The Sun.
London, England, 1864-09-20 00:00:00

The Railway Bridge at Blackfriars.

Foot passengers passing over the temporary bridge a
Blackfriars may now see the ruins of the old stone struc-
ture on the ono side, and trains of engines and carriages on
the newly constructed railway bridge on the other—one
telling of the days of the last century, when Fitt guided the
destinies of the country, the other indicating the wonderful
resources of engineering science of the present day. When
the stone bridge now in course of demolition was completed
political feeling ran high, and the names of Chatham-place,
Earl-street, and William-street, Blackfriars, still attest the
regard which was felt for the great Minister. The bridge
itself was intended to have been called " Pitt Bridge." The
engineers and contractors who have eparncd the Thames at
this spot will not, we fear, have any honour done to their
genius end enterprise such as that which the great States-
man received, and there will be no Cubitt-street er Peto-
place to hind down to posterity the names of those who, in
a marvellously short period, have built the new Blackfriars-
bridge. Engineering science can point to no greater feat
than that performed in the completion of this bridge across
the Thames in little more than twelve months.
The first stone of the abut meet on the Surrey side was laid
on the 2d of May in last year ; the bridge, so fir as its con-
struction is concerned, was completed on the 21 of June this
year, billesting, laying the rails, painting, and fixing the
decorations only remaining to be done, end even these might
have been accomplished had there been any necessity for
finishing them before the viaduct was complete to Ludgate-
hill. The bridge is 9.:3ft in length, including abutments, and
the river is crossed by 5 spans of iron, each 160 ft long ; two of
these spans laid side by side from the width of the structure.
The mode of building was by conreructing what is called an
American truer—that is, a powerful lattice-work of timber,
oored at the bottom, and strong enough to bear a load of
three tons per liner! foot. This was built with its ends
restingjust below the heads of the iron piers to support the
permanent iron girders. Upon this staging of timber the
iron bridge was put together. The main girders were first
proceeded with, then the broad iron plates of the bottom
were plac.:l on beams of timber sufficiently thick to admit
of the lower plates of the girders being a short distance
above the top, or heads, of the supporting columns. The
portions of ironwork were "keyed" to each other, end stout
iron angle irons at the side rivetted en to prevent any lateral
movement. When this part of the work was Complete, a
floor of iron was obtained on which to proceed with the
building up of the cross-barrel pieces, or lattice-work, of ,
the completed spans, and which serve to resist cempres••
sion, and also to provide for the great tensile strain to which
the bridge must be subjected. So soon as all these diagonal
cross bars of iron were placed in position, and an immense
iron lattice side, 16 feet in height wee formed, their ends
wire rivetted end secured by broad flange pieces—and
when thus secured the structure was complete. It stood, it
is true, tip on the timber staging, or trust—but when
this was removed, it was and is now perfectly self-sus-
taining. So soon as the last of the hundreds of thou-
sends of rivets were driven the timber was knocked from
under —it had done its work, and the bridge stood, sup-
ported only by its iron columns and abutments. The spans
of iron, though to the eye they appear perfectly horizontel,
still are not so. They are "cambered," as it is termed, to
the extent of five inches—that is, they arched to that smell
extent only—five inches in 160 feet. Wher, however, the
timber sfeging was removed, end the 600 tons of ironwork
in the span was left unsupported, the centre sunk to the
extent of two inches, caused by the minute compression of
the plates in the upper flanges?, but when once the at. acture
had been thus compressed it became all the me re rigid from
the reduction of the curvature of the arch. The strain which
the bridge is calculated to stand is very greatly in excess of
that which can by possibility be brought upcn it by the
ordinaly working of the traffic. With the view of giving
additional strength there is a centre girder between the two
two outer latticed ones, which assiets to carry the cross-
beams. This central girder is 41 fret in width, while those
at the sides are only three feet wide. The " struts" are
placed at intervals of four feet apart. They are bends of
iron about half an inch in thickness, and vary in width
from five to ten inches as the strain upon them increases.
Each of them has to tear a compressive weight of three
or four tons, and the lattice work between them is for
the purpose of preventing their " buckling" up under the
pressure. The girders which cross the bridge transversely
are placed at distances of four feet to correspond with the
portion of the ties and eta uts, and upon these again are laid
longitudinal girders. By these transverse and longitudinal
girders the whole floor is therefore clis:ded into a series of
square compartments 0' wrought iron of great depth and
strength. Above this framework of cells there is laid on a
wrought iron floor, covered with asphalts, and over this
again the sleepers and ballast for the roadway. At the top
of the bridge are seen a number of bent or curved arches of
iron stretching from ono side to the other. These aro placed
50 is position for the purpose a preventing lateral vibra-
tion, and ere secured to the upper flanges of the lattice gir-
ders. Between each pair of spans there is an open space to
allow for the contraction and expansion of the span move
meet, further facilitated by the iron roller frames upon
which they rest. The spaces a-e filled up with panels of
iron work, which will not prevent the slight movement
caused by the extremes of the temperature of summer and
winter. The supports for the bridge eve the masonry abut-
ments on the Surrey and Middlesex sides, and four piers,
each consisting of three clusters of four iron columns, which
rest upon masonry rising from the bed of the river. They
have a noble appearance at high and low water, and their
massive iron capitals give a suitable finish to the work. The
abutments, too, era peculiarly bold end imposing in their
character. The iron terminals are in keeping with the other
parts of the structure. They consist of en ornamental iron
scroll, beating upon it the words " London, Chatham, end
Dover Railway," and the motto " 111% icte," surmounted by
the royal cypher and the date " 1861." The scroll includes
the shield of the City of London and the arms of the coun-
ties through which the railway passes. The terminals above

