THE WEATHER PROPHECIES (?) OF VENNOR. 627 
is the surface wind only which comes from that direction; the storm-clouds them- 
selves always moving from the west or southwest. This fact has been known to 
scientific observers ever since the researches of Benjamin Franklin established it 
as a fact. A storm of this character which rages one day in Missouri or Iowa- 
will, on the next, be found in the regions of Lake Erie. Numerous cases like 
this have been noted in the Weather Review; and what is perhaps the main point 
to be observed is, that no record has yet been made of any great storm moving 
in the contrary direction 7. ¢., from the east or northeast. 
Another error which deserves notice all the more, since meteorologists of some 
repute hold to it, in common with the. general public, is, that tornadoes which 
occur on the same date are identical; for instance, it is maintained that the Marsh, 
field tornado and the one in Southern Illinois on the same date, were one and the 
same. Now, though these occurred less than four hours apart in point of 
time, it is hardly probable that they were identical, since the localities where 
they occurred are so widely separated that a storm could not possibly have 
passed from one to the other in so short a space of time; and further, since 
another storm happened the same afternoon in Kentucky, and still another in 
Northern Illinois, it looks more as if there were certain physical conditions oper- 
ating, which made tornadoes possible; and, indeed, this was the case throughout 
a large portion of the Mississippi basin. These conditions were in brief: 
1st. Low barometric pressure. 
2nd. High temperature. 
3rd. Strong southerly winds. 
4th. Probably, favorable electrical conditions. 
These are the combinations of circumstances which produce tornadoes, and 
“Tare seen to co-exist on days when these storms are numerous; as on May 6, 
*’ 1875, when there were tornadoes in Kansas, Missouri and Illinois, or the date of 
‘ the Mineral Point storm, on which day numerous similar storms were reported 
® from different localities. 
These facts seem to prove that tornadoes are the result of certain atmos- 
* pheric conditions, and that they are not necessarily identical, even though they 
1. occur on the same date, and at places not very distant from one another. 
3 Morrison, Ill., Jan. 8, 1881. 
ie 
THE WEATHER PROPHECIES (?) OF VENNOR. 
ISAAC P. NOYES, WASHINGTON, D. C. 
i A person who makes himself so conspicuous before the world as Mr. Vennor 
. has done during the past year by his attempted prophecies of the weather, must 
expect to invite criticism; especially so when his pretensions are so at variance 
with science and common sense. 
_ In the absence of facts it is not surprising that there is great ignorance—be 
the subject what it may. Only within a few years have sufficient facts been 
