332 



BEN NEVIS OBSERVATORY. — LOG-BOOK. 



[1885. 



Oct. 21. — At l h fog in valleys, thickest to eastward. 

 No fog in valleys all day, but cumulus fog on distant hills 

 in morning, which lifted and cleared away about noon. 

 Very little colour in the eastern sky at sunrise. Thermo- 

 meter box shifted at 14 u 15 m . 



Oct. 22. — At 3 h very faint brown colour 

 Green and Blue in S ^X un( l er moon. Colours in sky at sun- 

 Purple 



Yellowish-red 

 White 



inner red, 



Red 

 Yellow 

 Green 

 Red 



Yellowish- 

 white 



D 



Oct. 23.- 



ring. 



Red 

 Yellow 

 Green 

 Red 



Colours as in margin. 



rise faint. No fog in valleys all day. 

 Double corona observed at 19 b . Colours 

 as in margin. Radius — Outer red, 10° 53'; 

 green and blue, 6° 55'; purple, 4° 40' ; 

 42' ; white, 2° 25'. Similar corona seen at 

 midnight. Colours as in margin. The 

 outer yellow a very narrow strip. Occa- 

 sionally traces of a third ring were ob- 

 served. Radius of outer red, 4° 56'; inner 

 red, 2° 11* ■ outer yellow, 4° 23'; all good 

 measurements. 

 Double corona at 2 1 ', with at times faint third 

 No blue or green inside the 

 inner red. Yellow, both outer and inner, 

 only a thin strip ; reds and green broader, 

 and not so sharp. Radius of inner red, 2° 

 29' ; outer red, 4° 43' ; inner yellow, 2° 4' ; 

 Yellow-whitish ou ter yellow, 4° 8'. Lunar halo (colourless) 

 * seen at 3 h . Radius to inside of halo, 



21° 48' by stephanome ; outside of halo, 25° 13'. The 

 halo was somewhat indistinct, and the measurements are 

 rather rough. It was again seen at 4 h . At 3 h the cirrus 

 clouds were lying in ridges from W.S.W. 

 to E.N.E., motion not determined. At 20 h 

 faint brown colour in sky under moon. 

 Double corona at midnight formed on 

 driving scud. Colours as in margin. The 

 size varied according to the sort of cloud or 

 fog it was formed on. The following measurements were 

 taken within 3™ of each other. First, radius of inner red, 

 2° 14' ; outer red, 4° 18'. Second, radius of inner red, 

 2° 50' ; outer red, 4° 49'. 



Oct. 24. — At 2 h sky cloudless, and a faint white glow 

 all round horizon. No fog in valleys, except over Loch 

 Lochy, in early morning, but loose fog on hills round in 

 afternoon. Yellow, green, and blue colours in western 

 sky after sunset, and faint brown colour under moon at 

 night. 



Oct. 25. — At 2 h sky cloudless, except for a patch of 

 cumulus over Loch Linnhe, below Ardgour, apparently at 

 4000 or 5000 feet elevation, and approach- 

 ing Ben Nevis. Fog blowing across top at 

 3 1 '. At 4 h double corona, with traces of 

 third ring. As before, the yellows were 

 narrow, and the green broad. Colours as 

 in margin. Radius of inner red, 2° 10' ; 

 outer red, 4° 20'; inner yellow, 1° 45'; 

 ° 50'. White feathery fog crystals forming 



Red 



Yellow 



Bluish-green 



Red 



Bluish-white 



D 



Red 

 Yellow 

 Green 

 Red 

 Yellow 

 Watery-white 

 2> 



outer yellow, 

 in forenoon. 



Oct. 27.— Thermometer box shifted at 1 ' 20 m . St 

 Elmo's fire observed on lightning conductor at 19 h . No 

 sounds heard. 



Oct. 28.— Thermometer box shifted at 1 ' 20 m . 



