1893.] 



BEN NEVIS OBSERVATORY.— LOG-BOOK. 



97 



Nov. 21. — Sky cloudless till 7 h , and a little cloudy 

 with cirrus till ll h ; since then mist and log, with 

 drizzling rain and snow after 23 h . Fog on hills and 

 in valleys to N. and W. in early morning. By ll h it 

 had spread all round, and at times was blowing over Ben 

 Nevis, and at 12 h it had settled down on summit. 



Nov. 23. — Fog or overcast sky, clouds just tipping hill 

 tops all round. Thermometer box changed at h 20 m , 

 and raised one step up on ladder. Height above snow, 54 

 inches. 



Nov. 26. — Summit clear from 7 h till ll h , and again at 

 16 h and 19 h , but sky almost overcast. After 20 h fog was 

 very thin, and did not appear to be much higher than 

 Ben Nevis, as the moon and stars could be seen distinctly 

 through it. Lunar fog-bows and coronse were seen from 

 21 h till midnight. Thermometer box changed at 9 h 10 m . 

 Height above snow not altered. 



Nov. 29. — Mist with very heavy rain till 18 h , and snow 

 and sleet thereafter, the greatest hourly rainfall being 

 0"413 at I6 h . This evening the usual report could not 

 be sent to papers, owing to telegraphic communication 

 breaking down. No signals were got from either post- 

 office or low-level observatory all day. 



Nov. 30.— Therm nneter box shifted at 18 h 15 m . 

 Height above snow, 42 inches. To-day Mr Jackson, 

 telegraph lineman, came up and tested instrument, and 

 found all right at this end. In the evening, communica- 

 tion was opened with post-office and low-level observatory, 

 the fault being found in cable between Bed Burn crossing 

 and Achintee. The report was sent to daily papers at 

 the usual time. 



Dec. 2. — Summit clear after 4 h , and sky cloudless till 

 8 h , and fog on hills all around except to W. Fog on 

 again at 9 h . Air dry at 7 h , the humidity was 39 per cent. 

 Snow fell after 14 h , and sleet at 20 h . Thermometer box 

 changed at 6 h 15 m . Height not altered. 



Dec. 5. — Mist, with heavy rain and drizzle, with some 

 showers of snow and sleet all day. Glnzed frost forming, 

 temperature being 32° or less, except at 15 h and 16 h , when 

 it was 33°. 



Dec. 8. — Barometer falling quickly till 10 h , and till 

 this hour a strong S.E. gale blew. Thereafter the 

 barometer rose, and the wind veered to S.W. and W., and 



and thunder 

 Elmo's Fire 



moderated to a gusty breeze. Snow fell most of the day, 

 but owing to the strong wind and heavy snow drift the 

 gauge was not out. From 4 h to 7 h inclusive the tempera- 

 ture was taken from the tower box instead of the usual 

 screen outside. Flashes of lightning were 3een at 18 h , 

 and St. Elmo's Fire was noted at midnight. 



Dec. 9. — At 15 h 30 m thermometer box was changed. 

 The fresh box was put one step higher than last on ladder 

 stand. 



Dec. 10. — Barometer falling till 18 h . Wind backed to 

 S.E. by 6 h , and blew a whole gale till 18 h . Thereafter it 

 veered and moderated. At 17 h and 18 h the temperature 

 readings were taken from the tower thermometer. Heavy 

 drift all day ; but apparently there was no snow falling 

 till evening. At 10 h , 12 h and 13 h the summit was clear 

 and the air dry. 



Dec. 11. — Flashes of lightning seen at l 1 ', 

 heard at 10 h . Heavy drift all morning. St, 

 seen at 23 h . 



Dec. 14.— Flashes of lightning seen at 7 h 



Dec. 15. — Thermometer box changed at 15 h 30™. 

 Height of box same as last. Temperature rose in after- 

 noon to 36°, and with heavy rain and high wind, the snow 

 was thawing quickly all evening. 



Dec. 17. — Thermometer box changed at 14 h 10 m . 

 Height above snow not altered. 



Dec. 22. — Several flashes of lightning, accompanied by 

 clicks in the telegraph instrument, seen between 19 h and 

 20 h . 



Dec. 26. — Fog except at 23 h , when top was clear. 

 Sky covered with cir.-cumulus. Snow showers in early 

 morning, drizzling rain forming glazed frost in afternoon. 

 Thermometer box changed at 15 b 30 m . The box was 

 raised a step on ladder stand, being now the highest on 

 the fixed ladder. 



Dec. 28. — Sky cloudy till 6 h , and summit clear except 

 for passing mist. Mist and drizzle during the rest of the 

 day. 



Dec. 29. — Mist or fog, and drizzling rain, with S.W. 

 to W. winds. Glazed frost forming. 



Dec. 30. — Mist and heavy drizzle all day. Wind 

 veering from W. in morning to N.W. at night. Glazed 

 frost forming. 



INSTRUMENTS, ETC., 1893. 



Barometer No. 1385 has been in use all through the 

 year ; No. 1285 has not been used. 



Thermometers. Dry bulbs 535541 and 192677, with 

 wet bulbs 535542 and 192671, have been in use. A 

 new set was added to stock iu December — Nos. 861089- 

 86 1 090 — but they have not been used yet. 



From May 9 to September 24, when the large ther- 

 mometer screen was in use, maximum thermometer 117293 

 and minimum 116918 were in use. During the rest of the 



TRANS. ROY. SOC. EDIN. — VOL. XLI1I. 



year minimum thermometers 138533 and 138545 were put 

 out in the small box on ladder stand. The bent 

 thermometer for the tower storm-box has been used 

 occasionally. Black bulb No. 186 was in use from June 

 8, when it was brought up from low-level observatory. 

 The usual patterns of 5-inch rain gauge have been in use, 

 the smaller size in summer and the larger in winter. The 

 Campbell-Stokes sunshine recorder has been in use. The 

 anemometer has been out of order all through the year, 



