AN IMPROVED INSTRUMENT FOR SKETCHING AND DRAWING
Year: 1868

page_text: LETTERS PATENT to Charles Henry Chadburn, of Liverpool in the
County of Lancaster, Optician, for the Invention of "AN IMPROVED
INSTRUMENT FOR SKETCHING AND DRAWING."
Scaled the 1st June 1869, and dated the 3rd December 1868.
PROVISIONAL SPECIFICATION left by the said Charles Henry
Chadburn at the Office of the Commissioners of Patents, with
his Petition, on the 3rd December 1868.
I, CHARLES HENRY CHADBURN, of Liverpool, in the County of
Lancaster, Optician, do hereby declare the nature of the said Invention
for "AN IMPROVED INSTRUMENT FOR SKETCHING AND DRAWING," to be as
follows (that is to say):
This Invention has for its object an improved instrument whereby
an experienced or inexperienced person can sketch and draw objects
with great facility direct from the objects, whether the same be
landscapes, elevations, fortresses, or other buildings, interiors, animated
nature, or indeed any other visable object.

page_text: An instrument constructed according to this Invention may consist
of a pair of cross levers working on a fixed axis in or near the centre
of their length, and the ends of which levers or beams are connected
together at each end by a pair of links or connecting rods jointed
together at one end and to the extremities of the cross levers at the
other, so as to form two sections constructed on the lazy-tongs principle.
The axle or fixed centre upon which the cross levers work is formed
with a clamp or other suitable means of attachment for fixing the same
to a drawing board, drawing block, or a frame on which the paper,
canvass, or other material to receive the drawing or sketch is extended,
and which is placed in a vertical or nearly vertical position when the
instrument is being operated with. A pencil or other acing point is
fitted to one of the connecting rods on the lower end of the cross levers,
so as to be in front of the paper or other material which is to receive
the drawing. A sight hole is formed through or on the side of one
of the upper links, with a cross hair, or hair and bead, or other sight.
Springing from the axle on which the cross levers work there is a
horizontal rod or arm which extends therefrom, and which when in
position is at right angles to the vertical or nearly vertical surface of
the drawing board or frame for receiving the drawing to which it is
attached. This arm or rod is so constructed as to be capable of
extention or contraction by being formed with a teliscope joint or joints,
or constructed in two or more pieces connected together parallel to
each other by means of sliding blocks, or in any other convenient
mauner. The outer end of this horizontal arm is fitted with a vertical
standard or arm projecting upwards, and which is also capable of
extention, elevation, or depression in the same way as the horizontal
arm from which it springs; or it may be fitted into a slide at the end
of the horizontal arm and held in position by a set screw. The top of
the standard is provided with a sight; but in some cases it is prefered
to use a teliscope fitted with a cross hair or other sight, and which
tcliscope is placed in the position of the sight on the vertical standard
at the end of the horizontal arm, and passing through the sight hole
on the upper limb of the instrument, the bearings of the teliscope
replacing the other sights; the eye end of the teliscope being con-
nected to the top of the vertical standard by a vertical crutch piece,
which is capable of turning on its vertical axes, the teliscope being
suspended between two centres or pivots, and the other end of the
beliscope is supported in gimbol rings attached to the upper limb of

page_text: passes and works.
The improved sketching and drawing instrument is used as follows:-
The operator being provided with a drawing block or common drawing
board or frame upon which is streatched the paper or other material
intended to receive the drawing or sketch, to the upper end thereof
attach the instrument by means of the clamp, or other fastening, then
placing the same on an easel or other support so that the board or
frame will be in a vertical or nearly vertical position, then the operator
having taken a scat or stand in a position so as to conveniently apply
the eye to the teliscope or the sight hole on the vertical standard on
the end of the horizontal arm described, on looking through the
teliscope or the sight holes, all that has to be done is to actuate the
moving portions of the apparatus, so as to follow the outline of the
object being sketched by keeping the bead, point, or centre of the cross
hairs, moving the same over or upon the outlines, which movements
are noted, or delineated by the pencil or other tracer on the paper or
other material streatched on the vertical drawing block, board, or frame.
The sight or the eye end of the teliscope being a fixed point, all outline
or detail of an object is followed over by moving the upper limb
carrying the object end of the teliscope or the plain sight when the
teliscope is not used, which movement produces a corresponding one in
the lower limb carrying the tracer as herein-before described.
A common pentagraph may be used in the same way as the cross
levers and connecting links described if fitted with the sights and
horizontal arm and standard described, or with a teliscope fitted as
described, but the herein-before described arrangement of cross levers
and so forth will be found the most convenient form and arrangement,
sustaining more equally the weight of the teliscope or pressure used
in guiding the instrument, as that arrangement admits of the most
perfect adjustment of the several parts, that no more weight will be
thrown upon the hand of the operator in one position than another
when working the instrument. The lengthening or shortening of the
horizontal arm is to give the size required to the drawing, and the
elevation or depression of the vertical standard on the end thereof is
to regulate the line of sight. The size of the drawing may also be altered
by shortening or lengthening one half of the cross levers and links

