414 



I'.KN NEVIS OBSERVATORY. — LOG-BOOK. 



[1892. 



Almost cloudless, and 

 Broken fog below all 



formed above and passed into str.-cir. and fell rather 

 quickly : at the same time the fog below gradually dis- 

 persed. At 15 h the str.-cir. stratum fell to, and enveloped 

 summit. Mist for the rest of the day. After the mid- 

 night observation the thermometer box was lowered one 

 step on ladder stand. 



June 7. — Clearing all forenoon, 

 temperature over 50" all afternoon 

 day. 



June 8. — Fog on summit from 5 h till 8 h and at 20 h 

 and 21 h . Cloudy during the rest of the day, except after 

 22 h when the sky cleared. Fog all round below in fore- 

 noon which gradually dispersed giving place to thick haze 

 in afternoon. 



June 9. — Summit clear except for thin fog passing for 

 a few hours in forenoon, but thick haze all round below. 



June 10. — At 5 h to-day fog was observed rolling up 

 from S.E. and E. At 6 h it was continuous all round 

 below 3000 feet. By 9 h it rose and enveloped summit 

 for the rest of the day. Rain began to fall after 15 1 !. 

 The temperature being below 32°, ice formed from rain at 

 night. At 8 a.m. the temperature was 47 o, 0, at 13 h it was 

 37°-4 and at midnight 30°-3, a fall of 16°-7 in 16 hours. 

 After 21 h to-day a set of thermometers was put out in 

 summer box No. 2 ; and readings were taken of both the 

 big and the small box on ladder stand till midnight. 



June, 11. — The readings taken of dry and wet in large 

 box No. 2 were entered on daily sheet. Readings of 

 instruments in small box on ladder stand were discon- 

 tinued after 2 h . Mist and fog with showers of snow in 

 morning, summit clear at times in afternoon. 



June 12. — Fog all day, except at noon, snow falling at, 

 and almost continuously after 6 h . St. Elmo's Fire was 

 heard at 15\ 



June 13. — Fog till 7 h , clear thereafter, but sky cloudy 

 or overcast. Air very clear. Visibility 3 to 4 when top 

 was clear of fog. ■ Slight passing showers of snow during 

 the day. 



June 16. — Fog in early morning and again at night, 

 cloudy with gleams of sunshine during the day. A fog- 

 bow was seen at 4 h . 



June 20. — Mist till 8 1 ', summit clear and air dry 

 during the rest of the day. Showers of sleet and snow 

 in morning, and passing showers seen all round in evening. 



June 21. — Summit clear and air dry all day. Detached 

 fog below in forenoon, and thick haze at night. 



June 22. — Fog or cloudy sky till 19 h , almost cloud- 

 less thereafter. Thick haze below in early morning, and 

 again at night. 



June 23. — Summit clear most of the day. Sky cloudy 

 in forenoon, and overcast or almost so in afternoon. 

 Thick haze below in morning. Almost calm all day. 



June 28. — Fog till 10 h , clear for the rest of the day, 

 but some haze below and cum. and cir.-s. on sky. 



June 29. — Haze and fog all round in forenoon. Clear- 

 ing in evening, and sky almost cloudless at night. This 

 evening the haze rose in a. layer clear of hills. 



July 2. — Fog below till 3 a.m.; mist on summit for 

 rest of the day, and heavy rain after 8 h . 



July 8. — Bright display of St. Elmo's Fire seen at l h . 



July 9.— Mist and drizzling rain at times till 21 h , 

 clear and almost cloudless thereafter. Hoar frost on 

 roof at midnight. 



July 10. — Summit clear till 23 h ; sky somewhat 

 cloudy, but air very clear especially in evening to W. 

 and N.W. To S.E., at and after 19 h , a bank of haze, 

 which floated above hill tops, was seen steadily advancing. 

 At midnight it was on summit and brought mist with it. 

 Formation of cumulus from rising columns of mist and 

 air in forenoon was well marked to-day. 



July 11. — Thick mist in early morning. Clear at 

 and after 6 h , but thick haze, and at times fog below 

 all round, and sky somewhat cloudy with cumulus 

 during the afternoon and cir.-s. after 18 h . 



July 12. — Summit clear except for some mist passing 

 in morning. Cir. and cir.-c. on sky. Air dry at and 

 after 8 h , but broken fog on hills most of the day. At 

 midnight the sky was cloudless, and a veil of auroral 

 streamers converging in a point to S.E. of zenith filled 

 the whole sky except to S. and S.E. 



July 13. — The aurora noticed at midnight, last 

 night increased in brilliancy till U 30 m , when it was 

 very bright. It continued bright and active till h 45 m , 

 but thereafter gradually faded away, and at l u there 

 was only a trace of it left. Fog on N. and E. hills all 

 day. After 20 h it was continuous all round below 

 3000 feet. Sky almost cloudless all day. Air very 

 dry in early morning. Humidity gradually increased 

 in evening. At 23 h and midnight pearly cirrus was 

 seen about 10° above N.E. horizon. At 23 h 30 m while 

 watching the pearly cirrus, streaks of aurora were seen, 

 and the cirrus seemed behind these. Spectrum bands 

 seen in N. horizon at night. Photograph taken of 

 these and of the pearly cirrus. 



July 14. — Pearly cirrus continued visible till 2 h . 

 Sky cloudless till 9 h , but fog below in every direction, 

 which, after 9 1 ', rose and enveloped summit till 18 h ; 

 thereafter lifting clear of hills, forming an overcast sky 

 above, and no fog below. 



July 15. — Top clear almost all day, but sky over- 

 cast with cum. and cum.-s. Dew noticed at 3 h . 



July 20. — Mist till 10 h . Top mostly clear after that 

 and visibility great ; but detached patches of fog among 

 -hills after 19 h . 



July 21. — Air very dry in early morning, but sky 

 cloudy. Mist and drizzle in evening. 



July 23. — Mist cleared off at 4 h , but sky was partly 

 covered with cirrus and cumulus all day. Fog covered 

 the hills round at 4000 feet till 8 h , and then broke up 

 remaining as detached fog among hills all day. 



July 24. — Faint pearly cirrus seen at l h . Low lying 

 fog over Loch Lochy, Locheil, and other sheets of water 

 till 6 h . Fog hanging about the hill tops most of the 

 day and considerable haze. Fog also gathered over the 

 Atlantic at 22 h and gradually extended among hills to 

 northward at almost 3000 feet. Pearly cirrus seen at 

 23 h and midnight, bright, but not extending to more 

 than 10° elevation. 



July 25. — Pearly cirrus seen at l h . Fog lay in valleys 

 to northward at 3000 feet till ll h , at noon fog was 

 blowing over Ben Nevis, and haze and detached cum.- 

 fog continued all round during the day. At 23 h the 

 haze thickened into fog on summit. Portion of solar 

 halo seen at 13 h . 



July 26. — Glory seen at 6 h . The 17 h observation was 

 taken 6 minutes late ; no correction applied to readings. 



