1888.] 



BEN NEVIS OBSERVATORY.— LOG-BOOK. 



73 



rising from behind the hills to N.E. without cloud or fog. 

 No upper glow, the sky being cloudy, but earth shadow 

 before and Ben Nevis shadow after sunrise as usual. 



July 20. — Very thick haze all round all day, until fog 

 came on at night. Faint upper glow seen at 3 h 25 m . Sun 

 first seen at 3 h 49 m , rising above hills and shining through 

 dark haze. 



July 21.— Thunder was heard at 8 h 45 m and at 9 h 15 m , 

 but no lightning was seen. When clear of mist in the 

 afternoon the other hills round were mostly covered with 

 cum. fog rising up to and meeting the cumulus clouds 

 above. 



July 24. — Top clear for a few hours in forenoon, but 

 fog all round. At 10 h a solar halo was seen. 



July 25. — Top clear in afternoon and at night, but cum. 

 fog on hills round till about 20 h , after which it cleared to 

 W. Fog began to form in the valleys to N. after sun- 

 set. N. horizon faintly red at midnight. 



July 26. — Fog lay all round except to S. to about 

 3000 feet in early morning. Sun was just seen over this 

 at 4 h 5 m . No upper glow, earth shadow, or Ben Nevis 

 shadow, owing to the sky being covered with cumulus. 

 About 9 h the fog rose higher, covering Ben Nevis, and 

 continued to hang about the hill top all day. A heavy 

 shower of rain and hail came on at 17 h 50 m , evidently 

 thunder rain ; showers and drizzle fell from then on to 

 midnight. 



July 27. — Thin fog, with the moon occasionally seen 

 through it till 4 h , after which it sank and lay covering 

 almost all the hills round to about 3000 feet till 8 h , after 

 which it rose again and covered Ben Nevis also. The sky 

 from 5 h to 8 h was cloudless overhead ; though the fog 

 lifted sometimes again, the sky was always cloudy. 



July 29. — In the early morning the ground was all 

 white with freshly fallen snow. In early morning, hard, 

 icy, white fog crystals formed on all exposed surfaces. 



July 30. — Top clear in early morning, but detached 

 masses of fog on all the hills round. In afternoon, view 

 clearer, but passing showers seen. About 18 h one passed 

 over Ben Nevis, where it fell as snow (temperature 33 '9), 

 but immediately afterwards a rainbow was seen on it, with 

 all the usual colours quite bright. 



July 31.— Thin fog in early morning, with moon shin- 

 ing through it. The top cleared about 10 h , and remained 

 so, though with a cloudy sky above, till about 18 h , after which 

 thin fog came on. Great visibility all afternoon — the 

 Beauly Firth, with the Black Isle beyond, South Uist, 

 Barra, and the N.E. coast of Ireland were all visible 

 at the same time. The Irish coast showed as a faint 

 line of land between Islay and Cantire. 



Aug. 1. — Thin fog in early morning, but clear, or nearly 

 so, from 10 b onwards. Heavy masses of cum. fog hung 

 about the hills round during the day, and many passing- 

 showers were observed ; two of these fell on Ben Nevis as 

 slight snow showers. 



Aug. 2. — Sun just seen at 4 h 15 m . 'Earth shadow seen 

 before and Ben Nevis shadow after sunrise as usual. At 

 4 h , fog on hills to E. and low down on Moor of Rannoch. 

 A broad and ill-defined solar halo was seen at 8 h , formed 

 on cirrus clouds. 



Aug. 4. — Top cleared about noon. No fog in valleys, 

 and air clear all round but sky overcast. At 19 h the 

 ground was sprinkled with snow. 



ROY. SOC. TRANS. EDTN. — VOL. XLII. 



Aug. 5. — Top cleared about 10 h . No fog in valleys, 

 but air not so clear as yesterday, there being a little haze, 

 especially to S. The sky remained covered with cumulus 

 which about 19 h sank down and enveloped the hill top. 



Aug. 6. — Top clear from 8 h to 14 h , but sky overcast 

 with cir.-s., and fog on all hills round. 



Aug. 10. — Top cleared in early morning, but detached 

 masses of fog lay over most of the hills round. A solar 

 halo was seen at 8 h and 9 h . Horizon hazy all day, and 

 fog again at night. 



Aug. 13. — Ground sprinkled with freshly fallen snow 

 at and after 20 h . 



Aug. 14. — Top clear and sky overhead cloudless at 

 23 h and midnight, but fog on all the hills round, and 

 clouds, mostly roll.-c. at horizon. 



Aug. 15. — Fog on the hills round and blowing across 

 Ben Nevis also till about 1 h . Air very clear in afternoon, 

 especially to N. and W. The Outer Hebrides seen. Sky 

 cloudless at night and no fog in valleys. 



Aug. 16. — Aurora, single arch, no streamers seen, at l h , 

 2 h and 3 h . From 3 h to 9 h level-topped fog on hills to N. 

 and E., at about 3500 feet. The sun was first seen rising 

 above this fog at 4 h 46 m . The upper glow was seen about 

 half-an-hour before sunrise, and the earth shadow before 

 and Ben Nevis shadow after sunrise as usual. Hoar frost 

 on roof all morning till 6 h . Air not so clear as yesterday. 

 Cumulus fog rising above hills, and forming cumulus clouds 

 in afternoon, but sky quite cloudless at night. The sun 

 was last seen at 20 h 6 m . The earth shadow and upper 

 glow were seen after sunset. Aurora, similar to that seen 

 in morning, but slightly higher above the horizon, seen at 

 midnight. 



Aug. 17. — Aurora, single arch, no streamers, seen at l h 

 and 2 h . At 3 h , fog beginning to form on hills to N. 

 Continuous str. fog on hill tops all round from 4 h to 7 h , 

 and detached fog till 10 h . Sun first seen at 4 h 49 m . 

 Upper glow and earth shadow before sunrise as usual. 

 Shadow of Ben Nevis seen on the fog to S.W. At 5 h no 

 trace of glory round it. Loose cum. fog floating about 

 in afternoon. Slight haze at horizon most of the day, 

 but occasionally quite clear to W. South Uist seen 

 faintly. No fog in valleys at night. 



Aug. 18. — From 4 h to 8 h , thick-looking fog lay over 

 almost all the hills round at about 4000 feet. At 4 h 25 m 

 not a single peak was visible above this fog to S. Heavy 

 dew on everything in early morning. The upper glow 

 and earth shadow were seen before sunrise and after 

 sunset. After 8 h the fog on the hills got broken up into 

 detached portions, and formed towards the middle of the 

 day cumulus clouds, but thick haze hid everything except 

 the nearest hills all day, and turned into thin fog at night. 

 Dew was again observed on the thermometer box at 22 h . 



Aug. 1 9. — Faint haloseen at 7 h , the part to N. of sunmost 

 distinct. Mock sun seen also to N. of sun at same height 

 above horizon. Distance from sun (rough measurement), 

 119° 8'. (Evidently the 120° mock sun on horizontal 

 circle.) Thick haze all day, passing into fog and mist at 

 night. 



Aug. 23. — From 16 h till midnight a strong gale from 

 S.S.E. and S.E. blew, the anemometer recording velocities 

 of 70 miles between 18 h and 19 h , 73 miles between 19 h and 

 20 h , and 74 miles between 20 h and 21 h . During the storm 

 the wind was very squally. 



K 



