IMPROVE- MENTS IN THE MANUFACTURE OF TYPE AND OTHER RAISED SURFACES FOR PRINTING
Year: 1854

page_text: LETTERS PATENT to John Robert Johnson, of Stanbrook Cottage, Ham-
mersmith, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF TYPE AND OTHER RAISED SURFACES FOR
PRINTING."
Sealed the 11th July 1854, and dated the 7th April 1854.
PROVISIONAL SPECIFICATION left by the said John Robert Johnson at
the Office of the Commissioners of Patents, with his Petition, on the
7th April 1854.
I, JOHN ROBERT JOHNSON, of Stanbrook Cottage, Hammersmith, in the
County of Middlesex, do hereby declare the nature of my Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF TYPE AND OTHER RAISED SURFACES FOR
PRINTING" to be as follows:-
In the manufacture of type and other raised surfaces for printing it has
been usual for the most part to employ compounds of lead and antimony as
the metal for casting the same, and in some cases a small per-centage of tin
has been added. Now the object of my Invention is to obtain harder, tougher,
and more enduring type and raised surfaces for printing, by employing tin in
large proportions with antimony, and to greatly reduce or wholly omit the use
of lead with such metals when making type and raised surfaces for printing, by
which means the type produced is so hard, tough, and enduring, as to allow of
its being used as a punch on the ordinary type metal now used; and the best

page_text: proportions I am acquainted with are seventy-five of tin and twenty-five of
antimony, but this may be to some extent varied; and when lead is also used,
I find that it must not exceed fifty parts in a hundred of the combined metals
employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Robert Johnson in the Great Seal Patent Office on the
7th October 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ROBERT JOHNSON, of Stanbrook Cottage, Hammersmith, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of April, in the year of our Lord One
thousand eight hundred and fifty-four, in the seventeenth year of Her reign,
did, for Herself, Iler heirs and successors, give and grant unto me, the said
John Robert Johnson, Her special licence that I, the said John Robert
Johnson, my executors, administrators, and assigns, or such others as I, the
said John Robert Johnson, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE
MENTS IN THE MANUFACTURE OF TYPE AND OTHER RAISED SURFACES FOR PRINTING,"
upon the condition (amongst others) that I, the said John Robert Johnson,
by an instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the. Great
Seal Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said John Robert Johnson, do hereby
declare the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
In the manufacture of type and other raised surfaces for printing it has
been usual for the most part to employ compounds of lead and antimony as the
metal for casting the same, and in some cases a small per-centage of tin has
been added. Now the object of my Invention is to obtain harder, tougher,
and more enduring type and raised surfaces for printing, by employing tin in

page_text: large proportions with antimony, and to greatly reduce or wholly omit the use
of lead with such metals when making type and raised surfaces for printing, by
which means the type produced is so hard, tough, and enduring, as to allow of
its being used as a punch on the ordinary type metal now used; and the best
proportions I am acquainted with are seventy-five of tin and twenty-five of
antimony, but this may be to some extent varied; and when lead is also used
I find that it must not exceed fifty parts in a hundred of the combined metals
employed, for if the lead be employed in much larger quantity the hardness
and toughness of the alloy rapidly decreases, and the alloy then approaches the
ordinary type metal in its properties, notwithstanding the presence of a con-
siderable quantity of tin.
In carrying out my Invention I proceed in the same manner as when the
ordinary type alloy is made. I fuse the tin or tin and lead (when the latter
metal is employed), and when fused I take off the scum or dross and add the
antimony, continuing the heat until combination takes place, when the alloy is
again skimmed and run into ingots for use.
When the antimony is tolerably pure the best proportions are as given
above, one part of antimony to three of tin, or tin and lead; but when it con-
tains other metals I find that the quantity of antimony should be diminished,
or, which is preferable, the inetal should be re-purified. If this be not attended
to, the alloy, although of great hardness, does not possess the tenacity or
toughness necessary for type of extreme durability.
In witness whereof, I, the said John Robert Johnson, have hereunto
set my hand and seal, this Sixth day of October, in the year of our Lord
One thousand eight hundred and fifty-four.
Witness,
GEO. PITT,
4, Old Square.
JOHN ROBT JOHNSON. (L.S.)