298 möleswokth’s pocket-book
Breakwaters—continued.
MARSEILLES.
Depth of water, 38 feet.
Outer casing of beton, 25j tons each.
Average thickness of casing from 14 to 20 feet.
Slope 1 to 1 from bottom to water line.
2| tö 1 above water line. All other slopes
i to 1.
Inner casing of first-class rubble (of stones 2 to
5 tons -weight), about 12 feet thick.
Hearting, second-class rubble (of stones | to
2 tons weight), about 6 féet thick.
Nucleus of quarry rubbish.
' I *■ 2H V i P!' r
ALGIERS.
Depth of water, 50 feet.
Hubble base carried up to 33 feet from surface
of water; the remainder composed of large beton
blocks, 25| tons each.
Slopes of rubble buse, 1 to 1.
Outer dope of beton blocks, 1| to 1.
luner „ „ 1 n 1.
port said (Suez Canal).
Concrete blocks, 10 cubic metres eacn, com-
posed of 1 of hydraulic lime to 13 of mid, mixed
with sea water; it refiiains 4 days in the mould
and driea for 4 mouths before being put iu posi-
tion. In some instances the composition of beton
blocks is i lime or cement to -j sand and broken
atone, about the size of a man’s fiat.