566 OBSERVATIONS ON THE BAROMETER, 
TABLE 
OF THE MONTHLY MEAN HEIGHT OF THE BAROMETER FOR 
FORTY-SEVEN YEARS, FROM 1794 To 1840 INCLUSIVE. 
Inches. 
JONUATY 7. ieetees ee 29.80 Ins. 
February.........00. 29.85 + 29.846. below the general mean. 
Marcel serescsevcenses 29.89 
Apart sot bhiusbiens.. 29.90 
Mary. acces sesivepnsaws 29.94 \ 29.943. above the general mean. 
JUDE - ceccvnccccerers 29.99 
DID Gce na consenrnsne ede 29.94 
AUgust ..rsesceeees 29.99 & 29.953. above the general mean. 
September ......+++ 29.93 
October .......0.0s. 29.85 
November .......+. 29.76 \ 29.806. below the general mean. 
December ......... 29.81 
Annual mean PP a9. 29.88 
47 years ...... 
In my former essay (see Manchester Memoirs, 
Vol. III. page 488, new series), I mentioned a 
remarkable fact deduced from the then observa- 
tions of the Barometer, namely, that the altitude 
of the mercury was greater than the mean 
during the spring and summer months, and less 
than the mean during the autumnal and winter 
months, allowance being made for the effects of 
temperature. From the above table, the fact is 
