1893.] 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



95 



wind was S.W. at this time, aud the storm gradually 

 approached, and at 21 h a heavy shower of rain began to 

 fall, the drops being very large. The lightning continued 

 to play about the hill top till after 23 b , but very few 

 peals of thunder were heard during tliis time. St. Elmo's 

 Fire was seen and heard by the people iu the hotel 

 between 21 h and 22 h , but was not observed at the 

 Observatory. The telegraph instrument kept clicking 

 from 21 h till about the end of the storm. Several double 

 flashes were observed, and a photograph was secured of a 

 distant flash at 20 h 40 m . End of storm not well marked, 

 but probably about 23 h 30 m or 23 h 45 m . The storm 

 apparently travelled from S.W. to N.E. or N, and then 

 appeared to return to S.W. again. 



Aug. 16. — Top clear, but sky cloudy from 18 h to 21 h , 

 mist the rest of the day. A triple fog-bow and quadruple 

 glory were seen at 18 h 30 m , and in the outermost bow of 

 the fog-bow the outer edge was red, in the other two bows 

 the inner edges were red. 



Aug. 23. — The mist, which had been almost continuous 

 for the last two days, showed signs of clearing at 2 h , and 

 at 3 h the summit was clear aud the sky cloudless but for 

 a bank of cirro-stratus on the S.W. horizon, and fog was 

 on the hills all round. The mist came on again at 4 h , 

 and continued all day, but for slight breaks at 18 h and 

 23 h . 



Aug. 27. — Summit clear, but sky overcast, or nearly so, 

 from 7 h to 13 h , and from 18 u to 21 h ; mist or fog the rest 

 of the day till 21 h . Sky cloudless after 21 h , except for a 

 little cirro-cumulus at midnight, which disappeared soon 

 after the observation. A triple lunar corona was seen at 

 midnight and 22 h . A lunar fog-bow was observed at 

 midnight, and there was hoar frost on the roof at and after 

 22 h . 



Aug. 28. — The hoar frost was entirely off the roof at 

 4 h . Lunar coronee were seen at l h and 2 h , and lunar fog- 

 bows at 2 h and 3 h . 



Aug. 29. — Summit clear the greater part of the day, 

 but mist passing after 13 h ; sky cloudless at 10 b , 19 h , and 

 20 h . Fog continued in valleys and on the hills all day, 

 almost completely hiding the surrounding hills and at 

 times enveloping Ben Nevis. Air dry till 15 h , and at 18 h 

 and 21 h ; the humidity was very low in forenoon, the 

 lowest being 31 per cent, at 9 h and 10 h , the sky at these 

 hours being practically cloudless, and cumulus fog below 

 our level. Light N. breezes all day. A triple fog-bow was 

 seen at 17 h , the outermost bow having red outside and 

 the two inner having the red inside. A lunar corona was 

 seen at 21 h . 



Aug. 30. — At l h and 2 h the summit was clear, but 

 sky cloudy, and fog all round above 4000 feet, and at 3 h 

 mist came on and enveloped the hill all day, except for 

 short intervals at 19 h and 20 h ; drizzling rain after 19 h . 

 The humidity fell from 95 per cent, at ] h to 50 per cent, 

 at 2 h , but was saturated at 3 h and after. Moderate N. 

 winds, force 2-3 all day. Lunar corona seen at l h . 



Sept. 2. — Mist or fog till 13 h , after which the fog 

 lifted, but the clouds were just clear of Ben Nevis and 

 tipping the hills all round. The clouds sank again, 

 forming fog at 17 h and 18 h , after which the sky remained 

 cloudless till midnight. There was rather thick haze in 

 valleys, which passed over the summit as a thin fog at 

 22 h . Air dry from 13 h , lowest humidity 66 per cent, at 



19 h . Light N. winds till 13 h , calm till 20 h , S. breeze 

 thereafter. A lunar corona was seen at 22 h . The shadow 

 of Ben Nevis and pink afterglow were seen this evening. 



Sept. 3. — Sky cloudless or nearly so till ll h . The 

 stratus fog in the morning reached to 4000 feet, and kept 

 passing over the summit till 16 1 ', after which it gradually 

 disappeared, leaving thick haze in the valleys below ; fog, 

 however, began to re-form in the valleys at midnight. 

 Lunar coronse were seen at l h , 2 h , and 3 h ; a partial solar 

 halo at 17 h , and a lunar halo at midnight. Glories were 

 seen frequently in forenoon and afternoon. 



Sept. 4. — Summit clear and air very dry till 23' 1 ; 

 lowest humidity 33 per cent, at 10 h . Sky very cloudy in 

 forenoon, with various forms of cirrus, which almost 

 wholly disappeared after 15 h , except a few small patches. 

 A thin layer of stratus fog lay in the valleys to N.E., E. 

 and S. in early morning, but disappeared after sunrise; 

 small patches, however, continued to hang about the hills 

 near the horizon all day, especially to S. and W. There 

 was a thin haze below in forenoon which increased in 

 afternoon, when the visibility was barely 3. During the 

 afternoon a thick haze appeared over the Firth of Lome 

 and crept up Loch Linnhe, forming into stratus fog in the 

 evening. At 23 h this fog began to pass over Ben Nevis, 

 and assumed a slightly misty character at midnight, 

 causing saturation. Lunar coronse were seen at 2 h , 3 h , 

 and 23 h . Two or three butterflies were seen on the top 

 to-day. 



Sept. 8. — Several peals of thunder were heard to 

 southward about 2 h 57 m , and the telegraph needle gave 

 several sharp clicks ; nothing was heard after the 3 h 

 observation. Barometer pumping from 13 h to 18 h . 



Sept. 9. — Air remained saturated all day, though the 

 top was often clear after 9 h ; the clouds, however, were 

 usually just clear of the summit or fog was passing, 

 causing saturation ; the sky was cloudless at 22 h , but thin 

 fog was passing. At times the visibility was 3-4, when 

 the Paps of Jura, Skye, etc., were seen. 



Sept. 10. — Fog on or passing till noon, clear the rest 

 of the day. The sky was cloudless in morning, when the 

 top was clear of fog. The fog rose in afternoon, forming 

 cumulus clouds, which disappeared after 18 h , leaving sky 

 cloudless again till midnight, when cirrus began to form. 

 Air dry from 13 h to 19 h and at midnight; the dry bulb 

 read lower than the wet six times during the day. Air 

 very clear to westward in afternoon, Barra Head, etc., 

 being distinctly seen. N. breezes in forenoon, S. till 18 h , 

 veering to S.W. thereafter. There was a thick covering 

 of hoar frost on the roof and woodwork from 2l h . 



Sept. 11. — Sky cloudless or nearly so till ll h . Fog on 

 or passing till 17 h ; top clear and sky cloudy thereafter. 

 At midnight fog had formed all round and was passing at 

 times. Air very clear in morning, visibility 4. Air dry 

 all day ; lowest humidity 48 per cent, at 4\ The wind 

 veered from S.W. at l h to N. at 6 h ; it again became S. at 

 noon, but veered again to W. at midnight. The hoar frost 

 continued on the ground till after sunrise. A faint aurora 

 was seen at 3 h . 



Sept. 23. — From 4 h to 7 h there was so much drift that 

 no rain gauge was put out. The ground is deeply covered 

 with snow. At 17 h 10 m a dry bulb, wet bulb, and a 

 minimum were put out in small box on ladder stand No. 

 1. Duplicate readings were taken till 3 h on the 24th. Up 



