The republic. [volume] (Washington [D.C.]) 1849-1853, 1851-05-01
TO CONTRACTORS.

OFFICE OF THE COMMISSIONER OF Pubic BulLprH
WAsHInoroN, April "a, 1851.
PROPOSALS will be received at this Office until
Il IL O'Clock, M, on the 10th day of May next.
for constructing bridge Tiber creek, at its
intersection with Now jersey avenue and street
north. Tho bridge. when finished. will be i72 feet
long, with elliptic arch of % feet span and 81
feet rise from its springing.
The pit for the foundation must be excavatod to
such depth superintendent the work, to be ap-
pointed by the Commissioner, may direct. A foun-
square, will then be laid three feet from centre to
centre, transversey to the axis of the arch, ex-
tending to the back lines Of the aide walls Three
rows Of sheet piling, three inches thick and five
feet long, will then Be driven on the upstream sides
ofthrec Of the logs viz One in the centre and at
each end ofthe pit, and quite and well spiked
to the logs; q piece Of timber, 10 by u inches
square, viii then be notchcd one inch into the trans
verse logs for the whole distance of the culvert
both sdes at the line Of the face Of the side walls,
the inner edge of which 10 to be chamfered and DO
properly secured to the foundation timbers; floor
ing three inches thick, of Carolina Georgia pine,
will then be laid the whole surface Of the foun
dation tmbers, and secured TO them by wrought
iron spike through each plank, into each log may
cross and in addition to this, nail OF oak
locust, II inches square and II inches long, must
be driven into each log through each plank, ex-
cept those under the side walls.
The side walls will probably be about six feet
high from the floor to the spring of the arch. The
arch will then be laid eighteen inches deop after
which the side walls will be carried up to its crown,
filing over the arch to its crown with solid mason
ry. The side walls will have average thickness
OF four feet. aa a4
Parapet walls, IL inches thick and 8! feet high,
will then be carried up upon string course Of
cut granite inches thick. the whole TO be COPIED
with good sandstone inches thick at the edges,
with saddle back of two inches. Wing walls
will be laid 10 far ~ may appear TO be necessary,
the average thickness of which will be % feet
The arch and parApct walls will be OF the best
hard brick; all the other masonry will be Of large
size blue rock gneiss, and the whole to be laid in
mortar made of lime, sharp sand, and a portion OF
hydraulic cemont, except that the side walls, on
which the arch is to rest must be laid for foot
from the face and four feet high, in hydraulic ce-
out any quick lime. i
The whole Of this work is to be done in the best
manner and of the best materials under the direc-
ton Of the before mentioned superintendent, and
to be completed by tho fret day Of September next
Persons proposing will state their price per cubic
yard for excavation Of the foundations per 100 feet
board measure for the flooring and piles; per cubic
foot for the squared timber; per perch of Is cubic
feet for the stone masonry; per thousand for the
course and per foot ncal for the sandstone coping;
including all materials, ccntring, Golfer dams,
tools, &c. And no proposal will be considered
which does not fully conform to this requirement
A contract will be entered into, and bond with
security will be required for its faithful perform
ancc Persons offering will, therefore, please to
give the names of their proposed soretics.
The Commissioner reserves the right OF reducing
the length of the bridge to 80 feet.
Any further information can be obtained by APP
plying at this Office where the Rnn may &c seen-
Commissioner of Public Buildings.