' B R I 
tonvs, or filling up, and be boarded or plated over at top, 
and the road filled in ; one part of the principle' of this 
patent being the abuttal of plates of iron throughout the 
breadth of the bridge, in the manner of the arch-joints 
of a hone bridge. Or thefe boxes may be a fucceflion of 
arches, with Ranches forming the arch-joints, and filled 
lip in the fpandrils, or not filled up : or they may be form¬ 
ed of hollow cylinders, with Ranches. Thefe arch-joints 
may have fheet-lead or other compofition placed between 
them, to fill up the uneven furfaces of the iron, and to 
prevent the preffure of iron againft iron. The arch-joints 
or handlings may be fcrewed together; or fhib-tenons 
or fillets, with correfpondent holes, mortices, and grooves, 
may be caft in the plates themfelves, and fitted into.each 
other. The fkirting or kirb, which keeps in the ground, 
may be cafl or framed with the boxes, or may be caft fe- 
parate and put on, or may be omitted. When two, three, 
or more, arches, are put together, the (paces betw een the 
■arches are formed by hollow fpandrils of wrought-iron or 
caft-iron, and framed, caft, or put together, as before- 
mentioned ; and may or may not be fitted tip folid, as the 
boxes of the arches before defcribed. Thefe hollow fpan¬ 
drils may be cylindrical, triangular, quadrangular, or of 
many fides. The piers of thefe bridges are formed, like 
the boxes, hollow; and may be filled up (olid or other- 
wife; and may be made of plate-iron, either wrought or 
calf, and framed or put together. Or they may be call 
in one piece ; may be in form cylindrical, triangular, qua¬ 
drangular, or of many fides, fimilar to the fpandrils. They 
may be caft with the hollow frame forming the piers, or 
be fattened to them. The dam is alfo formed hollow by 
piles of plate-iron, grooved, rebated, and dove-tailed, into 
each other; which, when fixed into each other, forma 
hollow box ; and, w hen driven or inferted into the bed of 
the river, form a dam for the pier; and, when the pier is 
built, are driven home to the bed of the river, make a 
box of dove-tailed piles, inclofmg the ground on which 
the pier hands, and fecuring it front being undermined by 
the water palling through the arch.” 
The principles of this invention will be readily compre¬ 
hended by a reference to the lubjoined engraving ; w here 
fig. 4, fhews the elevation of two arches eonftrubted ac¬ 
cording to this method, with the fpandril or fpace between 
the fpring of the arches filled up with a hollow cylinder, 
marked A. Fig.5, reprefents a triangular form for the 
fpandril; or it may be ottagonal, hexagonal, or a fquare, 
according to the fancy of the architect. Fig. 6, fhews an 
iron frame of fquare boxes for the piers, to be filled up with 
fand, chalk, or other materials. Fig. 7, is an iron frame 
for the darn, which, being funk in the bed of the river, 
inclofes the foil, and excludes the water from every pofli- 
bility of patting under it. 
Another invention of confiderable ingenuity is that of 
Mr. James Jordan, of Shepton Mallet, in the county of 
Somerler, for conftrubtjng bridges, aqueducts, &c. by fuf¬ 
pending them to incumbent arches, which carry the en¬ 
tire weight. This invention has likewife the' fanbtion of 
•letters patent, dated May 24, 1796; and the.method is 
explained as follows: “ I, the faid James Jordan, do de¬ 
clare, that my invention confirts in fufpending to an arch 
or arches, in manner herein after defcribed, bridges, (with 
or without draw-bridges therein,) aquedubls, the tops or 
coverings of buildings and other ereftions, inftead of the 
methods heretofore adopted for conftrudfing and fupport- 
ing them ; whereby the weight or weights thereof will be 
suspended, fo as to leave the parts under the fame, be¬ 
tween the buttrertes or other end-fupports of bridges and 
aqueducts, and between the walls or other inclofures of 
buildings and other erections, nearly as free as if n,o fuch 
bridge, aquedubJ, top,, or covering, were placed over the 
fame ; by which means, intermediate piers will be avoid¬ 
ed, the navigation of rivers be improved, manycaufesof 
obit rn cl ion and damage be removed, and bridges be con- 
ftrubted and placed in a way likely to preferve them from 
decay a much greater length of time than when they £ave 
D G E. 395 
