The Sun.
London, England, 1826-10-11 00:00:00

THAMES TUNNEL.

This singular and extraordinary undertaking is making;
rapid progress towards its completion, and there seems
every probability of ultimate success. The following is
brief outline of the present state of the works :
The communication with the spot where the working
people are employed is by means of a ;haft, 70 feet in
depth, 50 feet in diameter, and 150 .n circumference, to
which visitors descend by means of, windinr. staircase:
This staircase.—
.temporary nature, and it is
arrangementTiilltieisnlied,oli te cisornopniley of A t ,
:.(311 of the undertaking, to form
another l'itar construction, but of much larger
dimensions,
shaft
a of
as
a.,:,4age.way.
The diameter of this shaft
will be 20Q feet, winch, from the base to the surface of the
earth, will still leave a descent of about 60 feet. This
aseentOtowever, will be so constructed as not to create any
coutidarabrk,' diMeulty to the carriage of heavy burthens.
The apparatus by which the work is carried on, is by
means of a east-irate sisield,"Which is under the controal of
a lever, in which there are 36 boxes, which 'can either be
moved sine, or.jointly, at pleasure, in which the exmtva-
tors perform their operations. There are three tiers of
them, and when the propelling power is called into action
they move seine inches at a time. They are composed, of
iron, and the shield is formed to the extent of the proposad
undertaking, being 40 feet in width and 22 feet in height.
The shield is square, and "after forming the arch, the
corners are bricked, and the square completed ; and at no
time is there more than nine inches, and seldom above
six inches, left unprotected. On the excavators remov-
ing the rough earth, the bricklayers immediately follow with
three courses of bricks, which form the arch, and which is.
four feet in substance. The distance from he top of the
shield to the bed of the River is 20 feet, and the precau-
tion exercised in the formation of this important part of
the undertaking is so well adapted, that in the event of
any accident occurring, by the rush of water or the burst-
ing of a spring, the top-sleepers of each box, us they are
called, will immediately unfix ; and if the danger increases,
they can brick it in, which has already been the case, when
some of the land springs, before they came under the River,
impeded the progress of the undertaking., and which has
hitherto proved effectual.

The medium of communication will be by means of two
arches, each 17 feet 6 inches in height, and 13 feet 6
inches in width, separ.ated by a pier 3 feet 6 imles, one
of them intended for the communication froz, Wapping,
and the other from Rotherhithe, so that no possible ob-
. struction can occur ; and the gas lights 'tieing placed at so
short a distance from each other, win present a most sin-
gularly pleasing sight. Every 12 feet there is an opening,
by which passengers may recoicnize each other, but the op-
portunity of passing from one arch to another will be pre-
vented by an iron railing., In each of these communications
gas will be laid on, and any inconvenience arising from
this mode of lighting, will be counteracted by an admirable
system of ventilation, produced by sit aperture between,
quality
the two arches, the draft of which, at the resat moment,
is so great, that it will immediately eittinguish a link Or
iTltost•
hihal lee,trobhsfioltrlerdoooittilligrsgichelsdra,i:billiel,iftt:ia,nownfilehtneiictbiheiesl yielnligimllhoblprelteahettehe:odebr,scliaonwbioltirik,s
oiwTsollohlneepnoltetdrirnthi
oeoro!
rainodoiptaihiey
made
aarys
tar, but a very strong cement,. in the preparing and
el
: I (st
description,flltielli is
andfle di),
ofof awhoi;lsittdhoerogib.
the clay procured by the excavation,and. - e from
, manufactured
under the superintendence of the Company,
Previously to the ' commencement of the undertekinf.
the bed of the River was carefully bored, to ate ertion
the stratum of the soil, which
blue clay, of a very strong nature. The
,bottom, which
they are now excavating, is a gravelly soil, of a green-
ish hue; and it is assumed that this was the' original.
bed of the River. This idea is, indeed, borne. out by
the quantity of oyster, cockle,' and other shells of flab
which are almost hourly found among the clay. As thework
prodeeds the boring is ea.' eoutinued, and they are thus
enabled to ascertain what they have to contend with.—
singular instrument, they are
Through the means of a very
to it pites point, almost, where tho
enabled to ascertain
termination of the -work will come out on the
.Wapping'
commence the operation on
side, and in a short tim.e to _
,edi
te the progress of
the water, in order toot).
this side of
the undertAing-
the i Tunnel, front shafta to shaft, will be
The length of
completed; the ritunber of men at,
Iwo feet, when
'dthe Officers ofpre,sellt
,toyed is about 230 (hem es leers the Esta-
e )who relieve each other every eight hours, so
bbs anent , .
but the work isallnight, d they going on
aboutn 100 loads of rubbish per day. The bricks cotemmed
'are about 70,000 per week, and of the casks of cement
360, the distance already completed is about 296 feet, and
the meekly progress about 12 feet.