328 



BEN NEVIS OBSERVATORY.— LOG-BOOK. 



[1885. 



Fort William being perfect. Thermometer box shifted 

 after 18 h observation. 



Mar. 29. — From 21 u yesterday to 7 U to-day no gauge 

 was out, the quantity of drift flying about making its in- 

 dications useless. At 21 h to-day the door of thermometer 

 box was found standing open. At 23 h the sky to north- 

 ward broke a little, showing blue sky. 



Mar. 30. — Haze round horizon, and in valleys all day, 

 but without any definite marked upper limit. Brownish 

 colour near sun, getting fainter in afternoon. Thermometer 

 box shifted after 9 h . Lunar halo at 22 1 ' on cirrus clouds. 

 Radius by stephanome, 18°. At 23 h very faint brown 

 colour under moon. 



April 1. — After 9 U observation thermometer box was 

 shifted. At 10 h faint purple corona round sun. 



April 4. — At 8 h the sunshine recorder was found buried 

 in drift. Ice formed, in focus, on cardboard all day. 

 Thermometer box shifted at 14 h . Light dry drift, rising 

 to some 5 or 6 feet only, was blowing about thickly all 

 day. Faint copper colour in sky near sun in afternoon ; 

 dense haze mixed with cumulus at horizon, and filling 

 valleys. No sunset colours, except a faint dirty yellow at 

 western horizon. 



April 5. — No rain-gauge was out to-day, as the high 

 wind cutting away the surface of the snow made it 

 dangerous to expose it, but no snow was observed falling. 

 In the morning the fog-crystals were grey, but later were 

 of the usual white colour, and very loose in texture. 



April 6. — Fog crystals white, forming freely all day. 

 No gauge was out, but no snow was observed falling. 



April 7. — All the daytime great masses of cumulus 

 hung about the hill, and at the horizon. At 18 h red haze 

 to westward ; radiating beams from sun coming out under 

 cloud. Wind on Locheil, N.E. 



April 8. — At 2 h pillars of white light observed to N. W., 

 rising above dark haze or cloud bank. At 4 1 ' horizon to 

 E.N.E. faintly red, with pale green sky above. Solar halo 

 at 10 and ll h . Red inside. Radius by stephanome 

 (doubtful observation), 25° 50'. At ll h the top and 

 bottom of the halo were brighter than the sides. Haze at 

 horizon in afternoon ; copper coloured to westward, but 

 bluish looking elsewhere. At 23 h faint white light to 

 northward, seen through fog. 



April 13. — At 4 h very clear, with delicate sunrise 



trn«*.A\ colours, to N.E. At 5 h colours of eastern 



Green &ky as in margin. At b n taint copper 



Yellow colour in sky under sun. At 20 h thin 



R^d greenish haze over Loch Linnhe, blood-red 



Horizon s( . reak under cloudg tQ w N w> 



April 14. — Pallium of cum.-str. all day, not extending 

 far to eastward, however. Horizon and valleys got very 

 hazy in afternoon. 



Apiil 15. — Sky completely overcast with pallium of 

 cum.-str. till 20 h , when an easterly breeze sprang up, and 

 the sky cleared ; heavy densely packed clouds all round to 

 westwards. 



April 16. — At 14 h Robinson anemometer was cleared 

 of snow. Readings were taken between 17 h and 19 h . At 

 20 h the instrument was very stiff, and could not be moved 

 by the light winds which prevailed. 



April 17. — Sky remained cloudless till just before sun- 

 rise. At 4 h sky was dark red on eastern horizon, with 

 greenish tints above. Two long shafts of stratus cloud 

 stretched from about N.E. to S.E. pretty low down, and 



filmy cirrus clouds appeared. At 6 U faint solar halo was 

 observed, which vanished at 6 h 10 m , except two very 

 bright spots with red towards sun, one on each side of 

 sun, and at the same height above the horizon. Steph- 

 anome gave radius of 24°. At 7 h faint halo was again 

 observed ; at 8 h the highest part appeared brightest, and 

 at 9 h only that part remained visible. At 1 l h the halo 

 had entirely disappeared. At 13 h the halo was again 

 visible, and five observations gave 22° 45' (doubtful), 23° 

 40', 22° 15', 23°, 22° 15', of red ring (inside) as radius. 

 Thick haze lay on the surrounding hills nearly all day. 

 At 18 h this was of a blue colour, except to westwards, 

 where it was yellowish. At 19 h the western horizon 

 presented a very wild appearance, the lower clouds moving 

 very fast, and having very ragged edges. Robinson ane- 

 mometer was cleared again at 8 h , and continued working 

 throughout the day. 



April 19. — Wind strong at night, with considerable 

 drift. Rain-gauge taken in at 21 h , being filled with drift. 

 Put out at midnight, when rain began to fall. 



April 20. — At 15 h it was found that the solder of the 

 connecting wire, joining the Robinson anemometer with 

 the revolution counter, had given way. As the weather 

 looked rather threatening, it was not repaired. 



April 21. — Rain till 16 h . Snow thawing fast. Roof 

 of Observatory was visible near tower in the morning. 



April 23. — Robinson anemometer repaired. Hills very 

 clear in the afternoon. Cumulus clouds hanging only a 

 short distance above top of Ben Nevis, and spreading in 

 level sheet all round. Thermometer box shifted at noon. 



April 28. — Thermometers changed at 5 h . Sky very 

 wild at sunrise, fiery red to eastwards low down, with dense 

 black cumulus to westward. In afternoon the ice crystals, 

 forming from the fog, were at times of a very dark grey 

 colour, occasionally almost black. These were overlaid 

 with pure white. 



April 29.- — Robinson gave way again in same way as 

 before. Not repaired. 



May 4. — At 20 h v. 2 to northwards and north-westwards 

 below heavy cumulus clouds. Sun set behind Skye Hills. 

 Single streamer, rising almost vertically up above cumulus, 

 visible against some thin cirrus which began to form about 

 20 h 10 m . At 21 h dark fiery-red band, extending from 

 about W.N.W. to N.N.W. Sky of sickly green colour 

 above this. At 22 h this red band was still visible. 



May 5. — At 7 h a sudden fall of temperature was 

 followed immediately by a shower of snow. A fall of 

 snow was reported from Fort William about the same 

 time. 



May 6. — At 3 h small quantity of cirrus was seen almost 

 directly over hill top, apparently coming from W.N.W. , 

 but disappearing shortly after passing zenith. At 4 h 

 quantity of cirrus had increased, and formed a tolerably 

 compact flaky mass, still directly over hill top, but being 

 blown about in all directions for short distances without 

 moving away much from its place. At 5 h direction was 

 N.E. 



May 7. —Thermometers shifted at 9 h . 



May 10. — At 10 h strong copper-coloured corona round 

 sun. 



May 11. — At 13 h halo, red inside, seen on blue sky, 

 where no cloudiness was apparent. Horizon clear in 

 afternoon, but no strong sunset colours seen. 



May 13. — At l h and 2 h fog crystals forming, though 



