250 The Data on which we have to depend 
With cold winds the temperature of our inland lakes would 
be much more quickly cooled than by radiation; but for the 
formation of dew it is necessary that there should be scarcely 
any wind. It is also necessary that the water should abstract 
heat from the air, and not that the air should abstract heat 
from the water. 
Dr. Wells also clearly proved by his experiments that 
water fully exposed in a calm clear night in shallow vessels 
lost weight from evaporation, while dew was being largely 
deposited on the surface of the ground. An increase of 
weight from condensation of dew was only observed when the 
cold was so great that ice was formed, and in this case he 
found a slight increase in weight, but the existence of ice 
proved that the temperature of the water had been reduced 
far below the dew point. 
Tam not aware that any subsequent experiments have shown 
any inaccuracy in the experiments of Dr. Wells. 
It is to this uniformity in the temperature of water during 
day and night that our land and sea breezes are owing. 
During the day, the air over the land becomes heated, and a 
sea breeze is the result; during the night, the land is chilled 
by radiation, and the air being thus rendered much colder and 
heavier than that on the surface of the ocean, a land breeze 
is the result. 
In this manner, the extremes of heat and cold are very 
much moderated along the coast lines, and the climate is 
rendered much milder and more agreeable. 
There can be no doubt that like atmospheric currents will 
take place at Yan Yean. The heated surface of the sur- 
rounding ranges, during the day, will produce currents of 
cool air from the reservoir. During the night, the warmer 
air on the surface of the reservoir will give place to currents 
of cold air which has been deprived of its moisture by the 
chilling influence of radiation on the summits and slopes of 
the ranges. 
Mr. Hodgkinson’s theory, would, however, reverse the 
whole order of things. | 
If the surface of the sea and our inland lakes becomes 
during the night so much colder than the surface of the land 
as to condense double the amount of dew, we should have 
land breezes in the day, and sea breezes in the night; and our 
summer watering places would become inhospitable deserts. 
But as it is physically impossible for our inland lakes to 
lose from 5° to 15° of temperature by radiation during the 
night, so it is physically impossible for any dew to be con- 
densed on their surface. 
