The Ohio Democrat. (Logan, O. [Ohio]) 1886-1906, 1891-12-05
DRILLING TINY HOLES.
jewels Pierced for Drawing Wire Ono
Third of the Diameter of n Hair.

In a small room in the top story oi
one of the old buildings in Dutch street
n hole 1-1, 900 of an inch in diemeter can
be drilled through diamond. sap
phire, or a ruby. Formerly tiny holes
like that were drilled by haEA, hu1
now machine that John Wennstrom
has perfected, which makes S3,0OO revo-
lutions in minute, can pierce a sapphire
one-sixteenth of an inch in thickness
in ten minutes. A hole 1000 of an inch
in diameter has been considered re-
markable, bnt nowadays jewels with
holes much smaller in diameter are re-
quired for several purposes. They are
inserted in plates for drawing wire and
fiber and are used in electrical, mathe-
matical, and nautical instruments.
Thomas A. Edison had several plates
made for drawing platinum wire IL, 600
to 2-1 900 of an inch in diameter Or
dinary fine wire is drawn through steel
plates, but if steel were used for minute
work it would be worn away too much
and would cause an enlargement OF the
wire. Therefore diamonds, sapphires,
anu TuDltS ilC loCN Nlith viz
holes are needed and when it is neces-
sary to have wire of the same thick
ness throughout its length, the wear on
Jewels being hardly perccptible. Sap
phires and rubies are next to diamonds
in durability. Agates are too soft.
For many years the Jenots, husband
and wife, were the only borers of jewels
in this country. They came from
France about twenty five years age
and, settling here supplied the trade
with pierced jewels. The husband
taught his wife the secrets of the art,
and when he died Nine. Jenot con-
tinued in the business. She died few
years ago. Her jewels were pierced by
hand, and she was never able to pierce
Jewel for draw plate with hole less
than D. 600 of an inch in diameter.
The process of boring by hand was
costly and laborious and the holes
were frequently crooked But the
Jenots had plenty to do, because they
were the only borers in this country
who could compete with French borers.
A draw plate with hole 1000 of an
inch in diameter costs now $40, and one
with "a hole a., 900 of an inch can be
bought for $3.50 In drawing very fine
wire several plates are used, all wires
below 81, 900 of an inch requiring inter
mediate plates, owing to the lack OF
tensile strength. Platinum is used for
the smallest wire that can be drawn.
The cross web in fine microscopes is of
platinum.
The development of the science OF
electricity has created a demand for
very fine wires. The platinum wires
in incandescent lamps are drawn
through sapphire plates, and the very
| finest platinum wires are used in many
delicate and sensitive electrical instru-
ments. Torpedo magnets and electrical
meters require very fine wires. Thirty
six miles of insulated wire used by the
government in experiments with tor
pedoes measured only about five inches
in length by three in diameter when
wound on spool The fiber used as
carbon filaments in incandescent lamps
is scraped to an even thinness by being
drawn through sapphire plates from 80
1000 to Al, 600 of an inch in diameter.
Fiber that has been drawn through
steel plates has not the smooth finish
of fiber from sapphire plates. Brass
wire for brushes used by silversmiths
and jewellers can be drawn to $4,000
of an inch--the diameter of hair. The
holes in watch jewels are from 1,00C
to 12-1, 900 of an inch.
BY the old method of boring, the drill
was fixed and the jewel, embedded in {
holder, was pressed and revolvet
against it. In Wennstrom's machine
the drill revolves and the jewel is fixeC
on bed-plate A hole of the required
size is bored straight through and ther
the openings are smoothed For hole
81, 900 of an inch and larger the point
of the drills have diamond cutters, bu
for the smallest holes the drills are o
soft iron into which particles Of dia
mond dust become embedded as th
drills pierce the jewels. By an auto
matte appliance a drill is raised AM
lowered at intervals to allow the dia
mond dust to collect under the point .
the drill Diamond dust, which has tn
appearance of gray mud, is made b.
pulverizing chips in an iron mortar an
grinding the particles with an agat
fineness. The dust, mixed with oil,
, applied to the points of the drills wit
camers-hair brushes. After the jewel
e have been pierced they are embedde
}, in brass holders for the openings in tn
!. draw plates. For some purposes
, pierced Jewel is cut into halves, an
each half is then mounted in hinge
= holder that can be opened and shr
e like knife. Instead of stickin
: the end of length of ibe
g through the hole, which is sometime
S adelicate operation, the holder is opene
a and the fiber placed in one of the groove
a of the split jewel. After jewel hs
e been pierced, wires of different sizes al
= inserted in the hole until one fits pc
d fectly, and then the diameter of til
u wire is measured. In one measurin
9 instrument two blunt points are move
p toward each other by screw, IL
= ratchet in the handle being so delicatel
n applied that hair between the poin
c IS held firmly, but not crushed. In a
IS other instrument the diameter of VIII
n is indicated by hand on dial
IS The use of jewel points as cutie
e has also been increased by the inve
N ton of electrical appliances The fiji
g lines--2oO to an inch-on the cylinde
Is of the phonograph and the graphophol
m are cut by steel points, but it has bet
i'd ascertained that grit in the paraffine i
k. iures the points and causes ragged line
" Experiments are to be made with
Up sapphire point that John Wennstro