AN IMPROVED INSTRUMENT INTENDED TO FACILITATE THE EXECUTION OF PERSPECTIVE DRAWINGS
Year: 1868

page_text: LETTERS PATENT to William Edward Gedge, of the Firm of John
Gedge and Son, of No. 11, Wellington Street, Strand, in the
County of Middlesex, Patent Agent, for the Invention of "AN
IMPROVED INSTRUMENT INTENDED TO FACILITATE THE EXECUTION OF
PERSPECTIVE DRAWINGS."-A communication from abroad by Paul
Gelibert, of 39, Faubourg St. Martin, Paris, France.
Scaled the 25th May 1869, and dated the 28th November 1868.
PROVISIONAL SPECIFICATION left by the said William Edward Gedge
at the Office of the Commissioners of Patents, with his Petition, on
the 28th November 1868.
I, WILLIAM EDWARD GEDGE, of the Firm of John Gedge and Son, of
No. 11, Wellington Street, Strand, in the County of Middlesex, Patent
Agent, do hereby declare the nature of the said Invention for "AN
IMPROVED INSTRUMENT INTENDED TO FACILITATE THE EXECUTION OF PERSPECTIVE
DRAWINGS," a communication to me from abroad by Paul Gelibert, of
39, Faubourg St. Martin, Paris, France, to be as follows:-
The perspectometer the subject of this Invention is an instrument
for fixing the perspective of an object with exactness, constructed upon

page_text: rules infallible, because based upon a natural law it always gives certain
results. The perspectometer is single or double. The single perspecto-
meter is a small scale or graduated rule (see Fig. 1 of the annexed
Sheet of Drawing) the length of which is regulated by the physical
conformation of the person using it. It is divided into one hundred
equal parts. The double perspectometer is composed of two scales of
equal length (Fig 2.) It has the advantage of abridging by more
than one-half the operation of fixing the point of sight. It is a per-
spectometrical principle that the object to be reproduced be brought
beneath two lines intersecting each other at right angles. To draw
with the perspectometer whether single or double it is necessary to
retire from the object which it is desired to reproduce until it can be
wholly embraced, closing one eye and keeping the arm stretched without
effort. With the double perspectometer all that is required is to bring
the outer angle of the instrument on the point which it is desired to
obtain, taking care to hold the instrument perfectly level, and then to
ascertain by inspecting the guide frame what number lies between the
outer vertical line of the perspectometer as well as under its horizontal
base.
The regulator is an instrument which is composed of a vertical stem
of wood or of iron carrying a shifting rod or bar to be raised or lowered
according to the height of the model, being fixed at any desired point by
an adjusting screw (see Fig. 3.) To guide the draughtsman especially
if a beginner the models are placed in a perspectometrical guide frame
(see Fig. 4.) These frames form a perfect square and are made of wood
or of cardboard or even painted on the walls.
To be enabled to vary the proportions of the drawing without
detriment to its exactness, and without the necessity of entering into
embarassing calculations, pieces of perspectometrically proportioned
cardboard are provided to be placed on the paper or canvass which is to
receive the drawing, a square still further facilitates this work (see
Figs. 5 and 6.)
"
The "horizontonometer is an instrument which the draughtsman
places at a distance from his seat so as to embrace with his perspec-
tometer the entire space existing within the frame 1, 2, 3, 4, (Fig. 7.)
The plate A, A, which divides in two is raised up to the level of the
eye, and when it has attained this point it fixes the line of the horizon;

page_text: the point of sight is fixed by the guide placed in the centre. The
frame 1, 2, 3, 4, is a guide to all the measurements to be taken.
To sum up, this apparatus is a guide to the eye of the draughtsman
providing him with marked points which permit him to fix in exact
5. proportions any desired perspective.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Edward Gedge in the Great Seal Patent
Office on the 28th May 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD GEDGE, of the Firm of John Gedge and Son, of No. 11,
Wellington Street,, Strand,, in the County of Middlesex, Patent Agent,
send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of November, in the
year of our Lord One thousand eight hundred and sixty-eight, in
the thirty-second year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said William Edward Gedge,
Her special licence that I, the said William Edward Gedge, my exe-
cutors, administrators, and assigns, or such others as I, the said William
Edward Gedge, 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 "AN IMPROVED INSTRUMENT INTENDED TO FACILITATE. THE EXECUTION OF
PERSPECTIVE DRAWINGS," a communication to me from abroad. by Paul
Gelibert, of 39, Faubourg St. Martin, Paris, France, upon the condition
(amongst others) that I, the said William Edward Gedge, 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.

page_text: NOW KNOW YE, that I, the said William Edward Gedge, 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, reference being had to the accompanying
Sheet of Drawing, and to the figures and letters of reference placed
thereon :-
The perspectometer the subject of this Invention is an instrument
for fixing the perspective of an object with exactness, constructed upon
rules infallible, because based upon a natural law it always gives certain
results. The perspectometer is single or double. The single perspec-
tometer is a small scale or graduated rule (see Fig. 1 of the annexed
Sheet of Drawing) the length of which is regulated by the physical
conformation of the person using it. It is divided into one hundred
equal parts. The double perspectometer is composed of two scales of
equal length (Fig. 2.) It has the advantage of abridging by more
than one-half the operation of fixing the point of sight. It is a per-
spectometrical principle that the object to be reproduced be brought
beneath two lines intersecting each other at right angles. To draw
with the perspectometer whether single or double it is necessary to
retire from the object which it is desired to reproduce until it can be
wholly embraced, closing one eye and keeping the arm stretched without
effort. With the double perspectometer all that is required is to bring
the outer angle of the instrument on the point which it is desired to
obtain, taking care to hold the instrument perfectly level, and then to
ascertain by inspecting the guide frame what number lies between the
outer vertical line of the perspectometer as well as under its horizontal
base.
The regulator is an instrument which is composed of a vertical stem
of wood or of iron carrying a shifting rod or bar to be raised or lowered
according to the height of the model, being fixed at any desired point by
an adjusting screw (see Fig. 3.) To guide the draughtsman, especially
if a beginner, the models are placed in a perspectometrical guide frame
(see Fig. 4.) These frames form a perfect square and are made either
of wood or of cardboard or even painted on the walls.
To be enabled to vary the proportions of the drawing without
detriment to its exactness, and without the necessity of entering into
embarassing calculations, pieces of perspectometrically proportioned
cardboard are provided to be placed on the paper or canvass which is to

page_text: receive the drawing, a square still further facilitates this work (see
Figs. 5 and 6.)
The horizontonometer is an instrument which the draughtsman
places at a distance from his seat so as to embrace with his perspec-
tometer the entire space existing within the frame 1, 2, 3, 4, (Fig. 7.)
The plate A, A, which divides in two is raised up to the level of the
eye, and when it has attained this point it fixes the line of the horizon;
the point of sight is fixed by the guide placed in the centre. The
frame 1, 2, 3, 4, is a guide to all the other measurements to be taken.
To sum up, this apparatus is a guide to the eye of the draughtsman
providing him with marked points which permit him to fix in exact
proportions any desired perspective.
In witness whereof, I, the said William Edward Gedge, have
hereunto set my hand and seal, this Twenty-eighth day of May,
in the year of our Lord One thousand eight hundred and sixty-
nine.