1822.] Prof. Brandes on the Depression of the Barometer. 263 
OS P39 4 BH 7b ee  9) 
And from equation (8), when u = 0°. 
O0O=—14 2— 324 4 — 5? + &e. 
O= +1 — 2 +4 3+ — 4 4 5t — &e. 
0= —1 + 2° — 3° + 45 — 5° + &e. 
O= + 1— 28 + 38 — 48 + 58 — &e. 
OS 1— op gee gee ee 0) 
Arnzcre VII. 
Results of Observations on the extraordinary Depression of the 
Barometer, which took Place on the 25th of December, 1821. 
By Prof. Brandes, of Breslau. 
(To the Editor of the Annals of Philosophy.) 
SIR, 
Tue extraordinary depression of the mercury in the barometer 
which was observed-in England, France, and Germany, on the 
25th of Dec. 1821, has attracted the attention of natural philo- 
sophers in each of those countries ; and I presume, therefore, 
that it will be found very interesting to know what was the state 
of the barometer, and at what place it was lowest, &c. For the 
purpose of deciding these questions, I have brought together all 
the observations which I have been able to procure; and I have 
been fortunate enough to obtain sufficient materials for giving a 
complete table of what has been observed respecting this subject 
on the Continent. 
The barometer was lower at Dieppe and at Boulogne than it 
was In any other part of the Continent. Ii will be very interest- 
ing to have the observations made in England, and I hope that 
the observers there will have the goodness to publish in the 
journals, with the utmost accuracy, first, the time when the least 
elevation of the barometer was observed ; secondly, that height 
itself; and, thirdly, the mean altitude.* We should then be 
able to ascertain at what place the barometer was lowest ; and 
we should see whether it was found lower in England than on 
the coast of the channel. 
I have met with some observations in the English journals 
which give the time and the height very accurately, but the 
greater number of them do not mention the time of the lowest 
state of the barometer; nor even do they inform us whether the 
* Th urnals which we receive regularly are the Annals of Philosophy, the Philos 
sophical Magazine, and the Edinburgh Philosophical Journal. 
