1887.] 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



353 



streamers. The black bulb was out till 16 h , maximum 

 registered, 99°"0. The thermometer-box was shifted at 10 h 

 30 m . 



Nov. 14. — At 2 h and 3 h three of the lights of the west 

 coast lighthouses could be seen. The sky, cloudless at l h 

 became overcast with stratus at 2 h (through which the 

 stars were dimly visible till 6 h ) and remained so till 15 h , 

 after which it rapidly cleared and was cloudless at 19 h . 

 Fog came on at 20 h and enveloped summit till 23 h but at 

 midnight the summit was again clear and the sky cloudless, 

 but fog covered the surrounding hills. 



Nov. 15. — By l h the fog that lay on the surrounding 

 hills had disappeared. At l h and 2 h the west coast lights 

 were visible. The sky was cloudless or almost so till 

 noon, after which it became overcast, and remained so till 

 17 h . At 18 u it was again cloudless, but at 19 h fog came 

 on, and enveloped the summit for the rest of the day. 

 Bright meteors with long trains were seen at the following 

 times : — 



1" 8 m 30", path from S.S.W., 30° altitude to S.W. 15° 

 altitude. 



l h 15 m 15 s , path from S.S.W., 40° almost parallel with 

 above. 



l h 17 m 45 s , path from S.S.W., 20° almost parallel with 

 above. 



l h 19 m s , path from Mirach (Andromeda) to a Arietes. 



l h 22 m s , path from Rigel towards S.S.W., almost 

 parallel to horizon. 



lh 24m q s , path from Sirius towards S.S.W., almost 

 parallel to horizon. 



l h 32 m 30 s , path from a Arietes to western horizon. 



l h 33 m 30 s , path from (?) towards western horizon. 



2 b 5 m 10 s , path from S. 15° altitude to S.S.W., 5° 

 altitude. 



2 h ll m 30 s , path from S.E. by E., 12° altitude to S.S.E., 

 5° altitude. 



2 h 12 m s , path from S.E. by E., 12° altitude toS.S.E., 

 5° altitude. 



2 h 17 m 45 s , path from low to southward inclining to 

 horizon to S.S.W. 



Nov. 18. — The record of the direction anemometer to- 

 day is very doubtful till 15 h , as the vane had been 

 sheltered by the chimney and other instruments on the 

 tower, which were all covered heavily with snow and ice. 

 At 15 h the vane was broadside to the wind. After that 

 hour the snow was cleared away, and the vane worked all 

 right for the rest of the day. 



Nov. 20. — At 3 h and 4 h a pale light (probably auroral) 

 was seen behind the clouds to northwards. At 4 h 20 m the 

 thermometer box was shifted. At 8 h a solar corona was 

 seen. Radius of red 1 , 4° 10^', and of red 2 , 6° 48'. At 

 the same hour a few hexagonal starry snow crystals were 

 falling. A glory was seen at 10 h , having three well-defined 

 colour-rings — red, green, and yellow. At 22 h and 23 h an 

 aurora was seen. It had no streamers, had ill-defined 

 boundaries, and was of uniform brightness. 



Nov. 21. — At 18 h and 19 h an aurora was seen. No 

 streamers were observed. At midnight dry and wet bulbs 

 were 34 inches above snow. 



Nov. 22. — Fog covered the hill top till 3 h , and passed 

 occasionally till 15 h , but during the rest of the day the 

 top was clear and the sky cloudless. At 21 h and 23 h an 

 aurora was seen, at the former hour with streamers. The 

 air was very dry at midnight, the humidity then being 19. 



At 22 h 15 m the thermometer box was shifted one step up 

 on ladder-stand. 



Nov. 23. — The sky was cloudless till 8 a.m., after which 

 it became overcast or nearly so, and at 19 h fog came on 

 and enveloped hill top for the rest of the day. All morn- 

 ing and till 1 7 h the air was very dry. At midnight the 

 " fog "-crystals deposited seemed to be a mixture of icy 

 crystals and snow (white) crystals. At 4 h there was a 

 trace of an aurora in northern sky. 



Nov. 24. — From 7 h till 13 h " glazed frost" was forming 

 on all exposed surfaces. Hard dry conical snow was fall- 

 ing at night. At 22 h it was observed that the fog at 

 times had a misty feel. 



Nov. 25. — St Elmo's fire was seen faintly at 4 h for 

 only about half a minute, and again at 4 h 35 m brightly, 

 and for some minutes. At l h 59 m there was a "dot" 

 signal in telegraph instrument (current down the line), and 

 at 4 h 9 m a " dash " signal (current up the line). The wind 

 was very variable to-day. Heavy rain began to fall after 

 23 h . 



Nov. 27. — Top was clear at 16 h and 17 h , and again after 

 22 h . At midnight a lunar halo was seen, having a trace 

 of red inside at part nearest zenith only. Radius of inner 

 edge per stephanome was 21° 2', and of the middle or 

 brightest part 22° 36', 22° 24', 21° 48'. At 20 h a hare's 

 tracks were seen on the snow at the thermometer box. 



Nov. 28.— The thermometer box was shifted at h 30 m . 

 Fog came on at 4 h , and fine snow began to fall in needle- 

 shaped crystals. At 22 h it was clear at times, and a corona 

 was observed, and a halo was seen faintly through the fog. 

 The following measurements of radii of colours in corona 

 were obtained by stephanome, viz. : — 



Order of Colours. 



Moon. 



White, 



Yellow, 



Violet, 



Blue, 



Red, 



Radii of 

 Inside. 



0° 56' 



2° 42' 



Radii of 

 Outside. 



1° 36 



Radii of 

 Middle 



2° 5' 



3° 

 to-day 



35' 



at 4 h on snow at 



A hare's tracks were again seen 

 rain-gauge. 



Nov. 29. — The fog cleared off hill top at 8 h , but lay in 

 detached masses on lower hills and in valleys more or less 

 all day. From 15 h 10 m to 15 h 20 m a solar corona was ob- 

 served, and the following stephanomic measurements were 

 obtained, viz.: — 



©White. yt U £ W ; Blue. Green. Red. Blue. Green. Red. Blue. Red. 

 *"*• ish Red. 



T T IT T T 



2° 3' 3° 26' 3° 44' 4° 2' 6° 12' 9° 41 



Triple lunar corona? were seen at 18 h 10 m and again at 

 23 h 15 m . The following measurements were obtained at 

 22 h 15 m per stephanome, viz.: — 

 ]) White. Yellowish Red 1 . Violet. Blue. Red 2 . Violet. Blue. Red 3 . 



TIT 



1° 50' 2° 42' 5° 0' 



At times the white space about }) widened, making the 

 corona a double one only red 2 (2° 42') being then the 

 first coloured ring from the moon. 



ff ov . 30. — At h 5 m a strato-cirrus cloud layer was seen 

 to northward lying N.E. and S.W. and advancing 



