ON METEOROLOGICAL OBSERVATIONS ON BEN NEVIS. 



109^ 



For the year 1893 Table I. gives the monthly mean and extreme 

 pressures, temperatures, hours of sunshine, amounts of clouds and rainfall, 

 and number of days of no rain on the one hand, and on the other of days 

 when the rainfall was not less than one inch at the two observatories, the 

 mean pressures at the top being reduced to 32° only, while those at Fort 

 AVilliam are reduced to 32° and sea level. 



The mean temperature of the year at Fort William was 48°-5, being 

 3°-2 greater than that of the previous year, and 1°'3 in excess of the mean 

 annual temperature of the place. The mean at the top of the mountain 

 was 33°"0, which is 3°"3 in excess of the previous year and 2°'2 greater 

 than the mean annual temperature deduced from all the observations 

 made since 1881. The following show the deviations of the monthly- 

 results from their respective means : — 



Top of Ben Nevis Fort William 

 o o 



January . 

 February . 

 March 

 April . 

 May . 

 June . 

 July . 

 August 

 September 

 October 

 November 

 December . 

 Year 



Thus the outstanding feature of the meteorology of the year was the 

 abnormally high temperature which prevailed during the six months from 

 March to August. The mean temperature at the top for the six months 

 was then 5° above the mean, whilst at Fort William it was only 2°'8, or 

 but little more than half the excess at the top of the mountain. The 

 reason for this extraordinary difference is the remarkable and prolonged 



