88 
wish anyone to be misled into supposing that I am recom- 
mending this as a favourable time of year and that there 
are no disadvantages, for naturally the roads and villages 
are in a dirty and unpleasant condition, and in fact the roads 
have usually been dirty for a long time before the real snow 
melting begins. The early melting of the roads arises partly 
from the dirt on the roads, which absorbs the heat; but 
besides that, any snow which is pressed down sooner be- 
comes soft than snow left as it fell. The reason of this we 
have seen to be that both the heat from the earth and the 
sun can sooner influence it. Besides the disadvantage of 
dirty roads, all the filth which has remained frozen during 
the winter has to be thawed. 
Another point chat must be taken into consideration is 
that the snow melting is not a thing which necessarily goes 
on steadily for a few days and is then finished, but, on the 
other hand, as the temperature has now risen and passes 
more frequently above and below freezing point, the weather 
becomes more unsettled, and during the month of March 
snow frequently falls — in fact, about as often as in any 
month of the year ; and this also means that the sky is 
more clouded. Dr. Ludwig* gives the average cloudiness 
of the sky in the Oberengadine stations for ten years, and 
from his figures it seems that the cloudiness, which in 
January averages only 4’5 (scale 0 — 10), in February 4 *6, 
increases in March to 5 ’3, and in April decreases to 4*8. 
Some figures which I have prepared from other high places 
fully bear this out. This is the opposite to what we find 
in the neighbourhood of London (Greenwich), for from some 
figures before me for a number of years we have January 
7tJ, February 7‘9, March 6*4, April 5 -9. 
We have so far examined the snow as removed by the 
sun, but there are a] so occasionally times when a warm 
* Oberengadin yon Med. Dr. J. M. Ludwig. Stuttgart, 1877. 
