The Cairo bulletin. [volume] (Cairo, Ill.) 1872-1878, 1878-01-12

Calfn, tlls., Jan, ., 1913.
9ealed proposals y i'll DC received ut this
office, directed to the city council OF Caro-,
limos, uuill O'Clock Tuesday evening,
February lOib. n. d. 1875, tor lie coDstfuc-
ton OF o one span iron bridge, together
with he approaches or abutments ana
foundation, across Cache river, about one
AND one All niles IRON Mound CRY raj =
road uepo aud four miles north OF tue city
OF Cairo, IN the counties OF Alexander and
Pulaski, stats OF Limos, according 10 The
plans 4nd speclU cations prepared ny I'm
p. Heiy, Esq, Z. f., now on tile aud suit
iect 10 examination IN this office, tue speci-
locations Of which are u follows, viz:
Said bridge and trcste work o he made
up of eighteen (lSJ Opy ming, OF eight eli (lS)
feet lrom centre to centre OF pc Is, and one
span OF one hun ired llyOl feet a,rOss the
river bed,
The one hundred COO feet spsn t. be OF
iron. aud 50 pTopOTuOued that load OF ten
(lOl tons dist ibuted over tweUty (l0) llneal
teet at the centre Of the span, shall not
strain the iron over twelve thousand
~ OU0) pounds per square inch tensile, or
over seven thousand nye hundred & jl0)
pounds per square inch shearing strain
the strain in compression to be IN al,
least in the proportion to the ratio OF
length to diameter, by GOrdon's formula.
The span OF said bridge to be one hun
dred (lUV) feet in the clear and the roadway
twelve az feet wide.
The door to be OF white oak plank two
and oue-hai (2i) inches thick and not ov er
| twelve az inches wide.
The floor beams 10 be OF white oak and ia
proportion to the balancr of the one hun
| Dire "a VI feet -paH structure. and also to
| be provided with q suitable axle guard,
| The above TO rest upon iron columns pro-
| pOrtiOned TO the structure to be supported,
| the columns at each end OF the bent or iron
span to be placed on mud sill l2Xl2, twen-
| " (20l feet long mOrllCed aud tenoned TO a
| sufficient number Of white oak pies, hrm.
| ly driven into the river bank.
TREsTLE WORK.
| The bents to be formed OF tour posts lOXl0
inches square, the TWO inner parts TO stand
| perpendicular and the two outer parts 10
be framed and stand AZ a batter OF one In
eight The cap and Sil oil the bents to be
l2Xl2 inca square timber, tie caps to he
| twenty (2O) feet long, and the sills to pro-
iect on each end two feet past the outer
ebge Of the GU side posts. The posts TO be
mofliced and tenOned into the caps and sills
and each tenon to be pinned with two
tbree-quarter 90 inch square iron pirs. ant
each bent to be br4ced by two diaguna
braces OF l2X2l inch plank, well lite d anc
spiked on caps, posts and sllis.
| The bents TO rest or siapd u on four mut
sills l2Al2 Inches and eight (t) feet long Sc
In the ground and placed on the alignmen
Of the work.
The carriage way OF the .tresilework I,
be sixteen us feet wide, the floor planl
o be three 81 inches and not over twelv,
~ inches wide, aud to be well spiked OF
to-the strlngers and ioor beams.
The door beams 10 be mtde up as follows
two (N stringers of SXl2 inches ret on tn
caps aud sixteen (l6) Ieet apart from out
SIDE to outside. The. space between sal,
ttriugeTs 10 be equsly dividedSiorsssevel