Oct. 29. — Rain-gauge measurements in early morning 

 quite untrustworthy through drift. Thermometer box 

 shifted at 9 h 10 m . At 14 h brown colour in sky under 

 sun. At 17 1 ' sky very watery to westward. At 19 h faint 



glow to northward, apparently auroral. At 23 h cir.-str. to 

 eastward, on which dim lunar halo was observed. 



Oct. 30. — Top clear at times in early morning, showing 

 very ugly sky above. Very great drift during the day, 

 the whole surface of the hill top being cut up into great 

 trenches wherever the skin of the last fall of snow got 

 broken. At 15 h rain-gauge was taken in, and not put out 

 again till 22 h , as it was only getting filled with drift, and 

 was in danger of being blown away. No snow fell, ap- 

 parently, till after 20 h . 



Nov. 1.— Thermometer box shifted at 12 h 10 m . At 23 h 

 10 m set Robinson going. 



Nov. 3.— At 20 h 10 m tied up Robinson. 



Nov. 5. — Thermometer box shifted at 2 h 15 m . 



Nov. 6. — Started Robinson anemometer at 22 b . 



Nov. 8. — Robinson anemometer tied up at 19 h . Fog 

 crystals forming freely at night. 



Nov. 9. — At 7 h fog very thick, but of a faint red colour. 

 Fog cleared suddenly at 13 h 10 m sinking below Ben Nevis, 

 but still covering all the other hills. It continued blowing 

 across the top at times all afternoon, but was quite below 

 Ben Nevis at night. Faint white light, possibly auroral, 

 to N. and N.N.W. at horizon all night. 



Nov. 10. — At 7 h bright yellow and orange colours at 

 eastern horizon, and faint glow on cirri clouds above. 

 Fog covering the hills to 3000 or 4000 feet all day ; 

 quite level topped. No unusual colours in sky. Started 

 Robinson anemometer at 14 h 5 m . Aurora at night. It 

 got gradually fainter as the night went on ; no streamers 

 were observed except one at 21 h . 



Nov. 11. — At 6 h deep scarlet colour at eastern horizon. 

 At 7 h broad orange band fringed with faint purple above 

 to eastward. Also very faint upper glow. From sights 

 taken during the night it was determined the aurora of 

 last night extended from 2° above horizon to from 10° to 

 15°. At 9 h glory with one ring observed. Radius to 

 outside of the red, 2° 21'; inside, 1° 44'. At 15 h glory 

 with 3 reds observed. The inner a mere blotch, the next 

 well-marked ring with most of the colours ; outermost the 

 same, but much fainter. Radius of red 1 = 3° 46' ; red 2 

 = 1° 52' — (red outside in both rings). At 16 h 30 m pink 

 band above E. and N.E. horizon ; no sunset colours except 

 faint afterglow. Aurora with streamers at night. At 

 22 h the fog, which had stood at about 4000 feet all day, 

 rose suddenly higher than, and enveloped, the top. The 

 temperature fell at once, and the wind lulled gradually. 

 After the midnight observation the Robinson anemometer 

 was tied up. 



Nov. 13. — Very icy fog crystals on exposed surfaces. 

 Thermometer box shifted at 22 h 20 m . 



Nov. 14. — New 5-inch rain-gauges with slightly rounded 

 bottoms came up to-day. One was put out at 15 h instead 

 of the old pattern with stop-cock. 



Nov. 15. — Haze and detached cumulus at horizon all 

 morning. At 8' 1 reddish look all round horizon above the 

 haze. No fog in valleys. Red or brown colour under 

 sun all day. At 14 h whitish-green colour all round 

 horizon. At 15 h cloud or fog-bank on Atlantic beyond 

 Mull. At 19 h faint corona observed. Colours hardly 

 distinguishable. Outside radius, 3° 46'. At 22 h low fog 

 bank to S.W. and faint brown colour under moon. 



Nov. 16.- — At 9 h large glory on passing fog; colours 

 as in fig. 6 ; the inner red being close to the shadow of 

 the observer's head. Radius of red 2 , 7° 38'. Third red 



