1890.] 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



225 



Oct. 1. — At 2 h rain was falling heavily, and while the 

 observer was on the roof, the hissing noise that accom- 

 panies St. Elmo's Fire was heard. Sparks of light were 

 seen on the pencil and other objects held up by the 

 observer, but not on the tower, chimneys, etc. Being 

 nearly full moon, it would not be easily seen at a distance. 

 A similar noise was again heard faintly at 12 h . 



Oct. 2.— Luuar corona seen at 5 h . Radius to outside 

 6= 7° 14'. Faint solar halo seen at 10 h . Temperature 

 rose rapidly at night, and heavy rain came on. 



Oct. 7. — A very small part of an aurora was seen at 

 20 h , but, owing to fog passing at the time, it was im- 

 possible to observe it properly. 



Oct. 8. — Summit clear and sky cloudless till 10 h , after 

 that overcast with cirro-stratus till 22 h , when fog came 

 on. Air very dry at 2 h . Fog lay in valleys and on hills, 

 but breaking up into detached portions to 1ST. and E. At 

 8 h haze was visible to W., which gradually spread all 

 round, obscuring view of hills on opposite side of Glen 

 Nevis, barometer rising rapidly in forenoon. Air very 

 clear to W. in early morning, Barra Head and Tobermory 

 lights visible at 4 h . 



Oct- 12. — Mist till 14 h , which then sank down about 

 300 feet below Ben Nevis, but continued to pass over 

 the hill top at times. Air dry for a few hours in the 

 afternoon. At 20 h mist came on again. 



Oct. 13. — Top clear occasionally in forenoon, but thick 

 fog lay over hills all round, and rose to a considerable 

 height above Ben Nevis. Air dry at 8 h . 



Oct. 15. — At 5 h , while observer was on the roof, St. 

 Elmo's Fire was seen on anemometer for a few seconds, 

 but was not visible on any other object. 



Oct. 16. — The thermometer box was shifted at 13 h 

 20 m . Height above snow 48 inches. 



Oct. 18. — Summit clear after 8 h . Sky partly covered 

 with cirro-stratus till ]8 h , and almost cloudless since. 

 Fog in valleys and at times passing over Ben Nevis till 

 19 h ; since then fog only visible on hills to W. and N. 

 Air very dry since 21 h . Humidity about 45 per cent. 

 A halo, but not well defined, was seen at 15 h . No 

 measurements were got. 



Oct. 19. — Sky almost cloudless till 3 h , but overcast 

 with cumulus till 9 h , partly covered with cirrus and cirro- 

 stratus till 21 h , and mist since. Haze in valleys and 

 cirro-stratus at horizon almost all day. Detached cum.-fog 

 lay over hills all round except to W., and at 20 h fog was 

 passing over the top of Ben Nevis. 



Oct. 21. — Continuous mist till 15 h , after which it sank 

 and covered all the lower hills to 4000 feet for the 

 rest of the day. Sky nearly overcast with cirrus and 

 cirro-stratus till 19 h , and almost cloudless since, except 

 for a little cumulus at midnight ; dew forming on ther- 

 mometer box at 23 h . 



Oct. 22.— Fog lay on hills all round to 4000 feet, but 

 sky half covered with cumulus till 3 h , after which the fog- 

 rose and enveloped the summit, only clearing off at times 

 till 14 h , but continuous mist since. At 10 h a portion of 

 a fog-bow was seen on upper surface of fog under Ben 

 Nevis. Radius, 30° 21'. Glories were also seen at ll h . 



Oct. 26. — Summit clear at 2 h , but sky nearly covered 



with cirro-stratus. At 3 h sky was perfectly cloudless, 



but detached cum.-fog lay on hills all round. At 4 h sky 



was overcast with cumulus-stratus, and fog passing. At 



EOY. SOC. TRANS. EDIN. — VOL. XLII. 



6 h sky was perfectly cloudless again, but fog came on 

 again at 7 h , and has been almost continuous since.. 

 Heavy snow fell all afternoon. A weasel was seen at 

 15 h passing between iron cage and thermometer stand,, 

 quite close to observer who was at the thermometer box. 



Oct. 27. — Sky overcast, or nearly so, with cumulus and 

 fog passing at times ; heavy layers of fog lying over 

 hills all round. Showers of snow fell at intervals 

 throughout the day. Dry and wet bulbs changed at 23 h . 



Nov. 3. — Top clear for several hours in forenoon, but 

 sky overcast and continuous fog on lower hills. St. 

 Elmo's Fire was seen at 21 h . A lunar corona was seen 

 at 6 h . 



Nov. 4. — Lunar corona seen at 5 h . A raven was seen 

 in the afternoon. 



Nov. 5. — Summit enveloped till 15 h , clear thereafter 

 and sky cloudless till 22 h , but overcast at 23 h and 

 midnight. At 4 h it was mist that covered the summit, 

 and an icy deposit was forming on all surfaces, though 

 the temperature was only 26° - 9. A glory having three 

 red rings was seen at 16 h . 



Nov. 6. — Thin mist, but very wet, on summit at 4 h , 

 depositing an icy crust to windward of things. The 

 raingauge was unworkable after 15 h , owing to the wind 

 and drift. It was taken in and not put out again till 

 midnight. 



Nov. 7. — Top clear from ll h till 17 h , and during some 

 of this time the sky was cloudless. Faint aurora seen at 

 19 h . Box shifted at 17 h 20 m . 



Nov. 11.— E.S.E. gale, force 8 to 11, till 2 p.m. 

 Wind continued from much the same direction during 

 the rest of the day, but with force below 6. The 

 barometer was falling irregularly and pumping wildly 

 till 2 p.m., but thereafter it rose rapidly. Dense fog 

 during storm, depositing brown fog-crystals. A great 

 crop on tower and ladders. There was no raingauge out 

 till 17 h . Apparently a little snow was falling in forenoon 

 and at 15 h and 16 h . Sky cloudless at midnight. Fog 

 around, below, and passing summit at times. Note on 

 hourly sheet, 13 h : — " Solid blocks of ice flying about." 



Nov. 13. — St. Elmo's Fire seen brightly at l h and 4 h . 



Nov. 14. — Very heavy drift about midday, forming 

 great wreaths about the observatory, and stopping the 

 raingauge measurements. 



Nov. 15. — Thermometer box shifted after 9 h . 



Nov. 18. — Solar halo seen at 9 h , 10 h , and ll h , and a 

 lunar halo at 18 h and 19 h . At ll h the following 

 measurements were made : — 



Radius, 20° 40' 48", 20° 20' 0", 20° 30' 12". 



Nov. 23.— Thermometer box shifted at 21 h 33 m . 

 Height above snow not altered. 



Nov. 25. — Top clear of all save passing fog from 9 h to 

 20 h , but cum.-fog on hills round. Thermometer box 

 shifted at 14 h 20 m . Height above snow not altered. 



Nov. 26. — At l h the temperature was 23°-l, and small 

 drops of rain were falling ; the top at the same time was. 

 covered with fog, not mist. Thermometer box shifted at. 

 14 h 15 m . Height above snow not altered. A double, 

 lunar corona was seen at 17 h . Air very dry at night, 

 sky cloudless, and no fog in valleys. Several snow bunt- 

 ings have been flying about the hill top for the last few 

 days, and to-day a weasel or stoat was seen, white iu 

 colour. 



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