METEOROLOGICAL OBSERVATIONS ON BEN NEVIS. 223 



The mean hourly velocity of the wind at the top of Ben Nevis was 

 12 miles for the year, being the lowest velocity of any year since the 

 observations began . The maximum mean monthly velocity was 18 miles 

 an hour in December, and the minimum only 6 miles in June. For the 

 three summer months, June, July, and August, the mean was at the rate 

 of 9 miles per hour, but for the three winter months, December, January, 

 and February, it was 15 miles per hour. These are respectively the 

 lowest mean summer and the lowest mean winter velocities of the wind 

 hitherto recorded at this Observatory. 



The rainfall for the year at the top of Ben Nevis was 133'56 inches, 

 being 15'56 inclies greater than the rainfall of 1895. It was, however, 

 11-95 inches under the average of the past observations. The highest 

 monthly amount was 19-54 inches in March, and the lowest 2-91 inches in 

 May, being the smallest rainfall of any previous May. The heaviest fall 

 on any single day was 2-94 inches on January 17, which is absolutely the 

 least daily maximum fall yet recorded for any year. 



On the top rain fell on 259 days, and at Fort William on 237 days, 

 these numbers of days being the average rainy days at the two Observa- 

 tories. At the top the maximum number of rainy days was 26 in March, 

 April, and October ; and at Fort William, 24 in January, March, and 

 December. The minimum number of days of rain at the top was 12 days 

 in May, and at Fort William 7 days, also in May. 



During the year the number of days on which an inch of rain, or more, 

 was precipitated was 44 at the top and 16 at Fort William ; at the latter 

 place an inch of rain was not reached on any day of April, May, June, 

 July and November, but at the top, on the other hand, this amount was 

 exceeded on 7 days of March, while May had only one such day. 



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

 January 3, 4, 5, 6, 7, 9, 22, 29, 30, 31 ; February 2, 3, 12, 13, 17, 18, 19 ; 

 March 11, 12, 13, 14, 23, 30, 31 ; April 14, 15 ; May 2, 3, 4, 11, 17 ;. 

 September 4 ; October 11, 13, 14, 15, 17 • November 8. 



St. Elmo's Fire was seen on January 12, 27 ; June 20 ; October 5 ; 

 December 26. 



The Zodiacal Light, March 12, 13. 



Thunder and lightning was reported on January 20 ; April 10 ; 

 June 4 ; September 16. 



Lightning only, September 14 ; December 31. 



It was intimated in last year's Report that an intermediate station 

 had been established on Ben Nevis, at a height of 2,322 feet, or neai-ly 

 midway in height between the two Observatories. This temporary 

 station was established for the purpose of ascertaining with greater pre- 

 cision than has hitherto been possible the extent to which anticyclones 

 descend on the mountain ; but more particularly the relations of pressure, 

 temperature, humidity, rainfall, cloud, and wind at this intei'mediate 

 station with the observations at Fort William and on the summit of Ben 

 Nevis. The three stations are in a line with each other, and the heights 

 are 4,406, 2,322, and 42 feet. The observations were made by Mr. Muir, 

 of the Royal High School of Edinburgh, during September. A report on 

 the observations was prepared by Mr. Muir and read by him at a Meeting 

 of the Royal Society of Edinburgh last winter. The observations at this 

 intermediate station have been again resumed this year, and arrangements 

 have been made for a continuous record of observations from July 19 to 

 September 30. This year the weather fortunately has hitherto (till 



