412 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



[1892. 



per cent. After 22 h a light was observed in the sky 

 to N. extending from N.W. to N.E., and to about 45° 

 altitude, probably an aurora but it was indistinct owing 

 to bright moonlight. 



March 16. — Sky almost cloudless till 9 h , overcast with 

 cirro-cumulus till 13 h , fog and mist since. Air very dry 

 in forenoon ; the computed humidity at l b being 12. 

 Rain began to fall at 18 h with a temperature of 30° - 5, 

 and ice forming on all exposed surfaces. Temperature 

 has been steadily rising since. Haze all round below in 

 early morning. A solar halo of 45° was seen at ll h . 



March 17. — Distant tbunder heard at 9 h 20 m , and 

 flashes of lightning seen at 10 h 30 m . 



March 19. — Strong S.E. wind all day, increasing to 

 a gale in the evening. Top clear after 6 h , but fog on 

 hills to S., and frequently blowing over summit in the 

 afternoon, and dark haze in the valleys all round. Sky 

 a little cloudy in forenoon but cloudless after 17 h . An 

 aurora, single arch, but no streamers was seen at 23 h and 

 midnight. 



March 20. — The S.E. wind continued till 12 h and 

 gradually fell in force. Sky cloudless till 10 b , variable 

 amounts of cir. and cir.-str. on sky till 20 h ; fog on 

 summit at 21 1 ', cloudless again since. Fog on hills to 

 E. and S. most of the day and passing over Ben Nevis 

 frequently. Haze round the horizon all day. An aurora 

 at i h , and a halo with mock suns at 16 h 55 m was seen 

 from plateau of storms. 



March 22. — Thermometer box shifted at 7 h 1 5 m . Height 

 above snow not altered. 



March 23. — Silver frost forming till 5 h . Mist and 

 fog with occasional breaks till 19 h . Sky cloudless since, 

 but fog below all round. A solar fog-bow seen at ll h . 

 Thermometer box shifted at 7 1 ' 15 m . A mouse was seen 

 in snow porch at 23 h . 



March 24. — Sky cloudless till 5 h , but mist lay over 

 hills all round and passing over summit. Mist since. 

 Sky cloudless again at 21 h , and mist all round, and very 

 thin mist passing over Ben Nevis. Temperature fell 

 suddenly between 4 h and 5 U from 3l°*S to 26°-l. An 

 aurora seen at 21 h , 23 h , and midnight; faint streamers 

 were seen at 23 h . 



March 25. — Sky cloudless, and thin mist passing over 

 summit till 5 1 ', continuous mist or fog since. An aurora 

 with streamers seen at l h , 3 U , and 4 h . 



March 26. — Thermometer box shifted at 9 h 20 m . 

 Height above snow 55 inches. A bunting seen in snow 

 porch to-day. 



March 27. — Fog and overcast sky till 22 h , cloudless 

 since. Temperature very low all day. To-day is the 

 coldest yet experienced at the observatory. Mean 

 temperature 8°-l, and minimum registered 2°*7. Air 

 very clear to "W. and S. in forenoon. Very light showers 

 of snow fell during the day. Passing shower clouds to 

 N. and W. in the afternoon. An aurora single arch at 

 21 h , 23 h , and midnight, but no streamers. A mouse seen 

 in snow porch at l 1 '. 



March 28. — Fog came on at 4 1 ' with occasional breaks 

 till 18 h , cloudless since. An aurora seen at l h , 2 h , and 

 :;'', and at 21 1 ', 22 h , 23 1 ', and midnight. At 23 h there 

 were three arches, the 1st and 2nd arches were well 

 defined, the 3rd or highest arch was not so well defined, 

 but was distinctly visible. At midnight there were two 



arches, the lower one being very bright. The streamers 

 were faint. 



March 29. — Sky cloudless except for a little cirro- 

 stratus till 15 h ; fog since. Dark haze to W. and S. 

 near horizon. An aurora with single arch and faint 

 streamers at l h , 2 h , and 3 b , and a solar halo at 8 h 

 and 13 h . 



March 30. — Fog on summit till 10 h . Sky clear since, 

 except for some thin cirrus and cirro-str. till 23 h , since 

 then a little cumulus has appeared. Light haze among 

 valleys all afternoon. Part of an aurora seen at mid- 

 night. 



March 31. — Summit clear and air dry all day. Hard 

 packed stratus fog on hills to W. and N. almost all day, 

 and haze among valleys. Aurora seen at l h and 2' 1 , and 

 a halo at 17 h 40 m . Dry and wet bulbs shifted at 

 12 h 15 m . 



April 1. — Thick haze all round. Aurora at 22 h and 23 h . 



April 2. — Thick haze below all day, but thinning 

 towards midnight. A solar halo seen from 9 h till 17 h , and 

 a lunar halo with mock moons at midnight. At 19 u 10 m 

 the setting sun was distorted, the lower part in the haze 

 being larger than the upper part in the clear sky. 



April 3. — Sky nearly overcast all day with cirro-cum. 

 and cirro-str. moving from the S.W. Very thick haze all 

 round. Lunar halos seen at l h , 20 h , 23 h , and midnight, 

 and mock moons at l h and 20 h . 



April 5. — Continuous mist and slight drizzle till 20 1 '. 

 Sky cloudless or nearly so till 22 h , but detached cum.-fog 

 on hills all round, and cumulo-cirrus near horizon to S., 

 W., and N. Thin mist since. A double corona at 23 1 '. 



April 6. — Mist or overcast sky all day, and loose fog 

 among hills when summit was clear. A solar halo 

 seen at 15 h 10 m . 



April 7. — Sky clear, but thin fog blowing over summit 

 all day, and thin haze all round, and fog among valleys. 

 A solar corona at ll h , and lunar coronse at 20 h , 21 h , and 

 22 h . Thermometer box lowered one step at 16 h 10 m . 



April 8. — Fog till 4 h , summit clear since. Sky partly 

 covered with cum. till 7 h , cloudless since except for a little 

 cirrus at times. Detached cum. above horizon to E. and 

 S.E., and some cirrus near horizon to "W. and N. in the 

 afternoon. Haze in valleys all round all day. A little 

 fog over hills to S.E. at midnight. Hoarfrost on ther- 

 mometer box and office roof during the night. Aurora 

 with single arch seen from 22 h till midnight. 



April 9. — Sky cloudless all day, but a little fog over hills 

 to S.E. till 5 b , no fog after that below. Thick haze all 

 round during the day but thinning somewhat in the 

 evening. Cirrus near horizon to W. and N. at 20 u and 21 h . 



April 10. — Sky cloudless except for a little cirrus above 

 the horizon to W. and S. in the afternoon. Light haze in 

 valleys all day. 



April 11. — Sky cloudless except for a little cirro- 

 cumulus in the afternoon. Cum.-fog over hills to N.E. 

 at 22 h , and at 23' 1 there was fog on hills to N.E. and S.E., 

 and at midnight fog on hills all round except from S.S.W. 

 to W.S.W. Thick haze among valleys all day. 



April 15. — Sky almost cloudless till 9 h , when cumulus 

 began to form all round below and to rise above level of 

 summit. This cumulus developed into shower clouds in 

 all directions, and up to 21 u showers of snow fell on the 

 summit at intervals. During the evening the clouds were 



