The Washington times., 1922-10-29

motorized lathe. Il
To all appearances one side Of
the disc was as smooth as glass,
but Mr.. Weaver explained that It
had been covered with diamond
dust. The small particles Of
crushed diamond are SO hard that
they have bitten into the steel
and there they remain. But
for their presence on the disc. the
diamond when It comes in con.
tact with, the metal would merely
cut streakes in the steel in the
same manner that you can mark
up or write your name on a
window pane with the diamond
in your ring.
To make certain that the di.
,-..iond continues it's effective
ness as a diamond cutting. 1t Is
necessary to replenish from time
to time the diamond dust on the
smooth surface. The dust Is
kept together by keeping 1t IN
oils. This oil is poured over the
surface Of the steel. Most Of II
disappears with the grinding,
while some Of 1t sticks in the
steel.
This matter OF replenishing
the cutting surface of the steel
means more diamond dust and
more diamond dust means that
more diamonds must be crushed.
COST PROHIBITIvE.
To keep destroying diamonds to
get diamond dust with which to
attempt perfection in cutting
would make the almost per-
fectly cut diamond so expensive
as to be prohibitive for the aver.
age diamond buyer.
The test at the Bureau which
was made without rel gard to ex-
penditure Of time, labor or mate
rials. merely proved that per.
fection can be approximated,
but never achieved. even under
the most favorable and restricted
conditions. The Bureau declared
it is physically impossible and. r
commercially absurd.
BY the use of scientific ap-
paratus at the Bureau, Mr..
Weaver has been able to deter
mine how imperfect his per.
feet" cut diamond is. Here is
his conclusion:
Take one of the flat surfaces
Of one Of the facets Of the di.
mond and draw a line across it.
Continue that line across an
imaginary extension Of that flat
surface for one mile. Then draw
another imaginary line across an
imaginary facet or the facet that
would have been produced had the
cutting been perfect. Extend
that line one mile. Now meas
ure the distance between the
two mile.long lines and u will be
ten feet.
II the diamond had been per.
fectly cut. the two lines would
have coincided.
Try the same test on the aver.
age diamond and the distance be-
tween the two imaginary lines
will range from 20 to 100 feet.
OBTAINED OPTICAL DATA.
The Bureaus only and partly
successful experiment was con-
Quoted wholly for scientific pur.
poses and justified itself in the
optical data yielded. 1t was
long known that perfect di.
mond cutting was out Of the
question from a commercial
point Of view. and the expert.
ment in question proved this
beyond doubt, as we'll as estab-
fishing to the satisfaction Of the
scientists that 1t Ia a physical
impossibility.
So that gliscening stone upon
your finger, that coveted baubie
in your jewelers. window, that
scintillating gem that looks out
at you from the advertisement in
newspaper or magazine. is not a
perfectly cut diamond. For that
matter it is not a perfect di.
amond, which Is what the d.
amond merchant would have you
infer.
Perfection is as rare in di.
almonds as the stones themselves.
Diamond buying and horse
trading are the most hazardous
enterprises known. but tho lat.