132 . REPORT—1846. 
in that covered by the receding wave it would fall, while in that in which 
the two waves interfered so as to counteract each other, a quiescent state of 
the atmosphere would result, This appeared to be the case in the area of 
greatest symmetry, in which the larger waves so interfered as to exhibit the 
smaller secondary waves uninfluenced by them. This leads us to the real 
character of the symmetrical wave ; not that there is such a reality in nature, 
as will be shown in the next part of this report, but that it results from the 
combination of large normal waves moving in different directions so as to 
interfere*. 
I do not place any stress upon these deductions, as I have alluded to them 
merely to show the progress I have made, and that a complete discussion of 
the observations is likely to be attended with highly important results. The 
results of the examination of Mr. Brown’s observations, as detailed in the next 
part of the report, are I apprehend calculated to throw much light on the 
inquiry, and when these observations are discussed with reference to the 
views there set forth, our knowledge of these interesting movements will I 
have no doubt be greatly increased. 
Parr IL. 
Examination of Mr. Brown's paper on the Oscillations of the Barometer. 
In the Philosophical Magazine for April last, Mr. William Brown has 
published a paper on the oscillations of the barometer, with particular reference 
to the meteorological phenomena of November 1842. The object of this 
paper is to show that the barometric oscillations are produced by the meeting 
of opposite or nearly opposite aérial currents; that one current thus meeting 
or impinging on another, deflects it, and under some circumstances produces 
a rise of the mercurial column, but under others occasions a fall in many 
cases of considerable magnitude. In order to elucidate his views, Mr, Brown 
has collected barometric observations from eleven stations, which are scattered 
over an area included by the following angular points:—The Orkneys, 
Christiania in Norway, Paris, Plymouth and Cork. These observations are 
in most cases given as read off from the scale. In addition to these the 
paper is accompanied by six plates, in which the direction of the wind at 
numerous stations is indicated for every day during twenty-six days in the 
month by arrows. The anemonal observations published in the body of the 
paper not being in all cases for consecutive days, a comparison of them with 
the plates is rendered difficult ; nevertheless the plates form a very valuable 
portion of the communication, and if they have been laid down from accurate 
observations, they furnish us with an important addition to our knowledge of 
the arrangement of the aérial currents, especially with respect to the distribu- 
tion of pressure. It is a matter of regret that Mr. Brown did not so arrange 
his observations and plates, that the accuracy of the latter could have been 
seen by inspection. 
I have alluded to this paper as peculiarly interesting at the present time, 
when the attention of meteorologists is directed to the important and interest- 
* T have accompanied these curves with one on a smaller scale, representing observations 
at the Orkneys by the Rey. C. Clouston. The very striking departure from symmetry is 
extremely apparent in this curve by the depression of the 19th sinking considerably below 
the readings at any other station. This curve is more in accordance with those from the Irish 
stations in the rise from the 7th to the 11th, and it appears to be connected with Heligoland 
by the depression of the 11th being but slightly developed ; in this respect it also agrees with 
the Stokesley curve. The depression of the 11th is very apparent in the 8.W. curves, and it 
gradually decreases as we approach the N.E., where it is much less. The Orkneys appear 
to have been under the anterior slope of the wave coming from the N.W. 3 
a 
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