The republic. [volume] (Washington [D.C.]) 1849-1853, 1850-11-22
TO THE PUBLIC.

vTNHE subscribers, having had many years expe-
l. rience in planning and building public and
private buildings and bridges, are prepared TO
furnish plans and specifications Of their NEW
WOODEN BRIDGE for railroad and other compa-
nies, (according 10 the plan described in the an
nexed article from the Washington Republic. J
They will also attend personally To the erection OF
bridges In any part Of the United States, and Will
warrant their work to stand given number OF
years. H. * o. 8. WARREN,
Architects and Bridge Builders,
Noy20-3t Providence, Rhode Island.
IMPORTANT IMPROVEMENT IN BRIDoEs.-We have
had opportunity of examining models of the new
bridge for railroads and other purposes, invented
by Messrs. r. * D. s. Warren, Architects and
Engineers, Of Providence, Rhode Island, recently
secured at the Patent Office by caveat. We con-
slider this worthy the notice of all persons inter-
ested in having safe, durable, and economical
bridges constructed One OF its notifications con-
ssts OF four trusses composed Of horizontal parallel
chords, connected by angular and arched braces,
clamps, and keys. The braces arranged as
to form series Of pyramids, longitudnay as well
as transversely, the trusses being placed in pairs,
each pair forming section OF a pyramid trans
versely BY this arrangement the structure 10 rem
dered very frm and secure from osciatng, later
ally or longitudinally, on the entrance OF heavy
trains OF cars; and also prevented from sinking and
rebounding at the middle Of its length when the
train enters upon and suddenly leaves the bridge,
which is generally the cause of the failure of iron
bridges, particularly in frosty weather. The
Messrs. Warren, who, we learn, have constructed
many bridges Of various kinds in the United States
have found by experience that, in building bridges
OF wood, as much iron work should be dispenfe ed
with rs possible; as bridges built mostly of wood
and loaded down with long iron rods, and cast
iron splicing plates and shocs, in numerous
bridges heretofore constructed, have often failed,
particularly at the North, during cold and frosty
weather. The mode OF construction adopted by
these gentlemen will enable the architect to bridge
rivers of three hundred feet width by single span
by simply increasing the height of the trusses, less
than thirty feet being sufficient for span of three
hundred feet. Light abutments and piers will an
swer, there is no longitudinal lateral thrust,
the pressure being entirely vertical. This bridge
not only possesses great simplicity strength, dura-
bility, aud economy, but also facilities for making
repairs whenever necessary. The floor for the iron
rails Of the track may rest upon the upper or lower
range of chords or strings. The bridge may also
be closed on its four sides and rooted left open.
This principle Of truss is also well adapted for roof
of great span, where small pieces Of timber are
abundant, and large timbers are scarce, rendering
it unnecessary to resort to heavy girdcrs and the
usual kind of expensive framing. This adaptation
is effected by simple modification OF the truss.
The bridge Possesses other advantages, which will
be evident to the architect and engineer, upon an
examination of the models and drawings, to be
seen the office of Mr.. w. p. Elliot, architect and
engineer, opposite the Patent Office, Washington
city.