47 
In vol. 1, 3rd series, of the Memoirs of the Society, in a 
paper “ On the Irregular Oscillations of the Barometer at 
Manchester,” I gave reductions of the mean monthly 
temperatures observed by myself from 1849 to 1860, and 
in the present communication I give the values for the 
succeeding years down to the end of 1868, completing a 
period of 20 years. It is scarcely necessary to remark that 
these values have all been carefully reduced to the Green- 
wich standard, and corrected by means of the tables of 
diurnal range computed and published by Mr. Glaisher. 
As will be seen by the notes appended to Table I., I have 
been indebted for a few months' results to Mr. Mackereth’s 
observations made at Eccles, and which closely represent 
those made at Old Trafford. 
Table II. contains the differences of the mean tempera- 
ture of each month from that of the whole period 1849 to 
1868, but unfortunately the month of August is almost 
entirely deficient in the earlier series, and this is a gap I see 
no chance of filling with observations made at any station 
which would be at all fairly comparable with the remainder 
of the series. 
The mean temperature of the months of the various 
periods have been as follows : 
1849 to 1860. 
1861 to 1868. 
1849 to 1868. 
O 
O 
O 
January 
38-3 
37-2 
37-8 
F ebruary 
37-8 
38-9 
38-2 
March . . 
41-3 
40-1 
40-8 
April 
46-6 
46-8 
46'6 
May 
51-8 
517 
51-7 
June 
575 
56-4 
57-0 
July 
60-5 
58-3 
59-6 
August 
— 
57-6 
58-7* 
September 
55-2 
55-1 
55-1 
October 
48-5 
49-0 
48-7 
November 
41-2 
41 1 
41-2 
December 
389 
40-4 
40-4 
Mean 
47-3 
47-9 
* From 9 years only. 
The mean of the period 1861 to 1868 appears to have 
been on the whole rather colder than the average of the last 
