1872.) The Origin of the Great Cyclones. 427 
Atlantic, and they are most numerous at the end of 
summer.—JOSEPH JOHN Murpuy, Old Forge, Dunmurry, 
Co. Antrim.” 
On referring to Mr. Meldrum’s paper, which I had never 
before seen or heard of, I discovered with great pleasure 
that his long-continued and accurate researches beautifully 
sustain the theory.* Mr. Meldrum gave at length full 
accounts of the particular storms which verified his belief, 
but which our space does not permit us to quote. 
The writer commenced by observing that in various 
papers published during the last ten years he had stated as 
the result of an examination of a large body of observations, 
that the tropical cyclones of the Indian Ocean south of the 
Equator originated between two contrary streams of air, 
viz., the N.W. monsoon and the S.E. trade-wind; and, in 
a paper read on the roth of November last, he remarked 
that what had been found to hold good in that part of the 
ocean might be found to do so generally. 
As, then, observation had shown that the tropical cyclones 
of the Indian Ocean, south of the Equator, were formed 
in the belt of the calms between the N.W. monsoon, a 
continuation of the N.E. trade and the S.E. trade-wind, 
and nowhere else, there was at least a presumption that 
the cyclones of the Bay of Bengal were also formed in that 
belt, at those seasons when it stretched across the Bay, and 
separated the N.E. trade-wind from the S.W. monsoon ; 
and this presumption was strengthened by the fact that 
most, if not all, of the cyclones that occurred there did so 
at the change of the monsoons; that is, when two contrary 
winds prevailed in the Bay, and were more or less in conflict. 
These general considerations rendered it possible, if not 
probable, that the cyclones of the Bay of Bengal were 
formed between two contrary and pre-existing winds. 
But that was not sufficient. It was necessary to bring 
the matter to the test of facts; and this could only be 
done by examining the observations taken in particular 
storms. 
The storms and cyclones reported and traced by the U.S. 
Signal Service, as published from day to day in the press 
telegrams, also seem to establish the theory which was at 
first put forth with great diffidence. These reports show, 
in general, that the cyclones which come to us from the 
tropics and Gulf of Mexico move from the tropics westward, 
* Mr. MELDRUM on the Origin of Storms in the Bay of Bengal. 
