METEOROLOGICAL OBSERVATIONS OX 1!EN NEVIS. 



49 



In Table III. are given for each month 

 metric readings at the top of Ben Nevis : — 



Table III. 



the lowest observed hygro- 



Of these relative humidities, the lowest 10 occurred on January 27 with 

 a dew-point of — 22°-9, and the highest 42 on July 30 with a dew- 

 point of 25°-4. It is to be noted that with these humidities the accom- 

 panying dew-point fell in five of the months below zero, thus being in 

 striking contrast with the lowest monthly humidities of the previous year, 

 when the lowest was only 23, and the dew-point fell below zero only in 

 December. 



The sunshine recorder on Ben Nevis showed 897 hours out of a possible 

 4,470 hours, being 132 hours more than in 1898, or 20 per cent, of the 

 possible sunshine. This far exceeded the average of past years, which 

 is only 750 hours, being only exceeded in 1888, when the number of hours 

 was 970. The minimum occurred in 1884, when only 510 hours were 

 registered by the sunshine recorder. At Fort William the number of 

 hours was 1,139, being 102 hours fewer than in 1898. At both observa- 

 tories the monthly maximum was in August, being 231 hours at Fort 

 William and 212 hours at the top of Ben Nevis, amounts nearly d uble 

 the average of any previous August. This unwonted amount of sunshine 

 was occasioned by the strongly pronounced anticyclonic character of the 

 weather of August 1899. In the following month, September, only 12 

 hours were recorded at the Ben Nevis Observatory, or less than 1 per 

 cent, of the possible sunshine. In no previous summer month has the 

 recorded sunshine been so decidedly deficient. 



At the Ben Nevis Observatory the mean percentage of cloud was 82, 

 or a little under the average, the highest being 96 in September, and the 

 lowest 60 in August. At Fort William the mean was 74, the highest 

 being 87 in November, and the lowest 54 in August, or little more than 

 a sky half covered with cloud. 



The mean raiuband observation (scale 0-8) was 2 '2 at the top for the 

 year, the maximum being 3"0 in July, and the minimum 1-5 in February. 

 The annual mean at Fort William was 3*7, the maximum being 4-8 in 

 November, and the minimum 2 9 in February. 



The mean hourly velocity of the wind at the top of the mountain was 

 at the rate of 15 miles per hour, the maximum monthly velocity being 20 

 miles in February and the minimum 10 miles in May, July, and August 



The rainfall for the year at the Ben Nevis Observatory was 187 '30 

 inches, being 31-82 inches, or 22 per cent, above the average. This large 

 annual rainfall has been only twice exceeded, viz. in 1898 and 1890, when 

 it was respectively 240-05 inches and 197-95 inches. It is noteworthy 

 that while the rainfall at the top of Ben Nevis was 22 per cent above 



1900. H 



