632 
NATURE 
[ April 21, 1870 
i ———— 
The deep sea tower or ventilator is probably not prac- 
ticable, but we consider it does not form an essential part 
of the scheme. The whole tube might be formed of 240 
separate pieces, each 400 feet long, and submerged without 
the tower by working from one shore end. The sub- 
merging and joining together of these parts in deep water 
would, however, be a perilous operation. No doubt this 
is the main difficulty of every plan of this class of scheme. 
In the present case it must be overcome and the opera- 
tion 240 times successfully repeated, in order to complete 
the structure, and we may accordingly appreciate the 
chance in favour of the completion of this kind of sub- 
merged roadway. 
Of the second class of works, viz. building the whole 
tube in deep water, we have but one scheme. It is the 
more satisfactory to observe that, of all the schemes 
which have been proposed with a view to establish a per- 
manent railway communication between England and 
France, it is the most elaborate and complete, offering a 
solution on all material points in connection with this 
subject. The authors of this project—Messrs. Bateman 
and Révy—have published a full account of their scheme, 
and we cannot do better than refer to their work fora 
short dcscringeD of the plan they adopt. 
Our object “has been to devise a scheme by which all 
difficulties of operating in water should be avoided. We 
propose to lay a tube of cast iron on the bottom of the sea, 
between coast and coast, to be commenced on one side of the 
Channel, and to be built up within the inside of a horizontal 
cylinder, or bell, or chamber, which shall be constantly pushed 
forward as the building up of the tube proceeds. The bell 
or chamber within which the tube is to be constructed 
will be about Soft. in length, 18 ft. internal diameter, 
and composed of cast-iron rings 8 inches thick, securely bolted 
together. The interior of the bell will be bored out to a true 
cylindrical surface, like the inside of asteam cylinder. The tube 
to be constructed within it will consist of cast-iron plates in 
segments 4 in. in thickness, connected by flanges, bolted together 
inside the tube, leaving a clear diameter of 13ft. when finished. 
Surrounding this tube and forming part of it, will be constructed 
annular discs or diaphragms, the outside circumference of which 
will accurately fit the interior of the bell. These diaphragms 
will be furnished with arrangements for making perfectly water- 
tight joints for the purpose of excluding sea water and securing 
a dry chamber, within which the various operations for building 
up the tube, and for pressing forward the bell as each ring of the 
tube is added, will {be performed. Within this chamber, 
powerful hydraulic presses, using the built and completed portion 
of the tube as a fulcrum, will, as each ring is completed, push 
forward the bell to a sufficient distance to admit the addition of 
another ring to the tube. The bell will slide over the water- 
tight joints described, one of which will be left behind as the 
bell is projected forward, leaving three always in operation 
against the sea. The) weight of the bell and of the machinery 
within it will be a little in excess df the weight of water 
displaced, and therefore the only resistance to be overcome by 
the hydraulic presses when pushing forward the bell, is the 
friction due to the slight difference in weight and the head or 
column of water pressing upon the sectional area of the bell 
against its forward motion. In like manner, the specific gravity 
of the tube will be a little in excess of the weight of water 
which it displaces ; and in order to obtain a firm footing upon 
the bottom of the sea, the tube will be weighted by a lining of 
brick in cement, and for its further protection will be tied to 
the ground by screw piles, which will pass through stuffing boxes 
in the bottom of the tube. These piles will, during the con- 
struction of the tube within the bell chamber, be introduced in 
the annular space between the outside of the tube and the inside 
of the bell, and will be screwed into the ground as they are left 
behind by the progression of the bell. The hydraulic presses 
and the other hydraulic machinery, which will be employed for 
lifting and fixing the various segments of the tube, will be 
supplied with the power required for working them from 
accumulators on shore, on Sir William Armstrong’s system, 
and the supply of fresh air required for the sustenance of the 
workmen employed within the bell and within the tube will be 
insured also by steam power on shore. As the tube is com- 
pleted, the rails will be laid within it for the trains of waggons to 
be employed in bringing up segments of the rings as they may 
be required for the constructions of the tube, and for taking back 
the waste water from the hydraulic presses, or any water from 
leakage during the construction. 
