to construct a continuous
tube, 13 ft. in internal diameter, of iron rings each 10 ft. long, each
ring being built out from the completed portion of the tube by means of
a horizontal chamber or bell, which slid telescopically over the last
few rings previously put in place, and was moved forward by hydraulic
power. About the same time Zerah Colburn produced plans for a tube
constructed of 1000 ft. sections, which were to be built in dry dock and
then successively attached by a ball and socket joint to the completed
portion, the whole being raised from the bottom and dragged out to sea,
by the aid of a large number of ships, as each section was attached and
launched. Thomas Page, again, the builder of Westminster Bridge,
proposed to place eight conical steel shafts at intervals across the
Strait of Dover, and to connect them by long sections of tube lowered
from the surface, the whole structure being covered with concrete when
finished. No attempt was made to put any of these plans into execution,
and the same was true of several bridge schemes propounded about the
same time; in one of these, spans one-half or three-quarters of a mile
in length were contemplated, while another required 190 towers, 500 ft.
apart and rising 500 ft. above the water-level, which obviously would
have constituted an intolerable nuisance to navigation. The case,
however, was different with a train ferry which was vigorously advocated
by Sir John Fowler. His proposal was to employ steamers 450 ft. long,
with a beam of 57 ft. and a speed of 20 knots, having railway lines laid
down on their decks on and off which railway vehicles could be run
directly at each side of the strait. Dover was to be the English port,
while on the French coast a new harbour was to be formed at
Audresselles, between Calais and Boulogne. This plan in 1872 received
the sanction of the House of Commons, but was rejected in the House of
Lords by the casting vote of the chairman of the committee. According to
another similar ferry scheme, which was worked out by Admiral Dupuy de
Lome in 1870, a new maritime station was to be constructed at Calais, so
far off the shore that it would command deep water at every state of the
tide, and connected with the French railways by a bridge.

After the conclusion of the Franco-Prussian War, negotiations
concerning the tunnel were resumed between the French and British
governments, and in 1872 the latter intimated that it had "no objection