334 



BEN NEVIS OBSERVATORY.— LOG-BOOK. 



[1885. 



glow was gone, bat there was a white glare in the sky 

 above a brick-red streak at horizon. Sun rose egg-shaped, 

 long axis horizontal, and took 4 m 20 s to rise. At 9 h the 

 shadow of Ben Nevis was seen on pink-coloured haze 

 above the horizon to N.W. At 10 h brown colour under 

 sun, and misty looking glare round it. At ll h faint solar 

 halo, white. One bright spot horizontally to eastward 

 of sun. Brown colour under sun, and faint pinkish hue 

 above sun inside the halo. Radius of halo by stephanome 

 23° 3'. Brown colour under sun all afternoon. Halo 

 faintly seen till 13 h . At 16 h faint glow all round horizon 

 from about 5° to 15°. Eastern horizon dirty green 

 under this. At 16 h 20 m distinct upper glow; it had 

 the appearance of a cloud of very loose texture lit up from 

 below. Trace of this upper glow at 17 h , and red and 

 yellow sunset colours. Sun set about 15 h 50 m . No 

 unusual colours in sky at night. 



Dec. 19. — Dense fog above Loch Linnhe and in Cale- 

 donian Valley to about 4000 feet in early morning. At 

 3 h faint blue corona 3° 4', radius round moon. The edge 

 of the corona was the brightest part ; but the whole space 

 was blue, and no other colour was visible. At 4 h similar 

 corona, 3° 20' radius, but with very faint red edge to it 

 outside. At same hour brown colour in sky under moon. 

 At 8 h faint upper" glow. At 8 h 16 m this glow formed a 

 pyramid, height about 20°, base 45°, the base line 

 being 6° above horizon. At 8 h 25 m this glow was almost 

 gone. At 8 h 40 m a white glare had taken its place. At 

 9 h dense haze and fog in valleys, with the shadow of 

 Ben Nevis distinctly seen on it. At 10 h and during the 

 rest of the day, brown colour under sun. Sunset colours 

 weak, and afterglow very faint. The haze and fog rose 

 higher at night and gradually covered the hill top. 



Note. — The sun when rising was much elongated 

 horizontally ; it took 6 minutes to rise. At 17 h lunar 

 corona, red outside. Radius to outside of red, 4° 13' ; 

 inside of blue, 2° 55'. After midnight Robinson anemo- 

 meter was tied up. 



Dec. 20. — In early morning fog crystals were brown in 

 colour and loose in texture. During the forenoon these 

 were overlaid by white ones considerably harder and 

 ._ , more icy. The former ones came with S. 



Yellow wind and fog, the latter with S.S.W. or 



Blue S.W. and mist. Double corona at mid- 



Red night ; colours as in margin, but very 



BhuU wMte Pale and faint Radius of inner red > 3 ° 3 '- 

 Fog to 4000 feet all round. Thermometer 



box shifted at 23 h 15 m . 



Dec. 21. — At 5 h triple lunar corona, reds outside. 

 Radius of inner red, 1° 5'; middle red, 1° 55'; outer red, 

 2° 55'. Also lunar fog-bow. Very soft snow falling all 

 afternoon. 



Dec. 22. — Thermometer box shifted at 15 h 15 m . Lunar 



Red halo, white, at 23 h . Radius to inside, 



Yellow 20° 41' and 20° 1G'; outside, 27° 29' and 



Blue 27° 23'. Two measurements. 



5*^, Dec. 23.— Triple lunar corona at 4 h , 



Yellow , . r . 



Pale green colours as in margin, outer ring very 



faint. Badius of innermost red, 1° 35' ; 



Dec. 24.— Robinson anemometer was started at 15 h , 

 but was tied up again after midnight. Fog (or mist) in 

 valleys to at least 4000 feet all evening. 



Dec. 25. — All exposed surfaces and the louvres of the 

 thermometer box heavily covered with solid ice all day. 



Dec. 26.— Thermometer box shifted at 8 1 ' 10 m . Ice 

 forming on exposed surfaces at night, but not so freely as 

 yesterday. Drizzling rain fell in the evening, though the 

 sky was clear, and the mist hardly rose higher than the 

 hill top. 



Dec. 27. — Ice on everything, and louvres of thermo- 

 meter box badly choked ; ladder outside tower impassable. 

 Thermometer box shifted at 22 h 30 m . 



Dec. 28.— Thermometer box shifted at 10 h 30 m . 



Dec. 29.— Thermometer box shifted at 17 h 15 m . Very 

 squally at night. 



Dec. 31. — Robinson anemometer started at 22 h 10 m . 



Red 



Yellow 



Bluish-yellow 



i 



innermost yellow, 1° 11' ; outside of green, 

 2° 26' ; middle yellow, 2° 48' ; middle red, 

 3° 12'. 



Notes of Instruments in use during 1885. 



Fortin Barometer 1385, Negretti and Zambra. 



Dry and Wet Bulbs 192,660 and 192,672, Adie and 

 Wedderburn ; also 192,677, Adie and Wedderburn, and 

 50,852, Negretti and Zambra ; and occasionally 50,945, 

 50,851 or 50,850, Negretti and Zambra. 



Maximum Thermometer 117,293, Adie and Wedder- 

 burn, from July 25 to Oct. 6. 



Minimum Thermometer 138,533 or 138,545, Adie and 

 Wedderburn, Jan. 1 to July 24, and Oct. 7 to Dec. 31 ; 

 116,918, Adie and Wedderburn, July 25 to Oct. 6. 



Small size of louvred Thermometer Box on ladder 

 stand, Jan. 1 to July 24, and Oct. 7 to Dec. 31. Large 

 louvred box (old clock box), July 25 to Oct. 6. 



Solar Radiation Thermometer (black bulb in vacuo) 

 186, Hicks. 



Radiation Minimum (T-hollow cylindrical bulb) 46,309, 

 Hicks. 



Sunshine Recorder, Casella (made specially). 



Ozone test papers supplied by Casella. 



Anemometers, Robinson (velocity) and Chrystal (direc- 

 tion) by Frazer, Edinburgh. 



Rain Gauges. Jan. 1-Jan. 8, gauges with side screw 

 plug. Till Jan. 14, various. Jan. 15-Nov. 14, gauges 

 with rounded bottoms and stopcock. Nov. 14-Dec. 31, 

 gauge with slightly rounded bottoms and screw plug. 



The rain gauge measurements were interrupted several 

 times by drift. 



From Feb. 21, 8 h , to Feb. 22, 7 h , no temperature obser- 

 vations could be taken. 



With the above exceptions, barometer, dry bulb, wet 

 bulb, rain, wind, cloud and sunshine records are con- 

 tinuous. 



The Radiation Thermometers could only be used in 

 moderately fine weather. The anemometers were often 

 frozen up, or out of repair. 



The ozone tests were read twice daily for twelve hours 

 each, but the usual saturated condition of the atmosphere 

 made their indications very unreliable. The papers were 

 occasionally blown away in strong gales, and the observa- 

 tion thus lost. 



