246 
SECOND REPORT -1832. 
done on the subject. M. Gay-Lussac, who has communicated 
some valuable observations towards its attainment, thought 
that it would never repay the labour of complete investigation. 
In the present state of the science, however, we look upon it 
otherwise, and feel strongly assured that in a few years the 
more direct method of the dew-point will be banished alto¬ 
gether *. 
Atmospheric Phcenomena and Precipitations. 
In the introduction to this Report I have stated my intention 
of by no means undertaking to examine the wide field which 
this subject opens to us. My remarks will be confined to one 
or two individual points, upon which some general views have 
been entertained. Those I have selected are Wind, Rain, and 
Electrical Phenomena, including the Aurora Borealis. 
The direction and force of the Winds we have already seen 
to be intimately concerned in the modification of climate, and in 
the distribution of temperature in the atmosphere. The peri¬ 
odical winds of the equator and tropics correspond in regularity 
to the uniform course of the seasons and the limited range of 
the barometer characteristic of that part of the globe : nor has 
anything particular been added to our knowledge of these great 
currents, of late years, which requires notice here f. 
In temperate climates the irregularity of the wind in general 
seems so great as to baffle inquiry. There are a few leading 
points, however, which show that there is something to be seized 
in this question, and that an analysis of it may one day lead to 
more general results. It is undoubted that the south-west is 
the predominant wind of Europe, and the east winds in spring 
may be considered as almost accurately periodical in the climate 
of Britain J. M. Schouw has gone a step further, and has 
shown that the prevalence of westerly winds diminishes as we 
advance towards the east of Europe §. The west winds at 
London exceed the east in the ratio of 1*7 to 1. At St. Peters¬ 
burg this is diminished to 1“3 to 1 ||. 
M. Erman has determined the mean direction of the wind in 
Russia and Siberia to be as follows : 
* In addition to the references already given, we may mention, for the use of 
those who may pursue the subject, a paper by Mr. Meikle on this point, in the 
Edinburgh New Phil. Journal , ii. 22; and some articles in Poggendorff’s An- 
nalen for 1829, by M. Dove, whose remarks on the connexion of the horary 
oscillations of the barometer with humidity we have already noticed. 
4 There is a paper by Captain Hall on this subject in the second edition of 
Mr. Daniell’s Meteorological Essays. 
f See Mr. Marshall “ On the Causes of East Wind in Spring,” Edin. Journal 
of Science. 
§ Beitrdge zur vergleichenden Klimatologie. 
lj Bulletin des Sciences Mathematiques, x. 201. 
