for opening a Roachmy under the Thames, S79 
the third stratum, which has been found to resist infiltrations, 
that the substrata, to the depth of 86 feet, are of a nature that 
present no obstacle to the progress of a tunnel ; we are informed 
that no water was met there. It is therefore through these sub- 
strata that it is proposed to penetrate, and to carry the line that 
is to cross the deep and navigable part of the river, leaving over 
the crown of the tunnel ahead of earth of from 12 to 17 feet in 
thickness, quite undisturbed, (See Fig. 5). 
Admitting that, in descending to, or in ascending from, that 
line, we should come to a body of quicksand, such as that which 
was found within about 200 feet from the shore, it is then we 
should find in the combinations of the framing, before described, 
the means that are necessary for effecting, upon a large scale, 
what is practised, on a very small one, by miners when they 
meet with similar obstacles. Indeed, were it not for the means 
of security that are resorted to on many occasions, mines would 
inevitably be overwhelmed and lost. 
Although we may encounter obstacles that may retard the daily 
progress of the work, it is with satisfaction we contemplate that 
every step we take tends to the performance and ultimate com- 
pletion of the object ; and, if we consider that the body of the 
tunnel must exceed the length of Waterloo Bridge, it must be 
admitted that, if, instead of 2 years, S were necessary to com- 
plete the undertaking, it would still prove to be the most econo- 
mical plan practicable for opening a land communication across 
a navigable river.” 
In order to execute the tunnel beneath the Thames by the 
method described in the preceding paper, it is proposed to raise a 
capital of L. 160,000 by transferable shares of L. 100 each. 
The following are the heads of expence : 
Preparatory expences, . . . L. 9000 0 0 
Expences of the execution of the work, which will 
require two years, 
Expence of materialSj 
Purchase of ground, 
Unforeseen expences, 
24.000 0 0 
87.000 0 0 
20.000 0 0 
24,000 0 0 
Total. 
L, 166,000 0 0 
6000 0 0 
Value of steam-engine, &c. 
L. 160,000 0 0 
