1890.] 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



223 



by a peal of thunder, the only peal heard, though all 

 afternoon the appearance was very thundry. Part of 

 rainbow seen at 8 h . 



May 6.— A rat was seen at 2 h . 



May 7. — Hard str.-cir. was seen to E. at 4 h . A solar 

 halo was seen at 15 h . 



May 8. — Top clear, and air dry all day. Fog in N. 

 and N.E. valleys in forenoon, passing showers in distance 

 and on Ben Nevis in afternoon. Sky partly covered with 

 cir.-s. till 8 h , and after 22 h , radiating at 4 h from E. by S. 

 and W. by N., and at 23 h from N. and S., and overcast 

 with cumulus, cum.-s., or nimbus during the rest of the 

 day. A rainbow was seen at 15 h . 



May 11. — A solar halo was seen at 14 h and another at 

 18 h . 



May 13. — Thermometer box was shifted down on step 

 at h I0 m . Hard packed cir.-s. on sky at 17 h not showing 

 any well defined radiating point. 



May 1 9. — Mist or fog on Ben or passing all forenoon ; 

 clear, and air dry all afternoon. Dry and wet bulbs were 

 changed after 18 h . 



May 20. — Fog in valleys to N., E., and S. in forenoon, 

 and thick haze in distance to S. and S.W. at 20 h . 



May 21. — The 17 h observation was made at 17 h 5 m . 



May 23. — Top clear all day ; sky somewhat cloudy. 

 From 3 h to 5 h , fog and haze lay in valleys to 3000 feet to 

 E. and S.E. (the hill tops being clear), and afterwards 

 gradually spread and rose higher, passing top of Ben 

 Nevis at times in forenoon. The haze increased and 

 thickened, being very thick all round in afternoon. The 

 air was dry except at 6 h . 



May 24. — All last night the Northern sky was bright 

 with sunset or sunrise colours. At l h these were red, 

 yellow, pale green, and blue. A little cirrus on sky till 

 4 h ; but cloudless during rest of day. The upper glow 

 was seen at sunrise and sunset, showing pink streamers in 

 both cases. 



May 25. — Upper glow seen at 3 h and 21 h . In early 

 morning atmosphere was very clear about level of hill 

 tops, but there was fog and haze in valleys to N. and 

 N.E., which spread in every direction and rose higher 

 till in afternoon it was all around, and passing top of 

 Ben Nevis at times. 



May 26. — Fog passing and air saturated at times till 

 1 p.m.; summit clear and air dry for the rest of the day, 

 but haze and fog in valleys to N. and E. Faint after- 

 glow noted. At 23 h pearly cirrus was seen (first time 

 this year) in N. and N.E. sky. Photographs were taken at 

 23 h 27 m and 23 h 54 m . At 11 h 40 m it was about 13° 

 above horizon, and from this point the line of greatest 

 brightness seemed to incline towards a point on the horizon 

 about N.E. by E. 



Notes taken of pearly cirrus. 23 h — Ribbed cir.-c. type 

 seems low : stars seen through. Moving apparently from 

 E. slowly. Midnight — Part seen to N. fading, but still 

 bright to N.N.E. Looked at through telescope — seems 

 like wavy sheets of stratus seen edgewise ; has apparently 

 a bright and a brighter side : moved through 1° in 2 

 minutes from a N. or W. of N. direction : one long 

 streak had a dark wavy line running throughout its 

 whole length. 



May 27. — l h pearly cir. to N. gone, but bright to N.E. : 

 traced to 11° above horizon, but brightest part only 7J° : 



extends now to E. by N., but faint. 2 h , pearly cirrus to 

 E.N.E., from 5° above horizon up to 20° : Very faintly 

 marked to N.N.E., but still there. 2 h 50 m , Plate taken of 

 pearly cirrus to E. by N. 3 h , no pearly cirrus or any kind 

 of cloud in. sky, only faint bands and streaks of haze near 

 horizon, and pink " foreglow " streamers. 



Sky cloudless most of day. Fog on hills to E. and N. 

 till 4 h , fog all round to 4000 feet at 7 h , passing summit at 

 9 h , and all gone at 13 h . Thin haze in afternoon, all round 

 below, and thin haze bands in sky near horizon. Hard 

 low str.-cir. seen to E. at 20 h motionless. The cirrus in 

 sky at 21 h radiated from E. Noted afterglow till 21 h 

 45 m . Streamers were seen from 21 h 30 m till 21 h 35 m . 

 There was more red in W. sky than last night. N. sky 

 bright all night. 



May 28. — Faint foreglow at 3 h . The cirrus in sky at 

 4 h radiated from N. by E, and S. by W. A.t 5 h there 

 was a band of peculiar haze all around above level of 

 summit, but there was none below. Fog in valleys to 

 W„ N. and N.E. at 6 h . It gradually rose and spread, and 

 at ll h it was all around to 4000 feet, and at and after 

 14 h it enveloped summit. 



May 31. — Thermometer box changed at 9 h 15 m . 

 Height above snow not altered. 



June 5. — Clearing in afternoon. A solar halo was seen 

 at 18 h . Thermometers shifted at 19 h . Height above 

 snow not altered. To-day the large dust counting instru- 

 ment was fixed in the middle room of tower. 



June 7. — A solar corona was seen at 21 h , and the after- 

 glow at 22 b . Showers of snow fell in morning. 



June 8. — Foreglow was seen at 3 h . A solar halo was 

 seen at ll h and 12 h : — 



ll h radius 22° 38', one observation. 



12 h „ 23° 48', mean of five observations. 



June 11. — To-day the snow disappeared from about 

 post A, where the depth is measured. 



June 13. — A fogbow and a glory were seen at 5 h . A 

 glory was also seen at 20 h . When the observer stood near 

 the tower, the shadow of tower was seen projected on the 

 fog, cutting the glory formed round the shadow of the 

 observer. The plane of shadow of edge of tower could 

 be traced outwards into the fog, and the same could be 

 done with that of the chimney. In both cases the 

 shadows diminished in perspective. 



June 14. — Mist or fog till 9 h ; sky somewhat cloudy 

 during the rest of the day, but air dry. Fog on hills 

 around especially to N. most of the day. Thick haze 

 was seen to S., approaching, after 20 h . 



June 15.— Thick haze all around, below 3000 feet in 

 early morning. Fog sheets were forming on top of this 

 haze at 4 h and 5 h . At and after 3 h the fleecy cum.-cir. on 

 sky was gradually descending and becoming heavier, till at 

 6 h it lost its cum.-cir. appearance, and formed a dull 

 uniform pallium, which before 7 h descended on Ben and 

 enveloped it during the rest of the day as wet drizz- 

 ling mist. Splendid sunrise. The clouds at and above 

 horizon were thin, streaky, and almost transparent cir., 

 and cir. -stratus, and these showed almost every shade of 

 colour, in thin delicately tinted streaks, while higher up 

 the under surface of the cum.-c. was all aglow with 

 various shades of red. 



June 22. — Summit clear at and after 17 h . Cirrus on 

 sky lying N.W. and S.E., and at midnight there was fog 



