| NAMES OF TUNNELS. | LENGTH IN YARDS. | COST PER YARD. |
|---|---|---|
| Norieu, St. Quinten Canal | 13,128 | $ 14.00 |
| Pouilly, Canal de Bourgoyne | 3,660 | 393.75 |
| Soussay, Canal de Bourgoyne | 3,852 | 45.50 |
| Maurages, Canal de Marne | 5,320 | 325.00 |
| St. Argnan, Canal d’Ardennes | 288 | 200.00 |
[Click image to enlarge.]
Among railroad tunnels, the following are selected from different parts of the continent:
| NAMES OF TUNNELS. | LENGTH. | WIDTH. | HEIGHT ABOVE RAILS. | NUMBER OF SHAFTS. | SECTION ABOVE RAILS. | COST PER RUNNING YARD. | TIME IN CONSTRUCTION. | MATERIAL. |
|---|---|---|---|---|---|---|---|---|
| YDS. | FT. | FT. | SQ. FT. | DOLS. | MO’S. | |||
| Chezy | 496 | 24.27 | 18.04 | 0 | 365.84 | 411 | 32 | Sand and clay. |
| Arschwiller | 2928 | 24.27 | 18.04 | 6 | 374.77 | 176 | 95 | Sandstone. |
| Alouette | 1350 | 25.58 | 20.00 | 21 | 428.68 | 305 | 23 | Clay. |
| La Motte | 279 | 24.92 | 21.98 | ... | 519.71 | 180 | 30 | Clay, marl, sandstone. |
| Nerthe | 5072 | 26.24 | 24.60 | 24 | ... | 412 | 36 | Limestone. |
| St. Martin | 1509 | 25.25 | 19.35 | 10 | 415.34 | 475 | 60 | Porphyritic rock. |
| Blaisy | 4483 | 26.24 | 24.60 | 20 | ... | ... | ... | Limestone. |
The cost of the Thames tunnel was greatly increased by a shield, designed by Brunel, to keep out the water. Omitting this tunnel from comparison the English works exceed the French, or Continental, in cost of construction.
The boldest work of the kind yet undertaken is the [Mt. Cenis tunnel], to connect France and Italy by a continuous railway. In length it is seven miles, with a width of 26′ 6″ and a height of 20′ 8″. Its completion is anticipated in April, 1871.