818 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



[1891. 



April 21. — Sky somewhat cloudy, and fog passing at 

 intervals all day. Shower clouds all round in afternoon, 

 and slight showers of snow falling on summit ; chiefly 

 snow-hail. Haze bands in sky at 4 h . 



April 22. — Fog on hills and passing summit at times 

 most of the day. A lunar corona was seen at midnight. 

 Shower clouds all around in afternoon. 



April 23. — Cloudless till 10 h ; increasing amounts of 

 cum. till 16 h , and almost overcast during rest of day. 

 Lunar corona? seen at 22 1 ', 23 b , and midnight. At 2 h 

 peculiar greenish hazy appearance in all south-western 

 sky, from about 45° altitude to horizon, and from S.S.W. 

 to W. about moon. Same noted at 3 h , and also that 

 there was more green colour in north-eastern sky (sunrise 

 colours) than usual. Foreglow seen at 4 h 15 m . 



April 24. — Lunar corona seen at 3 h . Fog touching 

 top occasionally, and overcast sky all day, but no fog in 

 valleys. 



April 25. — Thick haze below in valleys all day up to, 

 or a little over, the level of hill top. Sky cloudless to 

 horizon at night. 



April 26. — Sky cloudy and occasional fog on hill top, 

 but no fog in valleys, and air free from haze. 



April 28.— Thermometer box shifted at 19 h 20 m . 

 Height above snow not altered. 



May 4.— Thermometer box shifted at 3 h 15 m . Height 

 above snow not altered. Fog hanging about the hill, 

 but occasionally rising above, forming clouds and leaving 

 air clear till 20 h , when it cleared away and left sky 

 cloudless. Aurora seen at 23 h and midnight. Brightest 

 at 23 h . One sharp-cut arch with dark space below, and 

 apparently the top of a second arch just showing above 

 horizon. Highest part of lower edge of upper arch about 

 7° above horizon. 



May 5. — Thick haze all day, and cum. and thin fog- 

 blowing over the hill top occasionally. Sky in forenoon 

 about half covered with cirrus and cirro-stratus, on which 

 at 8 h a halo with two mock suns was seen. At 12 1 ' 

 halo was again seen. Three measurements of radius to 

 inside of halo gave,— 22" 26'; 22° 39'; 22° 20'. 



May 7. — Top clear from l'2 h to 18 1 '. Detached fog 

 floating about, but no low fog in valleys. Sky partly 

 covered with cumulus and cum. -cirrus. Dry and wet 

 bulbs shifted at 14 u 10 m . Box and minimum not shifted. 

 This afternoon the snow at the First Gorge was measured, 

 and was found to be overhanging the cliff 189 inches. 



May 10. — Air clear in forenoon, but haze round 

 horizon in afternoon. No fog in valleys but patches of 

 cumulus at horizon, though sky overhead was almost 

 cloudless all day. Light to N.N.AV, probably auroral at 

 midnight, but the whole northern sky was too bright to 

 be sure of it. 



May 11. — Fog lay in the valleys to N. till 9 h and 

 there was haze at horizon all day. A solar halo was seen 

 most of the day. 



May 12. — The sun rose at 4 1 ' 4 m . Before rising, at 

 about 4 h 2 m , a sun pillar rising vertically upwards was 

 seen with a bright patch, or mock sun in it. A solar 

 halo was seen at intervals during the day. 



May 13. — Thermometer box shifted one stage down 

 on ladder stand at h 5'". 



May 16. — Thermometer box shifted at 14 h 25 m . 

 Height above snow not altered. 



May 17. — Top clear from ll k to 17 h , but sky mostly 

 cloudy and showers passing. Air very clear to S.W. at 

 15 h . Jura, Islay, Oronsay all seen clearly. To-day the- 

 black bulb maximum went up to 155°3, probably during a 

 break in the clouds about noon. Heavy squalls from N. 

 and N.E. at night. For the last few days the records of 

 the raingauges have been very doubtful owing to drift. 

 The old snow on the hill top is hard and icy, but what 

 has fallen since the last thaw is dry and powdery, and 

 blows about freely. 



May 18.— Thermometer box shifted at 8 h 10 m . Height 

 above snow not altered. 



May 20. — A shower of soft hail — like St Elmo hail — 

 came on at 18 h and lasted about half an hour, giving a fall, 

 melted, of 0T18 inch. 



May 25. — Masses of cum.-fog blowing about the hills 

 all day, but very clear views occasionally between them. \ 



May 30.— Thermometer box shifted at 14 h 8 m . Put 

 one stage higher on ladder stand. 



June 1. — At h 5 m thermometer box put one stage 

 lower on ladder stand ; same instruments left out. Fog 

 hanging about the hills and blowing over Ben Nevis 

 also at times till ll h . Haze at horizon all afternoon and 

 night. A solar halo was seen at 13 h , and a mock sun at 

 19 h . 



June 2. — Horizon hazy all day. Thin dry fog blowing- 

 over the hill top occasionally. Fog in valleys to N.E. in 

 morning. 



June 3. — Air hazy and fog among the hills to northward 

 all day. 



June 4. — Thermometer box put one stage down on 

 ladder stand at h 8 m . Air hazy and fog on hills to 

 northward all day. Detached fog among the hills to E. 

 and S. in evening, and fog blowing over Ben Nevis also at 

 midnight. 



June 6. — Fog over hills to northward at 3000 feet and 

 in detached portions among other hills at same height till 

 8 h , after which it disappeared, but the air was rather hazy 

 all day. 



June 7. — At 3 h the foreglow was seen. Fog lay on 

 the hills to N. and E. at about 3000 feet all morning till 

 6 h . From 7 h to noon fog was all round and passing, but 

 after that it was clear till 20 h ; for the rest of the night fog. 



June 9. — Haze or light fog in valleys till noon, and fog 

 among hills to N. at night. Solar halo seen at 17 h . At 

 20 1 ' the Skye hills were seen rising above a dense belt 

 of fog. 



June 10 — Sun rose at 3 h 25 m over fog which covered 

 all the hills except to S.W. all morning at about 4000 

 feet. The foreglow was seen at 3 h . The fog gradually 

 broke up about noon. Air rather hazy all day ; the fog- 

 gathered on the hills to northward again at night. 



June 11. — Sun rose at 3 h 15 m . Ben shadow very 

 distinct after sunrise. Low fog, not above 2000 feet, lay 

 among the hills to N.E. till 7 h , and detached layers to 

 S.W. till noon. At 9 U the air was very clear to N., — the 

 town of Inverness being visible. Haze in the valleys all 

 day, and fog among the hills to N. at night. The after- 

 glow was seen at 22 h . 



June 12. — Sun rose at 3 h 18 m above fog which lay over 

 the hills to N. at about 3000 feet till 6 h , after which there 

 was only detached fog in the valleys till evening, when 

 fog gathered over the Atlantic. At 23 h and midnight, fog 



