fe 
ae — 
Professor Olmsted’s Reply fe Dr. Christie. 373 
Awe, XXUL aaReply. to Dr. Christie on Hail Storms ; Z by Devison 
aad Professor of Mathematics me Natural Philosophy i 
pe tae College. a. y co , 
bd 
To the Editor of the ‘American Journal of Science. ‘ a. i 
~ Dear Sir,—In the New Edinburgh Philosophical Journal, * ig an 
“article on “Indian Hail Storms,” communicated to that Journal by 
“A. Turnbull Christie, M.D. The writer mentions several facts | 
| ‘relative to the occurrence of hailstorms in the southern parts of India, 
‘and of course within the limits of the torrid zone, which facts appear 
to him inconsistent with the views I had offered respecting the causes 
. hailstorms, in an article first published in the eighteenth volume of 
‘this Journal, and Sepuphiatied in the New Edinburgh Philosophical 
Aourna 1. 
These ‘facts are of so interesting A ars that I could not wish 
ae to be’ witheld from your reader, although they should subvert 
the explanation I had ventured to suggest ; but whether they subvert 
or Confirm that explanation, your readers will have an opportunity of 
judging, if they will do me the favor, afier reading the annexed arti- 
fe to peruse the subjoimed remarks. The article is as follows. 
[From the New Edinburgh: Philosophical Journal 8 ae 
* On Indian. Hailstorms ; by A. Turnsuty Curistiz, M. D. 
= the last number of your J ournal a new theory of hailstorm i is 
proposed by Professor Olmsted of Yale College, viz. that they are 
“€aused by “the congelation of the watery vapor of a body of warm 
and humid air, by its suddenly mixing with an exceedingly cold wind 
‘inthe higher regions of the atmosphere.” od 
According to this theory it is very easy to account for those hgil- 
storms which so frequently occur in some parts of the temperate zones, 
. asin the south of France, or in the United States of America; for in 
such situations it is very possible that an intensely cold wind, pro- 
-ceeding from the north at a great height, might meet with a warm 
« body of air highly charged with moisture, and thus cause a very sud- 
den congelation, with the other phenomens that generally accompany 
such storms. But this explanation could not apply (even according 
- to the Professor’s own chow to hailstorms in the torrid zone, for 
his zone, — differ so little in tem- 
wey two currents of air, wit 
* This a of that work not ‘bavi yet 5 us, the above extract is peep 
~ fom = adelphia ee Gazette, of Jun 
wh 
