REPORT ON METEOROLOGY. 
235 
in spring, connected as they probably are with the melting of 
the snows in Norway * * * § . Mr. Meikle, however, has lately re¬ 
marked, and we think with justice, that the circumstance of 
their opposition to the direction of rotation of the earth, will 
cause an atmospheric accumulation by diminishing the centri¬ 
fugal force of the aerial particles j~. 
The accidental variations of barometric pressure are greatly 
influenced by latitude. At the equator they may be said to be 
almost reduced to nothing ; for it rarely happens that any 
change takes place to interfere with the regular course of the 
diurnal tides. A hurricane creates almost the only exception. 
The amount of variability increases towards the poles, in a great 
measure owing probably to the irregularity of the winds beyond 
the tropics. The mean amount of variation may be stated at 
the equator at two lines, in France at ten lines, in Scotland at 
fifteen lines, throughout the year; but this quantity has its 
monthly oscillations. Hence, a series of lines of equal varia¬ 
tion of pressure, or isobarometrical lines as they have been 
termed, may be constructed J. These do not appear to follow 
the parallels of latitude, but, like the isothermal lines, undergo 
inflections, and are stated to have a striking similarity to the 
isoclinal magnetic lines of Hansteen. If so, it is probably by 
the medium of temperature that these two are connected. 
The great extent of country over which the accidental varia¬ 
tions of the barometer take place, is one of their most striking 
features ; and in a future and more advanced state of Meteoro- 
logy we may be able to draw the most interesting and import¬ 
ant conclusions from the great atmospheric tidal waves which 
are thus perpetually traversing oceans and continents. The 
best example we possess of a systematic examination of these 
great progressive fluctuations, is, it is to be regretted for the 
present character of the science, of rather old date. The Meteo¬ 
rological Society of the Palatinate was set on foot in 1780, and by 
the distribution all over Europe of instruments of the best con¬ 
struction then known, made at one common establishment, 
founded a set of observatories which annually afforded compa¬ 
rable results of the most intrinsic interest §. It is to be lamented 
that a system which at the present time has no successor, should 
have lasted only ten years, having ceased with the life of the 
* See Mr. Marshall “ On the Causes of the East Winds in Spring,” in the 
Edinburgh Journal of Science. 
f Edinburgh New Philosophical Journal, iv. 108. 
X Kamtz, Jalirbuch cler Phgsi/c und Chemie , 1827; and Bulletin des Sci. 
Math. x. 199. 
§ Published at Mannheim under the title of Ephcmerides Societatis Meteo- 
rologicce Palatines. 
