1900.] 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



275 



July 10. — Almost cloudless sky since 8 b . Fog below 

 all round in forenoon, but breaking up in afternoon, no 

 fog below after 17 b . 



July 11. — Fog came on after 2 b , but clear again after 

 13 h and air slightly dry. Sky almost overcast and a 

 considerable amount of fog around close to summit, which 

 was continually pouring over hilltop in the evening. 

 Mist and slight rain at midnight. 



July 12. — Summit clear at times tiU 19 h , sky almost 

 cloudless thereafter. 



July 13. — -Hilltop clear almost all day but sky very 

 cloudy. In early morning sky was half covered with 

 cirro-stratus moving moderately rapidly from S.W. till 3 h 

 and at 5 b from the S.S.E. Fog all round below to about 

 2500 feet till 6 h , then breaking up and finally disappear- 

 ing during forenoon. A lunar halo seen at l h and the 

 shadow of Ben Nevis at 4 b . 



July 15. — Summit clear at 4 U , the mist having sunk 

 below hilltop, leaving sky almost cloudless till 8 b , except 

 for a little cirro-str. above horizon to N. ; very cloudy 

 thereafter. Mist came on again after 20 h with showers 

 of drizzling rain. Glories and shadow of Ben seen at 4 h . 



July 27.— Summit clear since 3 h and sky cloudless, or 

 nearly so, till 10 b . Overcast since. Fog in valleys all 

 day and slight haze in distance to S. in the afternoon. 



July 31. — Cloudy or overcast till ll h and air dry. 

 Mist since with heavy showers of rain. Fog in valleys 

 during forenoon. 



Aug. 4. — Summit clear and air dry from 13 u to 18 b but 

 sky cloudy or overcast. Detached fog below rising at 

 times and passing over hilltop. 



Aug. 14. — Fog or mist until between 3 and 4 in the 

 morning. Cloudy from 4 h till 15 h , after which the sky 

 became cloudless. Fog below from 4 h onward. Hazy 

 from 7 h . Lunar corona seen from 22 b till midnight. 



Aug. 15. — The temperature was high all day and 

 reached 63°, being the highest recorded this year. The 

 sky was cloudless all day. Thick haze all day. Lunar 

 corona seen at 23 b and midnight. 



Aug. 18. — Mist or fog occasionally, but mostly clear, 

 with cumulus on sky. Glory seen at 5 h . 



Aug. 23. — Thunder was heard to-day and the telephone 

 showed the presence of earth currents, but the severe 

 thunderstorm experienced in some parts passed below the 

 summit of the Ben. 



Aug. 25. — Clear sunny weather most of the day with 

 detached fog around. Fog-bow seen at 18 h 45 m . 



Aug. 28. — Glory seen at 7 h : patch of yellowish white 

 light round head, followed by greenish blue passing into 

 yellow and pinkish red. Radius from centre to red 

 3° 24'. 



Sept. 7. — Lunar corona seen at 22 h ; 

 to red margin 2° 37'. A fog-bow was 

 time but no measurement was obtained. 



Sept. 8. — Glory and solar fog-bow seen at 6 h , but they 

 were too fleeting to measure. 



Sept. 11. — A number of lunar corona? and glories seen 

 to-day. Lunar Coronce. — At 2 h too fleeting to measure. 

 At 3 h radius from centre to red 4° 19'. At times a second 

 larger corona seen, of which, however, only an approximate 

 measurement was got; radius 7° 46'. At 22 h fleeting 

 lunar halo and fog-bow seen. Glories. — At 8 b double 

 glory — outer, showed in succession inwards red, yellow, 



radius from centre 

 seen at the same 



green, blue; radius from centre to circumference 6° 51'; 

 inner, red and yellow distinct, green and blue doubtful ; 

 yellowish white patch round head ; radius to red 2° 24'. 

 Double glory at 14 h . The cross bar of stephanome was 

 slack so that only rough measurements were obtained. 

 Colours in succession, red, yellow (green, blue) ; radius to 

 outer red 5° 57', radius to inner red 3° 44, radius to 

 yellow 2° 42'. All measurements taken from the centre to 

 periphery of the colour. Fog lay below all day and at 

 times rose and enveloped the summit. 



Sept. 12. — Fine, sunny weather all day and the air very 

 dry (humidity 38-57 per cent). Fog lay below all day 

 but never covered the summit. Lunar halo at 2 b . 



Sept. 13. — Air very dry to-day (humidity 29-59 per 

 cent.). Almost cloudless, but hazy, and fog in the valleys 

 below. Shadow of Ben seen at 5 h . 



Sept. 14. — Cloudless to-day, but hazy, and fog on 

 Rannoch Moor, etc. Earth shadow and shadow of Ben 

 Nevis seen at 6 b . 



Sept. 15.— Cloudless to-day, but very thick haze. 



Sept. 16. — Fog at times to-day, but mainly clear, sunny 

 weather. Shadow of Ben seen at 6 h and glories at 8 b 40 m . 



Oct. 3. — Thin fog or scud till lS h , cirrus clouds or 

 cloudless since. Lunar corona from 19 b to 23 h . Lunar 

 halo at 20 b and 21 h . 



Oct. 10. — Clear till 4 h , and again at ll h , fog or mist 

 during the rest of the day. Glories at ll h . 



Oct. 16. — Clear, sunny weather, with fog on horizon till 

 15 h . This was succeeded by cum. and cum.-str., which 

 gave place at 19 h to mist. Thermometer box changed at 

 h 15 m . 



Oct. 30. — Fog till 16 h , cloudless or cirrus clouds since. 

 Lunar halo seen at 19 h and 20 b . Thermometers changed 

 after 17 h . 



Nov. 1. — Temperature continued high to-day (range 

 37°-45°) and practically all the snow disappeared off the 

 summit. 



Nov. 2. — Temperature fairly high and very steady all 

 day. Mist all day and slight drizzle in evening. 



Nov. 3. — To-day a white ptarmigan was seen near the 

 Hotel. 



Nov. 4. — Clear, sunny weather to-day till 16 h , when the 

 fog which lay below all day rose and covered the summit. 

 Lowest humidity 48 per cent. Thermometer box changed 

 after 9 h . To-day a few snow-buntings were seen at 8 b 

 flying eastwards. 



Nov. 7. — Fog all day but clear at midnight. Lunar 

 corona at 22 b — radius of red (outside) = 2° 34'. At 

 times a second larger corona was seen, also with the red 

 outside, but no measurement of the latter was obtained. 

 At 23 h a double corona was seen — colours and radii as 

 follows : — 



Red = 4° 36'. 

 Green 



Red = 2° 55'. 

 Orange = 2° 20'. 

 Green 

 Blue 

 Violet 



White = 1° 36'. 

 The corona? were formed on fog. Measurement taken to 

 outside of colours. 



]y ov% 8. — A lunar corona and halo were seen at 2 b but 



