On the Climate of Strathpeffer Spa. 41 
3500 feet. A narrow wooded ridge of 600 to 800 feet forms 
the southern boundary of the valley. The western end is 
closed by hills, which, at a few miles’ distance, rise to 2000 
and 3000 feet, and extend in a broken form across the 
country to the west coast. At the eastern extremity the 
Strath opens out, assumes its more typical form, and slopes 
down gradually to the sea. By this configuration northerly 
winds are excluded, and those from the west and south-west, 
often laden with rain, are obliged, before reaching Strath- 
- peffer, to pass over a wide belt of hills. There follows hence 
not only a certain mildness in the winters, but also a com- 
paratively low rainfall. It is also obvious that the sharp 
ridge of hill to the south must cut off from the southern 
slope of the valley a proportion of the winter sunshine, 
having regard to the low altitude of the sun in this latitude. 
Furthermore, the undulating and rounded contour of the 
surrounding hills is another indication of moderate rainfall, 
for in very wet districts the hills are usually cut into sharper 
forms. Lastly, numerous evidences of climate may be taken 
from the state of vegetation. In many other places an 
uniform deflection of the trees points to the prevalence of 
strong winds from one quarter. There is no appearance of 
that kind at Strathpeffer. It will be noticed that trees and 
shrubs of various species, including some of the more delicate 
conifere and rhododendrons, thrive exceptionally well. 
From this it may safely be inferred that they enjoy both 
shelter and warmth, and, more particularly, exemption from 
extreme degrees of winter cold. The hill slopes in the 
vicinity of the Spa are now, to a great extent, covered with 
plantations of larch and fir. This must influence the night 
temperatures, from the well-known circumstance that the 
currents of cold air which pass down at night from the hills 
into the valleys are intercepted and warmed by intervening 
woods. 
It will thus be evident that commonplace observation may 
properly supplement the use of instruments in the deter- 
mination of climate. The most varied phenomena may 
indeed be utilised for this purpose. In addition to what has 
been already mentioned, observations on the flowering and 
