Richmond enquirer. [volume] (Richmond, Va.) 1815-1867, 1833-05-03
TnEAsvRr DEPARrMENr, ,
April lith- l422

VNHE President OF tho United States having decided
IL on the plah OF the Bridge authorized to be built
across tho Potomac River, at the City OF Washington,
Proposals, sealed and endorsed will be received by the
Secretary OF the Treasury until the 10th OF Nav
sve for the materials and workmanship Of the same
ably to the terms aud specifications oil the work.
The Bridge will have IL arches and draws ~ piers
and abunens with their half piers The arches 10 he
96 feet span and 25 feet rise above the sprngng line and
TO be curves OF several centers, semi epses The nj.
and abumens rise feet above low water and to be
OF sufficient breadth to sustain each the its Deepen.
dent arch
The draws to be each 65 feet wde-oae to be placed
at the Maryland Washington channel the other at the
Virginia channel The bridge be SO feet wide between
the parapcs aud the carriage aud WAYS 10 be horizon
tai from abutment 10 abument The PIERS arches and
abumeuts to be Of granite, aud be founded ON piles or
on the solid rock according TO the of the bottom
The parapets to be each is inches thick and feet
above the roadway. The arches to be feet inches
thick at the key and feet inches the sprngng line;
except The facing ring stones the extrados of which
will be segment OF circle TO be described with the
greatest radius Of curvature.
The launches, to be filled in with good rubbe mason
ry laid in mortar heis that shall be sufficient i'm adj
dion TO the weight Of the dead walug together with
that oil the parallel brick walls backs Sc TO ba
lance equaliberate the arches.
The road way TO be nine inches thick Macamzed and
to rest on flat stones laid the brick spandrei walls
he foot ways to be raised above the level OF carriage
way and Tagged The water to DO carried of by sui
cien drains aud pipes the backs Of the arches and
through the piers and abutments.
On the alling, the piers forming the facing
OF the pier heads, pasters OF granite to be placed
The piers to be at least IL feet broad and 80 feet long
the sprioging ne and to be 10 feet broad at low water
The pier heads TO be runcated semcones, cappedthe
upper radius feet inches, and the lower such that the
pier-head shall batter in 10 than feet below
low water
The draw-p piers to be % feet broad the spring ing
line ana 10 batter as In the OF all the other
except on the side OF the draw which is be vertica
TO 6 feet below low water.
The piers at a greater depth than feet below low
water, to batter in L. and TO have sufficient osets
around them.
The abuments to have the thickness as the draw
mi axc lueu anft ha .,aL, e IL
masonry of the piers, half piers abutens to be OF
rough range work of hard granite ofvery large
laid In hydraulic cement The arch stones pilasers
don, and parapes TO be range work, rough hammered
he parallel walls the back of the arches piers
be oil hard brick and together with all the other
above the sPingng line TO be laid in the best lime
The timber to be used in the foundations be yellow
pine white oak.
The masonry of the piers and abuments be carried to
me depths Indicated by the following table, which exhi-
bits also the depth of the auvia deposit at distances OF
ll5iset proceeding from the w Washington abutment.