1892.] 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



411 



on the hill top. When clear the wind was usually stronger 

 than when mist was on. 



Feb. 10. — In afternoon one of the rain-gauges was found 

 to be leaky and some observations are lost. 



Feb. 13. — Top clear, but detached patches of fog 

 among hills, and sky mostly cloudy till 16 h , fog on summit 

 the rest of the day. Two snow-buntings seen at cliff at 

 8 h the first this winter. 



Feb. 15. — Thin fog till 6 h . Sky cloudy with cirrus and 

 cirro-stratus moving from N.E. till 18 u pretty clear or only 

 cirrus after that. Patches of cum.-fog on hill top round 

 most of the day. Taint solar halo at 1 l h . Thermometer box 

 shifted at 9 h 18 m . Height above snow not altered. At 

 ll h it was found that the hinges of the thermometer box 

 had given way and the door was lying open. It was 

 repaired at once without removing the box. 



Feb. 16. — Fog in patches on hills till 4 h and on Ben 

 Nevis also most of the day after that, except for a few 

 breaks in forenoon, during which some sunshine was 

 registered. In a break at 6 h a double lunar coronsa was 

 seen, and at 9 h a solar fog-bow. 



Feb. 18. — Fog on hills round and occasionally blowing 

 over Ben Nevis also till 6 h , fog only on hills to E., and 

 no low fog in valleys till 16 h , clear except for a bank of 

 stratus to W. after that. Aurora seen 22 h to midnight. 

 Single arch low down. To-day the snow at the first 

 gorge was measured and found to be overhanging 251 

 inches. 



Feb. 19. — Aurora continued visible till 2 h and was also 

 seen faintly at 21 h and midnight. Sky cloudless except 

 for occasional cirrus all day, but thin fog blowing over 

 the hill top from 6 h to 10 h . No fog in valleys, but 

 patches of cumulus and cum.-fog above and on hills 

 round. 



Feb. 20. — Bright meteor seen at W.S.W. horizon at 

 l h 3 m , estimated about as bright as Venus. At 14 h a 

 portion of halo seen above sun. Detached fog on hills 

 round most of the forenoon and blowing over Ben Nevis 

 also after 16 h . 



Feb. 22. — At 7 h the top was clear occasionally, and 

 the horizon from S. round by W. to N. was brightly 

 coloured. From S. to S.W. the predominant colour was 

 orange, from S.W. to W. reddish-green, from W. to N.W. 

 pale blue, and from N.W. to N. dark blue. 



Feb. 23. — Strong S.E. gale most of the day. Top 

 clear 10 h to 15 h but fog on hills frequently blowing over, 

 and dark haze in the valleys. At 16 h the sun gleaming 

 through the fog was occasionally — not always — a bright 

 green. 



Feb. 25. — Thermometer box shifted at 7 h 15 m . Height 

 above snow not altered. 



Feb. 26. — At 10 h a suow-bunting was seen at the door 

 of observatory. 



Feb. 27.— Haze in valleys and round horizon all day. 

 Flat stratus fog on Moor of Rannoch and patches of 

 cum.-fog among the haze in afternoon. Aurora seen 22 h . 

 No arch, but streamers to about 20° altitude rising from 

 behind the haze and continually shifting. It was not 

 seen again all night. Sky almost cloudless all day. 



Feb. 29. — Thin fog and low clouds all day, but clear 

 at midnight when aurora was seen. Single arch, no 

 streamers. The midnight observation was 8 minutes 

 late. No corrections applied to readings. 



March 1. — Thermometer box shifted at l h 17 m . 

 Height above snow not altered. Aurora seen at l h , 2 h , 

 and 3 h . At l h it was a single arch without streamers, 

 but at 2 h there was no arch but shifting streamers to 

 about 45° altitude. 



March 3. — The fog-crystals that formed on the 2nd 

 and 3rd were white, dry, and quite easily removed. 

 '' March 4. — Fog cleared at about 10 h but left thick haze 

 in valleys all round ; it seemed to stand up to about 

 5000 feet high, and the air was saturated most of the 

 day. No unusual colours in sky. Earth shadow well 

 seen at sunset. An aurora was seen at 21 h . Single 

 arch, no streamers. It was again seen at 22 h , but at 23 h 

 and midnight the moon was so far west as to obscure its 

 light. Thermometer box shifted at ll h 10 m . Height 

 above snow not altered. 



March 5. — Aurora was seen at 3 h . Single arch, no 

 streamers. Thick hnze in valleys all day up to about 

 4000 feet. Thin fog occasionally blowing over Ben 

 Nevis. Sky cloudless all day except a streak of cirrus 

 low down to westward at 18 h and 19 h . 



March 6. — Clear sky, but haze below, and thin fog 

 blowing over the hill top till 4 h ; after that fog and 

 cloudy sky with haze and fog all round. At 7 h the sun 

 was seen coming up above the low lying haze and fog, it 

 was distorted, the lower part in the haze being smaller 

 than the upper part in the clear sky. 



March 8. — Sky cloudless from 5 h to 7 h , but detached 

 fog in the valleys and on hill sides all round. At 15 h 

 star shaped crystals of snow were falling. 



March 10. — Dining last night and this morning almost 

 all the last fall of snow has been blown off, leaving only 

 a few drifts. Top clear occasionally but fog always 

 blowing over at short intervals, and air saturated. 



March 11. — Up to 9 h thin log was on the hill top, 

 but after that it gradually cleared and after 17 h was 

 cloudless. Fog hung about the hills till 19 h , after that 

 there was only a little haze to the E., but no fog in 

 valleys. Thermometer box shifted at 15 h 15 m . Height 

 above snow not altered. 



March 12. — At l h the sky was about half covered 

 with cirrus in long strips radiating from a point about 

 10° south of the zenith. The moon was shining brightly 

 also near the zenith. The cirrus strips were tinged with 

 red to the E.N.E. and W.S.W., the colour flashed on and 

 off them like the pulsations of an aurora. No halo or 

 corona, surrounded the moon. After 4 h sky was cloudless 

 again and continued so till 13* 1 , but detached fog lay 

 among valleys almost all day and rose to height of Ben 

 Nevis about noon and enveloping summit at times till 

 15 h , almost continuous fog since. Air very dry in 

 forenoon. Lunar halo at 19 h , and a lunar corona 

 at 23 h . 



March 13. — Overcast 

 slight showers of snow. 



sky till noon, fog since, with 

 Solar halo at 10 h . 



March 14. — Summit clear after 17 h , but sky a little 

 cloudy and fog among hills to E. till 21 h . Sky cloudless 

 since. Thin haze in valleys below. 



March 15. — Cloudless and very fine all day except at 

 13 h and 14 h , when thin fog was blowing over summit. 

 Haze all round below, and some detached cum.-fog on 

 hills to S. Air dry at times throughout the day, and 

 very dry this evening. Computed humidity at 22 h , 15 



