'The Expedition for the survey of the rivers Euphrates and Tigris, carried on by order of the British government, in the years 1835, 1836, and 1837; preceded by geographical and historical notices of the regions situated between the rivers Nile and Indus. In four volumes. With fourteen maps and charts, and embellished with ninety-seven plates, besides numerous wood-cuts. Volume the first.' [‎62] (109/905)

62
FLOODING OF THE EUPHRATES. [CHAP. III.
him in one view by the accompanying plate; which shows,
in minute detail, the changes of the river between the 26th
of July, 1835, and the 13th of June, 1836, when we entered
the Persian Gulf The historical term used to describe the body of water between the Arabian Peninsula and Iran. . This will enable those who are interested
in the subject to ascertain the variations more readily than
they could he obtained from any general description. 1
Mean velocities From the measurements and calculations of Lieutenants
Cleveland and Murphy, it is found that, at Hit, the mean of
the velocities of the current, at high and low water, in the
Euphrates, is 4*46 feet per second; and that, at Baghdad, the
mean velocity of the Tigris is 7*33 feet per second. The mean
velocity of the Danube, at Pesth, has, by Mr. George Rennie,
been ascertained to be 2-33 feet per second ; and M. Girard
determined the mean velocity of the Nile, at Cairo, to be only
1 foot 11 inches per second.
It may not be uninteresting to mention here, that, from the
shatfd 'Arab 6 observations of the two officers above-mentioned, Mr. Rennie
Danube. found the quantity of water discharged by the Euphrates, at
.Hit, to be 72804 cubic feet per second; and the quantity dis
charged by the Tigris, at Baghdad, to be 164103 cubic feet.
The sum of these quantities (=236907 cubic feet) may, per
haps, be taken as a near approximation to the whole quantity
discharged in a second by the Shatt el Arab, which is formed
by the united waters of those rivers. Mr. Rennie estimates
the quantity discharged by the Danube, in an equal time, at
338100 cubic feet.
Having thus followed, in a general way, the courses of the
four great rivers which rise in Central Armenia, I enter next
upon the proposed geographical account of the countries in
their neighbourhood; these are, Iran, or the territory east
ward, and Arabia on the west; and, in the course of the
description, some notices concerning their ancient boundaries
and condition will occasionally be presented,
1 The graduated scale was planned, as well as executed, by Acting Serjeant
Major William Quin, Royal Artillery, storekeeper during the Expedition, who
kept the daily register of those changes, as well as the ranges of the ther
mometer ; and from whom I have received the most valuable and unremitting
assistance during the three last years in preparing the different maps accom
panying this work.
of the
Euphrates,
Tigris, &c.
Water dis-