Meteorological Sketches: 00 
sation, their weight be increased beyond that which the extent of 
their surface can sustain, they then descend in the form of rain; and 
as the condensation ordinarily increases as the drops increase in mag- 
nitude, it is common to have more rain fall on the surface of the 
ground than on, an equal space upon the top of a house or church. 
Clouds, fogs, and rain are therefore essentially the same, the latter 
being the continuation or extension of the same process which pro- 
duced the former. ' : 
Owing to the evaporating properties of the atmosphere in the 
higher regions, as well] as the intensity of cold which there uniformly 
prevails, distinct clouds are seldom, if ever, found at a greater ele- 
vation than the summits of the highest mountains, which is about 
five miles. At an intermediate region, however, the clouds are 
often at a temperature above freezing, while the air at the surface 
is much below the freezing point, and the earth covered with snow. 
This condition of the clouds seems not unfrequently evident by their 
appearance to the eye of an observer. Snowy or frozen clouds are 
usually dim and undefined in their aspect or appearance ; and a fall 
of snow may not unaptly be termed the fall of a frozen cloud. 
an | 
Of Hail. 
Hail of small size, as it falls in wintry storms, appears as frozen 
rain-drops. From the occurrence of this phenomenon in a freezing 
state of weather, we find evidence that a stratum of air in the region 
of clouds is at a temperature above the freezing point, or warmer 
than that which is found at the surface at the same time. A heavy 
fall of snow when the temperature is much below the freezing point, 
affords, perhaps, the same indication. 
Summer hail of large size, which is deposited in a definite path or 
vein, or in a locality of limited extent, is usually accompanied by 
heavy thunder and vivid or continued lightnings, or a heavy rambling 
sound or rapid concussions, high winds, &c., and is believed to be 
the production of a vortex or whirlwind in the atmosphere, or spout 
as it is sometimes called, which is connected at its upper extremity 
with an overlying stratum of unusually cold air. A portion of this 
cold stratum probably descends on the exterior of the vortex, and on 
approaching the earth’s surface, is pressed into the vortex and there 
entwined or laminated with the layer of warm and humid air of the 
surface, which is drawn in at the same time. A rapid condensation, 
