92 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



[1893. 



by 19 h ; at and after 21 h it was calm. Temperature very 

 steady to-day, 41° to 45°. 



June 7. — Mist or fog almost all day. In the clear 

 intervals the sky was observed to be heavily overcast, and 

 there was thick haze all round, and broken patches of 

 fog on lower hills. 



June 8. — Mist in early morning and a little fog in 

 evening. Sky almost cloudless in forenoon, but heavily 

 clouded with cum. and cum.-s. in afternoon. Thunder 

 was heard in distance from 19 h to 20 h , and a heavy 

 shower of rain fell between 20 h and 21 h . Thick haze all 

 around all day. 



June 9. — Summit clear till after 22 h , when a thin dry 

 fog which did not saturate the air hung about the hill top. 

 In the early morning (till 4 h ) the sky was almost cloudless, 

 and thick haze was all around and below. There was 

 also low in the valleys a layer of stratus fog. In the 

 course of the forenoon this fog rose gradually in large 

 cumulus masses, and by 14 1 ' it was clear above the hills. 

 The haze which it left behind in valleys was not so thick 

 as the haze in morning. In the evening the cum. layer 

 gradually sank again, passing the summit downwards at 

 18 h , 19 h , and 20 h . At 21 h the sky was almost cloudless, 

 the cumulus being all below level of summit. At 22 h , 

 23 h , and 24 h fog hung about the top. 



June 10. — Cum. fog all round below and hanging about 

 hill top, and occasionally enveloping it till ll h . There- 

 after the clouds rose clear of hills, leaving haze, but no fog 

 in valleys. The cum. clouds above all but vanished by 

 20 h , but a stratum of cum.-s. came up from S.E. thereafter 

 and covered sky at 21 h and 22 1 '. This also soon vanished, 

 and at 23 h and midnight the sky was cloudless, except at 

 and near horizon to E. and S. Spectrum colours in N. 

 sky all night. At midnight a distinct slightly pinkish 

 afterglow filled the N. sky above the spectrum colours — 

 20° to 45° altitude. 



June 11. — Summit clear all day, except for a little fog 

 at 9 h . Sky cloudless till 4 h , but cloudy during the rest 

 of the day, with various forms of cum. All evening the 

 cum. clouds were of the real summer type, large piled-up 

 masses that looked very grand. Haze below all day, 

 which thickened after 17' 1 so much as to reduce visibility 

 to 0-1. At the same time cum. began to form in it 

 below level of summit. From 20 h the general appearance 

 all round was gloomy and thundery. 



June 12. —Summit clear, except for a little fog passing 

 at 17 h . Sky only slightly clouded till 8 h , and cloudless 

 after 22 h , but heavily clouded during the rest of the day, 

 with heavy, thundery-looking cum. types. Thick haze all 

 round all day. Showers of rain fell in evening. Distant 

 thunder was heard in various directions from 14 h 45 m to 

 19'', but no lightning was seen. 



June 13. — Cloudless till 6 h , cloudy till 10 h , and heavily 

 clouded sky with thundery cumulus till 19 h ; cloudless again 

 at night. Thick haze below and all round all day, with, 

 in early morning, low str. fog on lochs and river courses. 

 Distant thunder was heard from 13 h till 17 h , but at 18 1 ', 

 and till 18 h 20 m , the thunder cloud rested on summit, 

 when several peals of thunder were heard close overhead 

 and the lightning was very vivid. The last flash of light- 

 ning seen came into the Observatory, and a loud report 

 was heard in office. The same flash affected the telegraph 

 wire and fused the faces of the lightning protector plates. 



The same thing was done by the same flash at Fort- 

 William. 



June 14. — Sky almost cloudless till noon, slightly 

 clouded during the rest of the day. Fog low down in 

 some valleys and on lochs and rivers in forenoon, rising 

 later on, and by noon the valleys were clear. Thick haze 

 all around all day. 



June 15. — Sky slightly cloudy in forenoon, but almost 

 overcast all evening. Thick haze all around all day, and 

 low fog to E. and S. in forenoon. Solar halo seen at 16 u . 



June 17. — Sky cloudless almost all day. Thin fog 

 passing till 7 U . Air dry during the rest of the day. 

 Cum. fog all round below till 18 h . Thereafter it dis- 

 appeared ; but at 20 h low str. fog was observed on 

 Atlantic about Mull. This gradually crept eastwards, 

 and by midnight there was a low stratum of fog below 

 1000 feet in valleys in every direction. Air much clearer 

 to-day than during last week, the visibility being 3, 

 though there was a thin blue haze all over the hills. 



June 18. — Sky cloudless till 22 h . Fog in valleys or 

 hanging about the hills most of the day. This fog in 

 early morning was a low str. stratum in valleys ; later in 

 forenoon it gradually broke up into cum. type, but did 

 not rise higher than level of summit. This cum. type on 

 sinking in evening gradually disappeared except to N.E. 

 and E. (where the cum. continued to form and rise); 

 but a fresh stratum rolled in into all valleys from W., as 

 it did yesterday, but more quickly. After 21 h this 

 stratus fog gradually rose, and at 22 h it was passing 

 summit. At 23 h and midnight the sky was overcast 

 with cum.-s., and the fog below was broken up into 

 detached patches. Very little haze all day. Temperature 

 high all day, all except the miduight reading being above 

 50°, and from 9 h till 18 h it was above 60°. Calm or 

 almost so till 21 h , when a northerly breeze set in. 



June 19. — Sky almost cloudless till 5 h , but mist or fog 

 in valleys, which rose and covered summit ; also from 6 h 

 till 14 h . The fog cleared after that, and the sky 

 gradually became cloudless, till at 22 h a stratum of fog 

 came up from W. all over the country to level of summit, 

 which at midnight it covered also. Solar halo seen at 

 16 h . Temperature falling all day; at midnight it was 

 35°T. 



June 20. — Fog on or passing over summit all day. 

 Till 8 h it was of a misty nature, but thereafter it became 

 a dry fog. The stones of hill top were quite dry all day, 

 and from 9 h till midnight the hygrometer indicated a 

 slight dryness of the air. 



June 21. — Top cleared after 2 h , and sky was pretty 

 clear till after 4 h , but haze and broken fog below all 

 round. After 4 h , and during the rest of forenoon, fog 

 hung about the hill top. It rose clear of summit in 

 afternoon, but came down again after 19 h . Although a 

 thin fog was frequently on hill top to-day, the air 

 remained slightly dry. 



June 22. — Calm all forenoon, with mist and drizzling 

 rain, and temperature ranging from 36° to 39°. After 

 noon the temperature began to fall, reaching 32° at 18 h , 

 and 30° at miduight. Heavy rain accompanied the fall 

 of temperature till 15 h , when it changed into snow and 

 sleet, which fell heavily during the rest of the day. 



June 26. — Summit cleared in afternoon, aud till 22 h 

 the air was very clear in all directions (V. 4) ; but the sky 



