New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1904-01-31

TO ma now many Ideas, especially IN the HELD
Of mechanical invention. had a much earlier ORR
gin than is commonly supposed. The latter
principle is illustrated by the history of the de-
vice employed the other day to lower an i'm
mense drawbridge into place the Lackawan-
ma road at Newark In point of size and IN
certain other important details. the sand jack
employed for that purpose PROFESSIONALLY out
ranks any of it's predecessors. Engineers are
enthusiastic in their admiration of the feat per-
formed with It.
The drawbrdge weighed about one thousand
tons. II had been previously lifted off from its
original pivot and to be put in place on a
new one. 1t rested four scOws at an elevation
Of eleven feet above it's proper level and In this
condition was towed to its present site. To rig
a crane that would handle such a load was out
OF the question. The only available plan was TO
a form of support underneath that would
gradually subside Hydraulic jacks could have
been employed For the sake OF economy. and
to time. another expedent was substituted
Into enormous boxes. containing fine. dry sand.
fitted vertical plungers which would sink
when the sand permitted to escape from
below. These preparations having been made
before the draw raised from it's earlier
resting place. it was only necessary to open the
holes in the sand boxes to complete the work
OF transfer.
1t IS n curious fact that within about two
years mechanism Of the same character was dis
covered IN Egypt In its issue Of September G.
1902. The Engineers Record" cited the follow
ing account. given by Ludwig Borchardt In a
German publication, the "Centralblatt der
Bauverwaltung":
Three similar tombs found near the
pyramid of Onnos. all dating from about 500
Il. c., and one ready for the interment of a
mummy. 1t chamber about II feet long
feet wide and 10 feet high to the crown OF the
arch roof of large cut stones. the first stone
arch or the kind on record. The sarcOphagus
was In place. and II was the heavy lime
stone cover slab which TO be lowered when
the mummy was In position. This stone was Is
feet long. 3 feet thick and Just trife narrower
than the tomb chamber. 1t was upheld by six
rough pillars OF inferior masonry evidently
temporary. and had two massive lemons on
each side. fitting In vertical slots or inches In
the walls. These inches were carried down
about 614 feet below the floor OF the chamber.
and In them would be placed sand to support
wooden posts on which the weight OF the slab
about seventeen tons. would come when the
temporary masonry pillars were removed
Between the two inches on each side OF the
chamber pit was excavated large enough TO
hold man and the inches had openings at Diff
ierent elevations connecting with this pit When
IL was time to lower the stone Il would only be
necessary 20 have man enter each pit and
open these passages one after the other. In order
10 aIIow the sand to escape and the timber posts
10 settle slowly. Such posts were found In the
inches or the two tombs containing mummiesl
When the slab was In place the men could
crawl over II and thus leave the chamber
For how many other purposes and at how
much earlier a period than Is here specified the
Egyptians utilized this device II Is at present
Impossible to say. II Is not Incredible how
ever. that 1t was applied a larger scale to
more ancient and more formidable UNDERTAKINGS
owing TO the temporary character OF its ser
vice II would doubtless be removed 10 most
cases. like scarolding. when its work was done,
SO that no subsequent trace could be found
Sun another interesting line of speculation
which rs excited by this discovery relates to the
manner In which the invention itself was sug-
gested- The Romans Greeks and Egyptians
long used as a tmepiece the clepsydra, a verti-
cal tube containing water. on the top OF which
was q float The latter subsidized gradually as
the mud escaped at the bottom and communi-
Gated Its motion to an index outside Although
the purpose Of this apparatus was foreign to
that now under consideration. the general ar
rangement might well have afforded a useful
mint TO fertile mind. Though the material In
side the tube was water instead Of sand IL was
or course. known that the two would behave In
substantially the same fashion. As some author
tiles suspect that the clepsydra originated with
the Chhldeans. IT is not beyond the range OF |
possibility that these people invented the sand
jack too.