- 
‘50 
which rather abate than increase, as - 
might be expected. 
We should, on this principle, further 
suppose the heat would increase gra- 
dually with the return of the sun to our 
‘Jatitudes, from its southern declination, 
and stand always in proportion to its po- 
sition. We find, however, that expe- 
rience also contradicts this point of the 
theory under discussion; for after the 
sun has passed our zenith,* the land- 
winds set-in at once with all their inten- 
sity, in the manner before described, and | 
they cease as abruptly before its return 
again.t 
A material change in the temperature 
of this climate is certainly effected by 
the approach of the sun from the south; 
but the heat which is thus caused, and 
‘which increases by imperceptible de- 
“grees, is never so great, and is only felt 
by those who expose themselves to it un- 
protected; for the air remains propor- 
tionally cool, and our houses afford, in 
this season, a pleasantretreat. We find 
it far otherwise in a land-wind; for this 
_penetrates our inmost recesses, and ren- 
ders life miserable every where. 
I have before observed, that winds 
equally hot with those of periodical du- 
‘ration, are felt in all parts of the country, 
and at different seasons; a circumstance 
alone sufficient, if proved, to overthrow 
the ground-work of the old theory. 
For a confirmation of this, T will ap- 
peal to the general observation, that im- 
mediately before a long rain the weather 
is sultry, and that a single shower is al- 
‘ ways preceded by a warin disagreeable 
wind, 
We are very particularly reminded of 
the approaching great monsoon in Oc- 
tober, by the oppressive heat we have in 
_ the calm evenings of that month, which, 
I am persuaded, would equal that of the 
land-winds in May, if the atmosphere 
were not cooled in the latter part of the 
night by breezes that have wafted over 
extensive inundated plains. 
_ I can refer, secondly, to my Meteoro- 
logical Journal, according to which, the 
4th of June 1800, at Madavaram, a 
place not far from Bengalore, the ther- 
mometer rose for a short time to 104° 
just before a slight shower ef rain, and 
¢ The sun is in the zenith at Madras 
about the 26th of April. 
¢ The sunis again in our zenith on its 
gouthern declination about the 19th of Aue 
gust. 
Proceedings of Learned Societies. 
[Feb, 1, 
at atime when heavy clouds darkened 
the western hemisphere. : 
Further, in the months of March and 
April 1804, we had often at Bengalore, 
in the -afternoons, strong gusts of wind 
from the eastward, which, in common, 
were styled land-winds, and were reall 
as hot and disagreeable as moderate land- 
winds are in the Carnatic. I could 
‘have multiplied instances of this kind, 
but am of opinion that in a fact so much 
known, it would be perfeetly needless. 
’ The Jast refuge of the defenders of 
this theory, is the valleys of the Ghauts, 
in which they pretend the heat is gene- 
rated by the concentrated and reflected 
rays of the sun, i 
I will not deny but the heat occasioned 
by these causes, may contribute much to 
raise the heat of the land-winds; but the 
sudden appearance of the latter, their 
usual strength, and abrupt disappear- 
ance, all militate against that explanation 
as a principal cause. 
The heat of these winds should in this 
case, to say a few words more on the 
preceding subject, decrease regularly 
from the point where it is greatest to~ 
wards the opposite, on both sides, as is 
the case on the coast of Coromandel. 
On the contrary, we find that, imnredi-+ 
ately on our having ascended the Ghauts, 
or on the top of hills* elevated above the 
clouds, we have escaped their heat all at 
once. It is hereby remarkable, that 
the direction of the wind remains to ap- 
pearance nearly the same every where. 
In Mysore, for example, the wind is, in 
the land-wind season, west during the 
greater part of the day; in the afternoon 
it is from the east, and commonly warmer 
than the former. 
This, together with what had been 
said before, will, I hope, be thought suf- 
ficient to establish my opinion relative 
* Major Lambton, at the top of Carnati- 
ghur, one of the highest hills in the “Car- 
natic, about three thousand two hundred feet 
above the level of the sea, found, inthe mid- 
dle of the land-wind season, the thermo- 
meter at 79° and 80° in the mornings, and 
at noon $29 and 84°, when it was below at 
103°, and more. This observation may be 
the more depended upon, as the Major re- 
mained for a considerable time on the top 
of this hill, ‘in the pursuance of his most 
accurate survey, in the course of which he 
pays great attention to this, as well as to all 
other points that could influence his learned 
labours. 
fo 
e 
a 
“ 
. 
