656
CHANTABUN — CHANTILLY
sea in the line of the tunnel being 210 feet in depth at the deepest oint. It is obvious that a tunnel can be driven which would escend at an inclination of 1 in 70 or 80 on the English, sweep under the Channel, and rise with the strata on the French side, if it can he made in an impervious stratum which cannot be traversed by the sea-water under high pressure. The only stratum satisfying this condition is the Lower Grey Chalk, and especially the lower and more clayey horizon overlying the Glauconitic Marl. Of the three English schemes, the first (Scheme A), proposed by Sir John Hawkshaw, starting from St Margaret’s Bay, and the modification of it (Scheme D) starting from Fan Hole, present serious engineering difficulties because of the great volumes of water in the Upper and Middle Chalk. The third (Scheme C) provides for a tunnel in the same impervious stratum throughout the whole of its length. The general question as to danger from the influx of water either from the sea or from the land is also satisfactorily answered. The water which percolates in enormous volumes through the chalk from the land into the sea, as may be observed between Dover and St Margaret’s, does not descend lower than the top of the Lower Grey Chalk, and an examination of the cliffs on both sides of the Strait proves that even where these lower rocks are traversed by faults, the water does not descend to the bottom of the series. There are no springs at this horizon in either the French or English cliffs. These considerations led to the selection of the sites at the Shakespeare Cliff and at Sangatte for the experimental shafts, and to the placing of the experimental drift-way under the Strait twenty-two miles long in the lowest stratum of the chalk. The selection is amply justified by the experience gained in the course of the work. The works executed on the English side, under the superintendence of Mr Brady, by the Submarine Continental Railway Company, Sir Frederick Bramwell being the consulting engineer, and Professor Boyd Dawkins scientific adviser, consist of two shafts of small importance, and a third on the west side of the Shakespeare Cliff, sunk into the Chalk Marl down to a depth of 164 feet from the surface. From the bottom of this a drift-way, i feet in diameter, has been driven to a distance of about 2300 yards. This passes below low-water mark at a distance of 1350 yards from the shaft, leaving the shore diagonally in the direction of the head of the Admiralty Pier, and, running eastwards under the sea at an inclination of 1 in 72, it maintains the same position in the rocks throughout, being within a few feet of the Gault clay. Had it not been stopped by order of the Government in 1884, there is every reason to suppose that it would have been carried easily and without mishap across to the other side. The length already made proves that no danger need be apprehended from faults. It has cut through all those visible in the Shakespeare Cliff, and although at the time of driving there was a slight weeping of salt water through them to the amount of 3'3 gallons per minute, they gradually became blocked up and water-tight. When it was last examined by the writer of this article, after standing for five years, it was as dry as any similar driftway could be, and the marks of the boring machine on the polished surface of the chalk were as distinct as on the day when they were made. On the French side the French Submarine Railway Company sank a shaft at Sangatte 18 feet in diameter to a depth of 226 feet. Unfortunately it intersected a fault in the upper strata which was in communication with the sea, and consequently let the water down to the area of work, which was at the same horizon in the rocks as on the English side, a few feet above the Gault. Two drift - ways had therefore to be made, the upper for the excavation and the lowrer for the drainage of the water descending the shaft towards the
working face. The former, which was cut by Beaumont’s English machine, wras 7 feet in diameter. It wras carried to a distance of about one mile from the bottom of the shaft, underneath the bed of the sea, and traversed in its course several faults, winch, like those on the English side, were perfectly water-tight. Authorities.—Blue-book Correspondence respecting the proposed Channel Tunnel and Railway, presented to both Houses of Parliament, 1875 (Commercial, No. 6).—Blue-book Correspondence with reference to the proposed construction of a Channel Tunnel, presented to the Houses of Parliament, 1882 (C. Blue-book Report from the Joint Select Committee of House of Lords and House of Commons on the Channel Tunned, together with the Proceedings of the Committee, Minutes of Evidence, and Appendix, 1883 (47).—Channel Tunnel, 1869, Statement by Executive Committee, with Engineers' Report and Diagram, &c. London, 8vo. — Bramwell. “ The Making and Working of a Channel Tunnel,” Royal Inst. Proc., 19th May 1882.—Crampton. “ Creusement du Tunnel sous-marin entre Calais et Douvres suivant un systems hydranlique propose par' M. Crampton,” Mem. Soc. Ingen. Civil., 4me ser., 6me vol.—Tylden Wright. “The Channel Tunnel,” North of England Institute of Mining and Mech. Engin. vol, xxii., 1882.—Boyd Dawkins. “The Channel Tunnel,” Manch. Geol. Soc., 2nd May 1882; Brit. Assoc. Reports, Section C, 1882, 1899. (w. B. D.) Chantabun, the principal town of a province of Siam of the same name, situated on the east side of the Gulf of Siam, in 102° 6'E. long, and 12° 38' N. lat. The town lies about 12 miles from the sea, on the banks of a river which is navigable for small boats. Inside the bar which protects the entrance to the river a wide estuary offers secure and commodious anchorage for coasters. The town has now a population of about 5000. About 900 tons of white pepper is produced per annum, and sent to Bangkok for trans-shipment to Europe. Coffee, which has been grown on a small scale, has given good results. The ruby mines are scattered over an area about 15 miles square in the district of Krat. There are now fewer than 500 men working at these diggings. The sapphires exported from Chantabun come exclusively from Pailin on the east or Battambong side of the Patat, where some 2000 Shans, mostly British subjects, and about 2000 Lao from the lower Mekong valley are employed at the diggings. Some £350,000 worth of rubies and sapphires is exported annually. In 1893 the town of Chantabun was occupied by a small French force, about 400 strong, consisting mainly of Annamite tirailleurs. This occupation was effected under Act 6 of the Convention of the 3rd of October in that year, agreed to between the French and Siamese Governments, and was to last until the execution of the stipulations of the Convention, and more especially until the complete evacuation and pacification of the left bank of the Mekong and of the zones in which, by the treaty of the same date, the Siamese Government had to withdraw all armed forces. The occupation, which has in no way affected the trade or administration of the province, still continued in 1901, notwithstanding both the assurances made to the British Government in.1893 that it would only last a month and the repeated representations made on the subject by the Siamese Government. Chantilly, a French town in the arrondissement of Senlis, department of Oise, 24 miles in direct line S.E. of Beauvais, on railway from Paris to Creil. The manufacture of lace and blonde is a decayed industry. A magnificent castle was erected, 1876-85, in Chantilly Park by the due d’Aumale, on the foundations of the ancient chateau and in the style of the chatelet, the only remnant of the ancient pile of the Montmorencys. On the terrace is a bronze statue of Anne de Montmorency, and, opposite to the court of the chatelet, the pleasure ground known as Voltaire’s Parterre. The whole is surrounded by fosses supplied with water from the Nonette. The due d’Aumale installed in the castle a valuable library, specially rich in incunabula and 16thcentury editions of classic authors, and a collection of the paintings of the great masters, besides many other objects
