1887.] 



BEN NEVIS OBSERVATORY.— LOG-BOOK. 



349 



blue, 24° 28' and 21° 13'. No trace of an inner ring 

 was visible. 



May 15. — Cum. -fog round Ben Nevis in forenoon, and 

 cum. -clouds overhead in afternoon. 



May 16. — At h 7 m the thermometer box was put one 

 stage down on ladder-stand. Haze round horizon all day, 

 often rising so as to form cloudy patches, with clear sky 

 under them. 



May 18. — At 8 h hard conical-shaped snow falling. At 

 night the snow was soft, and in large flakes. 



May 22.— Thermometer box shifted at 15 h 15 m . The 

 northern horizon was faintly red all night. 



May 23. — At 3 h low fog was lying over Loch Eil. 



May 26. — Faint solar halo seen at 12 h and 13 h . 

 Snow almost gone off hills round. At 4 h two strangers 

 with a horse came up. This is the first horse up this 

 year. 



May 27. — Solar halo seen at ll h ; colours strong, red 

 inside and blue outside ; but ring very broad, and edges 

 badly defined. The view to S. and E. was very clear in 

 afternoon, but haze formed there at night. Dense cumulus 

 fog hid all the hills to northward at night ; it extended to 

 at least 4000 feet. To-day William Stewart and J. 

 Rankin came up with two horses with stores, for the first 

 time this year ; the horses came right up to the Observatory 

 over the snow. 



May 28. — The air was so dry that the wet bulb had 

 to be moistened a few minutes before every hour till 9 h ; 

 it did not remain frozen more than 10 minutes at a time. 

 Dense fog lay over the northward and eastward hills till 

 noon, when it broke up and disappeared. It gathered again 

 in the same manner in the evening. The moon (6 days 

 old) was visible all afternoon. 



May 29. — At 3 h a distinct upper glow was seen to 

 north-eastward. No unusual colours were seeu round the 

 sun during the day. Fog on hills round all day, except 

 for a few hours in the afternoon. 



May 30. — At h 5 m thermometer box was shifted one 

 stage down on ladder-stand. Continuous fog over all the 

 lower hills till 10 b , after which it began to break up and 

 rise as cumulus. Upper-glow seen at 3 h . Horizon and 

 valleys hazy all day. 



May 31. — Low fog lay in the valleys till 8 h , after which 

 it broke up, and cumulus clouds formed. Thick haze 

 round the horizon all day, and at night heavy clouds 

 above and mingling with it. 



June 2. — Low fog in valleys to N and N.E. in early 

 morning, especially over Loch Oich. A faint solar halo 

 was seen at 17 h . 



June 3. — In early morning str.-fog on Moor of Rannoch 

 and iu valleys among the hills to N.W. It cleared off 

 about 9 h . Solar halo seen at ll h and 12 h . At 1 l h radius 

 of red, 22° 18'; blue, 22° 43'. At 12 h solar halo was 

 observed, red inside and blue out, colours bright. Outside 

 this halo on the S.E. side was a segment, coloured red 

 inside, that appeared to cut into the halo, but did not 

 extend inside it (see fig. 15). Radius of inner red, 22° 18' 

 and 22° 0'; outer red at furthest point from sun, 25° 28'. 

 At 15 h 10 m dry and wet were put out in large box 35 

 inches above snow. Double readings were taken till mid- 

 night, but the small box values were entered on the daily 

 sheet. 



June 4. — The dry and wet bulb entries on daily sheet 

 are now taken from the instruments in the large box. 



June 5. — Loose cum.-fog hanging about all after- 

 noon. 



June 10. — A faint glory was seen on the fog to S.W. 

 at 4 h ; no measurements got. Fog on hills to 4000 feet 

 in early morning. About 6 h this fog rose above the level 

 of Ben Nevis, but it was dry and no rain fell. 



June 13. — At 23 h the mist broke overhead, and at mid- 

 night sky was clear, and fog over hills to S. and E. 

 Northern sky green, with filmy cirrus above. 



June 16. — After sunset and during the night the 

 northern horizon, and the lower surface of the cir.-cum. 

 clouds on the sky, were both dark red in colour. 



June 18. — At 6 h and 7 h the sky was overcast, with a 

 heavy thunder cloud. Thunder and lightning were noted 

 at 6 h 27 m , and thunder at 6 h 31 m . Heavy rain fell 

 while thunder-storm lasted. Dew formed on thermometer 

 screens, black bulb, and Observatory roof at night. 



June 20. — A segment of a solar halo was seen at 4 h and 

 a full halo at 6 h . No measurements were obtained. 



June 21. — A faint " foreglow " was seen at 3 h , and at 

 same hour the earth shadow seen to westwards was topped 

 by a belt of rosy colour, having streamer-like gaps 

 therein. 



June 22. — At 22 h pink afterglow observed. At mid- 

 night northern horizon red and green. 



June 24. — At 3 h faint upper glow seen to N.E. and 

 earth shadow to S.W. A faint afterglow was also seen 

 at 22 h . At midnight N. horizon red and green, with 

 pearly-white cirrus clouds above it. 



June 25. — At 2 h a cloud bank was seen to southward, 

 not far off, about 6° above horizon, of peculiar perpendicular 

 columnar structure. Pink upper glow observed at 3 h , and 

 a faint afterglow at 22 h . At 18 h a wasp was seen on roof. 

 For the past few days large numbers of flies have been all 

 about the hill top. 



June 26. — At l h pearly-white cirrus to northward. 

 In early morning str.-fog gathered in the valleys ; it rose 

 higher in the forenoon, and about noon broke up into 

 cumulus and disappeared. 



June 27. — In early morning str.-fog again in valleys ; it 

 gradually rose till it covered Ben Nevis as well as all the 

 other hills. The stones of the hill top, however, were 

 never wetted by this fog. 



June 28. — Upper surface of fog layer was about the 

 level of Ben Nevis all day, sometimes rising over it, but 

 never sinking so low as to expose many of the other hills. 

 At 20 h a glory was seen. Three rings, badly-defined and 

 too fleeting to measure, but the middle ring was distinctly 

 the brightest. Red outside in all rings. Pearly-white 

 cirrus reaching to about 30° altitude at midnight to north- 

 ward. 



June 29. — Pink upper glow observed at 3 h . Fog-bow, 

 occasionally double, observed at 5 h and at 6 h . Thick con- 

 tinuous fog over all the hills round in early morning. At 

 9 h this had risen above level of Ben Nevis, and continued 

 so all day. At night it cleared to northward, and pearly 

 cirrus at about 20° altitude was seen. 



June 30. — At 3 h faint upper glow seen to north-east- 

 ward. Pink afterglow seen at 22 h . The fog cleared away 

 gradually to-day, leaving only a general haziness in the 

 valleys. 



July 1. — At 3 h faint upper glow seen. Thick foggy- 

 looking haze in the valleys all morning, rising into cum.- 

 fog in the forenoon. 



