The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1871-12-14
Arfsf1esnI atnma

more ornamental than brick, cheaper tnan hIt
lral building stone, and susceptible OF more Or
more free from the imperfections
If natural material as taken from the quarry,
and which moreover will possess the great adj
rantaoe of reduced cost. Artificial stone has
been produced by several inventors conspicuous
among whom are Ransome of England, Frear
of Chicago, and Coignet and Sorel of France.
The three first-named depending upon lime in
some of its chemical forms, have succeeded in
producing a coarse variety of sandstone, to re-
sist a crushing process of about 1000 pounds per
square inch. But Sorel, chemist of Paris,
worked in new field with new material, and
process by which stone to resist
crushing process of &c, 900 pounds a square inch
has been made, and which it is reasonable to
say, embodies some of the secrets of nature
and is almost identical with the method by |
which many of the rocks and stones that cover. |
the earth's surface during geological ages are |
produced. While chemists and biologists are |
unable to distinguish a natural stone from one
made by the Sorel process, the assumption
would seem safe, that if he has not discovered
natures secret he has approached very near to
it. Biologists agree that some of natures most
indestructible rocks contain magnesia, which,
treated with chloride of magnesium, in a GER
tain manner, has the power of setting, like
common plaster, when mixed with water,
though forming much harder and stronger
mass; and the further fact that if mineral sub
stances were incorporated into the mixture
chemical change in Setting took place and
the whole agglomerated and formed hard,
compact mass. Sorel also found that magnesia
could be obtained from the natural rock
known as magnesite, by burning, in the same
manner as lime is obtained from limestone,
and with this he produced a new cement,
which, though capable of being used as COM
mon lime-mortar, is much harder and more
durable, and combined with mineral sub
stances, forms compact stone, readily
moulded at will into blocks of any texture,
shape, color or size, manufactured at low
price, and can be worked with the chisel pre-
cisely as the natural stone is.
The process has been introduced into this
country and company in Boston is now en-
gagged in manufacturing by it, not only stone of
exceeding strength, great beauty and suscepti-
bility of ornament, at very low cost, but is ap-
plying it to certain mineral articles which enter
into the mechanic arts, such as emery Wheels
&c, also articles of interior decoration, man
ties, chimney pieces, table-tops and the like.
The method of manufacture, which is pro-
tected by patents, is briefly described as fol-
lows: The magnesite, which is hard, white
stone resembling chalk, is burned in kiln I'M
til it is thoroughly decarbonized. 1t is then
run through a common burr-mill and ground to
a fine powder. Thus oxide of magnesium is
obtained: this is mixed with dilute chloride of
magnesium, and cement is thus formed,
which mixed with any kind of broken
stone or sand forms stone in color
and fneness resembling the stone or sand
used: thus sand produces sandstone, mar
BILE, etc. The mass is thrown into molds of
plank or plaster or any other suitable material,
and is tamped or rammed; the mass readily
sets and stone is taken from the mold. The
Setting" requires from one hour to one day,
depending somewhat on the chemical proper
ties of the solid ingredients used, the carbon
ates as rule requiring longer time than the
silicates. Building blocks will bear handling
and may be used when three or four days old,
although they do not attain their maximum
strength and hardness for several months
In regard to the durability of this material,
it has been proved by Gen. Gilmore, U. S. A.
and other scientific gentlemen, to be fully equal
to the natural stone. In Gen. Gillmore's re-
port of tests of various artificial stones made by
him, he treats of the Sorel process at consider
able length, especially as regards its durability
and strength, its cost, &c. He records the re-
suit of trials of two-inch cubes made by him at
the Boston navy-yard, reduced to the crushing
pressure upon one square inch. The pressure
varied from 1857 to 21.562 pounds, the stone
made of the finer pulverized materials and of
the greater age being the strongest. The pro-
portion of the oxyde of magnesium in no case
was over Is per cent. and in some reduced to
H. The pieces tested were picked up at ran
dom in the Union Stone Company's yard and
he says that Gin strength and hardness this
stone greatly surpasses all other known artif-
cial stones and is equalled by few, if any of the
natural stones that are adapted to building pur-
poses. The artificial marble takes high de-
gree of polish, being in this respect fully equal
to the best italian varieties" DR.. c. T. jack
son, the well-known geologist submitted the
stone to the severest frost-test, and says: SIT
is evident that this stone will withstand the ac-
ton of frost more perfectly than any sandstone
or ordinary building stone now in use. see no
reason why it will not stand as well as granite"
Durability and strength being proved, the
next consideration is COST and it has been
shown that cubic foot of stone, ready to be
laid in the wall of building oan be produced
at much less cost per cubic foot than quarried
material. Magnesite, the raw material from
which the cementing agent is obtained, is very
plenty in the United States; large deposits hav-
ing been found in various parts of the country,
and the process of obtaining the oxyde is as
cheap and simple as the production of lime.
Its cost in Portland would be as low as Rosen-
dale cement. The bittern water, the chemical
moistening material, can be had in abundance
at the cost of transportation from the salt
works. The Union Stone Company use for
their dry materials quarry-chips, and such stuff
as is usually thrown away-common cobble
stones, sea-sand, and the refuse of stone works
These are ground to fine powder, mixed with
the cement, thoroughly triturated with the
moisture, and formed in the mold. At the
Middlesex Agricultural Society's fair last year,
a large stone was exhibited, which was made
on the spot The mixture was brought on the
ground, laid, and pounded down, and in the
course of a week was transformed into stone as
hard as granite In the vicinity of Boston sew
eral large granite bases for large engines and
other machines have been put down, to the per-
feet satisfaction of the parties purchasing and
at quarter of the cost of quarried stone.
Perhaps by calling attention to this impor-
tant and practicable invention we may suggest
to the minds of some of our enterprising people
a method whereby large amount of now
worthless material can be utilized and become
a source of profit to the community, and be-
neficent influence on our domestic life.