352 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



[1887. 



was clear from 10 h till 13 1 ' after which the fog came on 

 again. 



Oct. 14. — At 22° and 23° an aurora was observed. It 

 had no streamers. 



Oct. 15. — The fog cleared away at noon, but lay on 

 surrounding hills, its upper surface being about on a level 

 with the summit. On it, at 14 h , were observed a double 

 fog-bow and glories, of which no measurements were 

 obtained. A solar corona was seen at 14 h 10 m , and again 

 at 16 h 10 m , triple each time. The following measurements 

 were recorded : — 



O Red 1 



14 h 10 m . 





16 h 10 m . 



Red 2 



Red 3 



Q Red 1 Red 2 



2° 20i' 





2° 6' 3° 35' 



Red 3 



Oct. 16. — After 4 b the fog rose and enveloped summit, 

 but cleared down again after 16 h , leaving a clear top for 

 the rest of the day. The air was very dry after 20 h . 

 Robinson's anemometer was set agoing at 14 h , and worked 

 well for the rest of the day. 



Oct. 17. — Thecum.-fog that lay in valleys in early morn- 

 ing gradually rose, and as mist began to pass the summit 

 at 7 h completely enveloping it at 10 h . At 19 h Robinson 

 had to be tied up. 



Oct. 18. — Robinson was let loose at 9 h . 



Oct. 19. — Robinson was tied up at 20 11 . 



Oct. 21. — The fog cleared away at 10 h , and the summit 

 remained clear till midnight. Till 14 h the thermometer 

 box and the thermometers had a coating of hard snow on 

 them; after that hour they were cleared. A feeble 

 aurora was clear at 22 h . 



Oct. 23. — Mist and fog covered the summit all day 

 except at 20 h and midnight. At the latter hour a faint 

 glimmering light, probably auroral, was seen to northwards. 

 At 9 m the anemometer (Robinson's) was tied up, having 

 been working since 13'' yesterday. 



Oct. 26. — Glazed-frost or a coating of ice formed on 

 all exposed surfaces all forenoon. At 22 h the anemometer 

 (Robinson's) was let loose. 



Oct. 28. — A flash of lightning was seen at l h 7 m , as the 

 anemometer was being tied up. A very heavy shower of 

 snow and snow-hail fell during a squall that began at 3 h 

 27 m and ended at 3 h 33 m . At 4 h the rain-gauge recorded 

 0-335 inch. 



Oct. 29.— At l h 5 m St Elmo's fire was seen in jets 3 

 to 4 inches long on every point on the top of the tower 

 and on the top of the kitchen chimney. Owing to the 

 number of jets on each cup of anemometer, this instrument 

 was quite ablaze. On the kitchen chimney the jets on 

 the top of the cowl were vertical, and those on the lower 

 edge of same horizontal. The fizzing noise from the 

 different places was very distinct. While standing on 

 office roof watching the display, the observer felt an 

 electric sensation at his temples, and the second assistant 

 observed that his (the observer's) hair was glowing. While 

 standing erect the sensation and glow lasted, but on bending 

 down they always passed off. On raising the snow-axe a 

 little above his head a jet 2 to 3 inches long shot out at 

 the top. At l h 15 m the fire vanished from every place at 

 the same instant. A shower of snow and snow-hail 

 (conical) was falling at the time, and the wind was a 

 variable S. to S.W. breeze — very flawy. (The measure- 

 ments of length of jets were only roughly estimated; the 

 jets on kitchen chimney varied from 3 to 6 inches approxi- 



mately). At 19 h St Elmo's fire was again seen. At 21 h 

 25 m the thermometer (ladder-stand) box was shifted, 

 the hinge of the box door having fouled, and the louvres 

 being choked with hard snow. 



Oct. 31.— From 16 h till 20 h the summit was clear. 

 At 20 h a lunar corona was seen. At 23 h the rain-gauge 

 was covered with drifted snow, and could not be found. 



Nov. 1. — The rain-gauge was found at 5 h and brought 

 in, and was not put out again till 19 h . 



Nov. 2.- — In afternoon it was observed that the snow 

 crystals forming from the fog were slightly brown. 



Nov. 3. — The rain-gauge was not shifted at 4 h , 5 h , and 

 6 h , owing to the heavy drifting at these hours. 



Nov. 4. — At l h the summit cleared, leaving amount 5 

 of strato-cirrus on sky, which moved quickly from E.N.E., 

 and retreated slowly towards N.W. ; its southern limit was 

 sharply defined. At l h 20 m the thermometer box was 

 shifted. The road is now quite impracticable for horses. 



Nov. 6. — At l h , 3 h , and 4 h a lunar halo was observed. 

 At 4 h there were apparently four distinct cloud-strata, viz., 

 beginning with the lowest: — 1st, cumulus-fog on hills; 

 2nd, cumulo-stratus and scud moving quickly from east- 

 ward; 3rd, cirro-cumulus moving from (S.E. ?) slowly; 

 4th, cirro-stratus pallium with halo moving from 

 (S.S.E 1). 



Nov. 7. — The barometer was pumping wildly almost all 

 day. The measurements of amount of snow to-day are 

 very doubtful, owing to drift. 



Nov. 9. — A lunar corona was seen at 4 h . The ther- 

 mometer box was shifted after the 4 h observation ; its 

 height above the snow was not altered. Thin fog was 

 passing the summit occasionally in the forenoon, but 

 during the afternoon the summit was clear and the sky 

 cloudless. An aurora was seen at night, faintly at 8 h and 

 9 h , but with well-defined streamers at midnight. 



Nov. 10. — Fog was observed on eastern hills at l h , 

 which gradually crept westwards till by 7 h all the sur- 

 rounding hills were covered. From 7 h till 10 h it brushed 

 past the summit at times, but after 10 h and for the rest of 

 the day it enveloped the Ben, breaking, however, at times 

 overhead, showing a clear blue sky above. As this fog 

 came up to the Ben, the air temperature became very 

 unsteady. 



Nov. 11. — Fog on summit till 13 h , sinking thereafter to 

 about 4000 feet, leaving Ben clear for the rest of the day. 

 At 1 4 h a glory was seen on fog in the corrie to northwards. 

 A pink afterglow was observed from 16 h 45 m till 17 h . 



Nov. 12. — Fog began to blow over summit at 9 h , and 

 settled thereon after 12 h . At 9 h a glory was observed, and 

 measurements of its red rings were obtained, viz. : — 



Bed 1 , 

 Red 2 , 

 Red 1 , 



From 20 h till 23 h the summit was clear, but the sky 

 was overcast with thin stratus. 



Nov. 13. — To-day began with a clear top, but an over- 

 cast sky of thin stratus. Fog came on at 4 h and lasted 

 till 8 h , and was passing summit at times till 14 h . A fog- 

 bow was seen at ll h 20 m and a glory at 15 u . The follow- 

 ing measurements of red rings of glory were obtained, viz.: — 

 Red 1 , 0° 53'; red 2 , 1° 50'; and red 3 , 3° 46'. An aurora was 

 sun at 20 h , 22 h , and 23 h . At 22 h 20 m it broke up into 



(!)• 



(2). 



2° 46' 



2° 53' 



4° 41J' 



4° 31' 



