II 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



[1894. 



May 17.— Fog lay among the hills to N. till 8 U after 

 which there was little or no fog among the hills, and the 

 air to W. was very clear, the outer Hebrides being clearly 

 seen. The N. horizon was red all night. At 16 b the wet 

 bulb was dry and the value for that hour was interpolated. 



May 18.— Dry and wet bulbs shifted at 3 h 8 m . Box 

 not shifted. The shadow of Ben Nevis was clearly seen 

 after sunrise at 4 h . Fog lay in the valleys to N. till 8 h 

 after which it broke up. Some cir.-s. and cum. near 

 horizon all day, but at 19 h fog came on summit suddenly. 



May 22. — Earth shadow and Ben shadow well seen at 

 sunrise. At 5 h some glories seen in passing fog on summit. 

 Fog lay on Rannoch Moor at 3 h and 4 h , and light fog was 

 blowing over the summit from 5 h to 10 h ; after that haze, 

 rising higher than the summit, surrounded the hill. 



May 24. — Cirrus and cir.-str. gradually overspread sky 

 from the North. Solar halo seen at all hours from 6 h to 

 17 h . Considerable haze all day. Wet bulb dry at 15 h , 

 and value in daily sheet interpolated. 



May 25. — Solar halo seen at ll h . When top was 

 clear in afternoon there was no fog below. 



May 27. — Thermometer box shifted at 7 h 10 m . Height 

 above snow not altered. 



May 29.— Thermometer box shifted at h 15 m . Height 

 above snow not altered. Fog on or passing almost all 

 day. St Elmo's Fire heard and felt at 14 b , and just before 

 14 h hail came on, but it changed to small hard snow, not 

 like the ordinary St Elmo snow. 



May 30.— St Elmo's Fire heard and felt at 15 h . It 

 appeared to be stronger than yesterday, but on neither 

 occasion was there any strong current in telegraph cable. 

 Heavy shower of ordinary snow after 15 h . 



May 31. — At 16 h there was a fall of conical snow like 

 St Elmo's snow but no sounds were heard, so the dis- 

 charges if present must have been faint. 



June 2. — Two ravens seen at 6 h . 



June 6, — Solar halo seen from 5 h to 9 U . 



June 7. — Masses of fog lay among the hills and oc- 

 casionally covered Ben Nevis also till 9 h , after which it 

 rose forming cumulus clouds and leaving the air clear 

 below. As the clouds sank again towards evening a slight 

 shower of rain fell about 18 h , but no measurable quantity 

 was got in gauge. At 23 h a bank of fog at about 4000 feet 

 height rilled the valley to N. A mouse was seen at the 

 observatory doorway at ll h . 



June 13. — Summit cleared about l h by mist sinking 

 down and dispersing, It lay in detached masses among 

 the hills most of the day and from 14 h to 17 h cum.-fog 

 rose up the S.W. side of Ben Nevis in great masses. 

 After 18 h fog lay over the Atlantic and the Western hills 

 about as far as the head of Loch Shiel. It seemed to be at 

 about 3000 feet height. Cirrus gathered to West and 

 X.W. after 21 h . Air very clear all day, no haze. 



June 14. — Great masses of stratus fog lay among the 

 hills at about 3000 feet till 8 U , after which they rose 

 slightly and the clouds that had gradually formed over- 

 head sank down and mingled with them. Mist in Ben 

 Nevis almost continuously from 9 h onwards, but there 

 was no fall of temperature when it came on. 



June 15. — Thermometer box lowered one stage on 

 ladder stand No. 2 at h 5"'. 



June 18. — Strong display of St Elmo's Fire at 2 h . 

 It was too light to see anything but the hissing noise was 



very loud especially from the objects on the tower. 

 Ordinary snow was falling heavily at the time. 



June 21. — Detached fog gathered among the hills in 

 early morning, first seen far N., gradually increasing till at 

 5 h it lay as stratus fog over Loch Laggan and Moor of 

 Rannoch. It took a more cumulus form as the day went 

 on, and from 8 h onwards the summit was mostly in fog. 

 Hoar frost on roof in morning. Solar corona seen at 7 h . 

 At 14 h the summit was clear for a short time and there 

 was no fog below. 



June 25. — Summit clear till 3 h . No fog below at l h 

 and 2 h but detached patches among hills at 3 h . Sunrise 

 colours very brilliant at 2 h and 3 1 '. 



June 26. — Thermometer box lowered one stage on 

 ladder stand No. 2 at h 5 m . 



June 28. — Sky cloudless after ll h ; fog lay on the 

 surrounding hills, and passed over the summit all forenoon, 

 after which it disappeared but haze remained in the 

 valleys, especially to the S.W. At 19 h the haze to W. 

 appeared to lift and the Outer Hebrides were seen. A 

 halo was seen shortly before 10' 1 . Thermometer box was 

 lowered one stage on the ladder after the midnight 

 reading. 



June 30. — Thick haze all day and sky cloudless or 

 nearly so : the haze extended to between 20 and 30 

 degrees above the horizon. Only very thin detached 

 patches of low lying stratus fog were seen to the N. and E. 

 in the early morning and these disappeared soon after sun- 

 rise. The sun rose behind haze at 3 h 20 m . Air very dry 

 all day. 



July 4. — The snow has disappeared from about the 

 gauge but there are still large, patches of snow to the East 

 and West of the observatory. The hourly readings of 

 the dry and wet bulb in the summer box were entered 

 in the daily sheets, and the readings in the small box 

 discontinued. 



July 6. — Heavy rain began to fall after 15 h and lightning 

 followed by thunder was first observed about 17 h 15 m . 

 The storm continued till about 19 h 30 m . Earth currents 

 were first noticed in the telegraph cable at 16 h and the 

 instrument clicked all through the storm. The mist 

 frequently lifted from off the Ben during its progress but 

 never for any length of time, showing thick cumulus-fog 

 clinging to the hill sides all round. 



July 7. — At 14 h 52 m peals of thunder were heard to the 

 S.W. and some faint earth currents were noticed in the 

 telegraph instrument. A thunder cloud was observed 

 stretching from S.W. to N.W., having cirrus trailing out 

 behind. St Elmo's Fire was heard at 16 h 20 m and was 

 particularly loud during a sharp fall of hail which lasted 

 but two or three minutes. No flashes were seen. 



July 15. — The sky was only slightly cloudy from 4 h to 

 14 h but fog lay all round to about our level and frequently 

 passed over the Ben. A triple fog-bow was seen about 

 mid-day and again at 19 h 30 m . Some fine glories were 

 seen in the evening, one surrounding the shadow of the 

 tower had five series of rings at 20 h . 



July 21. — The top cleared at l h ; bright luminous rays, 

 like auroral streamers, reaching an altitude of between 50 

 and 60 degrees, were seen to N. and N.E. No arch could 

 be seen but this was probably owing to the fog which lay 

 up to our level and was passing frequently over the 

 summit. St Elmo's Fire was heard, hissing strongly at 



