lines, viz., with culvert outlet under the dam, was, at the advice of Sir
Robert Rawlinson, altered to a side tunnel outlet clear of the dam.

Some years previous to the failure of the Dale Dyke reservoir there
occurred, in 1852, a failure of a similar character--though, as far as
the author is aware, unattended by such disastrous results--at the
Bilberry reservoir at Holmfirth, near Huddersfield, which had never been
filled previous to the day of its failure, and arose from the dam having
sunk, and being allowed to remain at a level actually below that of the
by-wash; so that when the storm occurred, the dam was topped and
destroyed. An after examination proved that the bank was badly
constructed and the foundation imperfect.

Besides the above instances, there have been numerous failures within
recent times of earthwork dams in Spain, the United States, Algeria, and
elsewhere, such as that which occurred at Estrecho de Rientes, near
Lorca, in Murcia, where a dam 150 ft. high, the construction of which for
irrigation purposes was commenced in 1755 and completed in 1789, was
filled for the first time in February, 1802, and two months later gave
way, destroying part of the town of Lorca and devastating a large tract
of the most fertile country, and causing the death of 600 people. The
immediate cause of failure in this case the author has been unable to
ascertain. In Algeria the Sig and Tlelat dams were destroyed in 1865; and
in the United States of America, at Williamsburg, Hampshire Co.,
Massachusetts, in 1874, an earthwork dam gave way, by which 159 lives
were lost and much damage done to property. In another case, viz., that
of the Worcester dam, in the United States of America--impounding a
volume of 663,330,000 gallons, and 41 ft. high, 50 ft. broad at the
crest, and formed with a center wall of masonry, with earthwork on each
side--which gave way in 1875, four years after its completion; here, as
in almost all other instances of failure, the leakage commenced at a
point where the pipes traverse the dam. In this case they were carried in
a masonry culvert, and the leak started at about 20 ft. on the up stream
side of the central wall. The opinion of Mr. McAlpine as to the cause of
failure, which agrees with that of the most eminent of our own water
engineers, was to the effect that "earthen dams rarely fail from any
fault in the artificial earthwork, and seldom from any defect in the
natural soil. The latter may le