page_text: giving the greater or less movement to the tracer than traversed by
the sight.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Henry Chadburn in the Great Seal
Patent Office on the 3rd June 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, CHARLES
HENRY CHADBURN, of Liverpool, in the County of Lancaster, Optician,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of December, 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 suc-
cessors, give and grant unto me, the said Charles Henry Chadburn, Her
special licence that I, the said Charles Henry Chadburn, my executors,
administrators, and assigns, or such others as I, the said Charles
Henry Chadburn, 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 POR SKETCHING AND DRAWING," upon
the condition (amongst others) that I, the said Charles Henry Chadburn,
my exccutors 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 Charles Henry Chadburn, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement (that is to say) :-
This my said Invention has for its object an improved instrument
whereby an experienced or inexperienced person can sketch and draw

page_text: objects with great facility direct from the objects, whether the same
be landscapes, elevations, fortresses, or other buildings, interiors,
animated nature, or indeed any other visible object, and which may
be appropriately called the "catholograph."
An instrument constructed according to this Invention may consist
of a pair of cross levers working on a fixed axis in or near the centre
of their length, and the ends of which levers or beams are connected
at each end by a pair of link or connecting rods jointed together at
one end and to the extremities of the cross levers at the other, so as
to form two sections constructed on the lazy-tongues principle. The
axle or fixed centre upon which the cross levers work is formed with
a clamp or other suitable means of attachment for fixing the same to
a drawing board, drawing block, or a frame on which the paper, canvas,
or other material to receive the drawing or sketch is extended, and which
is placed in a vertical or nearly vertical position when the instrument
is being operated with. A pencil or other tracing point is fitted to
one of the connecting rods on the lower end of the cross levers, so
as to be in front of the paper or other material which is to receive the
drawing: A sight hole is formed through or on the side of one of
the upper links with a cross hair or hair and bead point or other sight.
Springing from the axle on which the cross levers work there is an
horizontal rod or arm which extends therefrom, and which when in
position is at right angles to the vertical or nearly vertical surface
of, the drawing board or frame to which it is attached. This arm or
rod is so constructed as to be capable of extension or contraction by
being formed with a telescope joint or joints, or constructed in two
or more pieces connected together parallel to each other by means of
sliding blocks, or in any other convenient manner. The outer end
of this horizontal arm I fit with a vertical standard or arm projecting
upwards, and which is also capable of extention, elevation, or depression
in the same way as the horizontal arm from which it springs, or it
may be fitted into a slide at the end of the horizontal arm and held
in position by a set screw. The top of this standard is provided with
a sight. In some cases I prefer to use a telescope fitted with a point,
5 cross hair, or other sight, and which telescope is placed in the position
of the sight on the vertical standard at the end of the horizontal arm,
and passing through the sight hole in the upper limb of the instrument
the bearings for the telescope replacing the other sights; the eye

page_text: end of the telescope being connected to the top of the vertical standard
by a vertical crutch piece, which is capable of turning on its vertical
axis, the telescope being suspended between two centres or pivots, and
the other end of the telescope is supported in gimbol rings attached
to the upper limb of the instrument, and through which the object
end of the telescope passes and works. In place of the telescope a
plain tube fitted with the required sight or sights may be used.
The improved sketching and drawing instrument is used as follows:-
The operator being provided with a drawing block or common drawing
board or frame upon which is stretched the paper or other material
intended to receive the drawing or sketch, to the upper end thereof
attach the instrument by means of the clamp or other fastening, then
placing the same on an casel or other support so that the board or
frame will be in a vertical or nearly vertical position, then the operator
having taken a seat or stand in a position so as to conveniently apply
the eye to the telescope or to the sight hole on the vertical standard
on the end of the horizontal arm described, on looking through the
telescope or the sight holes all that has to be done is to actuate the
moving portions of the apparatus so as to follow the outline of the
object being sketched by the bead, point, or contre of the cross hairs,
moving the same over or upon the outlines, which movements are noted
or delineated by the pencil or other tracer on the paper or other
material stretched on the vertical drawing block, board, or frame. The
sight or the eye end of the telescope being a fixed point all outline
or detail of an object is followed over by moving the upper linib carrying
the object end of the telescope, (or the plain sight when the telescope
is not used), which movement produces a corresponding one in the
lower limb carrying the tracer as herein-before described.
A common pentagraph may be used in the same way as the cross levers
and connecting links described, if fitted with the sights and horizontal arm
and standard described, but the herein-before described arrangement of
cross levers and so forth will be found the most convenient form and
arrangement, sustaining more equally the weight of the telescope or
pressure used in guiding the instrument, as that arrangements admits of
the most perfect adjustment of the several parts, that no more weight will
be thrown upon the hand of the operator in one position than another
when working the instrument. The lengthening or shortening of the

