band of pink, 

 showing all round, but most brightly to N.W. These 

 belts extended to about 15° above the horizon all round. 

 The zenith was blue. The sun rose at 8 h 42 m , and these 

 colours faded away, leaving a hazy red and yellow all round 

 horizon. Before the sun rose the snow on the hills to N. 

 and N.W. was smoky green in colour, when contrasted 



with the snow on Ben Nevis. The sky was cloudless 

 down to the horizon. At 10 h hazy red corona round sun. 

 This continued most of the afternoon. At 16 h 30 m there 

 was a very faint pink glow to N.W. on cirri clouds, the 

 sky below being bright red and yellow. At 20 h and 21 h 

 aurora observed, single arch, stretching from W.N.W. to 

 N.N.E. No streamers ; height of top of arch about 20°. 

 At 22 h the eastern part of the arch had a wavy or toothed 

 structure below. 



Dec. 23. — To-day the feathery snow crystals, forming on 

 exposed surfaces, were grey-brown in colour. 



Dec. 24. — The snow crystals forming to-day are white 

 in colour, and contrast strongly with those of yesterday. 



Dec. 25. — Before sunrise (at 8 h ) sky dirty green to 

 S., with pale yellow above, and a faint pink tint on cirrus 

 clouds. At 10 h the sky below the sun was red. At ll 1 ' 

 triple glories seen to northward. Very faint rosy corona 

 round sun at noon. At 16 h very thin scud was passing 

 across the hill, which "glowed" with the same colour as 

 the usual sky afterglow. At 16 h 25 m distinct patch 

 of afterglow. Other ^ : 2 0° to 30° »~ \ 



colours as indicated in Pink glow * 



margin. At 16 u 40 m Yellow Yellow 20° 



the glow was gone, and ^_._J^Z *l d __ _ ¥ 



the sky coloured orange °° = * 



and green, but fading gradually. All day the lower hills 

 were hid in level-topped fog, rising to about 3000 feet. At 

 17 h lunar corona observed. Very misty. Radius of red, 

 2° to 3°. Very green and yellow in appearance. No blue, 

 and red faint. At 20 h very faint blue corona round moon. 

 No other colour visible ; the radius of blue about 2° 5'. 

 At 22 h small corona. Red, too small to measure, with 

 yellow inside it. Blue extending to about 3° 10' radius. 

 At 23 h there was no corona, but a slight darkening of the 

 sky under the moon. At midnight corona without blue 

 margin. Radius of red, 2°. 



Dec. 26. — At 8 h the S.E. horizon was of a bright golden 

 colour. The valleys were filled with fog, not rising higher 

 than 2000 feet. At 9 h a raven was seen near the second 

 gorge. At 13 h solar fog-bow, and at 22 h lunar fog-bow, ob- 

 served ; too large for stephanome. 3 



Dec. 27. — In the middle of the day dense Bi ue 3 

 fog over all the lower hills, rising nearly to Bed 2 

 the height of Ben Nevis, say about 4000 Blue' 2 

 feet. Also brown colour under sun. Sun- E,e 5- 1 . 

 set colours faint. No afterglow. At 18 h whitish 

 lunar corona observed. Colours as in mar- 

 gin. Radius of blue 1 , 1° 50' ; radius of red 2 , 2° 25' ; 

 radius of red 3 , 4° 30'. At 17 h very faint lunar halo seen. 

 At 20 h lunar corona with colours as in Red 2 

 margin. Outer red, rather faint. Radius Blue 

 of red 1 , 2° 2'; radius of red 2 , 4° 5'. At Red 1 

 21 11 double corona still seen. Its size Yellow 

 appeared to vary, being small when the ^ 



sky was clear of low clouds, and enlarging as the scud 

 passing over the hill thickened. 



Dec. 2S.— At 10 h lower hills buried in fog to about 3000 

 feet. By noon the fog was broken up into detached pieces 

 in the valleys, and mixed with haze-copper colour under 

 sun all afternoon. At sunset sky was orange and yellow 

 to S.W., and blue-black to N.E. No afterglow. At 21 h 

 the moon was surrounded by a white glare of about 5° 

 radius. No halo or corona. This glare lasted all night, 

 but at 23 h and midnight there was also a faint blue corona. 