a connection with the river under them. The materials 
for fuch arch Or arches, to which bridges and other works 
are to be fufpended, on tbe principles of my invention, 
may be of the different kinds herein after fpecified, or any 
other whatfoever, capable of being ufed in the conllruc- 
tion of the fame ; and the form and llrength of the.feve- 
ral parts may vary, according to the nature, extent, and 
other circumflances belonging to and dependent upon 
them. It will likewife appear, from the explanations 
herein after given of fome of the methods in which my 
invention mav be applied, that mod of the works erebted 
on the principles thereof will not have a lateral, but only 
a perpendicular, preffure on the buttrettes, walls, or other 
end-fupports; which in many cafes will be of great ad¬ 
vantage. To explain more fully the nature of my inven¬ 
tion, and the manner in which the principles of it may be 
applied in feveral cafes, although witli many variations in 
the form and ftrength of the parts, (the principle being 
ilill retained,) reference may be bad to the annexed Plate, 
where fig. 8 reprefents the elevation, and fig. 9 half the 
tranfverie-feftron, of a bridge without a draw-bridge, and 
with one of the buttrettes unfinifhed. It may be formed, 
and eredted, in the following manner: A, fhews the ho¬ 
rizontal rib of the bridgeway, compofed of well-fealoned 
timber, in different lengths, fo as to break the heading 
joints, and in three thick'neffes, (but it may be in more,) 
w ith caft-iron plates, folid or hollow, clofeoropen, as wide 
as the thicknefs of the ribs; the timbers and the iron to 
be bolted together, as fliewn at A, fig. 2, by ftrong 
wrought-iron bolls, with large heads and nuts. Thefe 
ribs may be put together 'on land, and be conveyed to 
their place on the buttrettes, by means of floating rafts 
or veflels, with proper mechanical or other fupports there¬ 
on, and by fuch other powers on the land as the nature of 
the cafe may require. Thefe ribs are to be completely 
fixed in their place, and are to be flayed and fupported in 
the middle, from the heads of two or more temporary 
piles, previoufly driven into the river to receive them. 
When botli the ribs are thus placed, they will form the 
main parts for the fcaftblding, by which much expence 
will be laved. B, is one of the circular fufpending ribs, 
compofed" in. this bridge of eight ribs of well-feafoned 
timber, (but may be of fuch number and fcantiing as 
ftrength and convenience may require,) and two ribs of 
caft-iron, in long lengths, (one or both of which may be 
omitted in final 1 bridges;) the whole bound together by 
ftrong wrought-iron bolts, large nuts, and heads. The 
timbers are to be of different lengths, calculated to give 
ftrength and unity to the whole, and to break the heading 
joints, between which may be placed thin plates of cop¬ 
per, or any other metal. The points of the circular ribs 
are to be bound, and connected to the horizontal l ibs, by 
different iron ftraps and bolts, as fhewn at C, fig. 8. Thefe 
ribs may be erebted by beginning at the ends, and uniting 
them fucceflively and progreflively towards the crown, 
fcaftblding and fiipporting the works from the horizontal 
ribs. D D, figs. 8 and 9, fhew the fufpending bars of 
wrought iron, or other metallic fubftances, with large 
heads, plates, and nuts. Preparation is to be made in the 
different ribs, to admit thefe bars to be patted through 
from the top of the circular ribs, after which the plates 
and nuts are to be applied, to connebt the circular with 
the lower ribs. E, fig. 9, is one of the girders or bear¬ 
ers, lying croffwife, about fix feet from each other. Thefe 
girders are to be received in a box-mortice at one end, 
and a pulley-mortice at the other, fo that they may be fix¬ 
ed or difplaced, without affebting the ribs: they are to 
be fecured to the ribs by iron ftrap-bolt's patting through 
the fides, and fattened by fmall fcrew-bolts to the girders, 
which will likewife prevent the ribs fpreading from each 
other. F F, fig. 9, are bearers laid on the girders, longir 
tudinally with the ribs, to be of different lengths, to give 
ftrength, and to be fecured to the girders by ttrap-boTts 
palling through the bearers; to admit the removal of the 
latter, they are to be ftapled to one fide only of the gird- 
T STS. 
