Meteorology of Melbourne. 165 
made, the inferences which appear to be deduceable from 
them, and particularly in regard to the nature of the hot 
winds. 
Referring to the journal which I have kept since the Ist 
of December, I must first briefly advert to the thermo- 
metric observations. It will be seen that the highest point 
reached by the thermometer has been 112°, in the shade, and 
the lowest 45° in the night. There has been no night on 
which the thermometer has not sunk to 74°. We have 
therefore had none of those very hot or very cold nights, such 
as are not uncommon in the summers of South Australia :— 
and the heat, though on some occasions very intense, has in 
no instance been very continuous. 
The mean monthly temperature has been estimated in two 
different ways:—First, by averaging the sum of the daily 
highest and lowest readings of a Sike’s thermometer. Se- 
condly, by exposing to the airin the shade a copper vessel, 
containing ten gallons or more of water, closely covered to 
prevent evaporation, and taking the temperature of this 
water twice a day, viz. at 6am. and6 p.m. The results of 
these two methods of observation have been found during 
December and January to correspond within a single degree. 
The mean temperature of December was 68°, and that of 
January 70°, and that of February 69°, and of March 68° ; 
bemg ten degrees above the mean of the corresponding 
summer months in London in 1844. On the two days when 
the thermometer stood about an hour after noon at the 
highest point, 112°; viz., on the 28th and 29th January, it 
sunk in the course of the night to 664° and 66°; thus 
showing a range of 46° during the twenty-four hours. 
My observations on the barometer have not been suf- 
ficiently complete to admit of calculating with precision its 
mean height. I have recorded the reading of the barometer 
every day about noon; and during changes of weather, I 
have observed it at all hours; but not at other times. 
Approximatively, the reading was for December, 29:82; 
January, 29°88; February, 30-0. 
The hygrometric observations are of more immediate in- 
terest and practical importance. They have been made 
principally with a Mason’s hygrometer, the accuracy and 
convenience of which is now generally admitted. It appears 
that the mean dew point of December was 50:0; that of 
January, 49:5; and that of February, 50°3; having thus 
been practically the same during the three months. I have 
