The Mitchell capital. (Mitchell, Dakota [S.D.]) 1879-1918, 1904-01-22
MODERNS COPY FROM
ANCIENT ENGINEERS
Bridge In New York Moved
just a. Egyptians Handled
Monoliths.
r OF SAND JACKS
They Were Used to Settle the Great
Stones of the Pyramids Into Place,
and No Better Device is Vet
Known.

Chicago Chronicles: Few achievements
of the engineers of modern times have
bee. more gigantic or more successful
than the resent movement of the Laclla-
wanna railroad bridge at Newark. N. j.
1t was found necessary to remove the
%struture, a heavy steel affair, some fifty
feet, and officials desired that as little in
t%erruption Of traffic as possible should
take place. The problem is one that has
often been solved, but in this case public
attention has been directed to a special
method. After the draw span had been
lifted from its old position and tioated to
Its new one on barges, instead of lowering
1t to its bearing by screws or hydraulic
jacks. it was lowered by means of sand
jacks" On the barges We're boxes filled
with sand on which the bridge rested and
the same was allowed to run out of suit
able openings in the boxes and SO let the
bridge down.
This is exactly the method that was
used in Egypt 1000 years ago in placing
the huge iintels of the temples on the coll
umns. The stones were dragged by main
force up inclined planes formed of bags Of
sand to a position over the tops of the
columns. Then the bags were pierced and
the sand. slowly escaping. let the stone
gently down to Its bearings.
Ancients Knew the Art.
- - kA4oS q 64AAL1luk was
used in erecting the obelisks. which we
today find difficult to handle with steam
to aid US. Just as the lintels, so the
obelisk was dragged to the top of a heap
OF sand bags until Its base was over, but
far above the foundation. Then as the
sand was gradually removed the base
would be lowered until the obelisk re-
clined In a slanting position on the side
OF the slope Of sand, with its base rest
Ing on the foundation. 1t was, of course,
not yet upright, but by far the most diff
fcult part Of its erection, the raising of
the summit through the lower part of the
quarter circle 1t must describe, had thus
been overcome. and 1t was then but a
matter of wedging up the upper end little
by little and building up the sand slope
until the fnal position was reached.
Partly to make the turning on the low
er edge easier, but principally to prevent
Its being cracked off, the sharp angles of
corners. In the obelisk now in Central
park the crabs that seem to support it
fill the space made by the cutting away
Of the corners for the reason specified.
Used in Esypt's Tombs.
In some Of the tombs cut in the cliffs
that hem in the Nile valley. as well as in
those built in the pyramids. sane jacks
still more closely resembling those used at
Newark can be found. The protection of
the chambers that contained the sar-
cophagi, while leaving the richly deco
rated V%estibules and passages Of the
tombs accessible, was one of the most i'm
portant matters in their construction, and
to do this enormous stone slabs. resem-
bling the masonry on each side, were
the burial chamber. The slabs were
somewhat wider than the full width of
the passages and slid in grooves at the
side up into a pocket in the roof.
The tomb was built with the slab in
place in the pocket, leaving the passage
open under 1t. 1t was supported by small
square Columns of stone or wood hidden
IN the grooves and resting on sand that
filled the lower ends of the grooves, which
extended down into the floor. Ingenious
ly contrived channels led from the bottom
of the grooves to the outer part of the
passage and when the last s~arcophagus
had been placed in the chamber the plugs
that closed the channels were taken out
TO let the sand escape. The slab slowly
descended until its lower edge rested in a
groove in the floor of the passage and it
could then never more be raised, for sides,
top and bottom were embedded in the ma
sonry and there was no crack where a
lever could be inserted or a hold of any
kind be obtained. The slab was usually
OF such thickness that 1T gave no indica-
ton or the holiowness behind 1t when
struck and to all appearances the passage
would seem to end in a cul de sac.
Other Engineering Feats.
In the great pyramid of Giseh there
were four such slabs in the passage lead
ing to the principal chamber. but, for
some reason, only one of them had been
lowered. Yet 1t was only by cutting
around 1t through the masonry that the
explorers succeeded in reaching the burial
chamber and the passage in the pyramid
OF Aboukir was SO well concealed by a
similar slab that 1t was not discovered
until a shaft had been sum to the center
of the structure.
There is a stone built In a retaining wall
at heliopolis. ancient Palmyra, of a size
to make our modern monoliths seem
small. 1t is some sixty feet long and ten
feet square. 1t is used where smaller
blocks would have answered as we'll. SO
that evidently the builders were not
greatly concerned about Its size, although
1t IL many feet up in the wall. The Ro-
mans who put 1t there, IL 1t was the
Romans. must have used the same meth
DDS as the Egyptians, for they had no
other appliances capable of handling such
q mass and 1t canno be doubted that 1t
was dragged up an artificial slope and
lowered into place by removing the sand
or earth under it. We may well wonder
why they should perform such a remark
able feat ut such great pains to 10 little
purpose. but at the same time We can