No. 544.
Mr. Baker
to Mr. Evarts.
Caracas, October 29, 1878. (Received November 18.)
Sir: As tending to help toward the formation of an idea of the climatology of this country, it may be worth while to transmit a brief account of a notable rain-fall which occurred here on the afternoon of the 3d instant. I translate and incorporate the following extract from the report of the session of the 7th of the present month, of the Society for the Promotion of Physical and Natural Sciences (Sociedad de Ciencias fisicas y naturales), as the same appears, in La Opinion Nacional of the 22d instant, premising that this part of the report is to be credited to Señor Ledo Aveledo.
On the 3d of October, at half after 1 p.m., it commenced to rain without interruption, until 3 p.m.—105 millimeters (4.13 inches) having fallen in this time, which is about the eighth part of all the water that on an average falls annually in Caracas.
From the 1st January, 1868, from which our observations date—the pluviometer has never gathered a greater quantity in an equal time.
The fall in an hour and a half of one-eighth of the annual quantity of water brings to view a true tropical rain. This rain as I understand was quite local; it did considerable damage to streets, bridges, & c.; some houses were flooded, a few others were undermined; several persons were reported drowned, and the rain was accompanied for a short time with hail, a phenomenon which it appears from the same report previously took place at Caracas on the 16th of September, 1874.
Apropos of the cause of hail, I think it worth while to also translate and incorporate the following observations from the same report, to be credited in like manner to Señor Ledo Aveledo:
Concerning the hail which fell in Caracas on the 16th of September, 1874, we then wrote the folio wing:
As is known, hail has an electrical origin, since it never falls except during tempestuous storms.
Facts tend to demonstrate that the phenomena of heat, light, electricity, and magnetism recognize one and the same cause, these phenomena being only different manifestations of the same agent.
May it not be supposed that a part of the heat of the atmosphere is transformed into electricity, and that the absence of said heat occasions greater condensation of the vapor of water, causing an increase of rain, this being observed to increase immediately after flashes of lightning?
Perhaps, then, the phenomenon of hail may be explained by supposing the strata of air which the rain traverses to have fallen to a temperature below zero, and to have congealed the drops of water.
It is interesting to observe that we here have from a Venezuelan physicist an opinion concerning and an apparently plausible application of the new and very important theory of the “correlation and conservation of the physical forces.” I understand, however, from Prof. A. Ernst, of the University of Caracas and president of the above-named society, that this application of the theory was previously propounded by Herr Baumgartner, of Vienna.
I have, & c.,