The morning news. [volume] (Savannah, Ga.) 1887-1900, 1895-11-03

worth not one-half their price, owing to
inferior quality.
The fact that the diamond can be
burned was first observed by Cosmo
of Tuscany i'm 1851. He used powerful
lens concentrating the sun 8 rays, and
found that in the heat the DIAMOND was
consumed. Previous to that time 1t was
believed that this hardest of all stones
was understandable by either ael0s or
fire. If enclosed in a retort or cruclbie,
from which air is excluded, II does, IN
deed seem unaffected by any amount OF
heat that we can apply, but II air or
oxygen gas be admitted and the tempera-
ture be raised to a point that corresponds
to 1000 DEGREES of Farenheit's scale, the
diamond will burn like coal, uniting with
oxygen to form carbon di0xide. 1t IS also
proved that if a diamond be neated IN a
Gr1Icibls with iron the latter is convert
ed into steel by union with Uhe carbon Oh
the diamond
carbon that differs greatly from the gem
form being brown, grayiSh black, ana
black; this is known as black diamond,
bort, bortz, carbon or carbonado, ana is
entirely distinct from the crystalline
Then there are rounded masses, with
greasy lustre, and an imperfect radlated
crystalline structure Within, apparently
made of a twining of many cubic crystals,
white gray to black, and translucent.
These are called round bort ana are
found in irregular masses with no crys-
talline form or aspect. Both these forms
are obtained in the province OF bahla,
Brazil Round bort has varied from %
to 500 a carat within the past fifteen years.
All these are valuable for their cutting
power, and command good prices, tnough
the African or Cape bort, as II is called, IS
less esteemed than the Brazilian carbon
ado because its crystalline structure rem
ders ii liable to break or cleaVe under
strain yet it is used in saving marble.
Both carbonate and round port are nara
er and tougher than crystalline diamonds,
and are less dense, owing, probably, 10
porous structure, or to minute caVltleS.
l., ,@+ a.. hoe
the materials by coating them with lamp
black and wax, which produced nne
compact black appearance and increased
the price, the wax being SOLD at the price
of the best grade of carbon.
Its great hardness gives the diamond,
in all its forms, a high importance In the
imperfect crystals, the fragments and
cleavages, and the powder produced by
crushing them. are all used Tor cutting,
polishing, and engraving precious stones,
glass etc, but the hard, black varieties,
bort or carbonado are extensively em-
ployed in large operations what IS called
the diamond drill, invented by Lesshot in
1850 has revolutionized the methods of
tunneling, mining and well-boring IN the
course of a few years. The general IDEA
of it is a steel tube of the size desired
for the boring say from one to eight
inches in diameter, on the extreme END
of which are fastened number of small
pieces of bort BY means of suitable
machinery this tube is then rotated, pres
sing against the rock to be penetrated.
The result is that the tube rapidly cuts
its way into the rock, making smooth,
circular hole; while a rod or core of the
rock passes up inside of the advancing
tube and Is removed piece by piece as
it rises These cores are often of great
value, as exactly showing the kind and
thickness of rock traversed in any such
working; and drilling in mining and en-
gineering operations is frequently re-
sorted to simply for this purpose. 1t was
due to diamond drills that the Mt Gents
and other great tunnels were completed
in a few years time
AT the great salt deposits of New Iberia,
La, the company desired to ascertain the
depth of Hle mas of rock salt, and sank
a boring for the purpose. The drill pene-
trated through COO feet of solid salt, the
cores furnishing the evidence, and 10000
feet can be drilled in perpendicular line.
Tools with diamond edges are used for
"trueing'' and growing the faces of en-
cry wheels and grindstones; for trueing
the faces of hardened steel, rubber, porce-
lain, granite, celluloid, and calendar rolls;
for trueing the inside of case-hardened
cylinders for gas engines; for cutting all