140 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



[1889. 



sides. The sun was seen at 3 h 25 1 " rising above the hills, 

 and shining through the fog ; after it was about 2° up, it 

 passed behind a bank of haze which was lying clear of 

 and above the horizon to N.E., and was almost com- 

 pletely hid by it. The sun did not begin to record till 

 8 h . Dew again formed at 23 h and midnight. 



July 6. — Fog lay among and over most of the hills 

 round till noon, after which it rose forming cum.-fog all 

 round Ben Nevis and cum.-clouds overhead, and from 15 h 

 onwards the hill top was covered with fog or mist. 

 Haze above the fog all morning. 



July 7. — From 20 h onwards the roof of observatory, 

 and most of the ground was white with snow. 



July 12. — After 2 h the fog sank, leaving the sky clear, 

 but covering all the hills round and occasionally blowing 

 across Ben Nevis also. The sky soon became overcast 

 with low cumulus, and continued so most of the day, 

 while the fog, though not thick, continued to hang about 

 the hill top. After 19 h glories were seen on fog to S.E., 

 rather misty and badly defiued. Two and occasionally 

 three sets of colours — clear space between 1st and 2nd 

 Radius of first red . . 1° 30' 



Radius of second red . . . 6° 2' 

 Other colours were very faint. 



July 15. — Top clear after 18 h , but thick rolling fog 

 over all the hills round, and passing over Ben Nevis also 

 at times. 



July 16. — Detached patches of fog among hills till 6 h , 

 and fog or mist blowing across Ben Nevis most of the 

 day afterwards, but occasional very clear views to S. and 

 "W. At 10 h a rainbow was seen to N.W., the highest 

 part being rather lower than the top of the Ben. Near 

 the top of it there was a dark gap in the bow. 



July 17. — Earth currents in telegraph cable from 10 h 

 to 12 h , deflection usually to right side, that is, a current 

 up the wire. At the time mist was changing to fog. 



July 18. — Shortly before l h the fog sank leaving a 

 cloudless sky, but still covering all the hills round except 

 a few of the highest peaks. This continued till 6 h , when 

 the fog again rose and covered Ben Nevis also for the rest 

 of the day. The sun was first seen at 3 h 55 m rising 

 above the fog. The first glimpse was green. 



July 21. — Top clear but haze and fog all round till 

 13 h , and after that mist on the top of Ben Nevis. No 

 sunrise, the haze hiding the sun's disc. A glory was seen 

 between 10 h and ll h , and a halo at 12 h . 



July 23. — Fog hanging about the hill all day, but 

 clear views through breaks. Short heavy showers of rain 

 and hail fell in afternoon. A rainbow was seen at 19 h 

 and 20 h . 



July 26. — Mist till 5 h after which top clear, but sky 

 cloudy, and no fog below till 18 h , when the clouds sank 

 and fog covered the top till 21 h , after which the sky was 

 cloudless, but fog covering all the hills round, and 

 occasionally blowing across Ben Nevis also. 



July 27.— Fog on hills to about 4000 feet till 5 h . 

 The sun was first seen above this fog at 4 h 10 m . The 

 sky remained cloudless till 9 h , when cirrus began to 

 appear. Fog again gathered on the hills at from 2000 to 

 3000 feet, beginning to W. at 19 h , but spreading all 

 round. A bright mock sun was seen at about 19 h 30 m , 

 coloured red next sun, and blue outside. 



July 28.— Fog on lower hills to about 3500 feet till 



4 h , after which it rose and covered Ben Nevis also, 

 hardly breaking again all day. As soon as the fog rose, 

 the wind, which had been blowing 20 to 25 miles per 

 hour, fell considerably. Up to 4 h the sky was overcast, 

 but the air very dry. Sunrise colours very bright. Sun 

 first seen at 4 h J l m . Earth shadow seen before sunrise. 

 The observations at 13 h and at midnight were each 3 

 minutes late. The following observations were taken by 

 Sling Thermometer : — 



At 15 h 5 m on roof 44°'7 



Dry bulb at 15 h 44°-9 



At 15 h 58 m on plateau at foot of M'Lean's Steep . 43°'8 



At 16' 1 7 m on plateau of Storms in line of posts . 43° *8 



Dry bulb at 16 h 42°-9 



The fog was much thicker down on the plateau than on 

 the top of the hill. 



July 29. — Mist till 3 h , after which it sank, covering 

 hills to 4000 feet or more all round till 8 h , when it rose 

 again over Ben Nevis also. Sky overcast with cum.-str. 

 all this time, but air dry, the humidity at 6 h being 53, 

 and at 7 h 52. Sunrise colours bright. Sun seen at 

 4 h 16 m . Mist and fog continued on or about the hill top 

 till 20 h , after which it sank, lying over the hills in 

 detached sheets at 3000 or 4000 feet height, and the 

 sky cleared. 



July 30.— Fog over all hills round at 4000 feet till 4 h , 

 after which it rose and blew across Ben Nevis also, and 

 continued to hang about the hill till 13 h . In the 

 afternoon haze gathered to the S.W., and after 21 h fog 

 was again blowing across the hill top. The sun was first 

 seen at 4 h 12 m . Before sunrise the earth shadow was 

 observed. At 4 h 25 m the shadow of the observatory was 

 seen on a fog bank to S.W. Very red glories were 

 formed on this fog. Three sets of colours, but none 

 distinct except the reds : — 



Radius of red 1 too small to measure. 

 red 2 ... 1° 20' 

 red 3 ... 2° 42' 



July 31. — Thick haze all round all day, and occasion- 

 ally very light fog blowing across the hill top. 



Aug. 2. — Mist till 23 h when it cleared off leaving sky 

 overcast, and low lying fog among the hills round. 



Aug. 3. — Cloudy sky and fog lying among the hills 

 round till 4 h , after which fog or mist covered Ben Nevis 

 also, which continued with only a few short breaks all 

 day. 



Aug. 8. — Sky cloudless, but stratus near horizon till 

 5 h , and covered with variable amounts of cumulus during 

 the rest of the day. Cumulus fog lay on the lower hills 

 in forenoon, and shower clouds in afternoon, on which a 

 rainbow was seen at 14 h . Cirrus was observed at 20 h ; 

 its radiating points were W.N.W., E.S.E. Hoar frost 

 on roof in early morning. A glory was seen about 

 18 h 30 m . 



Aug. 10. — Summit clear at times during the day ; but 

 sky overcast or nearly so, chiefly with nimbus. A lunar 

 corona was seen at l h . 



Aug. 14. — Summit clear at times in afternoon. Be- 

 tween the hours of 14 and 20, inclusive, only 1 mile of 

 wind was recorded by the anemometer. 



Aug. 18. — Showers of hail and sleet fell this morning, 

 as well as heavy showers of rain. 



Aug. 19. — Summit clear at times in evening, but sky 



