By DAVID GRAVELL.


The construction of dams, in some form or other, may probably rank among
the very earliest of engineering works. Works of this character are not
infrequently referred to in the accounts of the earliest historians; but
it is to be feared that they are not always perfectly trustworthy. The
subscribers to the Mudie of the period had to be considered, and their
taste for the marvelous was probably not much inferior to that of our own
day. When, therefore, Herodotus describes the reservoir of Moeris as
formed for the control of the river floods of Nile-nourished Egypt, and
of another constructed by Nebuchadnezzar at Sippara, of 140 miles in
circumference, we must make allowances. But there is no question as to
the existence in the East at the present day, and especially in India and
Ceylon, of the remains of what may correctly be termed stupendous works;
and the date of the construction of which, as regards India, is in many
cases prehistoric. In Spain also the Moors, whose occupation of the
peninsula terminated in the thirteenth century, have left reservoir dams
of great magnitude, situated mostly in the south-eastern provinces of
Murcia and Alicante, and many of which are still serviceable.

In India and Ceylon the greater number of the ancient dams or bunds are
now in ruins, and this can occasion but little surprise, considering the
meteorological condition of these countries. In Ceylon, for instance, the
whole rainfall of the year occurs within a period of six to eight weeks,
and often amounts to as much as 12 in. in the twenty-four hours, and has
been known, comparatively recently, to reach nearly 19 in., the latter an
amount only 2 in. or 3 in. less than the average rainfall of Lincolnshire
for the whole year. In London it is only 25 in. and in the wettest