Year: 1887

page_text: Date of Application, 22nd Apr., 1887.
Specification Accepted, 3rd June, 1887.
We, CHARLES WILLIAM PRICE, and REUBEN CORSHAM, both of 62 Skinner Street,
Bishopsgate, in the County of Middlesex, Stationer's Assistants do hereby declare the
nature of this 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 Drawing and the letters of reference marked thereon,
that is to say :-
The object of this invention is to provide means whereby a measuring-rule or scalo
can be utilized for the purpose of drawing or describing circles of any definite radius
within the limits of the length of the rule or scale without the necessity of using
compasses or other similar drawing instruments.
For this purpose we pierce holes through the body of the rule or scale at the
principal divisions, or any other divisions thereof, as illustrated by way of example in
the drawing hereto annexed which represents an ordinary rule or scale of inches
made of ivory, box wood, steel or other suitable material. A A are holes pierced at
say every inch division on one of the straight lines of the rule or scale of such a
size as will enable the point of a pencil B to be passed through the same, so as to
come in contact with the paper or other material on
which the rule or scale is
laid, and upon which it is desired to draw a circle or circles. The smaller holes C
on the same line between the zero end of the rule or scale and the first inch division
are intended to receive a pin D of any suitable kind which being passed through
any one of such holes into the paper, or other material beneath the rule or scale,
forms a centre, round which the said rule or scale can be rotated.
It will now be understood that if the centre pin D be passed through one of tho
holes Cinto the paper or other material beneath, and the point of the pencil B or
other suitable marking instrument be placed in one of the holes A as shown and the
rule or scale be thereby rotated round the pin D the peucil will describe a circle or
arc of a circle E on the paper, of a radius equal to the distance of the hole in which
the pencil B is placed from that in which the centre pin D is placed. In the
illustration that distance is shown equal to 4 inches, but it is obvious that by placing
the centre pin D in any appropriate hole and the point of the pencil B in any

page_text: appropriate hole A circles of other radii within the limits of the length of the rule or
scale may be drawn.
The centro pin D may be composed of any suitable pointed object such as a needle or
a common pin for example, but we have found that an ordinary drawing pin, such as
is used by draughtsmen for fastening drawing paper to a drawing board is very
suitable for the purpose.
It is obvious that the holes for the pencil and for the centre pin may be of the same
size if preferred and arranged in any number and in any convenient or desirable way
on the scale, and they may be more or less conical to suit the shape of the point of the
pencil or other marking instrument.
Having now particularly described and ascertained the nature of the said invention,
and in what manner the same is to be performed, we declare that what we claim is :-
The improvement in measuring-rules or scales, which consists in piercing the same
with a hole or holes through which a pin may be passed to act as a centre, round
which the rule or scale may be rotated, and with holes through which a pencil may be
made to describe a circle or circular are as the said rule or scale is rotated round the
aforesaid centre, as hereinbefore described, and illustrated in the Drawing hereto
annexed.