366 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



[1901. 



thermometer box 

 Height of bulbs 



corona; were observed. At 15 h 15 

 was changed to the shorter ladder, 

 above snow 41 inches. 



May 31. — Strong squally S. winds, increasing in force, 

 and blowing a gale at midnight. Showers of sleet and 

 rain. Earth currents were noted at 15' 1 15™ and 15' 1 30 m . 



June 1. — Earth current noted at 15 b 40 m . 



June 6. — Summit clear from 13 h to 17 h , and sky over- 

 cast or almost so, but cloudless since. Some cum. at 

 horizon to W. after 20 h , also detached fog on hills to W. 

 and N. 



June 7. — A little cir., cir.-c, and cir.-s. on sky all 

 day, moving from the N.N.W. slowly. Detached fog 

 on hills to N. and W. almost all day. Slight haze in 

 afternoon. Solar halo seen at 16 h . 



June 8. — Sky cloudy almost all day, with cir., cir.-c, 

 and cir.-s. In the forenoon the motion was rather slow, 

 but in the evening the motion was rapid from the S.S.W. 

 Fog in valleys during the forenoon, and slight haze in the 

 distance. The haze became very dense in the afternoon 

 all round and high up. 



June 11. — Thunder heard and earth currents on tele- 

 phone at ll b 55 m . The man with hotel pony saw 

 lightning at the lake about the same time. 



June 14. — Summit clear most of the afternoon, and the 

 air slightly dry ; but clouds low down, tipping hill-tops 

 all round. 



June 15. — Summit clear after l h , but a little cir. and 

 cir.-s. on sky moving from W. Fog all round below. 

 Fog enveloped summit again after ll h . 



June. 18. — Some cir. and cir.-s. on sky, moving from 

 N.N.W. rather slowly in the evening. 



June 21. — Earth currents between 20 h and 21 h . 



June 26. — The clouds in afternoon were low down, 

 capping the hills all round, but at midnight the lower 

 clouds had all disappeared, leaving some cir.-s. on sky. 



June 27. — Summit clear almost all day, but sky over- 

 cast. Fog in valleys throughout the day, at times rising 

 up and passing over summit. Dew on thermometer box 

 and roof of Observatory at 3 h . 



June 28. — Detached fog in valleys in the early morn- 

 ing, but clearing away again during the course of the day. 

 After 19 h the clouds were descending, and by 20 h had 

 enveloped the hill-top and continued so during the rest of 

 the evening. 



June 29. — Fog all round, level with summit at l h , but 

 after 3 h it gradually sunk down to about 2500 feet at 5 h , 

 and remained in valleys more or less during the rest of 

 the day. Thick haze all round in afternoon. A solar 

 halo seen at 5 h . A meteor seen at 3 b 21 m falling near N. 

 cliff, shaped like a candle flame, but much larger, and very 

 bright. 



June 30. — Sky cloudless all day, except for a little 

 cir.-c. in the evening. Thick haze all round in the morn 

 ing, but it became thinner later and disappeared altogether 

 during the day. Fog on hills to E. and S. almost all day. 



July 1. — The fog that lay in valleys last night to the 

 K. and S. rose up and enveloped summit after 3 h , but 

 after 7 1 ' the fog cleared off and the hill-top has been clear 

 since. Sky has been cloudy all day, with hard-packed 

 cir.-s. Fog on hills to N. and N.E. in the evening. 

 Moderate to strong E.S.E. winds all day. At 15 h there 

 was a sudden fall in the wet bulb temperature, 



which makes the difference between dry and wet bulbs 

 (8° - 9) considerably greater than was observed at any other 

 hour of the day. 



July 2. — Fog on hills to N. and N.E. all forenoon, but 

 disappearing towards noon, and again reforming in the 

 same directions in the evening. Glories seen at 21 h . 



July 3. — Sky almost cloudless, and air very clear all 

 day. Some fog in valleys to N. and N.E. in the morning, 

 but it disappeared during the forenoon. 



July 4. — Sky almost cloudless till noon, overcast in 

 afternoon, and fog off and on summit after 21 h . Haze 

 around all day, thicker in afternoon. A little detached 

 low-lying fog to N. and N.E. in early morning. 



July 6.- — -Mist or fog till 15 b , sky cloudless since, the 

 fog sinking below the level of summit and finally dis- 

 appearing after 19 h . The temperature was fairly steady 

 till 15 h , rose suddenly about 7 degrees at 16 h , and 

 remained pretty steady thereafter, the air becoming very 

 dry at the same time, the humidity falling from 91 to 

 34 between 15 b and 16 b . Glories seen at 17 b and 18 h . 



July 7. — Mist or overcast sky, with slight showers of 

 drizzle till 12 b ; almost cloudless since. Fog in valleys all 

 day. 



July 8. — Fog in valleys all round all morning, but 

 dispersing during the day. 



July 9. — Thick haze all round in the afternoon. 



July 10. — Some cum. above horizon all day, and slight 

 haze above horizon in the evening. 



July 13. — Mist, with drizzling rain, till 23 h . Almost 

 cloudless since, the mist sinking below the level of 

 summit. Temperature rising slowly all day, but between 

 23 b and midnight it rose from 40° to 45°. 



July 14. — A solar halo seen at 6 h . Thunder heard 

 at intervals between 17 h and 21 h and St Elmo's Fire 

 at 21 h . Strong earth currents in telegraph cable all 

 evening. 



July 15. — Mist, with drizzling rain, till 22 b . Cloudless 

 since, but fog below all round. 



July 16. — Summit clear till 2 b and again from 9 h till 

 16 b , but sky nearly overcast with cir. and hard-packed 

 cir.-s. 



July 18.— Lightning seen at 23 b 50 m and 23 h 55 m . 



July 19.— Lightning seen at h 10 m and b 27 m . 



July 20. — Hill-top clear and air dry between 12 b and 

 19 b , but sky very cloudy and gloomy-looking. A severe 

 lightning and thunder storm began at 22 h and continued 

 till midnight, increasing in severity. The lightning 

 towards midnight was very vivid and appeared to be 

 immediately overhead. At times three and four flashes 

 were observed with only a few seconds between them. 

 Heavy rain began to fall at 23 h 45 m . At midnight no 

 outside observations were taken, except the direction and 

 force of wind ; the temperature and amount of rainfall are 

 interpolations. 



July 21. — Thunder and lightning continued till 3 h 

 and again from 22 L till midnight. St Elmo's Fire seen 

 at h 45 m . 



July 22. — Summit clear at times during the day, but 

 thick fog all round. Several flashes of lightning seen, 

 but no thunder heard, between h and l h . Rainbow seen 

 at 19 b . 



July 27. — Considerable banks of fog high up all round, 

 and fog passing frequently over summit during the day. 



