74 Ay - -REPORT1843. 
Dec. 1837.—Markree, Edinburgh, Halifax, Beaumaris, Oxford, London, 
barat Brussels, Alost, Louvain, Geneva, Ktemsmiinster, Turin, Parma, 
adiz. 
This term is in every respect full of interest, and fortunately the stations 
are numerous and well-situated. It exhibits the rise, culmination, and fall of 
a great wave, travelling from north to south, or perhaps from north-west to 
south-east, and exhibiting at its culmination, at many stations very remote 
from one another, features giving it a peculiar character and individuality. 
The breadth of this wave was such that at no single station are both the rise 
and fall wholly included in the term; so that it is by successive stages as it 
were that each station contributes its quota to our knowledge of its progress. 
Not a little remarkable either is it that Cadiz appears to have been entirely 
without its range, the barometrical curve of that station exhibiting nearly a 
level, varied only by the diurnal oscillations, which are unusually and stri- 
kingly prominent, and having, on the whole, a slight tendency to descent. 
Markree is the oniy other station in which (from the otherwise even and 
regular slope of its curve) these periodical movements are apparent. 
The Markree observations, as projected, exhibit only the descent of the 
wave, its culmination having passed that station, or being in the act of passing 
it at the very commencement of the projected seriesor 0 hour. Referring to 
the original register in which 36 hours (6 before and 6 after the projected 
term) are included,I find this partly corroborated, the barometer having been 
on the rise during that whole interval. Nevertheless, as it will appear from a 
consideration of the other curves, that the wave had in fact a double crest, 
separated by an interval of several hours, it is not quite certain that the absolute 
culmination, or true maximum of pressure, is exhibited at all in the Markree 
series. The moderate downward slope of the Markree curve (which de- 
seends on the whole only 0°33 inch in the 30 hours registered from its appa- 
rent maximum) supports this idea, the total fluctuation, as it appears in the 
more southern stations, having been more than double this amount. 
At Edinburgh the absolute culmination of the wave took place at 10 a.m. 
Ed. m.t.=10" 30™ Brussels M.. of the 21st hour, being marked in a manner 
characteristic of the locality, by a very sudden upward start of a whole tenth 
of an inch in the hour preceding that epoch, and a fall of very nearly the 
same amount in the hour subsequent, producing a high peak or pinnacle in 
the barometric curve at that hour (22nd hour, Sept. 21), which, as it will be 
hereafter referred to, I shall term the first culmination of the wave. From 
the 11th hour the Edinburgh curve preserves its level as far as 15 30™ (Sept. 
22), (1 30 p.m., Sept. 21, civil reckoning), when it dips for one hour to a 
slight minimum, and rises again to a maximum at 30 hours, thence descend- 
ing to another minimum at 6" 30™. Thus the interval from 25 30™ to 65 30™. 
is filled with the second culmination of our wave, which however is here not 
very marked, the whole descent to the minimum being only 0-046. To this 
succeeds a third culmination not quite so high as the second, and occupying 
2 hours (to 85 30™), when a very abrupt and sheer descent commences for 
the next 3 hours (through 0°197 inch) to another minimum, or rather to a 
motionless level or pause in the descent, continued for 3 hours more (to 
15"30™). From this point a very trifling rise takes place to a feeble culmina- 
tion at 16" 30™, after which the descent continues till the end of the registered 
series, which in this ease unluckily breaks off at 18"30™, instead of being 
continued to the end of the term. The total observed range is 0°388. 
The Beaumaris curve exhibits a singular contrast with the Edinburgh, 
being as smooth as the other is abruptly broken. It exhibits 4 hours of the 
ascent of our wave and 14 hours of. the descent (the term not having been. 
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