n some localities, and four in others.

Along the Ohio River, it fell to the depth of 8 to 10 inches on the 17th,
and east of the mountains to a greater depth on the 18th, one day later.
It fell to the depth of 4 inches at Marietta on the 29th also. Dr.
Hilldreth, American Journal of Science for March, 1855, says:--

"It is a singular fact that the deepest snow, 8 inches, fell on the 17th
of April, and at the head waters about Pittsburg over a foot. Also, on the
29th of the month, at Marietta, 4 inches, a very rare occurrence." This
depression of the temperature was quite general, but the fall of snow was
local. The latter was north of a line drawn from Fort Laramie, at the base
of the Rocky Mountains, in an E. S. E. direction--north of Forts Kearney
and Leavenworth, and of St. Louis, but south of Newport barracks in
Kentucky, and from thence to the Atlantic. Snow fell at every station
north of this line, at no station south of it. The depression of
temperature, however, was experienced over the continent, east of the
Rocky Mountains, under, and south of, the belt of precipitation. Now what
occasioned this general depression of temperature, and local fall of snow?
It will not do to say, as perhaps some calorific theorist may be inclined
to say, because the concentrated trade had been carried up where it was
cold, a month too soon; or that the sun had heated the land in advance of
it, and drawn it up.

For, 1st, it might be asked how, if it was warm enough to draw it up,
could it be cold enough to make it snow; or, 2d, how happened it to start,
when, as we have seen, it was warmer than the mean under it, and colder
than the mean to the north and west of it, when it commenced its journey?

But again, it snowed at posts north of the line, while the thermometer
remained above the mean; and the thermometer fell below the mean down to
Fort Brown in south-western Texas, and at Key West in the southern part of
Florida; and what is more remarkable still, at Key West, Fort Barrancas,
and every other south-eastern station, except Forts Brooke and Moultrie,
it not only fell below the _mean_ of the month, but _below the actual
temperature of March_. (See Table I.) At Forts Brooke and Moultrie it did
not rise above that temperature. West of the Rocky Mountains the
depression was not felt; nor at stations north, or north-west of the belt
of precipitation.

It is obvious, the calorific theory can furnish no rational explanation of