Evening star., 1928-04-22
BY BEN McKELWAY.


Each day now the gentleman with
megaphone in one hand who directs the
eyes of passengers on sightseeing buSSeS
may assert with increasing confidence:
"On your left, ladies and gentlemen, Is
the Lincoln Memorial. On your right
you see work in progress on the Ar
lington Memorial Bridge, a beautiful
span that soon will link the North and
South, being erected by the United
States Government at cost OF, etc,
etc" Construction work on the bridge
began two years ago this month. But 1t
has been only in the recent past that
the bridge began to take on some def
mite form, and by the slender skeleton
that now stands give the ignorant lay
man an idea Of what 1t Is to look like.
One now sees arches, resting on the
stone-faced piers. extending out over
the river and by some strenuous exercise
Of the imagination one may mentally
clear away all the cranes, lumber.
framework and debris which seem to
clutter things up generally, and visualize
the appearance of the structure two
years hence. Two gears hence the
bridge will be completed. barring those
manifestations of the devil that some
times dog the dreams of engineers in
the form of miscalculations, accidents
and exceptionally bad weather. But it
Is doubtful whether any one may cross
the bridge within two years, unless he
Chambers UP and down its approaches
on foot. Four good years lie between
today and the time fixed for turning
the bridge and its approaches and con-
Meeting highways over to the public
which will own 1t. Much remains to
be done.
But right now one Of the interesting
stages of the bridge construction is in
progress. Long since the engineers COM
pleted the task of sinking the founda-
tons to solid rock that lies far under
the bed Of the river. and from such
anchorages building the piers and fac
ing them with stone Today one strip
OF the arches TO rest on these piers has
been built out over the river. the strip.
about % feet wide. being constructed
of steel "arch centers" which support
wooden frames as molds for concrete.
Now concrete Is being poured over this
strip. 1t will require about three weeks
for the concrete to settle on each arch
When 1t does settle and harden and
become self supporting, the steel arch
centers will be lowered from beneath
it to rest on barges. The barges will
carry the arch centers upstream a few
feet and will then be placed in position
to form another strip. The process will
be repeated for each strip. There will
be one strip upstream from the one
new in place, and two downstream.
The outside strips will be faced with
granite, which now lies cut and ready
on the Virginia side Of the bridge, the
white blocks giving the appearance
from the Washington shore OF ceme-
terry filed with huge tcmbstones.
=
Such a description, possibly inaccu-
rate as to detail and not at all techni-
cal. gives a rough idea Of what is going
forward on the bridge now. It does not
enter into the care which must be exer-
cised by the engineers who watch, with
more tenderness than a loving mother
experimenting the baby's first steps,
the effect of loads and stresses and ex-
pansion and contraction as the business
OF building their arches progresses. They
have q height. figured down 10 inches.
for the crowns. or topmoSt points. OF
these arches when completed. Tney
know at what height they must oulo
each Of the steel arch certers. for when
the load Of concrete settles on them
they viii sink beneath its weight. In
theory they know how many inches the
steel viii sink. 50 they may calculate foI
this difference in height when they pun
il in nlace. But after the steel has set
tied the concrete will settle with IT'S own
weight. and when il Solidifies and the