190 REroKT— 1805. 



The mean hourly velocity of the wind at the top was 16 miles, the 

 monthly mean maximum being 26 miles in January, and the minimum 

 10 miles in June. For the five months from May to September the mean 

 was 11 miles per hour, but for the six months from November to April 

 the mean was 20 miles per hour. The relations here indicated among the 

 .seasons .substantially hold good year by year. 



The rainfall for the year at the top was 149-96 inches, being 3'63 inches 

 above the average. At Fort William the amount was 79'17 inches, which 

 is 4'07 inches above the average. The maximum monthly rainfall at 

 the top was 33"5.5 inches in February, and the minimum 1-32 inch in 

 September. At Fort William the maximum monthly fall was 13-02 

 inches in February, and the minimum fall 0-24 inch in September. 

 The above are the smallest monthly amounts yet recorded at either of 

 the Observatories, and the maxima are higher than any hitherto recorded 

 for February. 



These two months were a strong contrast to each other. In February, 

 cyclone succeeded cyclone in swift succession to each other accompanied 

 with heavy and destructive gales, deluges of rain, and heavy snowfalls ; 

 whereas September was for much the greater part of the month under 

 the influence of anticyclones, accompanied with clear sky, dry and well- 

 nigh rainless weather. At the top of the Ben 6-67 inches of rain fell on 

 February 6, being, except on October 3, 1890, the greatest daily fall on 

 the records of the Observatory. 



At the top the rain fell on 246 days, and at Fort William on 208 days, 

 being respectively 14 and 30 days under their averages. The maximum 

 number of days on which rain fell at the top and at Fort William was 27 

 days in January, and the minimum number 9 days at the top and 5 at 

 Fort William in September. 



During the year the number of days on which an inch of rain was 

 exceeded was 46 days on Ben Nevis and at Fort William 16 days. In 

 February the numbers were 11 days and 3 days respectively. 



Auroras are reported to have been observed on the following dates : — 

 February 13, 25 ; March 24, 25, 30, 31 ; April 28 ; August 23, 31 ; Sep- 

 tember 1, 2, 27, 30; October 2, 4, 5, 26, 27, 30, 31; November 23,24, 26; 

 December 1. 



St. Elmo's Fire was seen on January 25 ; February 4, 9 ; March, 3, 5, 

 6, 9, 12 ; May 29, 30; June 18; July 7, 21; November 8, 15. 



The Zodiacal Light was observed on March 24, 25, 26. 



Thunder and lightning reported on February 3, 8 ; July 6, 7, 21 ; 

 August 15; September 17; lightning only on January 29, February 4, 25. 



Almost daily during the last week of February there were strong 

 earth- currents in the telegraph cable between the base and summit of the 

 hill. 



At Fort William the mean atmospheric pressure at 32° and sea-level 

 was 29-845 inches, and at the top 25-291 inches, the difference being thus 

 4-554 inches, being only very slightly above their averages. At the top 

 the highest pressure during the year was 25-992 inches in June, and the 

 lowest 23-742 inches in December, the difference being 2*250 inches, a 

 rather large difference. 



Mr. A. J. Herbertson has made further progress in carrying on, at 

 the two Observatories and in the south of France, the research on the 

 hygrometry of the atmosphere referred to in last report. The work is 

 now in an advanced stage of preparation, and the results will shortly b<» 



