156 CLIMATE OF DARTMOOR. 
the heat of the air of these lower tracts has been 
elevated, the colder atmosphere of the Dartmoor 
hills rushes in either suddenly in the manner of an 
ordinary current, or by a gradual descent,—restrain- 
ing the process of increasing heat. ‘Towards the 
west and south-west, a current of wimd brought 
over land from opposite directions inevitably con- 
veys to us the chilly atmosphere of these central 
hills. Durimg summer, when we have the largest 
share of easterly and north-easterly winds, it is not 
uncommon for this chilly stratum of air tc be trans- 
mitted towards the South Hams and to check alower 
current of wind arriving from the sea, bringing with 
it the customary mists and clouds so characteristic 
of our climate :—“ the north wind driveth away rain.” 
In winter the climate of the moor is particularly 
damp. On the whole it may safely be affirmed, 
that the moor is productive of a local climate on a 
small scale, affecting sensibly the lower tracts by 
a cooling, dry, chilly or blighting current according 
to the period of the year. Vancouver has ascribed 
its blighting power to one particular hill,—Cawson 
hill, the highest. 
The common influences which induce the great 
alterations in the temperature of seasons do not in 
South Devon exhibit their full perfection of power, 
but are qualified and limited in force by the causes 
I have before recited. So remarkably is this shewn, 
that while it is no very uncommon thing for, per- 
sons to need fires at Midsummer, they have been 
found subjects of indifference (though rarely I al- 
low) at Christmas in some years. It has indeed 
happened to my own knowledge that cold gusts of 
wind, with perhaps cold rain, may render the sur- 
faces of our bodies colder at the first period than 
at the latter, and certainly, remarkably warm and 
fine days frequently enliven the Christmas week. 
