This fall is very local: at Silhet, not thirty miles further south,
it is under 100 inches; at Gowahatty, north of the Khasia in Assam,
it is about 80; and even on the hills, twenty miles inland from
Churra itself, the fall is reduced to 200. At the Churra station, the
distribution of the rain is very local; my gauges, though registering
the same amount when placed beside a good one in the station; when
removed half a mile, received a widely different quantity, though the
different gauges gave nearly the same mean amount at the end of each
whole month.

The direct effect of this deluge is to raise the little streams about
Churra fourteen feet in as many hours, and to inundate the whole
flat; from which, however, the natural drainage is so complete, as to
render a tract, which in such a climate and latitude should be
clothed with exuberant forest, so sterile, that no tree finds
support, and there is no soil for cultivation of any kind whatsoever,
not even of rice. Owing, however, to the hardness of the horizontally
stratified sandstone, the streams have not cut deep channels, nor
have the cataracts worked far back into the cliffs. The limestone
alone seems to suffer, and the turbid streams from it prove how
rapidly it is becoming denuded. The great mounds of angular gravel on
the Churra flat, are perhaps the remains of an extensive deposit,
fifty feet thick, elsewhere washed away by these rains; and I have
remarked traces of the same over many slopes of the hills around.

The mean temperature of Churra (elev. 4000 feet) is about 66 degrees,
or 16 degrees below that of Calcutta; which, allowing for 22 degrees
of northing, gives 1 degree of temperature to every 290 to 300 feet
of ascent. In summer the thermometer often rises to 88 degrees and 90