AN IMPROVED DRAWING COMPASS
Year: 1874

page_text: LETTERS PATENT to William Harvey Willson Campbell, of Norwich,
Connecticut, United States of America, now of No. 8, Southampton
Buildings, London, for the Invention of "AN IMPROVED DRAWING
COMPASS." A communication from abroad by Walter Smith, of
Boston, Massachusetts, United States of America.
Sealed the 29th January 1875, and dated the 7th December 1874.
PROVISIONAL SPECIFICATION left by the said William Harvey Willson
Campbell at the Office of the Commissioners of Patents, with his
Petition, on the 7th December 1874.
I, WILLIAM HARVEY WILLSON CAMPBELL, of Norwich, Connecticut,
5 United States of America, now of No. 8, Southampton Buildings,
London, do hereby declare the nature of the said Invention for “AN
IMPROVED DRAWING COMPASS," a communication, to be as follows:-
The object of my Invention is the production of a good and durable
drawing instrument, which can be produced at such a slight cost as to be.

page_text: within the reach of all classes, and which, though chiefly designed for
the use of pupils in schools of art and other drawing schools, may also be
advantageously used by draughtsmen and others in the place of the
more expensive instruments ordinarily used.
My improved instrument is constructed as follows:-It has two legs,
jointed together at the top in the usual manner, but these legs, instead
of being of solid metal, are formed of thin sheet brass or other thin metal.
One leg is formed by taking a piece of this thin metal and bending or
doubling it longitudinally so. as to form a flat hollow bar; this leg is
preferably made taper or diminishing in width from the joint to its outer
extremity, which is closed up and formed into a small socket and
furnished with a steel point. The other leg is tubular with a longi-
tudinal opening on the inner side, in which opening the said flat leg
enters when the instrument is closed. Into this tubular leg I fit a
tubular socket, which has one end closed and fitted with a steel point, as
above described, while the other end is formed to receive a pencil or
crayon. Inside this socket I fit a slide which carries an ordinary metal
knib or pen. The socket bas a longitudinal slot, and the slide has a
small hole which is accessible through the said slot, and by inserting
the point of the compass or other pointed piece into the small hole the
said slide is readily adjusted in the socket. When the pencil is to be
used this slide is withdrawn into the socket, and when the pen is to be
used it is projected from the end of the said socket. The said slide is so
formed and arranged within the socket that the pen when projected will
be in the proper position to produce a line when the compass is used in
the ordinary manner.
I form the joint of the instrument by using a small ring or washer of
suitable thickness to give the required strength and durability to the
joint. The thin metal of the legs is formed into jaws which embrace
this ring or washer; thin washers are placed outside these jaws, and a
pin is passed through them and rivetted or otherwise properly secured.
In some instances I provide the said instrument with a handle by
screwing a small metal piece into the said central ring or washer.
This instrument will be found very convenient for the reason that the
aforesaid socket provided with the point and slide, as above described,
takes the place of three pieces, namely, the point, pen, and pencil holder
used in other compasses. And by reason of its peculiar construction of

page_text: thin metal the said compass will be extremely light and convenient to
manipulate, and will be much less fatiguing to the hand than ordinary
compasses.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Harvey Willson Campbell in the Great
Seal Patent Office on the 29th May 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HARVEY WILLSON CAMPBELL, of Norwich, Connecticut, United States
of America, now of No. 8, Southampton Buildings, London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of December, in the
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reign, did for Herself, Her heirs and suc-
cessors, give and grant unto me, the said William Harvey Willson
Campbell, Her special licence that I, the said William Harvey Willson
Campbell, my executors, administrators, and assigns, or such others as
I, the said William Harvey Willson Campbell, my executors, admini-
strators, 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 DRAWING
COMPASS," a communication to me from abroad by Walter Smith, of
Boston, Massachusetts, United States of America, upon the condition
(amongst others) that I, the said William Harvey Willson Campbell, 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 William Harvey Willson Campbell,
do hereby declare the nature of the said Invention, and in what manner

page_text: the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the accom-
panying Drawing forming a part of this Specification:-
The object of my Invention is the production of a good and durable
drawing instrument, at such a slight cost as to be within the reach of all
classes, and which, though chiefly designed for the use of pupils in
schools of art and other drawing schools, may also be advantageously
used by draughtsmen, engineers, and architects in the place of the more
expensive instruments ordinarily used by them.
Figure 2 is a similar view of the said instrument with a portion of one
leg removed to show its transverse section, and with the extension slide
of the other leg reversed.
Figure 3 shews the said extension slide detached; and Figure 4 isa
transverse section drawn to an enlarged scale through the said leg and
slide.
Similar letters indicate the same parts throughout the Drawing.
A, B, represent the legs of the instrument, united at a by a pivot
joint. The leg A is by preference made cylindrical in form with a
longitudinal slit or opening on its inner face at a¹, where the edges of the
metal forming the leg are turned inward, forming lips or flanges b, as
shown in Figure 4, the opening a' being of sufficient width to receive
the U shaped leg B when the legs A and B are folded together. Within
the end of the leg A is fitted an extension leg or slide C, Figure 3, 2
similar in form to the leg A, and left open on its inner face in like
manner for the folding of the leg B within it. This leg or slide C is
made taper at one end, and like the leg B receives a fixed divider point c.
The opposite end C¹ of this extension leg forming a partial cylinder, as
above described, is adapted to receive a pencil, and within this cylindrical &
portion is fitted a slide D, also bent into a curved or nearly cylindrical
form, and open like the parts A and C on its inner side, as shown in
Figure 4, to permit the folding of the leg B within them. This slide D
has a pin or spur at its inner end projecting through a slot at d in the
extension leg C, facilitating its movement relatively to the leg or slide C; 8

page_text: b
its outer end is provided with a penholder at D¹, set obliquely to or at
one side of the opening or slit a¹, and in such relation thereto that when
the point c of the leg B is set for describing a circle the pen will face
the direction of movement of the leg A. Lips 6 are formed upon the
parts for retaining the enclosed slides in the proper relation to each
other, and may be of any form suitable for that purpose. A set screw E
at the joint serves to hold the legs at any desired angle of adjustment,
and also as a stem or handle for operating the instrument.
The several parts of this instrument, as described, may be struck up
into the desired shape from any suitable metal, and may be ornamented
in a style that is common to pocket pen and pencil holders, which these
instruments resemble when folded, with the pen withdrawn and the
extension piece C inserted with the point c inward and enclosed by the
leg A. When the parts are in this folded position the said instrument
can be conveniently carried in the pocket, and with the pen and pencil
thrown out can be used for ordinary writing purposes, as will be readily
understood.
Having thus fully described the said Invention, as communicated to
me by my foreign correspondent, and the manner of performing the
same, I wish it understood that I claim in drawing compasses the
reversible extension leg or slide C provided with the fixed point c, pencil
holder C, and penholder slide D, constructed and operating as herein
set forth and for the purposes specified.
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