Meteorological Essays and Observations. 343 
But in the unfathomable depths which supply the latter, the law by 
which the density of water is regulated, must, at particular seasons, 
maintain a temperature above the mean of the declining season ; 
whilst at others, the increasing heat of the latter must outstrip the pro- 
gress of the former. The following Table contains the dew-point of 
the several winds, divided into the two classes for every month in the 
year, beginning with the autumnal quarter. 
TaBLeE I. Shewing the Difference of the Dew-point in the Land and 
Sea Winds. 
Land Winds Sea Winds. 
NE. E. S.b, N. N.W. W.S.W.S. 
Tis sats BOWIE LITA) FAL LID Slat) aitae ro) 
CDCI UOTE oe gah bey 4) 0 53 53 
CTO er Et anaes tas 3 45 AO 
IN OVEIMDEIs sae wend ac leet Al AQ 
Wecemberi.nts: «)ia.0\ ene 3i (37 
SP ATUAU oe on ee 29 35 
REDruary Fs Bad yl 35 
Wet ia nce cies eh a 34 38 
12.3 a ae ner ah 45 42 
psi amt Pils baa SD. pei AT 44 
iho (ee ORR Sap ss3 54 54 
MODY PRs 4, a cera ach oA 52 55 
DAOUBE 50") G's a e's sb 56 57 
“ And here the effect anticipated is clearly perceptible, The vapour 
of the land winds, it will be seen, declines in force from September to 
January, in which month it reaches its minimum, and from that point 
gradually rises till it reaches its maximum in August; and this, it will 
be afterwards seen, is the exact progress of the mean temperature of 
the air, In the sea-winds the vapour follows the same course from 
September to November, and the balance is such, that the elastic 
force of both divisions is nearly the same. The north and south winds 
neutralize each other; and the north-west, west, and south-west, are 
equivalent to the north-east, east, and south-east. Having descended 
to about 40°, which is somewhere about the point of greatest density 
in water, in November, the accordance proceeds no further, In 
December, the vapour from the land has descended six degrees below 
that from the sea, and the difference continues in January. In Febru- 
ary the former rises two degrees, and the latter remains stationary. 
The differerice of four degrees continues through March, and is di- 
minished to three degrees in April and May. In June they again 
attain their former equality. The reason of this is obvious; the tem- 
perature of 40° being that of the greatest density, cannot be lowered 
tll the whole mass of the waters has passed this term; and in the 
