BRIDGE. 
another, which is the span or width of the 
arches ; so that the whole length of the 
bridge was more than 1530 yards, or nearly 
one mile. 
In France, the Pont de Garde is a very 
bold structure ; the piers being only 13 feet 
thick, yet serving to support an immense 
weight of a triplicate arcade, and joining two 
mountains. It consists of three bridges, one 
I over another ; the uppermost of which is an 
aqueduct. 
The bridge of Avignon, which was finished 
| in the year 1188, consists of 18 arches, and 
t measures 1340 paces, or about one thousand 
3 yards in length. 
The famous bridge at Venice, called the 
i Rialto, passes for a masterpiece of art, con- 
sisting of only one very flat and bold arch, 
I near a hundred feet span, and only 23 
! feet high above the water : it was built in 
1591. Poulet also mentions a bridge of a 
! single arch, in the city of Munster in Both- 
I nia, much bolder than that of the Rialto at 
Venice. Yet these are nothing to a bridge 
! in China, built from one mountain to ano- 
ther, consisting of a single arch, 400 cubits 
long, and 500 cubits high, whence it is 
! called the flying bridge; and a figure of it 
! is given in the Philosophical Transactions. 
Kircher also speaks of abridge in the same 
! country three hundred and sixty perches 
i long without any arch, but supported by 
j three hundred pillars. 
There are many bridges of considerable 
note in our own country. Idle triangular 
bridge at Crowland in Lincolnshire, it is said, 
is the most ancient Gothic structure remain- 
ing intire in the kingdom ; and was erected 
about the year 860. 
Lonclon-bridge is on the old Gothic struc- 
ture, with twenty small locks or arches, each 
of only twenty feet wide ; but there are now 
| only eighteen open, two having been thrown 
J into one in the centre, and another next one 
I side is' concealed or covered up. It is nine 
hundred feet long, sixty high, and seventy- 
four wide ; the piers are from twenty-five to 
thirty-four feet broad, with starlings project- 
ing at the ends; so that the great water-way, 
when the tide is above the starlings, was 
! 450 feet, scarcely half the breadth of 
the river ; and below the starlings, the wa- 
ter-way was reduced to one hundred and 
ninety-four feet, before the opening of the 
centre. 
London-bridge was first built with timber, 
between the years 993 and 1016 ; and it was 
repaired, or rather new-built with timber, 
1163. The stone bridge was begun in 1 176, 
and finished in 1209- It is probable there 
were no houses on this bridge for upwards of 
200 years ; since we read of a tilt and tour- 
nament held on it in 4 395. Houses it seems 
were erected on it afterwards ; but being 
found of great inconvenience and nuisance, 
they were removed in 1758, and the avenues 
to it enlarged, and the whole made more 
commodious ; the two middle arches were 
then thrown into one, by removing the pier 
from between them; the whole repairs 
amounting to above 80,000/. 
The longest bridge in England is that over 
the Trent at Burton, built in the 12th cen- 
tury, of squared free-stone, and is strong and 
lofty ; it contains thirty-four arches, and the 
whole length is 1545 feet. But this falls far 
short of the wooden bridge over the Drave, 
which according to Dr. Brown, is at least 
five miles long. 
But one of the most singular bridges^ in 
Europe, is that built over the Taaf in Gla- 
morganshire, by William Edward, a poor 
country mason, in the year 1756. This re- 
markable bridge consists of only one stu- 
pendous arch, which, though only eight feet 
broad, and thirty-five feet high, is no less than 
one hundred and forty feet span, being part 
of a circle of one hundred and seventy-five 
feet diameter. 
Of modem bridges, perhaps the two finest 
in Europe, are the Westminster and Black- 
friars bridges over the river Thames at Lon- 
don. The former is 1220 feet long, and 44 
feet wide, having a commodious broad foot- 
path on each side for passengers. It con- 
sists of thirteen large and two [small arches, 
all semicircular, with fourteen intermediate 
piers. The arches all spring from about tw'o 
feet above low-water mark ; the middle arch 
is seventy-six feet wide, and the others on 
each side decrease always by four feet at a 
time. The two middle piers’are each seven- 
teen feet thick at tire springing of the arches; 
and the others decrease equally on each side 
by one foot at a time ; every* pie r terminat- 
' ing with a saliant right angle against either 
stream. This bridge is built of the best ma- 
terials, and in a neat and elegant taste, but 
the arches are too small for the quantity of 
masonry contained in it. This bridge was 
begun in 1738, and opened in 1750; and 
the whole sum of money granted and paid 
for the erection of this bridge, w ith the pur- 
chase of houses to take down, and widening 
the avenues, See. amounted to 389,500/. 
