METEOROLOGICAL OBSERVATIONS OX BEN NEVIS. 57 



Of these relative humidities the lowest, 16, occurred on March 4 with 

 a dew-point of — 12°'9. The lowest dew point, — 19°-7, occurred on 

 February 11, the dry bulb being 12°'9 and the wet bulb 9°'2. A marked 

 feature of the table is the singularly high minimum humidities in April, 

 May, June, July, and December. 



The rainfall for the year at the top was 210-34 inches, being 

 52-61 inches, or 33 per cent., above the average. This large rainfall has 

 been exceeded only by that of 1898, which amounted to 240-05 inches. 

 The December amount, 48-34 inches, is the largest monthly fall yet 

 recorded at the Ben Nevis Observatory. The following are the four 

 wettest months of the yeai- : — 



Inches 



December 4834 



January . . . . . . . 35 32 



October 20 93 



AprU 20-22 



Total . . 124-81 in four months. 



Taking Scotland as a whole, the year 1900 was one of the wettest yet 

 recorded, and has been only exceeded by the rainfall of 1872. Excep- 

 tionally heavy daily rainfalls were of frequent occurrence, the two 

 heaviest being 6 81 inches on January 22, and 5-41 inches on December 8. 

 At Fort William the annual rainfall was 8219 inches, being 5-28 inches, 

 or 7 per cent., above the average. The largest monthly amount was 

 2085 inches in December, accompanying the extraordinary prevalence of 

 south-westerly winds during the month. 



At the top of Ben Nevis the number of rainy days was 276, and at 

 Fort William 246. At the top the maximum monthly was 30 days in 

 January and December, and at Fort William 31 days in December and 



28 days in January. In March there were only 15 rainy days at the top 

 and 10 days at Fort William. During the year the number of days on 

 which 1 inch of rain or more fell at the top was 69, whereas at Fort 

 William the number of days was only 15. 



The sunshine recorder on Ben Nevis showed 718 hours out of a 

 possible of 4,470 hours, or 16 per cent, of the possible sunshine. The 

 average of the past 17 years being 747 hours, the sunshine of 1900 was 



29 hours under the average. The two maximum months are June, 139 

 hours, and March, 103 hours, and the two minimum months January and 

 December, with 4 hours each. At Fort William the number of hours 

 was 1,040. This is lower than any recorded since these observations 

 began to be made, except in 1896, when the number was 1,036 hours. 

 The maximum, 182, was recorded in June, and the minimum, 1 hour 

 only, in December. This is the lowest minimum yet recorded, but the 

 same low minimum, 1 hour, was also recorded at the top for December 

 1883. In the three summer months, June, July, and August, of 1899 

 the hours of sunshine at the top were 425, and at Fort William 488 ; but 

 in the same months of 1900 these were respectively only 279 and 418. 



At the Ben Nevis Observatory the mean percentage of cloud was 84, 

 and at Fort William 73, both being very nearly the average. At the top 

 the high mean percentages of 97 in December and 96 in January were 

 observed ; and at Fort William 88 per cent, in July and 86 in December. 



Auroras were observed only once, viz., March 2. This is in accord- 

 ance with the number of sunspots being near the minimum at this time. 



