1893.] 



BEN NEVIS OBSERVATORY , — LOG-BOOK. 



89 



over occasionally. Fragment of solar halo seen at 8 h on 

 cir.-str. near horizon. 



Feb. 15.— Thermometer box shifted at ll h 10 m . Height 

 above snow not altered. When top was clear to-day, sky 

 was partly covered with windy cirrus, and cir.-s. and cum. 

 lay round horizon. Sky cloudless from 21 h to 23 h , but 

 thin fog blowing over. Aurora seen at these hours ; not 

 well defined nor very distinctly seen. 



Feb. 18. — Glimpses of sunshine after 10 h , but top clear 

 and air dry after 16 h till 21 h . The clearing was accom- 

 panied by a slight fall of temperature. At first fog lay on 

 the hills round, but it had broken up and disappeared by 

 20 1 ', though horizon was still hazy and some cir.-strat. was 

 seen. Mist or fog after 22 h . A rise of temperature when 

 the fog came on again. 



Feb. 21. — Top clear occasionally, but fog hanging about 

 the hills round always. Just after 12 h six snow buntings 

 were seen on M'Lean's Steep. Tn the afternoon there 

 were slight showers of snow, all six-rayed crystals of 

 regular form. 



Feb. 23.— Thermometer box shifted at 3 h 20 m . Height 

 above snow not altered. Sky apparently clear above all 

 day ; but fog either on hill top or forming a stratus 

 pallium just above it. In the middle of the day cum. fog 

 was rising freely from Glen Nevis and passing along 

 summit. Lunar corona seen at 21 h . 



Feb. 24. — Sky apparently clear, but mostly thin fog on 

 summit or stratus just above summit, and cloud on or over 

 hills round. Very calm all day. A few streaks of cirrus 

 seen at night moving from eastward. 



Feb. 25. — Sky pretty clear, but thin fog on hill top 

 most of the day. Lunar halo seen at 4 h , and lunar coronas 

 most of the evening. Glories, some double, seen at 17 h . 



Feb. 27. — "When top cleared at 10 k , fog lay on hills to 

 N.E., and continued to pass over the summit at intervals 

 all day ; but there was no low-lying fog in the valleys. 



March 1. — Top clear, but sky covered with ugly-looking 

 cirro.-stratus from 2 h to 9 h . Gale from S.E. from 6 h to 

 10 h with heavy drift; but air was dry from 7 k to 9 h , at 

 other times thin fog passing. Lunar halo 2 h to 5 h . No 

 rain gauge out till 1 l h , but little or no snow fell. 



March 2. — Thermometer box shifted at 12 h 15 m . 

 Height above snow not altered. Top clear at 12 h and 13 h , 

 but detached cum. fog among hills. Top clear again after 

 18 h ; no fog below, though at times thin fog passing and sky 

 getting gradually covered with cirro-stratus. Strong S.E. 

 wind rising after 20 h . Lunar halo from 22 h onwards. 



March 5. — Thermometer box shifted at 4 h 20 m . 

 Height above snow not altered. 



March 7. — Top clear and air dry for a short while in 

 afternoon, but fog on or over hills round and horizon 

 cloudy. The snow at first gorge was measured this after- 

 noon, and found to be overhanging the edge 240 inches 

 (20 feet). When measured last year (May 22, 1892) it 

 overhung 312 inches (26 feet). 



March 10. — Measurements of snowfall in morning very 

 doubtful, owing to drift. At 9 h the gauge was found 

 blown over on its side, and that hour's fall was lost. 

 Thermometer box shifted at 13 u 15 m . Height above 

 snow not altered. 



March 11. — Drizzling rain began at 6 h , when tempera- 

 ture was 27 o- 0, and the temperature only reached 32°"0 at 

 20 h and 21 h , being below freezing the rest of the time, 

 TRANS. ROY. SOC. EDIN. — VOL. XLIII. 



though heavy rain was falling and coating everything 

 with ice. 



March 13. — Thermometer box shifted at h 35 m . 

 Height above snow not altered. At 5 h a light was seen 

 above the horizon to E.N.E., possibly the zodiacal light. 



March 14. — The snow which fell at night after 20 h was 

 heavy and hard, and did not drift much. 



March 15.— Thermometer box shifted at 3 h 25°?. 

 Height above snow not altered. 



March 17.— Thermometer box shifted at 7 h 20 m . 

 Height above snow not altered. Top cleared first at 7 h ; 

 fog on hills to E. and again on Ben Nevis at 12 h . Faint 

 solar halo seen at 10 h . 



March 18. — Thin fog till 8 h ; top clear after that, but 

 air saturated till 19 h , dry afterwards. Fog on hills or 

 passing till noon. No fog below after that. Air clear in 

 afternoon. Rum, Mull and Jura seen. After 17 h the 

 upper joint was put on thermometer stand No. 2. The 

 box was taken off while fixing the upper part, but was 

 replaced at 17 h 25 m . Same box and thermometers as 

 before, height not altered. At 19 h the afterglow was 

 seen, and at 20 u the western horizon was still red with 

 sunset colours. 



March 19. — Sky cloudle-s, except for some passing 

 cumulus in forenoon and cirrus and cir.-cum. in middle of 

 day ; but fog on hills round at about 3000 feet all day, 

 which covered Ben Nevis also at 23 h and midnight. 



March 20. — Mist and drizzle till ll h , after which the 

 fog layer was just below or on the summit till 15 h , and 

 above it as stratus or as dry fog after that hour. At ll h a 

 fog-bow was seen, and again at 13 h . At ll h snow bunting 

 seen near doorway. 



March 21. — Sky clear, except for a little cirrus and 

 cirro-cum. ; but haze in valleys up to almost 4000 feet, 

 with, in morning, patches of fog among it. S.W. wind 

 force 2 to 3 all day, which was apparently not felt below 

 the top of haze. 



March 22. — A snow bunting was seen again this 

 morning at ll k . Haze in valleys to-day, but thinner than 

 yesterday, and apparently extending to a greater height, 

 no upper surface being apparent. Rum, Sky, Mull, etc., 

 were seen through the haze, and no hill tops rose above 

 it as the higher summits did yesterday. 



March 23. — Thick haze all round all day, Ben 

 Cruachan being about the furthest visible hill. Faint 

 solar halo seen at 15 h , and portions of lunar halo at 23 h 

 and midnight. 



March 24. — Thick haze all round all day, rather thicker 

 than yesterday. Some heather burning going on. Fog 

 on summit 5 h to 9 h , but no rain or snow. Fog on lower 

 hills or in valleys afterwards till noon. 



March 25. — Cloudless sky, but thick haze all round till 

 8 h . The sun when rising above the haze was distorted. 

 The haze continued, and the sky was cloudy till 16 h , after 

 which it was mostly fog. 



March 26. — Misty and drizzle in morning, fine later, 

 but haze all round. At 20 h 25 m strong earth currents 

 began to affect the telegraph, and from 21 h to midnight an 

 aurora was observed. It was brightest at 23 h , when there 

 was an arch whose under side rose about 1 2° above 

 horizon, and streamers reaching at times to about 70° 

 altitude. The arch and streamers were very unsteady, and 

 sometimes streamers appeared below the arch. The arch 



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