xxvm 



METEOROLOGY OF BEN NEVIS. 



two days, December 12 and 13, 1885, the amount precipitated was 8*86 inches. 

 For five day periods the following are the largest — December ] 1-15, 1885, 

 10-25 inches; October 1-5, 1885, 10-02 inches; November 5-9, 1884, 991 

 inches ; December, 6-10, 1884, 983 inches ; and December 30 to January 

 3, 1886, 9-25 inches. 



1881, . 



1882, . 

 1883,. 



1884, . 



1885, . 



1886, . 



1887, . 



1881, . 

 1882, . 

 1883, . 



1884, . 



1885, . 



1886, . 



1887, .- 



Means B. N. O. 

 „ F.-W., 



Jan. 



I 

 Feb. I Mar. April. 



May. 



June. July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. Year. 



Ben Nevis Observatory. 



16-94 

 2-84 



12-82 

 5-91 



4-86 

 4-59 



8-37 

 6-25 



12 



15 



m. 

 12-34 

 11-39 

 12-61 

 8-62 

 7-56 

 10-16 



in. 



6-09 

 10-25 



9-77 

 11-66 

 20-87 

 13-03 



19-10 



9-80 



14-57 



25-29 

 24-33 

 10-98 



146-50 

 107-85 



1780 13-30 5-90 7"53 3-97 7 '51 14-54 8*71 10-99 12-19 8-99 17 "58 129-01 



Fort- William. 



5-63 



8-34 



12-73 



12-70 

 8-90 









... 



6-25 



10-88 



6-41 



1-97 



4-23 















3 95 



6-15 



4-30 



5-50 



4-04 















2-44 



3-30 



6-74 



3-46 



















6-34 



5-80 



6-13 



13-77 



13-55 



11-61 



12-45 



4-85 



4-47 



4-21 



3-25 



375 



3-15 



11-71 



8-70 



6-64 



13-86 



4-76 



4-96 



4-98 



3-88 



3-05 



5-60 



4-95 



8-76 



5-58 



8-96 



7-31 



11-39 



3-49 



3-48 



1-86 



3-33 



7-90 



3-02 



4-55 



6-22 



5-09 



8-18 



11-03 



8-21 



5-66 



6-20 



8-06 



10-85 



10-20 



11-81 



12-10 



13-12 



19-53 



9-53 



4-43 



4-31 



3-32 



3-71 



6-32 



4-91 



6-01 



7-09 



8-56 



10-24 



82-67 

 71-13 

 71-24 



129-47 

 77-33 



From the commencement of the hourly observations of rain and other forms 

 of precipitation in the beginning of July 1884 to December 31, 1887, there are 

 1279 days. Of these 1279 days there have been 361 days in which either no 

 rain at all or less than the hundredth of an inch was collected ; so that on Ben 

 Nevis one day in from three to four days has been without rain. The fewest 

 rainless days occur in December, and largest number in April, the proportions 

 being about 1 in 6 and 1 in 2 days respectively. 



On the other hand, if we accept l'OO inch as representing a very rainy day, 

 there occurred in the same period 145 days on which 1-00 or upwards was 

 recorded, being thus in the proportion of 1 day in 9. The largest number of 

 such days was 9 a month, in December ; then follow September, October, and 

 November with about 6 each ; and the smallest about one a month, in April, 

 May, and June. The months of these groups are severally successive, the 

 former being the time of the year when the great annual fall of temperature 

 takes place, and the latter the time of the great increase of temperature. An 

 inch of rain was not recorded on any day in June 1885 and February 1886, and 

 in 6 of the 17 months this amount occurred only on 1 day in each month. 



Diurnal Phenomena. 



Diurnal Variation of Temperature. — During the four years the barometric 

 observations have been made without the break of a single hour. As, however, 