The tube will be formed of rings of 10 feet in length, each 
ring consisting of six segments, all precisely alike, turned and 
faced at the flanges or joints, and fitted together on shore pre- 
vious to being taken into the bell, so that on their arrival the 
segments may, with perfect certainty and precision, be attached 
to each other. The building of the tube will be commenced on 
dry land above the level of the sea, and will be gradually sub- 
merged as the tube lengthens. The operations on dry land will 
be attended with more difficulty than those under water, but all 
these circumstances have been carefully considered and provided 
for. 
The precise line to be taken betwixt the English and French 
coasts can hardly be determined without a more minute survey of 
the bottom of the Channel than at present exists. It will 
probably be between a point in close proximity to Dover on the 
English coast, and a point in close proximity to Cape Grisnez on 
the French coast. On the line suggested the water increases in 
depth on both sides of the Channel more rapidly than elsewhere, 
although in no instance will the gradient be more than about 1 
in 100. The tube at each end would gradually emerge from the 
water, and on arriving above the level of the sea would be con- 
nected with the existing railway systems, so that the same 
carriage may travel all the way from London to Paris, or, if 
Captain Tyler’s anticipations be realised, all the way from John 
O’Groat’s to Bombay. 
The distance across the Channel on the line chosen is about 
22 miles. The tube as proposed is large enough for the passage 
of carriages of the present ordinary construction, and to ayoid 
the objections to the use of locomotives in a tube of so great a 
length, and the nuisance which would be thereby created, and 
taking advantage of the perfect circular form which the mechani- 
cal operation of turning, facing, &c., will insure, it is proposed 
to work the traffic by pneumatic pressure. The air will be ex- 
hausted on one side of the train and forced in on the other, and 
so the required difference of pressure will be given for carrying 
the train through at any determined speed. Powerful steam- 
engines, with the necessary apparatus for exhausting and forcing 
the air into the tube, will be erected on shore at each end ; and 
supposing one tube only to exist, the traffic will be worked alter- 
nately in each direction. 
It has been found by calculation, that, for moving a large 
amount of tonnage and a great number of passengers, the most 
economical arrangement will be to send combined goods and 
passenger trains through the tube at 20-miles an hour, with 
occasional express trains at 30 miles an hour. Thus, an ordinary 
or slow train would occupy about 66 minutes in the transit, and 
a quick or express train about 45 minutes. In this way the 
tube, if fully worked, would permit the passage of 16 ordinary 
slow trains (8 each way), and 6 express trains (3 each way), 
each conveying both goods and passengers. About 10,000 tons of 
goods per day, or upwards of 3,000,000 per annum, and 5,000 
passengers, or nearly 2,000,000 per annum, might be taken 
through, or a less amount of goods and a larger number of 
passengers, or vice vers@, if circumstances rendered other pro- 
portions necessary or desirable. 
The horse power required for working the traffic with the 
above number of ordinary and express trains will be, on the 
average, 1,750 indicated, or about 400 nominal horse power at 
each end, 
We should gladly have referred to many other interest- 
ing and important statements contained in this work, but 
our limited space does not admit of our doing so. A 
general idea of the proposition may be gathered from 
the above description of the authors, taken from the 
popular part of their work. The Appendix, which 
really contains the substance of the scheme, is too 
elaborate and technical for the general reader, with- 
out devoting special study and attention to it. Suffice 
it to state, that the amount of information conveyed in 
those 40 pages of close print is very great, being an 
account of a succession of results of elaborate investiga- 
tions of physical, mathematical, and even of a chemical 
nature. One gains confidence from the mere fact, that 
in treating the subject the authors are evidently “ at 
home,” and do not evade a difficulty. 
