Lancaster daily intelligencer. [volume] (Lancaster, Pa.) 1864-1928, 1883-12-24
The Market House Accident.


The Market House Accident.
The demolition Of the Northern mark
ct house, th, ugh at first contemplation a
surprising event, was really one which
could not have failed to happen at some
time, if the original iron tie rods of the
roof were permitted to remain. The
calamity teaches us a valuable lesson a.
to the life of these rods. 1t is well
known that iron railroad bridges ar,
frequently examined TO determine th
condition Of the iron, because Of tn
distrust which engineers have as to thei
continued vitality under constant vibra
tion and the contraction Of heat ant
cold. We do not know what determin
alton has been reached as to the safe lif'
Of bridge iron, but we are under the i'm
preston that it is not vel
determined with defniteness, and
that observation is acutely directed to
the solution of the question. The de
struction of this market house viii
doubtless be noted with great interest
by those who are interested in the ques
tion of the duration of iron in structure
works. The building was put up il
1872, and the root was constructed under
the superintendent OF William X
Beard, the able master carpenter of the
Pennsy vania railroad here, whose ca
pacity as a builder is very highly es
teemed. II may be assumed that tht
work was well done and the fact that
IL has stood for eleven years Is sufficient
proof In itself of this fact. But for
eleven years the iron tie rods have been
contracting and expanding under the
violent changes in the temperature OF
our climate, with the result that the iron
had become crystalline and weak. There
was, besides the eleven years strain upon
1t, the weight of the roof. 1t is well
known that the most fibrous iron will
b. trysalzcd under comparatively
Moderate degree of conclusion. 1t vii
be crystallized even under the blow:
upon the chisel used to cut It. The strair
of the roof and the frequent contraction
and expansion, il is natural to believe
would have like effect.
If it is true, as stated, that these rods
have not been drawn mp, after the
braces OF the wooden arches, which they
held together at their base, had become
loose through the drying Of the wood
there is another good reason furnished
for the giving way of these arches under
the unusual weight upon them. The
snow fall was not as great as IL has often
been but the few inches which fell last
night being succeeded by sleet, were
made very heavy and with the
weight of the previous fall of snow,
there was enough TO try the
strength OF the roof severely. If
the arches had been properly braced the
iron stay rods might have stood but
certainly the lesson clearly taught by the
fall of the roof is that one OF such con.
struci ion is not safe a; for 1t will not do
to put roofs on buildings which require
that their supports shall be frequently
examined and repaired or renewed. II
may do where an engineer corps has
such examination rs II, constant duty {;
but it will not do where there IS not such
constant Intelligent supervision. We
want no more market houses with trussed
roofs, The new market houses have
roofs built On the same principle as the
Northern market house, but with
heavier stay rods. They Will br safe ful
years, as il was but that will hardly
answer the public demand that they
shall be always safe beyond peraiveu
iure. The disaster to the Northern
market might have been terrible. If The
fall had Lappened while the market was
being held no one would have got ou.
uDinjured 1t alive. Ii 1t had happened
when any one was on the street, loss Of
life would have been sure. Il was most
fortunate in its time and circumstances.
Even the adjoining house which it
crushed In part was untenanted for that
night. Let US be thankful for the great
calamity escaped, and see to it that VT
use the warning to make great Calas
tophe impossible in the future.