296 Miscellaneous Intelligence. 
Let us now proceed to account as best we may, for this bank, or in- 
creased atmospheric pressure. 
These experiments were made in south latitude, and in the trade 
wind region of that hemisphere. These winds strike nearly perpendi- 
cularly against the Andes, the tops of which range extend in many 
— — if not quite as high, as do the trade winds themselves. 
w, then, what is the effect of such an obstruction as the Andes afford 
to the passage of the south east trade. winds ? we may judge by the 
effect of similar obstructions to running water, we have no hesitation in 
saying that the effect isto bank up. 
ot Rock and other obstructions to the rapid current of Hurlgate— 
taking small things to represent great—may serve us with an illustra- 
tion that will assist me in making myself clear. Any one who witnessed 
the water running over that rock, could not fail to be struck with the 
fact, and the extent “ which the water was piled up, not over the rock, 
but up stream from it; not only was there this banking up of the water, 
before it reached the rock, but there was also a depression above—that 
is, up stream from this bank of = on the one hand, and below or 
down stream from the rock on the ot 
n like manner it appears to me, ‘bee Herndon’s observations have 
revealed the fact that there is, at times at least, in the intertropical at- 
mosphere of South America, an air-cast mould of the Andes. 
It is remarkable how clearly these observations ia ‘a piling up 
of the atmosphere to the windward of the Andes, and a depression in 
the general atmospheric level to the windward again of this air bank. 
If this conjecture afford the real es aay sept of the phenomena, we 
should look on the lea side of the es fora low barometer, or a de- 
pression in ths atmosphere, fireandibg to the hollow in the water 
below pe ock. 
The aie eight of the barometer in Lima, as far as I have been 
able to saensinin it, indicates that such a depression is perceived there. 
subsequent observations should confirm —— Se and 
establish them as realities, we should then be put in possessio of im- 
portant physical facts. We should be led to inte that the beight of 
— and of mountain slopes above the sea level, as determined 
y the barometer, would depend somewhat upon which way the win 
lies and the only safe rule of admeasurement in such cases, would be 
to establish a standard a ga at the foot of the mountains, both on 
the windward and the lea s 
region become a natural anemometer, which will give us sik terms 0! 
the barometer an expression for the whole amount of force em mployed 
p. 339.)—In the Supplement Number of the athe 99 
for July last, my father published a paper on ‘ ‘ Early pel 
