80 REPORT—1843, 
rupt, and (except for stations very nearly adjoining) not identifiable with each 
other. The Belgian range is the smallest (0°224), the London and Green- 
wich larger (0°304:), and the Halifax greatest (0°457), supposing it continued 
to the end at the same mean rate at which it breaks off at 19" 20™ (the term 
not being completed). 
Cadiz again contrasts itself strongly with all the more northerly stations. 
Its curve offers a general and moderate ascent over a range of 0°132, form- 
ing a line deeply indented by the very conspicuous effect of the two diurnal 
minima and their intermediate maxima, which seem to have attained their 
full development on this occasion. In other respects there is no peculiarity. 
The curve too is much smoother as respects subordinate undulations than 
any of the others, Brussels not excepted. 
Having thus discussed seriatim the terms of our British and European 
group, let us briefly review the principal results of our examination. 
1. We have succeeded in tracing distinet barometric waves of many hun- 
dreds of miles in breadth over the whole extent of Europe; that is to say, at 
least over an area having Markree in Ireland, Cadiz in Spain, Parma in Italy, 
and Kremsmiinster in Austria for its angular points. Not only the breadth 
but the direction of the front, and the velocity of progress of such waves have 
been clearly made out. 
2. Besides these distinctly terminated waves, we have been able, if not to 
trace the rate and law of progress, at least to render very evident the exist- 
ence of undulatory movements of much greater amplitude, so great indeed 
as far to exceed in dimension the area in question, and to require much more 
time than the duration of a term series (36 hours) for their passage over, a 
given locality. At the same time it must be recollected that the records of 
every meteorologist bear ample testimony to this conclusion in the fact of 
long-continued rises, falls and stations (both high and low) of the barometer, 
continuing for many days or even weeks. 
3. In Europe, Brussels is clearly entitled to be regarded as a point of com- 
paratively gentle barometrical disturbance. Very deep waves, it is true, and 
very extensive ones, ride over it; but with regard to smaller ones, it may be 
regarded as in a certain sense a nodal point where irregularities are smoothed 
down, and oscillatory movement in general is more or less checked ; and such 
movements increase in amount as we recede from Brussels as a centre, espe- 
cially towards the north-west, as far as Markree. 
4. The diurnal oscillations are very conspicuous in single days’ observa- 
tions hourly continued, this being rather the general rule than the exception. 
In particular, the afternoon minimum (4 P.M.) stands forth as a prontinent 
feature in almost all cases where there is not some violent barometric dis- 
turbance. 
5. But that to render them so conspicuous, it is by no means enough to 
cast up arithmetically heights above and below a mean quantity for the day. 
On the contrary, such a mode of proceeding has a powerful tendency to mask 
and conceal them. A medium curve must be struck, iberd mani or libero 
oculo, so as to represent, with the least possible amount of general curvature, 
the whole day’s observations; and upon this curve the diurnal fluctuations 
will usually appear as two principal indentations with corresponding inter- 
mediate protuberances, the protuberance and indentation immediately pre- 
ceding and following the hour of noon being by far the most conspicuously 
and constantly visible. 
6. Hanover offers barometric anomalies separating it from the Belgian 
type (to which latter the south of England as well as Geneva belongs). 
Possibly it is connected with a Scandinavian or Polish system. Edinburgh 