Blackfriars bridge, nearly opposite the 
centre of the city of London, was begun in 
1/60, and was completed in ten years and 
tl^ee quarters ; and is an exceeding light 
and elegant structure ; but the materials 
unfortunately do not seem to be the best, as 
many of the arch stones are decaying. It 
consists of nine large, elegant, elliptical 
arches ; the centre arch being one hundred 
feet wide, and those on each side decreasing 
in a regular gradation, to the smallest, at 
each extremity, which is seventy feet wide. 
The breadth of the bridge is forty-two feet, 
and the length from wharf to wharf nine hun- 
dred and ninety-five. The upper surface is 
a portion of a very large circle, which forms 
an elegant figure, and is of convenient passage 
over it. The whole expence was 1 50,840/. 
Bridges, iron, are the exclusive invention 
of British artists. The first that has been 
erected on a large scale is that over the river 
Severn, at Coalbrook Dale, in Shropshire. 
This bridge is composed of five ribs, and 
each rib of three concentric arcs connected 
together by radiating pieces. The interior 
arc forms a complete semicircle; but the 
others extend only to the cilia under the 
road-way. These arcs pass through an up- 
right frame of iron at each end, which 
serves as a guide ; and the small space in the 
haunches between the frames and the outer 
arc is -filled with a ring of about seven feet 
diameter. Upon the top of the ribs are laid 
cast-iron plates, which sustain the road-way. 
The arch of this bridge is one hundred feet 
six inches in span ; the interior ring is cast 
in two pieces, each piece being about seventy 
feet in length. It was constructed in the 
year 1779, by Mr. Abraham Darby, iron- 
master at Coalbrook Dale, and must be con- 
sidered as a very bold effort in the ^first in- 
stance of adopting a new' material. r I he to- 
tal weight of the metal is 378-^tons. 
The second iron bridge, of which the par- 
ticulars have come to our knowledge, w as 
that designed by Mr. Thomas Paine, author 
of many political works. It was constructed 
by Messrs. Walkers at Rotherham, and was 
brought to London, ar.d set up in a bowling- 
green at Paddington, where it was exhibited 
for some time. After which it was intended 
to have been sent to America ; but Mr. 
Paine not being able to defray the expence, 
the manufacturers took it back, and the mal- 
leable iron was afterwards worked up in the 
construction of the bridge atWearmouth. 
The third iron bridge of importance erect- 
ed in Great Britain, was that over the river 
Wear, at Bishop Wearmouth, near Sunder- 
land, the chief projector of which was Row- 
land Burden, esq. M. P. This bridge con- 
sists of a single arch, whose span is 236 ieet : 
and as the springing stones at each side pro- 
ject two feet, the whole opening is 240 feet. 
The arch is a -segment of a circle of about 
444 feet diameter; its versed sine is thirty- 
four feet, and the whole height from low- 
water about one hundred feet, admitting ves- 
sels of from two to three hundred tons bur- 
then to pass under, without striking their 
masts. A series of one hundred and live 
blocks form a rib, and six of these ribs com- 
pose the breadth of the bridge. The spand- 
rels, or the spaces betw een the arch and the 
road-way, are filled up by cast-iron circles, 
which touch the outer circumference of the 
arch, and at the same time support tlje road- 
way, thus gradually diminishing from the 
abutments towards the centre of the bridge. 
There are also diagonal iron liars, which are 
laid on the tops of the ribs, and extended to 
the abutments to keep the ribs from twisting. 
The superstructure is a strong frame of tim- 
ber planked over to support the carriage- 
road, which is composed of marl, lime-stone, 
and gravel, with a cement of tar and chalk 
immediately upon the planks to preserve 
them. The whole width of the bridge is thirty- 
two feet. The abutments are masses of al- 
most solid masonry, twenty-four feet in 
thickness, forty-two in breadth at bottom, 
and thirty-seven at top. The south pier is 
founded on the solid rock, and rises from 
about twenty-two feet above the bed of the 
river. On the north side the ground was 
not so favourable, so that it was necessary to 
carry the foundation ten feet below the bed. 
The weight of the iron in this extraordinary 
fabric amounts to 260 tons ; 46 of these are 
malleable, and 214 cast. The entire expence 
was 27,000 /. 
The splendid example of the bridge at 
Wearmouth gave an impulse to public taste, 
and caused an emulation among artists, which 
has produced many examples and more pro- 
jects of iron bridges. The Coalbrook Dale 
Company have constructed several, among 
which is a very neat one over the river 
Parrot at Bridgewater. Mr. Wilson, the 
engineer employed by Mr. Burdon, has also 
built several : and has lately finished a very 
elegant one over the river Thames, at Staines,, 
which is by far the most complete in design, 
as well as the best executed, of any that lm 
hitherto been erected. This bridge consists 
of a single arch, 181 feet in span, and 1& 
