IMPROVE- MENTS IN MEANS AND APPARATUS FOR MAKING PERSPECTIVE DRAWINGS."
Year: 1871

page_text: LETTERS PATENT to Samuel Russell, of Carlisle Terrace, Kensington,
in the County of Middlesex, Artist, for the Invention of "IMPROVE-
MENTS IN MEANS AND APPARATUS FOR MAKING PERSPECTIVE DRAWINGS."
PROVISIONAL SPECIFICATION left by the said Samuel Russell at the
Office of the Commissioners of Patents, with his Petition, on
the 12th June 1871.
I, SAMUEL RUSSELL, of Carlisle Terrace, Kensington, in the County of
Middlesex, Artist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN Means and AppARATUS FOR MAKING PERSPECTIVE DRAWINGS,"
to be as follows:-
This Invention relates to an instrument for facilitating the drawing
of the converging lines of perspective drawings, for which purpose one
of the cross bars of a double bar parallel ruler is prolonged beyond its
connecting or working point, and is connected on some point of this
extension with one leg of a jointed bar in such way that it can turn
freely, the other leg of this jointed bar being connected in a similar way

page_text: with the other leg of the cross bar of the parallel ruler, so as to cause
one leg of the attached jointed bar to project in increasing distance from
one of the principal blades or straight edges of the parallel ruler as it is
opened or drawn apart, and this projecting end of the attached jointed
bar is allowed to turn freely on a pin fixed in the drawing board, in
which are also fixed on a line parallel to the horizontal line of the
drawing two studs, one on either side of the fixed pin and at any con-
venient distance from it, so that as the combined instrument is caused
to turn on the fixed pin in the drawing board one of the principal
blades or straight edges of the parallel ruler will rest against one or
other of the studs, whilst the other principal blade or straight edge
of the parallel ruler may be moved in any direction over the surface of
the drawing and will always converge towards one or other vanishing
point. By altering the points of attachment of the jointed bar with the
cross bars of the parallel ruler combined with the distances of the studs
from the fixed pin in the drawing board any desired distance may be
given to the vanishing points.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Samuel Russell in the Great Seal Patent Office on
the 12th December 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
RUSSELL, of Carlisle Terrace, Kensington, in the County of Middlesex,
Artist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelvth day of June, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Samuel Russell, Her special licence
that I, the said Samuel Russell, my executors, administrators, and assigns,
or such others as I, the said Samuel Russell, my executors, adminis-
trators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein ex-
pressed, 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 “ IMPROVEMENTS IN MEANS AND APPARATUS

page_text: DADE EVALVE RAWINGS, upon the condition (amongst others)
that I, the said Samuel Russell, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, 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 Samuel Russell, 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 :---
'
,
This Invention relates to an instrument for facilitating the drawing of
the converging lines of perspective drawings. For this purpose one of
the cross bars of a double bar parallel ruler is prolonged beyond its
connecting or working point, and is connected on some point of this
extension with one leg of a jointed bar in such way that it can turn
freely, the other leg of this jointed bar being connected in a similar way.
with the other leg of the cross bar of the parallel ruler, so as to cause
one leg of the attached jointed bar to project in increasing distance from
one of the principal blades or straight edges of the parallel ruler as it is
opened or drawn apart, and this projecting end of the attached jointed
bar is allowed to turn freely on a pin fixed in the drawing board, in
which are also fixed on a line parallel to the horizontal line of the
drawing two studs or pins, one on either side of the fixed pin on which
the attached jointed bar turns, and at any convenient distance from it,
so that as the combined instrument is caused to turn on the fixed pin in
the drawing board one of the principal blades or straight edges of the
parallel ruler will rest against one or other of the studs, whilst the other
principal blade or straight edge of the parallel ruler may be moved in
any direction over the surface of the drawing, and will always converge
towards one or other vanishing point.
The Drawing hereunto annexed represents the instrument in plan.
A, B, C, D, E, F and G, represent parts which are similar to an ordinary
double bar parallel ruler, the cross bar G being extended beyond the pin
or working joint H. K and L are bars jointed at N; the bars K,'L, F;
and C have holes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or a greater or less
number; finger screws X, X, pass through these holes enabling the

page_text: bars K, L, to work on the bars G, F, in such manner that the bar K
shall be parallel to the bar F, and the bar L parallel to the bar G. The
bar K is extended beyond the last hole for connection with the bar G,
having at its extremity a hole which works on the pin P attached to the
drawing board by the plate and finger screw 9, 9; R, S, are two studs or
pins which fix in the drawing board on a line parallel to the horizontal
line of the drawing, one on either side of the pin P. By this arrange-
ment when the outer edge of the blade B is bearing against the stud S
the outer edge of the blade A will at any part of the drawing to which
it may be moved always converge towards the right hand vanishing
point, and when the blade B is made to bear against the stud R the
blade A will always converge towards the left-hand vanishing point.
By altering the points of attachment of the bars K and L with the
bars G and F, and adjusting the distances of the studs R, S, from the
pin P, any desired distance-may be given to the vanishing points. The
working joints H and T must be on the line of the outer edge of the
blade B.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that what I claim is,
the arrangement substantially as herein-before described and represented
herein-before
by the Drawing hereunto annexed, for the purpose
explained.
In witness whereof, I, the said Samuel Russell, have hereunto set.
my hand and seal, this Twelvth day of December, in the year
of our Lord One thousand eight hundred and seventy-one.
SAMBEL RUSSELL (L.S.)