TUNNELS. 
Comparative Table of some of the largest Tunnels. 
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Name of tunnel. Formation. 5 = es I | re Locality. 
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Feet. Dollars.| Dollars. 
Nerthe .......+--+| P. L.| 4 ...| Hard limestone,..| 24...| 610..| 29.5 >< 26.25 | 15,153 |....+.../.0.... «++| 1,298,450 | Near Marseilles, France. 
Riqueval . P. L.} 1803 | Chalk..........-.| 54...| 210..| 26.25 x 26.25 | 18,623) 2,139] 39.887 742,817 | St. Quentin canal, France. 
Pouilly..... P. L.) 1824 | Chalk and clay.,.| 32...| 164..| 20.34 >< 20.34 | 10,928 | 2,504 | 113.965 | 1,245,412 | Bourgogne canal, France. 
Asschviller.......- Picea | L809) | Zaccatecssenine cee Maal Ziresc|) BOsc0De 20.2011) cy Goe 1,878 | 68.38 |a. 504,897 Maine and Rhine canal, 
rance. 
Mauvage..... ewes) Zhe 1840) |i Aicccecnisecdeceste |e Z...| 25.59 25,59 | 15,752 | 2,085 | 94.43 |a.1,487,393 | Maine and Rhine canal, 
France. 
Rolleboise.........| Z--..| 1841 | Chalk........+...| S.8.| Z...| 24.94 < 24.94 | 8,670 626 | 62.98 546,099 | Rouen railway, France. 
Roule .... «| Z....| 1841 | Z... S.S.| Z...| 24.94 « 24.94 | 5,645 522} 62.98 355,513 | Rouen railway, France. 
WslOran ...0..0c00.| Aer 1839 | Zo. ncecccccceccee|S5.| Zoe.| 21.83 21.33] 4,548) 2,087 | 56.98 259,173 | National road, No. 126, 
France. 
Kilsby, (X).......|/L....| 1834 | Clay and sand....| 18 164..| 27 | X 23.50 | 7,233 | 1,252 | 194.31 1,405,417 | London and Birmingham 
railway, England. 
Blechingly........| L...,| 1840 | Blue clay.........| 12...] 97...| 294 25.05 | 3,972 626 | 162.86 423,271 | London and Dover rail- 
way, England. 
‘Thames and Med- | P. L.| 1822 | Chalk. ..........| S....| 194..] 30 > 38.7 | 11,880 939 | 45.59 541,550 leans and peey ca- 
way. . nal, England. 
BOX. . 200.0000) P. L.| 1837 | Marble, freestone,| 15...] 400..| 35 >< 39 9,680 | 1,252) 148,15 1, 434, 063 | Great Western railway— 
marl, &e. shafts 25 feet diameter, 
one-third of tunnel in 
rock—Fngland. 
Hare Castle.......|L....| 1824 | Rock and sand....| 15...| 187..] 14 16 8,778 939) 57.05 500, 799 ene ae Mersey canal, 
ngland. 
Nochistonge (D)..| L....| 1807 | Clay and marl,...| S....| 164..) 13.78 x 11.48 | 21,659 287 || nce eve soodebenc no Zumpango, Mexico; 
a Desagua. 
Blisworth.,. aE can 16.5 < 18 9,240 | 2,191 | 93.185 214,229 | G. J. canal, England. 
Sapperton P.L. 150) 5<5 12,900 | 1,878 | 12.44 160,476 | Thames and Severn canal, 
England. 
Black Rwock.. NL..| 1835 | Greywacke slate..| 6.. 139..| 19 17.23] 1,932 sees! 77.18 149,120 | Reading, Penn., railway, 
United States. 
Blaisy....... .|L....| 1846 | Chalk, clay, &c...| 22 646...) 26.25 < 96.25 | 13,455 | 1,043 | 136.06 1, 830, 730 ree and Lyons railway, 
rance. 
Edge Hill.........| P. L.| 1826 | Clay and freestone| S....| Z-..| 22 X16 6,600 |.... 30.15 198,969 | Liverpool and Manchester 
railway, England. 
Littlebourg .......| Lr .+..| 1840 | Z..scceeccescceees| 14...|(C)177| 27.5 XX 24 8,607 590 | 129.61 1,115,544 | Manchesterand Leeds rail- 
way, England. 
Weodhead .......| Z....| Z...| Millstone rock....| 5.-+-| 600..|....eseeeeeeeeee| 15,840 | 1,800 ]..... eeey| 1,026,705 Manchester and Sheffield 
railway, England. 
A tunnel has been projected at Mt. Cenis, on the line of the Lyons and Turin railway, of the 
length of 7.6 miles; the gradient in the tunnel to be 105 feet to the mile; the section of the 
tunnel to be 19 by 25 feet; no shafts to be used. By the aid of machinery it was expected to 
complete this work in five years, at an expense of $2,615,000. 
The inventor of the machine and the engineer of the road is the Chevalier Mause. His plans 
and estimates were submitted to, and approved by, a board of eminent engineers and geologists, 
among whom was the celebrated Mr. Robert Stevenson. 
The tunnel projected through the Hoosack mountain was to have been 44 miles long, 23 feet 
by 22 feet ; two shafts about 850 feet and 750 feet deep, 10 feet in diameter. The cost variously 
estimated at from $2,000,000 to $3,000,000. ‘Time estimated by different engineers at from 
four to ten years. The machinery designed for boring did not succeed, and the project has not 
as yet been commenced seriously. 
At the crossing of the Blue Ridge by the Virginia Central railroad there are four tunnels. The 
main tunnel is 4,280 feet in length; has been four years under construction, and is estimated to 
require two years more to complete it. No shafis are used. It is ventilated by machinery. 
A portion of it is lined. It is for a single track, and is in the clear 21 feet high by 15 feet in width. 
Where lined, the abutments of the lining are 4 feet thick; the arches 3 feet thick. The excavation 
in these places is 26 feet high by 23 feet wide. 
A portion of one of the small tunnels is through a very difficult formation of loose rock and 
earth. In the main tunnel much trouble is experienced from the water. 
The main tunnel is 700 feet below the crest of the mountain through which it passes. The 
workmen are arranged in three reliefs, and work night and day. No machinery is used for boring 
or excavating. It is the opinion of the engineer that no machinery can be applied when the tunnel 
requires lining, for want of space. He states that no excavating machine has yet been successful. 
La 
