climate. Even in mountainous countries situated near the equator, as
in the Himalaya and Andes, wild roses are very rare, and only found
at great elevations, whilst they are unknown in the southern
hemisphere. It is curious that this rose, which is also a native of
Birma and the Indian Peninsula, does not in this latitude grow west
of the meridian of 87 degrees; it is confined to the upper Gangetic
delta, and inhabits a climate in which it would least of all be
looked for.

I made the elevation of Dacca by barometer only seventy-two feet
above the sea; and the banks of the Dallisary being high, the level
of its waters at this season is scarcely above that of the Bay of
Bengal. The mean temperature of the air was 86.75 degrees during our
stay, or half a degree lower than Calcutta at the same period.

We pursued our voyage on the 30th of May, to the old bed of the
Burrampooter, an immense shallow sheet of water, of which the eastern
bank is for eighty miles occupied by the delta of the Soormah.
This river rises on the Munnipore frontier, and flows through Cachar,
Silhet, and the Jheels of east Bengal, receiving the waters of the
Cachar, Jyntea, Khasia, and Garrow mountains (which bound the Assam
valley to the south), and of the Tipperah hills, which stretch
parallel to them, and divide the Soormah valley from the Bay of
Bengal. The immense area thus drained by the Soormah is hardly raised
above the level of the sea, and covers about 10,000 square miles.
The anastomosing rivers that traverse it, flow very gently, and do
not materially alter their course; hence their banks gradually rise
above the mean level of the surrounding country, and on them the
small villages are built, surrounded by extensive rice-fields that
need no artificial irrigation. At this season the general surface of