320 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



[1891. 



deal of cirrus visible. At 3 h the dry bulb rose rapidly 

 on opening box, making correct reading difficult. Lunar 

 corona seen at l 1 ', 2 h , 3 h and 4 h . Weasel seen on summit 

 at 5 h . 



Aug. 24. — Dim lunar corona seen at 2 h . 



Aug. 27. — Summit mostly clear from noon till 19 h 

 with fog passing at times. Double glories seen between 

 ll 1 ' and 13 1 '. Rainbow seen at 19 1 '. The 4 h observation 

 was not taken till 4 1 ' 27 m . The barometer and anemo- 

 meter were corrected for time. Two weasels were seen on 

 the summit to-day. 



Aug. 29. — Fog rising and falling at intervals all day. 

 Showers of hail and snow between 5 h and 8 h . Hoar 

 frost from 22 1 ' till 8 h next day. Double glory seen at 

 10 h 54 m . Rainbow seen at 16 1 '. Splendid display of 

 aurora between 22 h and midnight. The aurora at 22 h 

 extended from W. by N. to N.E. by N., while the 

 streamers ran upward to within 30° of zenith. No clouds 

 in sky from 21 h to midnight. 



Sept. 3.— Fog or mist till 10 h and after 20 h . Glories 

 were seen at 10 h and a solar fog-bow at 12 h . Thin haze 

 all round in distance in the afternoon. 



Sept. 5. — A weasel was seen on office roof this 

 morning. 



Sept. 8. — Fog on hills to E. and N.E. and in valleys 

 to S. till 7 a.m., but almost continuous mist on summit 

 thereafter. Air very dry at l h and 2 h . 



Sept. 10. — Summit cleared at 3 h ; sky nearly covered 

 with cirrus and cirro-stratus. Detached cumulus fog on 

 hills and thick haze in valleys all round below till 15 h . 

 Since then fog has come on with occasional breaks. 



Sept. 11. — Mist till 4 h , and sky almost covered with 

 cirro-cumulus and cirro-stratus the rest of the day. Fog- 

 hanging about hills to 3000 feet the greater part of the 

 day and thick haze all round below. Faint halo was seen 

 at 14 h . 



Sept. 12. — Sky almost cloudless. Detached fog in 

 valleys to W. and N. and thick haze all round. An 

 aurora with faint streamer was seen at 4 h . 



Sept. 15. — A large weasel caught in trap at 18 h 20 m . 



Sept. 19. — Mist and drizzle till 23 h , since then summit 

 clear, but sky overcast with cir.-stratus and detached 

 fog in valleys. Lunar corona seen at 23 1 ' and a lunar 

 halo at midnight. 



Sept. 20. — Summit clear, but sky overcast with cirrus 

 and cir.-stratus till 14 h . Mist since. Detached fog in 

 valleys. A lunar halo seen till 4 h and a solar halo at 

 ll !l . Four measurements of radius to inside of lunar 

 halo gave— 23° 9', 23° 10', 23° 14', 23° 11'. 



Sept. 22. — Sky partly covered with cirrus and cir. 

 cumulus till 17 h 

 all day. 



Sept. 23. — Sky cloudless till noon, but fog blowing 

 over the hill top at times. Continuous fog since. Lunar 

 corona seen at 4 1 '. 



Sept. 25.— Summit clear from 13 1 ' till 17 h , but sky 

 overcast with cirro-stratus, and fog passing over Ben 

 Nevis at times. Solar halo at 16 h . 



Sept. 26. — Summit clear from 2 h till 5 h , and sky 

 almost cloudless, but thick cumulus fog all round. 



Sept. 28. — Very heavy rain at times. A fall of over 7° 

 in temperature from 20 h to 21 h . 



Oct. 5. — Strong S.E. gale all afternoon. At 22 1 ' and 



cloudless since, but fog on hills below 



23 h the anemometer registered 103 and 109 miles re- 

 spectively for the hours previous. 



Oct. 6.— The S.E. wind continued till 12 h , but 

 gradual^ fell in force. It backed to S. in the afternoon. 

 Top clear at and after 18 h . At 19 h brilliant flashes of 

 lightning were observed in the distance to W. and S.W. 

 In some of the flashes the distant clouds were seen as 

 dark sharply defined masses against an intensely bright 

 sky, from S.W. to N.W. Showers of hail fell in the 

 evening. 



Oct. 9. — At 17 h St Elmo's Fire was heard, and at 

 22 h it was seeu on the tower and chimneys. 



Oct. 13.— Severe S.E. and E.S.E. gale from 16 h till 

 22 h . At 19 h and 20 h it blew almost a hurricane. Except 

 for lifting some of the snow boarding from the roof, which 

 was easily replaced, there was no damage done. Heavy 

 rain, sleet, and hail fell at and after 22 h , but the rain- 

 gauge could not be changed till 23 h , when the gale 

 moderated to a squally S. and S.W. wind. St Elmo's 

 Fire was seeu at 18 h 30 m during the S.E. gale. 



Oct 16. — Summit clear till 3 h , but sky cloudy. At 

 2 h a lunar corona was seen. 



Oct. 18. — A lunar corona was seen at 5 h . 



Oct. 20. — Strong S.E. wind all afternoon, blowing a 

 gale at and after 19 h . St Elmo's Fire was seen at 23 h . 

 Brown fog crystals forming during the day. 



Oct. 22. — Summit clear at times to-day, but heavy 

 clouds all round, below and above. A glory and fog-bow 

 were seen at ll h 30 m . 



Oct. 23. — Summit clear most of the time up to 15 h , 

 fog thereafter. In the early morning the sky was almost 

 cloudless, but there was some fog and haze below, and 

 before the fog came on in the evening there were heavy 

 cumulus clouds all round. 



Oct. 24. — Showers of snow in the forenoon. Fog till 

 I7 h . Summit clear and sky cloudless thereafter. Aurora 

 seen at night. At 20 h there were bright streamers 20° 

 long, but no arch. At 21 h only a faint glimmer low in 

 northern sky. At 22 h two arches — the lower faint, the 

 upper bright ; no streamers. Approximate altitude of 

 top of upper 18°. 23 h bright single arch from W.N.W. 

 to N.E. 



Altitude (per Stephanome) of top of arch 13° 43'. 

 „ ,, base ,, 7° 36'. 



At midnight aurora in patches and streamers, ill-defined 

 owing to moonlight. 



Oct. 25. — Sky cloudless all day, except for a little 

 cumulus in afternoon. In the morning there was some 

 fog low clown over the lochs. Aurora seen at l h , 3 h , 4 h , 

 and at 23 h :— in the morning very faintly ; like filmy grey 

 clouds in the moonlight. At 23 h there was no arch,, 

 but some streamers were pretty bright. 



Oct. 26. — Summit clear most of the day : variable 

 amounts of cir. or cir.-s. on sky. A lunar halo was seen 

 at 4 h and 5 U . Faint aurora low to N. at midnight. 



Oct. 27. — Thin fogonsummitat times throughout theday, 

 but sky mostly cloudless. Haze and broken fog all around 

 below all day. Fog crystals forming at midnight. Lunar 

 corona? seeu in early morning, and auroras at l h and 20 h . 



Oct. 28. — Summit clear (except for a little fog at 6 h 

 and 7 h ), and sky cloudless all day. Lunar coronse seen 

 at 6 h and 7 h , and bright glories at 8 h and 9 h . Some haze 

 all round below, and in the forenoon some broken fog. 





