IMPROVEMENTS IN THE MANUFACTURE OF MARBLE
Year: 1884

page_text: I AUGUSTO GUATTARI of 91 Shirland Gardens, Paddington, in the County of
Middlesex, Engineer, do hereby declare the nature of the said invention for
"IMPROVEMENTS IN THE MANUFACTURE OF MARBLE " to be as follows:—
This Invention relates to a special process of indurating gypsum of the species
commonly called alabaster, and of transforming it into marble.
This process consists in submitting the sculptured objects to a temperature of 30°
to 40° Réaumur in a suitable stove and afterwards immersing them in a hot
solution of borate of soda and biphosphate of potash in certain proportions at a
temperature of 18° R. The objects after immersion in this bath are again placed
in the stove and submitted to a temperature which should not exceed 120° R. On
leaving the stove where they have been dehydrated they must be allowed to cool
and then be again immersed in a solution of borate to which is added nitric acid in
certain proportions.
The hardness and whiteness of the product depends essentially on the quality of
the acid employed.
The operation ray also be performed as follows:-The sculptured objects after
baving been withdrawn from the oven, that is to say, dehydrated, are placed in a
bath of borate of soda, then removed therefrom and dried and subjected to a higher
temperature namely 180° R in order to more rapidly evaporate the water they
contain. They are then again immersed in the same solution of borate to which is
added concentrated nitric acid or oxalic acid, after which they are removed from
the bath and exposed for two days in the open air; they are then simply warmed
and rubbed with a mixture of Canada Balsam and Naphtha. This process can be
modified according to the various results which it is sought to obtain and the
objects to be produced, but these modifications relate only to the proportions of the
solution and the time of immersion.

page_text: "
I AUGUSTO GUATTARI of 91 Shirland Gardens, Paddington, in the County of
Middlesex, Engineer, do hereby declare the nature of the said invention for
"IMPROVEMENTS IN THE MANUFACTURE OF MARBLE and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This Invention relates to a special process of indurating gypsum of the species
commonly called alabaster, and of transforming it into marble.
This process consists in submitting the sculptured objects to a temperature of 30°
to 40° Reaumur in a suitable stove and afterwards immersing them in a hot
solution of borate of soda and biphosphate of potash in the proportions of 8 parts
of borax to 1/50 part of biphosphate in 100 parts of water at a temperature
of 18 R. The objects after immersion in this bath are ag in placed in the stove and
submitted to a temperature which should not exceed 120° R. On leaving the
stove where they have been dehydrated they must be allowed to cool and then
be again immersed in a solution of borax to which is added nitric acid varying in
quantity from 50 to 30 % of the water of the solution.
The hardness and whiteness of the product depends essentially on the quality of
the acid employed.
The operation may also be performed as follows :—'
-The sculptured objects after
having been withdrawn from the oven, that is to say, dehydrated, are placed in a
bath of borate of soda, then removed therefrom and dried and subjected to a higher
temperature namely 180° R in order to more rapidly evaporate the water they
contain. They are then again immersed in the same solution of borax to which is
added concentrated nitric acid or oxalic acid, after which they are removed from
the bath and exposed for two days in the open air; they are then simply warmed
and rubbed with a mixture of Canada Balsam and Naphtha. This process can be
modified according to the various results which it is sought to obtain and the objects
to be produced, but these modifications relate only to the proportions of the solution
and the time of immersion.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
The herein described processes of indurating gypsum of the kind known as
alabaster and transforming it into marble, as specified.
Dated this 5th day of November 1884