271 
1891 - 92 .] Meetings of the Society. 
importance in Meteorology, most of which have appeared in the 
Society’s publications. 
His first inquiry resulted in determining, by Eobinson’s ane- 
mometer, the exact numerical value at the rate of miles per hour of 
the estimations of wind-force made by the Observatory staff. An im- 
portant paper followed on the formation of snow crystals from fog, 
which is one of the most striking phenomena of the meteorology of 
Ben Nevis. The conditions of growth, and rate of growth, of these 
crystals were detailed, as well as their intimate bearing on the 
methods to be adopted in carrying on any satisfactory system of the 
observation of air temperatures at High Level Observatories. 
He has calculated the mean temperature of every day of the year, 
both for the Observatory and Fort William, and investigated their 
relations to each other, and the striking differences as regards their 
amount and the varying times of occurrence of their means, maxima, 
’minima, and other noteworthy variations in the rise and fall of 
the annual curves. The question of the variation of the tempera- 
ture at different heights above the ground has also been investi- 
gated. He has paid particular attention to coronas, halos, glories, 
and the other optical phenomena exhibited in sunshine by mountain 
mists. These have been examined by a very extensive series of 
measurements and accurate records of the different arrangements of 
colours of these phenomena, which are justly regarded as an 
important, and to a large extent novel, contribution to this branch 
of physics. 
The relative frequency of the different winds has been ascertained, 
together with the percentage of the whole rainfall which falls with 
each wind. The relation of the results to cyclonic and non-cyclonic 
periods has been shown, from which it follows that four-fifths of the 
whole rainfall is precipitated during the passage of cyclones across 
that part of Europe. In non-cyclonic periods, almost the whole falls 
with N., N.W., and W. winds. The marked types of weather that 
accompany anticyclones according to the direction in which they 
lie to the Observatory at the time, and the equally marked wetness 
or dryness of particular winds according as they blow out of an 
anticyclone, or inwards upon a cyclone, have been clearly worked 
out. The diurnal variation in the direction of the summer winds 
has also been ascertained. 
He has recently completed an exhaustive examination of the winds 
of Ben Nevis, in conjunction with Mr Eankin. In this paper it is 
shown that while the winds at the High Level Observatories on the 
