1884.] 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



319 



time. Sua was at times obscured by thin haze ; a thick 

 bank of cloud or fog lay over the other hills. Reddish- 

 brown copper colour in sky under sun all day ; and more 

 faintly, pale green at northern horizon. Towards sunset 

 a rosy haze to N.E. The sunset was fine, though the 

 colours had not the peculiar tints of the sunset lights at 

 the beginning of the month. As the sun sank into the 

 low-lying cloud bank to westward, the south-western 

 horizon was coloured copper and reddish, while the north- 

 east was bluish-green, with pink clouds above it. After 

 Reddish sun nac ^ set ' colours were as in margin. 



Green The reddish colour was apparently on a 



Orange very fine filmy cloud; above it sky was 



Cloud purple, passing into blue at zenith. The 



reddish glow died down from the top, and the lower 

 colours turned into pale yellow, smoky to S., and pale 

 green to N.W. Finally, a dark red streak was left in 

 S.W., passing into yellow, green, and blue above. Venus 

 appeared shining with bluish light. By 19 h the colours 

 were all gone. Black bulb thermometer was put out at 

 13 h 35 m , highest reading 73° "3, corresponding shade tem- 

 perature 32 o- 0. Moon rose soon after 22 h , and till mid- 

 night was surrounded by a greenish-blue colour for about 

 15° on each side. Below this a reddish hazy colour near 

 horizon. Colour near moon gave faint green, and nothing 

 else in spectroscope. 



Jan. 17. — Mist from 4 U onwards all day. 



Jan. 19. — Very fine in forenoon. Southern horizon 

 yellow, northern faintly green ; no copper colour seen. 

 Black bulb put out, highest reading 76° - 2, shade tem- 

 perature 26"'5. At 14 h clouds began to appear, at 14 b 40 m 

 sky was entirely overcast, and at 16 h top was covered with 

 mist. Wind very high at night from S.W. 



Jan. 20.— Very stormy all day. At 21 b Mr Omond 

 and Mr Rankin went to take observation roped together. 



Jim. 21. — Very stormy in early morning and evening. 

 At 19 h , 20 h , and midnight, Mr Omond and Mr Rankin 

 took observation roped together. No temperature observa- 

 tions taken at 21 h , 22 h , and 23 h . At 19* a bright light 

 was seen along the edge of the cliff, forming a white glare 

 about 10 feet broad, and lighting up the whole top of the 

 hill. May have been due to snow blowing over and getting 

 illuminated from below. 



Jan. 22. — No temperature observation taken at l h , but 

 after that wind moderated, and ordinary observations were 

 resumed. About 9 inches of fresh snow lying over old 

 hard surface. 



Jan. 23. — Very stormy, with heavy snow-drift. At 14 h 

 box so choked with drift that wet and dry were unreadable ; 

 temperature taken from spirit of min. At 15 h the porch 

 was so blocked with drift that exit was impossible, but at 

 16 h observations were resumed. 



Jan. 24. — At l h the door of the thermometer box was 

 found torn off its hinges lying on the snow. Boxes were 

 shifted at 13 h , the first hour at which it was practicable ; 

 but dry and wet were not put out till ] 9 h . In spite of 

 constant drift, the fresh snow was very much blown away. 



Jan. 26. — In forenoon wind backed from S. to S.E., 

 and blew hard. As the drift made it impossible to read 

 thermometer at 13 h , Mr Omond and Mr Rankin went out 

 tied together, but found it impossible to go further than the 

 end of the snow porch with safety ; at 1 6 h they got as far 

 as the box, but could not see instruments as the drift blew 

 up into their faces. No temperature observations were 



TRANS. ROY. SOC. EDIN. VOL. XXXIY 



taken till 22 h , when wind moderated, and observations 

 were resumed. There was thus a gap in the temperature 

 observations from noon to 21 h inclusive. Quarter and half- 

 hourly barometer observations were taken in afternoon. 

 Lowest recorded reading (corrected to 32°) 23 - 173 inches. 



Jan. 28. — At 9 U the thermograph was taken in com- 

 pletely covered with fine snow, which had penetrated by 

 the hinges of the tin box. It was nevertheless working 

 as usual. From 9 h till noon the top was clear, and the sun 

 shone very hotly at times. At noon fog was observed 

 coining on from N.W. 



Jan. 30. — During the day the wind veered to N.W., 

 and at 20 h the fire smoked so badly that the observers 

 had to leave the house and stay outside for nearly an 

 hour, till it moderated. One flash of lightning seen at 

 20 h 30 m . At 22 h the needle of A B C telegraph indicator 

 was found at D. 



Jan. 31. — Top cleared at noon. Copper colour under 

 sun, and green to N.; but not strong. 



Feb. 1. — In evening the wind was very squally ; 

 observers needed to be roped at times. 



Feb. 2. — At 6 h fog cleared off, leaving cumulus (5), 

 and showing a filmy arch of light, extending from north- 

 eastern to south-eastern horizon. At 7 h the eastern horizon 

 was pale green and yellow below, and pink above. At 8 h 

 the pink, yellow, and green had risen higher, and a red band 

 was seen at horizon. By 9 h the sun was shining, with a 

 brownish haze under it ; sky bright and clear. At 10 h the 

 sky was hazy, and a very fine misty or dusty matter was 

 passing along above Glen Nevis ; it was only visible when 

 the sun shone brightly on it. At 10 h 15 m everything was 

 clear, and the colours in the sky very strongly marked ; but 

 at 10 h 30 m the other hills were buried iu fog. The fog con- 

 tinued gathering on and driving over the lower hills, and 

 between 16 h and 17 h the top of Ben Nevis was covered 

 again. At ll h the thermometer box was taken off ladder 

 and placed on a stand 17 inches above snow, while extra 

 joint was being fixed to ladder. After 16 h observation, the 

 max. and min. were put into fresh box on ladder 54 inches 

 above snow, while the old box was taken in. The dry 

 and wet were frozen hard into it, and while taking 

 them out at 23 h the dry bulb was broken. At mid- 

 night wet bulb No. 7 was put out as a dry bulb. 



Feb. 3.— At 4 h crystals of ice and sleet fell. By 15 h 

 the thermometer box was thickly covered with ice; this 

 was cleared off at 19 u , and no fresh ice formed till 7 h on 

 4th. 



Feb. 7. — About noon two birds, thought to be hawks, 

 were seen flying backwards aud forwards over the ridge to 

 N.E. of Ben. 



Feb. 9. — At 15 h hill tops round were seen with very 

 little snow on them. A weasel (white) seen at window next 

 Mr Omond's room. 



Feb. 13. — Not much snow on other hills; apparently 

 none below 3000 feet. 



Feb. 14. — At 16 h fog disappeared off Ben Nevis, leaving 

 white mist rolling about below round the other hills, but 

 sky clear. Faint copper colour to S.W. where horizon 

 was hazy, and very faint yellow-green to N. At 17 h sun 

 was setting into thick bank to S.W.; fog had partly cleared 

 off other hills, and was driving over top of Ben at times. 

 At 17 h 40 m , just after sunset, there was a pale crimson 

 streak above bank of cloud, then belt of stratus dark red, 

 then yellow-green passing above into pale green, then a 



3 Q 



