108 REPORT—1840. 
208. “Since 1827,” says Prof. Dove, “I have published a series 
of Memoirs in Poggendorff’s Annals, in which I have sought 
to prove that the totality of the non-periodic meteorological 
changes of our latitudes reduces itself to a fundamental pheno- 
menon, which I have called the Law of Rotation of the Wind. 
The fact of a regulated variation of the direction of the wind 
(regelmissigen Ueberganges der verschiedenen Windesrich- 
tungen) observed centuries ago, yet often disputed, stood iso- 
lated from the generally acknowledged, if not sufficiently proved, 
influence of the winds’ direction upon the pressure, tempera- 
ture and humidity of the atmosphere. If, then, the so-called 
Irregular Variations are nothing else than the transition or 
passage of the barometrical, thermal and hygrometrical values 
of the winds into one another, it is clear that the laws of these 
variations can only be known by ascertaining the laws which 
connect the mean variations of the wind’s direction with the 
distribution of pressure, temperature and moisture for the 
different points of the compass*”’. Such nearly, in the author’s 
words, are the objects of his more laborious investigations; and 
to the construction of a barometric compass-card, a ther- 
mometric compass-card, and so forth, a series of memoirs is 
devoted. When by this means any mean series of meteorolo- 
gical changes becomes interpretable in terms of wind-azimuth, 
it is easy to see that new checks may be obtained for the fun- 
damental law of rotation. 
209. To pursue the course of M. Dove’s laborious research 
is out of the question. We must content ourselves by gi- 
ving a specimen of his conclusionst. In the Worthern hemi- 
sphere 
The Barometer falls during E. S.E. and S. winds; passes 
from falling to rising during S.W. and rises with W., 
N.W. and N. winds, and has its maximum rise with N.E. 
wind. 
The Thermometer rises with E., S.E. and S. winds; has 
its maximum with S.W., and falls with W., N.W. and 
N. winds ; its minimum is N.E. 
The Elasticity of Vapour increases with E., S.E. and 8. 
winds; has its maximum at §.W., and diminishes during 
the wind’s progress by W. and N.W. to N.; at N.E. it has — 
a minimum. 
210. What has now been stated for the Northern hemisphere 
may be transferred to the Southern by changing N. into S., 
N. W. into S.W., &c., throughout. 
211. These views of Dove have not been received altogether 
* Untersuchungen (Pref.). ¢ Untersuchungen, p. 140. 
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