New-York tribune., 1902-07-22
NEW VENTURE BY EDISON.
on TIE MARKET FOR FIFTY
CENTS \ BARREL.

The big cement plant of Thomas Edison which.
1t is said, will have marked effect the market.
will begin operations to-day. Cement is promised.
it is said. for 30 cents a barrel.
The consumption of hydraulic cement has in
creased in America with astonishing rapidity of
late years. Most of the cement which is used in
this country is made here. too. although at one
time there were large importations very small
quantity is found in Europe in which the ingred-
tents are combined by nature In just the right pro-
portion. but almost all that is now sold is an
artificial product. 1t is quite good natural
Portland cement, but ii involves a larger expendi-
ture of labor. In the United States it is customary
TO mix two general classes of materaI-a clay and
limestone. Since these substances vary greatly
in purity In different parts of the country. the
formula must be modified 10 produce the desired
result Chemical analysis of the earth and rock
employed is an essential preliminary to the opera
tion. New-Jersey abOunds i'm proper kinds of mari
and limestone for the manufacture of cement. and
the industry there has already attained an eX-
tensive development
The special novelty of Mr.. Edison's enterprise is
the large amount of original machinery which he
employs. He simpliies the process of making
cement. and thinks that he thus produce it
more cheaply than IL is by others
Many of the opera tions which involve hard labor in
other factories here automatic. The works are
at Stewartsville, n. j. where nearly a score Of
buildings have been erected These Of all sizes
and shapes, and each performs some special duty
The quarries two and half miles away, and
are worked by giant steam shOves. short rail-
way conveys the material to Stewartsville in cars
OF novel pattern which facilitate unloading.
These ascend an inclined plane in the first build
ing Of the series. and dump their contents between
rollers. which are five feet in diameter, five feet
long and make 200 revolutions a minute Crushed
TO pieces than half inch through. the
rock goes drying house. and then to a store
house, preparatory to further treatment In the
storehouse the material Is automatically weighed
Samples are taken by purely mechanical means for
testing in the laboratory. The chalk or limestone
is kept separate from the mari The two being
mixed in the right proportions go on an endless
belt 10 the fine grinding rolls, which produce an
article that is as fine -four. This machinery is
like some that Mr.. Edison had in his iron pull
verizng works at Ogden.
The ground rock next undergoes Sitting by
curious process. 1t is subjected to blast of air
which carries the lighter particles off to recepta
Gle more distant than that into which the heavier
ones fall Gravitation separates the two. The
coarser particles are conveyed back to the roller
for further grinding.
Probably the most original part OF Mr.. Edison's
apparatus Is his furnace or Kiln. This is a cylin-
der nine feet in diameter and $50 feet long. Ii is
lined with hrebrick, IS kept rotating slowly, and
one end Is higher than the other. The powdered
and mixed material goes into one end and comes
out of the other. The heat here is about 1900 de-
gFees Fahrenheit, and II Is sufficient to partially
vitrify the rock That Is to say. IL gives 1t a
cllnkerike character. Another grinding and
other sitting necessary before the stun Is ready
TO be barrelled for storage and sale
There three 900 horse power boilers. store
houses for coal. numerous steam engines for light
ing. driving the belt COnVeyOrs and operating the
DIoWers A machine shop ana Forge are among the
other features OF the establishment At present IL
Is thought that 5000 barrels day be turner out
but the plant has been designed that with added
machinery the output can be doubled