1892.] 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



413 



steadily sinking, and after 21 h they were all below the 

 level of summit, leaving a cloudless sky above. Very 

 light variable winds or calm all day. 



April 16. — Weather very much like yesterday as regards 

 clouds — -fog being below in early morning. Cumulus 

 forming and rising in forenoon, and developing into 

 shower clouds during the afternoon, and falling below 

 summit after 21 h leaving a cloudless sky above. Very 

 light N. or N.E winds. At 14 h the humidity suddenly fell to 

 35 per cent., the only value below 70 to-day. 



April 17.— Sky almost cloudless till 6 h , fog till 9 h . 

 Cloudy with cumulus, which developed into shower clouds 

 till 21 h , fog till midnight. Ground fog in early morning 

 on Moor of Rannoch. Passing showers of snow in all 

 directions in evening and at times falling on summit. 

 Light N. and N.E. winds. Air saturated or nearly so all 

 day. 



April 18. — Fog "off and on" summit till 9 a.m. 

 Cloudy during the rest of the day with cumulus from 

 which showers fell at times in evening. 



April 19. — Sky cloudless or almost so till 9 h , but air 

 remained saturated. Sky cloudy or overcast till 18 u with 

 cir.-s. on which a bright halo was seen, and after l'5 h with 

 hard cir.-s. or str.-cir. Fog came on at 19 h , and snow fell 

 during the rest of the day. Haze crept steadily north- 

 wards in forenoon being first seen at 5 h at S.E. and S. 

 horizon and by 12 h it was all around. Radiating points 

 of a little cirrus that was seen at 5 h were N.N. W. and S.S.E. 



April 20.— Mist or fog till 13 h and after 19 h . Sky 

 cloudy in afternoon, with cumulus and cirro-stratus. 

 Halo seen at 15 h and 16 h . 



April 23. — St. Elmo's Fire was heard and felt by 

 observer when on roof at 7 b 30 1 ". 



April 26. — Fog till 8 h ; summit clear for the rest of the 

 day except for a little passing fog at 21 h . Sky about 

 half clouded with cumulus, from which showers were 

 seen falling in various directions in evening, but none on 

 summit. Air very clear to-day, "Visibility" 3 to 4. 

 Thermometer box was changed at 10 h 20 m . Height 

 above snow not changed. 



April 29. — Sky almost cloudless all forenoon, but 

 temperature very low, being below 20° till ll h . Sky 

 overcast with cumulus in afternoon, and fog on summit 

 at night, with snow falling after 19 h . Aurora seen at 

 l h and 2 h . 



May 1. — Aurora seen at midnight. Large waves of 

 light rising from a bright single arch to near the zenith. 

 The moon was seen through the arch. 



May 2. — -Aurora continued pretty bright till 2 h . At 

 l h it filled the whole northern sky up to zenith from 

 W.S.VV. to E.N.E. Haze below in forenoon in which 

 cum. -fog formed and gradually rose and enveloped the 

 summit in afternoon, but fell again after 18 h , and 

 continued at 4000 feet till midnight. Aurora seen at 

 23 1 ' and midnight. 



May 3. — Aurora seen at 2 U and again at night. 

 Almost cloudless till 5 h and after 19 h , but cum.-scud 

 or fog passing during the day. Air very dry before 

 the fog rose in early morning. 



May 4. — Faint aurora seen at l h and 23 h . Sky 

 cloudless, and air dry almost all day, but fog on hills 

 below, chiefly to N. and E. 



May 5. — Fog all round below in forenoon ; but it 



broke up in afternoon. Sky pretty clear all day. Air 

 very dry at night, the humidity at 21 h being computed 

 at 18 per cent, and at 23 h 19 per cent. Lunar halo and 

 aurora seen at 23 h and midnight. 



May 6. — Aurora seen at l h and 23 h , and a lunar corona 

 at l h and 2 h . Some cirrus on sky till 5 h ; almost cloud- 

 less during the rest of the day. Thick haze all round 

 below. 



May 7. — Fog rolled up from W. at l h and 2 U , and 

 was all around below 3000 feet at 3 h ; thereafter rising 

 and enveloping the summit for the rest of the day. 



May 8. — Summit cleared after l h and remained clear 

 till after 14 h when fog came on again. Thermometer box 

 changed at 7 h 30 ,n . 



May 9. — Fog cleared off after 4 h . Cum. on sky till 

 15 h . Cloudless thereafter. Thick haze below all day. 



May 10. — Thick haze all around all day. Almost 

 cloudless in forenoon ; some cumulus on sky in afternoon. 

 The haze to-day was very thick and rose high above the 

 summit of Ben Nevis. 



May 11. — Thick haze all round to-day. Cir.-s. moving 

 from S.W. on sky on which in the forenoon a solar halo 

 was visible. A lunar halo was seen at l h . 



May 12. — Cir.-s. on sky in forenoon, and cumulus in 

 afternoon which thickened and developed into nimbus 

 by 19 h . Fog on at 21 h . Thick haze below all day. 

 A lunar halo was seen at i\ and a solar halo at-5 h , 6 h , 

 and ll h . 



May 16. — St. Elmo's Fire was seen at l h . 



May 18. — A large rat was seen on the roof at l u . 



May 20. — Mist or fog and showers of drizzling rain or 

 snow till 17 h . Summit clear till 22 h , fog thereafter. 

 A mock sun was seen at 20 h . 



May 22. — Summit clear from 3 h till 17 h . Sky cloudy 

 or overcast, with cir.-c. in forenoon, and heavy cum. 

 and nimbus in afternoon which gradually lowered and 

 thickened and enveloped the summit at and after 18 h . 

 The air was exceptionally clear, but not very dry in 

 forenoon. Snow fell at night. 



May 25. — Mist till 21 h ; cloudless thereafter, but 

 broken fog all round below. Bright spectrum colours 

 in N. sky at 23 h and midnight. 



May 26. — Fog below in early morning which gradually 

 rose and at 8 h and 9 h enveloped the summit, and there- 

 after formed cumulus clouds overhead till 21 h when it 

 again sank to summit. Thick haze in afternoon — up 

 to clouds. 



May 28. — Summit cleared at 4 h , and except for some 

 fog at 9 h and 10 h remained clear till 15 h , when mist and 

 heavy rain with E.S.E. wind came on rather suddenly. 

 Solar halo seen at 5 h and 6 h . 



May 30. — St. Elmo's Fire was seen at 20 h . 



June 1. — Mist all day, with rain in forenoon and 

 showers of rain, sleet, and hail in evening. (To-day a 

 horse was brought right up to the observatory for the first 

 time this year.) 



June 2. — Top clear at times till 6 h . Mist for the rest 

 of the day. A solar halo was seen at 5 h . 



June 5. — Fog or mist till 9 h . Overcast with cum.-s., 

 and fog all round below till 21 h . Sky clearing and fog 

 sinking thereafter. 



June 6 Almost cloudless all forenoon, but unbroken 



fog all round below to 4000 feet. At 13 h and 14 h cir.-s. 