page_text: horizontal arm is to give the size required to the Drawing, and the
elevation or depression of the vertical standard on the end thereof is
to regulate the line of sight. The size of the Drawing may also be
altered by shortening or lengthening one-half of the cross levers and
links giving a greater or less movement to the tracer than that traversed
by the sight.
My improved sketching and drawing instrument may be used as an
ordinary pentagraph by simply mounting the cross lovers upon a vertical
fixed centre or point, and substituting a guiding pointer for the cross
hair or sight in the connecting link rod, but for this application I mako
no claim.
That this my said Invention may be the more readily and clearly
understood and carried out with facility, I have hereunto annexed
Drawings illustrating the construction and practical application of
the Invention. Like letters and figures marked on the Drawings having
reference to similar parts.
Figure 1 (Sheet 1) is a perspective view of one of my improved drawing
and sketching instruments seen fitted with a telescope, and Figure 2
(Sheet 2) is a side elevation of the same on an enlarged scale, which
for convenience is shewn with the legs and sight end of the telescope
broken off; Figure 3 is an elevation of the gimble rings and outer
end of the telescope fitted with a point sight on the upper ends of the
upper pair of link rods, which latter in this Figure are shown broken
off; Figure 4 a front elevation of one of my improved catholograph
fitted with sights in place of the telescope.
A is an ordinary frame drawing board on which is stretched a, the
paper or other material, to receive the drawing or sketch; B a screw
clamp constructed with Can horizontal fixed axis on which the cross
levers work, and to which is secured D a cap nut to which is attached
E an horizontal arm, shown in this modification as constructed of wood,
and which works e a slide rod fitted at its inner end with f a grater
strap attached toe and sliding upon E; g, a garter strap fixed on the
outer end of E, and through which e works; H, a vertical slide rod fitted
on the outer end of the slide bar e in such a way that it may be elevated
or depressed at pleasure, and which in Figure 1 is shown fitted with I,
Figure 2, a vertical crutch which is capable of being turned on its vertical
axis and to the jaws of which is pivoted J, a ring, which encompassed the

page_text: sight end of K (Figure 2) an ordinary telescope fitted with sights as
herein-before described, and supported at its outer or object end in
gimbole rings, as seen in Figure 3; Land L' are a pair of cross levers
working freely on their axis, and to the upper end of which are jointed
M and M' a pair of link rods through the top joint of which in Figure 3
is formed the outer sight hole, and in Figures 1 and 2 they are shown
fitted with gimble rings to receive the outer end of the telescope;
N and N' a pair of link rods jointed to the lower ends of the cross
levers, and which are formed with several holes to receive the joint
pins to enable the operator to adjust them so as to produce the drawing
of the required size; P, back supporting log which is hinged to the back
of the drawing board, and which it is preferred to form with a T head; Q
and Q' side legs attached to the side of the drawing board by R and R',
thumb screws, by which arrangement the drawing board may be placed
at any angle required.
Having now fully described and ascertained the nature of this my
said Invention and the best means I am acquainted with for carrying
the same into practical effect, I wish it to be understood that I do
not confine myself to the several dimensions or relative proportions
of the several parts of the instrument, as it will be readily seen that
the same may be considerably varied without departing from the
Invention, but what I claim is,―
Firstly. The peculiar arrangement of cross levers and connecting rods
working around a fixed axis, substantially in the manner and for the
purposes herein-before described and set forth.
Secondly. The application of the horizontal elongating and con-
tracting arm springing from the fixed axis of the cross levers in
combination with the vertical adjustable standard carrying the sight
or sight end of the telescope, substantially in the manner and for the
purposes herein-before described and set forth.
Thirdly. Mounting the sight end of the telescope within gimbole
rings, substantially in the manner and for the purposes herein-before
described and set forth.
Fourthly. The application and use of the telescope fitted with sights
mounted and operated substantially in the manner and for the purposes
hercin-before described and set forth.

page_text: And, lastly. The general arrangement and combination of the several
parts of the apparatus constructed and operated substantially in the
manner and for the purposes herein-before described and set forth.
In witness whereof, I, the said Charles Henry Chadburn, have
hereunto set my hand and affixed my seal, this Second day of
June, in the year of our Lord One thousand eight hundred and
sixty-nine.
CHARLES HENRY (L.s.) CHADBURN.
Witness,
W. WALKER,
of 4, Castle Street,
Liverpool.