,ho columns are ornamented with iron bosses. The fouuda-

tions of the piers, as we have explalacl on preliou 4 occa-
sions, were formed by sinking iron caissons an average of 28
feet below the bed of river. This work has been carried out
with so much care that no subsidence has taken place in any
of the piers since they were complet: I. The bridle his been
built from the designs ,auoishcd by Mr Cubitt, the engineer
of the London, Chatham, and Dover ; the contrac
tors for the building were Messrs. Peto and Co.
The first engine, with a long train of caulages attached,
passed on Tuesday, half way across the new Midge towards
the northern side. The train was accorapr-ic.l by Mr
Thomas, the resident manager, and Mr G. Sharp, inspector
of works. The levels were taken before the starting of the
train, and it was found that only the slightest deflection had
taken place. Another month w,ll elapse before the whole
of the permanent way of the bridge will be ready for exa-
mination by the Goverrm-nt Inspector, and the passenger
station, to be called the " Ludgate Station," now building
in Bridge-street, Blackfriars, will be ready for the public
accommodation. Tho principal objr'ct of testing the southern
half of the bridge has been to enable the managers of tho
line to shunt the trains from the Blackfriars Station.—
Bailwv Kays.

METROPOLITAN ORNITHOLOGY.—It is more me_
eially in the early morning in spring and summer
idea
of the wanderer through the streets may best form an
of the extent to which the practice of keeping singing-birds
and poultry prevails in particular districts of London.
There, amid the closely-built and pent-up houses, in warm
sunny weather, may be heard the warbling of thousands of
larks, blackbirds, thrushes, and others ; whilst from back-
yards, from areas, and even from cellars, come the crowing
of cocks, and other noises proper to the famyard. In the
very densest and poorest quarters of, London, in the most
dingy streets, there may te seen poultry, including ducks and
geese, the two last of which, in the hot summer days, look
truly miserable objects. In parts of Islington, however, and
elsewhere, better accommodation, in the shape of yards of
considerable extent, is provided for these bipeds. Many of
the enclosures are hidden from the general view by blocks
of houses, but they frequently boast of tall and spreading
trees, remnants of bygone days, when the surrounding
space was still open country. They are likewise often pro
vided with duck ponds, supplied by the natural springs
which yet exist in parts of Islington and Pentonville
Ducks, geese, and other poultry are here reared in cond.
derable numbers, and with tolerable success; but they
are rather noisy neighbours, particularly at break of
day. In one of the streets of Mayfair— not in itself an
important street, yet containing a few good houses—the
writer has had opportunities of observing a flock of poultry,
eight hens and a cock, which every day wander about,
exactly as they might do in a farm-yard. One evening,
passing through the street, he saw a single ben suddenly
vanish, as it were, into the bosom of the earth, and on corn--
big up to the spot, he found it was the last of the flock
which had at that moment dropped through an aperture in
a grarng which covered a small area in front of the house.
I Here, a common hen-ladder descending in the area ex-
plained how this little herd of poultry was kept ; namely, in
a cellar under 010 carriage-way, whence, of course, the
cock is heard sounding his Do .Profandis at all the proper
morning hours.—Chambers's .Tow nal.

The colonelcy of the 18th Hussars has become
vacant by the death of Lieutenant-General Byam,
but neither as regards that rcgim nt or the ButTs, which,
as we mentioned last week, is also vaunt, has any step
been taken to select a now colonel. With the exception of
Sir A. Clarke Kennedy, no line cavalry colonel has died
since March, ISGI, and the vacncy caused by his death was
given to Lieut.. Gen, J. Bloomfield Gough, whose claims
wore indisputable on the score of long and distinguished
service in the field. Of the existing cavalry generals, none
of the seniors have seen active sen :co in the field. At the
head of the list is Sir Charles O'Donnell, who has served
abroad; but the next bstch—Lieutenant• Generals Lord
Ressl3n, Hall, and Hankey—ws believe have been en-
gaged only on home service. Lord do lies may be sup-
posed to have been rewarded for his military service by the
Deputy Lieutenancy of the Tower, which he has held for
some time, and until we go souse way down among the
major-generals we do not light upon any striking claims on
the ground of good service. In the absene,, of any among
the seniors, it may be fairly conjectured that Sir Charles
O Donnell, who has often exhibited a most soldierly
anxiety to serve on the field, is to hay° the 18th
'lnseam-4774 and