IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL MARBLE
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by George Eugene Magnus at the
Office of the Commissioners of Patents, with his Petition, on the
18th December 1872.
I, GEORGE EUGENE MAGNUS, of No. 17, Addison Road, Kensington,
in the County of Middlesex, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL
MARBLE," to be as follows:-
This artificial marble is composed of Martin's or Keene's cement,
or a mixture of the two, gauged with sulphate of iron, in the proportion
of one pound of sulphate to four gallons of water, adding three ounces
of nitric acid. It is then cast in moulds into the form of plates of
various sizes, from three-eights of an inch to one inch thickness,
and upwards, according to the size of the plates. These plates can be
cast with moulded or bevelled edges, suitable for rusticated ashlar work.
When dry and hardened the plates are coated with a mixture of tar,
asphaltum, linseed oil, and umber, or a mixture called tar varnish,
commonly used in the japanner's trade. The plates are then placed in
a stoving chamber, the temperature varying from two to three hundred
degrees of Farenheit, and remain there from twelve to twenty-four

page_text: hours. When taken out of the stove and cooled the tar varnish coating
is rubbed down smooth with pummice stone. This coating fills the
fine pores in the surface of the plates, and forms a key for the colour
that is subsequently applied. The plates are then coated twice or more
with colours of any required tint, or with Kremnitz white, mixed with
oil and copal varnish, and put to dry in a hot chamber, rubbing
down with pummice stone between each coat. They are then polished
by the hand with rotten stone, as practised by japanners.
The marbling can be exccuted by hand, or by Magnus's process for
marbling enamelled slate, which is done by mixing the colours with
gold size, or with copal varnish, or both, and then floating them on
water. The surface of the plates being immersed in this receives the
colour. The plates are then dried, receive two or three coats of copal
varnish, and are finally polished by hand in the same manner as the
plain tinted ones above described. The plates are deeply and roughly:
scored at the back when wet and soft in the moulds to form a key
for fixing to the wall.
The great advantage of Muro marble is that it can be securely fixed
against a rough brick wall with great expedition, at an extremely
small cost, by an ordinary plasterer, by means of plaster of Paris only,
thus saving the great delay and cost of plastering and painting of walls.
Architrave, dado, and base mouldings can be made of the same material
as well as consoles, pilasters, and every article to which marble, slate,
or stone is adapted. Muro marble slabs are quite equal to the most
exquisite natural marbles in appearance and durability, at a com-
paratively insignificant cost, about one half of scagliola and any other
artificial marble, all of which it utterly throws into the shade.
The marbled plates are used for lining halls, corridors, staircases,
bath rooms, assembly rooms, banks, &c., and the plain tinted or
white ones for closets, passages, dairies, larders, and shops, and it is
for the application of plates so prepared to the lining of walls that this
patent is chiefly claimed.