346 J. E. Wiilet on Indian Summer. 
bends toward the earth, why not attribute it to a current from 
above? Mainly from the fact, that we are less familiar with de- 
scending currents, and that from the want of an indicator, we 
know less of their habitudes. 
3. This subsiding of atmospheric currents may occur at any 
time, when circumstances favor; but it will be most apparent, 
when a conjunction of circumstances render them continuous 
through a series of days, asin the autumn. ~~. 
Hence smoky days may occur in every month of the year, 
and a succession of them is called Indian Summer—near the au- 
the same hemisphere heated by summer and cooling by radiation 
favor, depress the smoke and produce Indian Summer. 
In the above discussion, I have attempted to show that Indian 
ummer, 
year, and probably dry fog are similar if not identical a 
ena, and attributable to the same cause; that the smokiness 
ue to ordinary i i 
in autumn and in the temperate zones, and the descending ¢O” 
rents originate in the subsidence toward the earth of the uppe 
currents from the equator or from the poles. : ‘the 
In conclusion, it is proper to say, that, by examination of 
a See an able paper on the subject by Prof, Henry, Patent Office Report. ol 
SERRE omaha oe oom hese hE 
