BRIDGING THE CHANNEL.

Star (Christchurch), Issue 315, 18 May 1869, Page 3

BRIDGING THE CHANNEL.

♦ That much-ridiculed idea of establishing a solid highway, between England and France, both for passengers and merchandise, is now very likely to become a realised fact. In spite of the oft-repeated declaration that it was ph3'sically impossible, it appears that a railway tunnel under the sea, or a railway bridge over the sea, from Dover to Calais, is not ouly possible, but tolerably certain of accomplishment. At the same time it is almost overwhelming to think of a bridge more than twenty miles long, with its foundations laid in the bed of the sea ! But there is no mistake as to the spirit in which the matter is being taken up on both sides of the Channel. French and English engineers arc bending their best euergies to the question, and the Emperor Napoleon seems quite enthusiastic on the subject. His Majesty has liberally subscribed to the object, and has placed one of the largest public buildings of Paris at the command of the company re cently formed for the purpose of constructing and testing various working models, preliminary to the commencement of the great work itself. The whole of tbis vast bridge, piers as weU as superstructure, will be of

■■ ■ ■ iron, and it is therefore not difficult to imagine that an enormous impetus will be given to the iron trade for materials to make a bridge over 20 miles long, with its foundations resting on the bed of the ocean, and sufficiently elevated to enable the tallest ships to pass free. The English in Paris are as much in earnest about the project as the French themselves, and one sporting lord has a bet with the Paris Jockey Club that a train will pass by this bridge from England to France before any of the P. and O. Company's steamers get through the Suez/ Canal. Of course a bridge 20 miles long, oii land, would be merely a question of time antl cost ; but across 20 miles of sea, other considerations than that of expense have to be taken into account. Still, even 40 or 50 yards depth of seawater is no trifling impediment in the way of putting down 20 miles of foundations ; but it is l-elieved the great work will be accomplished. A proposal has been made to make the balustrades of the bridge air-tight tubes, so as to render them available for the propulsion of letters and small packets by atmospheric pressure. There will then be an hourly post and parcel delivery between Paris and London 1 The following is a precise description of the intended structure : — "It is proposed to construct the bridge from the Shakespere Cliff, near Dover, to Cape Blanc Nez, a short distance from Calais, this route, although somewhat longer than the Gris Nez route, presenting certain important advantages, the soundings of which show a perfectly regular aud gradual descent from each shore, aud a maximum depth of each 157 feet 6 inches. The total length of the bridge is to be 32,822 yards, divided into ten arches of uniform span, resting on nine piers, rising to a height of 360 feet above the sea, so as to allow of the free passage of ships of the largest class. The arches are constructed on a new system, by which absolute rigidity is secured by the use of wire cables and wrought-iron — an ingenious and very simple system of scaffolding, rendering the placing of the parts extremely easy. Metallic framework piers, with foundations about 400 feet long, by 250 feet wide at the top, are to be employed, the centre pile being half as large again as the others. The piers are to be screwed down by 70 or 80 powerful screws, and are so arranged that they can be constructed on land, floated into position and fixed at once, the floating and fixing being calculated to occupy not more than half-a-day."