PHENOMENA OP HAILSTOHM8. 
217 
mission. The few inhabitants who survived this cruel epi- 
demic, removed to the village of Carichana. It was at Pa- 
l 'aruma, that, according to the testimony of Father Homan, 
hail was seen to fall during a great storm, about the middle 
of the last century. This is almost the only instance of it 
I know in a plain that is nearly on a level with the sea ; 
f°r hail falls generally, between the tropics, only at three 
hundred toises of elevation. If it form at an equal height 
ov er plains and table-lands, we must suppose that it melts 
as it falls, in passing through the lowest strata of the atmo- 
s phere, the mean temperature of which is from 27'5° to 24“ 
°t the centigrade thermometer. J acknowledge it is very 
difficult to explain, in the present state of meteorology, why 
II hails at Philadelphia, at Home, and at Montpelier, during 
|he hottest months, the mean temperature of which attains 
or 26° ; while the same phenomenon is not observed at 
h umana, at La Gluayra, and in general, in the equatorial 
Plains. In the United States, and in the south of Europe, 
^he heat of the plains (from 40° to 48° latitude) is nearly 
fhe same as within the tropics ; and according to my re- 
searches the decrement of caloric equally varies but little, 
i f then the absence of hail within the torrid zone, at the 
ev el of the sea, be produced by the melting of the hail- 
s tones in crossing the lower strata of the air, we must 
8u Ppose that these hail-stones, at the moment of them for- 
mation, are larger in the temperate than in the torrid zone. 
^ e yet know so little of the conditions under which water 
c °Qgeals in a stormy cloud in our climates, that we can- 
Il(, t judge whether the same conditions be fulfilled on the 
e fiuator above the plains. The clouds in which we hear the 
Rattling of the hailstones against one another before they 
1, and which move horizontally, have always appeared to 
7 6 of little elevation; and at these small heights we may 
Conceive that extraordinary refrigerations are caused by the 
natation of the ascending air, of which the capacity for 
? a ° r ic augments ; by currents of cold air coming from a 
P'Sker latitude, and above all, according to M. Gay Lussac, 
y the radiation from the upper surface of the clouds. I 
,. a " have occasion to return to this subject when speaking 
the different forms under which hail and hoar-frost appear 
11 the Andes, at two thousand 'and two thousand six bun- 
