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Scientific American Supplement, No. 810, July 11, 1891 by Various
page 36 of 160 (22%)
operations are rapidly progressing, mainly in accordance with a plan
devised many years ago by our distinguished countryman, Mr. McAlpine.
The total length of that part of the river to be regulated is about
two hundred and fifty miles, so that the enterprise ranks with the
cutting of the Panama and Suez canals as one of the greatest
engineering feats ever attempted. Work has been begun simultaneously
at three points: at Greben, where there are reefs to be taken care of;
at the cataract, near Jucz, and at the Iron Gate proper, below Orsova.
At Greben, where the stream is shallow, but swift, a channel two
hundred feet wide is to be blasted out of the rock, and below it a
stone embankment wall is to be built more than four miles long. From a
reef which projects into the river a piece is to be blasted away,
measuring five hundred feet in length, and about nine feet in depth.
The difficulties of working in this part of the river are very great.
Not only is the current extremely rapid, but in certain places ridges
of rock barely covered at low water alternate with pools a hundred
and forty feet deep, which give rise, in the rapid current, to
frightful whirlpools and eddies. These deep pools are to be filled at
the same time that the reefs are cut away, and it is estimated that
nearly three million cubic feet of loose stonework will be needed for
this purpose alone. In addition to the excavation, artificial banks
and breakwaters, for modifying the course of the stream, are to be
built; so that it is estimated that the masonry to be executed in this
section will amount to about five and one-half million cubic feet.

In the cataract section, at Jucz, a channel two hundred feet wide, and
more than half a mile long, is to be blasted out of the rock, and a
breakwater built, to moderate the suddenness of the fall. This
breakwater is to be about two miles long, and ten feet thick at the
top, increasing in thickness toward the bottom. The rock in which the
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