176 REPORT—1890. 
1883. The maximum was 61°°8 on July 4. Thus the extreme range 
of temperature for the year was 55°'4. 
The registrations of the sunshine-recorder showed 634 hours of sun- 
shine as against 970 hours of the previous year, the latter year thus 
showing a half more hours. The largest number, 213, was recorded in 
June, and the lowest, 9, in August, being the lowest that has occurred 
hitherto in any summer month. As the highest possible hours for the 
whole is 4,47, sunshine prevailed on the top of the Ben during only one 
hour in seven in 1889. 
The amount of the rainfall during the year was 120°66 inches, being 
about ten inches less than the average, the least rainfall being 1:94 inch 
in June, and the greatest 18°04 inches in December, and 17°69 inches in 
January. The number of days on which the precipitation was either nal 
or less than 0°01 inch, was 85, or 15 days fewer than the average; 
the least being 2 in February and August, and the greatest 15 in June. 
On the other hand, the number of days on which 1 inch of rain or 
more fell was 37, or nearly one day in 10, being a little less frequent 
than in previous years. The highest fall for any day was 2:93 inches on 
August 28; and from March 23 to 25 there fell 5°83 inches. No rain 
fell from June 16 to 27; on the other hand, from 3 p.m. of December 7 
to 1 a.m. of the 11th, there was only one hour without rain. 
Atmospheric pressure at Fort William was 29-891 inches, or 0-063 
inch above the average pressure. In November it was 0°255 inch above 
the mean, and in October 0°183 inch below it. June was not only the 
month of greatest pressure, but it was also the month of highest mean 
temperature, being about 5 per cent. in excess of its average. This 
conjunction of high temperature with high pressure during the summer 
months is a noteworthy feature in the meteorology of the Ben, these 
occurring during the times when anticyclonic weather prevails over this 
part of Europe. It will also be observed that during the time the tem- 
perature difference between the high and low level stations was only 
14°°7, or about two degrees less than the average of June. In June 
1887, when the anticyclonic systems were more pronounced than in 
1889, the difference fell as low as 12°°9. At these times the air is 
markedly dry as well as warm, pointing for the explanation to the 
descending currents of the anticyclones, and not to ascending currents 
from the superheated lower grounds. It may be remarked here that the 
observations of the wind on the top of the mountain show conclusively 
that the outflowing winds from cyclonic to anticyclonic regions set in 
sooner and at greatly lower levels than had previously been supposed. 
Observations have now been made on Ben Nevis for upwards of six 
years, or since the observatory was opened in the end of 1883, and, if 
the observations by Mr. Wragge be added, for nine years during the 
warmer months from June to October; and during the same time 
observations have been made near sea-level at Fort William. 
As these form a unique double series of observations in meteorology, 
and as they furnish the observational data necessary in all investigations in 
atmospheric physics into which height in the atmosphere enters, it is 
thought to be useful to embody in this Report, in Table IT., the more 
prominent of the results derived from the observations of the two 
stations. The times from which the data have been deduced are six 
years from January to May, nine years from June to October, and seven 
