The republic. [volume] (Washington [D.C.]) 1849-1853, 1851-04-29
TO CONTRACTORS.

OFricE OF THs ComMIssIossa OF PusLIo BulLDIsos,
,WAsHIsoroK, April "a, 1851.
DkOPOSALS will be received at this Office until
L IL O'Clock, m. ON the 10th day of May next,
for constructing bridge across Tiber creek ut its
intersection with New Jerscy avenue and ID street
north. The bridge, when finished will be I72 feet
long, with elliptic arch Of "a feet span and 81
feet rise from lite springing.
The pit for the foundation must be excavated TO
such depth superintendent of the work to be APP
pointed by the Commissioner, may direct. toun-
dation course Of sap pine logo. 10 by 10 inches
square, will then be laid three feet from centre to
centre, transverseiy TO the axis OF the arch, ex-
tending TO the back lines Of the side walls. Three
rows OF sheet piling, three inches thick and hvc
feet long, will then be driven the upstream sdes
ofthrce of the logs viz One in the centre and one at
each end ofthe pit, and quite and
to the logs; piece of timber, 10 by IL inches
square, will then be notcbed inch into the trans
logs for tho whole distance Of the cuivert on
both sides, at the line ef the face Of the side wa,
the inner edge of which 10 to be chamfered, and be
properly secured to the foundation timbers; floor
ing three inches thick, OF Carolina or Georgia pine,
will then be laid the whole surface Of the foun
dation timbers, and secured to them by wrought
iron spike through each plank, into each log it may
cross, and in addition to THE, tree nail Of oak
locust, Il inches square and IA 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
arch will then be laid eighteen inches deep, after
which the side walls will be carried up 10 its crown,
filling the arch to its crown with solid mason
ry The side walls will have average thickness
Of four feet.
Parapet walls, ID inches thick and 81 feet high,
will then be carried up upon string course OF
cut granite 8 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 SO far as may appear to be necessary,
the average thic kncss of which will be q feet
The arch and parapet walls will be Of the best
hard brick; all tho other masonry will be OF large
size blue rock gnciss and the whole to be laid in
mortar made of lime, sharp snnd, and portion OF
hydraulic cement, except that the sido walls, ON
which the arch il to rest, must be laid for one foot
from the face and four feet high, in hydraulic
ment and suitable quantity Of sharp sand. with
out any quick lime.
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 the first day Of September next.
Persons proposing will state their price per cubic
yard for excavation of the foundation; 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 inea for the sandstone coping
including all matcrials, centring, Golfer -dams,
toos, &c. And no proposal will be considered
which does not fully conform to this requirement
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 sureties.
The Commissioner reserves the right OF reducing
the length Of the bridge to 80 feet.
Any further information can be obtained by ap-
plying at this office, where the plan may be seen
Commissioner of Public Buildings.
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