The Portland daily press., 1897-10-26
ARTIFICIAL DIAMONDS.
Recent Experiments in Their Pr0duc-
tiOn.

Hudson Maxim in the Pail Mall va
zette.
l began the investigation of the supJeco
of artificial diamonds in connection WIN
work on calcium carbide and aoetylene
in America in 1894. I devised severai
forms of apparatus and processes, lor
which applied for patents in the Unlteo
States. Moissan had shown that artificial
diamonds could BIZ produced. although
micros cop ic in size, by saturating mol
ten metal, such as iron or silver with car
bon, and then cooling a globulo OF the
same with great rapidity, whereby d
cooled exterior portion of the metal "as
caused to shrink strongly upon not IN
terror portion, thereby causing the IN
terror portion to be cooled under con-
siderable pressure. By dissolving away
the the metal, Moissan had found that q
portion of the carbon held by the molpen
| metal in solution or in combination al
high temperature would, upon cooiine
under great pressure, separate from the
metal in the form of small carbon crys-
tails or diamonds, instead of graphite, 81
in gray cast iron.
Now, it is well known that the factor
of time plays very important, parts IL
crystalline formations, much larger CRY.
stalls being produced when allowed to form
slowly than when formed with rapidity
10 secure this end I devised an appara'
tus OF electric furnace, within which the
metal, in the presence of carbon, could be
| fused and raised to an exceedingly high
temperature by an electric current in
order that the maximum Of carbon might
be absorbed or taken up by the metal, che
device being provided with means fol
subjecting the molten metal to an exceed
ingly high pressure, either by hydraulics
| or other suitable means. By this method
pressure very many times as great AZ
attained by Moissan could be applied te
the molten metal, and any desired length
of time permitted to elapse in order te
secure the maximum size of crystals
By Moissan's method but a comparatively
light pressure could be exerted at best,
limited by the tensile strength of a thtr
layer of cast iron, while by my method
30, 000. to 100000 pounds to the square inoE
could, if requisite, be applied. Another
method devised by me was to pass cur
rent of sufficient quantity through q
small body, rod OF flament of carbon in
confined space, to cause its fusion, and
| thenssubject the same to great pressure
and allow to cool slowly.
DIAMOND OF ELECTRO DEPOSI-
| TON.
| The method for the production of arti
fetal diamonds which 1 have always con
sidered the most promising is by electri
cal deposition, for by this means 1 am O
the opinion Embellishments of much. large
size may be produced and at lower ex
pense than by any other method. file,
two applications for patents in tn
United States in 1895, for processes ant
apparatus for the production of die mond
| by ro-deposition, but it was not I'm.
til September year ago that l had ar
| opportunity to test my inventions for tn,
production OF diamonds in this manne
1 and to verify my theories. Now, it Ii
well known that if an electric current
be passed through a carbon flamen'
| immersed in an atmosphere of hydro-car.
| bon itsis decomposed and electrically de
posted upon the filament, the most rapid
deposition taking place at the points offer
| ing greatest electrical resistance-in othe
words, in the hottest portions of the fla
ment, this fact being taken advantage O
to secure uniformity of electrical rests
lance in electric lamp flaments. Now,
have predicted that If "A carbon rod, i'm
mersed in hydro-oarbon atmosphere
should be maintained at very high in
candescence by an electric current for
considerable time, the electro deposition
would assume crystalline form. Will
conducting some experiments at Faraday
House, Charing Cross Roads, London, ex
tending over period of three months
| beginning early in August year ago,
| had an opportunity of conducting on
considerable scale large number of ex.
periments with 100 available electrical
| horse power. The experiments related t,
the investigation of various methods fol
! the production of calcium carbide ant
other carbides. by the electric arc, by in
candescence and by electrically super
heated gases, and also to the effect of tn
electric current upon various gases.
In connection with this work conduct
ed some experiments to determine tn
possibility and practicability of produe
ing diamonds by electro deposition. TIL
results of these experiments have, unit
now, kept secret for the reason that pub
LEGATION prevents valid patents bein
taken in most countries, but since D1
Borchers has published some experiment
conducted by him, by which similar re
suits were attained, have determined t
protect myself by patents IN Englan
and America only, and to publish an &C
count of what have accomplished an
what expect to accomplish in the pro
duction of artificial diamonds and th
means employed and intended to be EN-
ployed. The apparatus employed by m
in my experiments for the production c
diamonds by electro deposition was con
structed as follows: A large graphit
crucibIe, about foot in diameter, an
twenty inches high, with large hole Gu
through the bottom, to admit the passag
of a four-inch carbon electrode, was in
verified upon heavy carton bedplate. In
side Of the large graphite crqelble wa
placed small gas carbon cruclnle, apou
four inches in diameter and six inche
high, having its bottom cut away; th
space intermediate of the small ami iarg
crucible was filed with finely broke
charcoal. A carbon rod, ABOUT nvt
Ielghths of an inch i'll diameter. was IL
terposed between the large vertical elet
trode and the carbon bedplate, III sue
wise as to pass through the center OF tn
small crucible without touching It, an
make contact with the vertically dispose
electrode and the bedplate: The !arg
vertical electrode was carefully tnsulate
from the graphite crucible, and tn
graphite crucible again insulated froI