Daring French Engineering experiment.
--The Straits of
Messina are destined to undergo an operation (on the part of a French engineer) somewhat akin to the daring experiment of the
Menai Bridge, but of a different character.
There are no projecting cliffs that would enable
Charybdis to communicate with
Scylla athwart a tubular shaft hung in mid air, over "the masts of some tall admiral; " besides, as a line of railway across the channel is the object in view, an artificial ascent and incline is out of the question, but a gigantic pair of swivel pontoons, nearly on a level with high water, is held to be perfectly practicable, and the engineer,
Mr. Oudry, has already demonstrated that in his lately achieved bridge over an arm of the sea at
Brest.
Between that naval arsenal and the opposite point at Reconveyance, there rolls the tidal estuary, called Penfield Inlet, across which he has thrown two
sheet iron tubes, each 254 feet long, resting for support each on a central fulcrum or swivel, sustained by two piles of granite, in diameter measuring 36 cubic feet, the weight of each joint of the movable bridge being about three million pounds; yet such is the well-poised and accurate mechanism of this enormous structure, that a couple of men can swing round and re-connect the bridge, as if it were mere watch work, on the principle of horizontal movement.--
Paris Letter.