IMPROVEMENTS IN MATHEMATICAL DIVIDING INSTRUMENTS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I PHŒEBE SARAH MARKS of 13¹ Cornwall Residences Regents Park in the Parish
of St. Marylebone in the County of Middlesex Spinster do hereby declare the
nature of my said Invention for "IMPROVEMENTS IN MATHEMATICAL DIVIDING
INSTRUMENTS" and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The object of my Invention is to provide a simple and efficient form of
mathematical dividing instrument for readily dividing a given line into any
number of parts.
My Invention consists of a hinged rule, having two limbs joined by a hinge at
one end. This hinge is (by preference) fitted with a set screw for fixing the limbs
at any angle when opened out.
One of the limbs is formed with a dovetail tongue or groove, whereby it is
attached to another rule, upon or in which it is capable of sliding.
The inner edges of the hinged rule are bevelled, and one of such edges is divided
into any desired number of parts, and the attached rule is also divided into any
desired number of parts.
The inner edges of the two limbs are made radial to the centre of the hinge, and
such centre forms either the zero point or the terminal of the divisions.
When it is desired to divide a given line into any number of parts, the limbs are
opened out until suitable divisions thereon or on one of them cut the terminal or
terminals of such line. The angle of the limbs is then fixed by the Borew. One
hand is then used to keep the attached rule firmly in position, and the hinged rule
is then moved along the attached rule as far as one integral distance, which is
then marked off, and the same process is continued until the requisite number of
divisions are obtained.
.
And in order that my said Invention may be clearly understood, reference is
hereby made to the accompanying Drawing.
a a is my improved rule or scale, with the hinge b and set screw c. d is the
dovetail tongue which fits and slides in the groove e of the attached rule f. The
under side off has several sharp points to keep it fixed while in use. One or both
of the rules may be divided in any requisite manner, and the attached rule f may
have a zero point (as shown) or any other division's, or may be divided as a vernier
scale

page_text: As an example of the ordinary method of using the instrument, let it be
assumed that the line gh is required to be divided into 17 equal parts. The
division indicating 8%, from the hinge end is placed at the zero point or line on f
and also at the end g of the line to be divided, as shewn in the Drawing. The
instrument is then opened until the limbo cuts the same line at h as shewn.
The instrument is then moved upwards (f remaining still) until the division
marked 8 is coincident with the zero line. The point where the limbo cuts the
line is now marked off, and the instrument is again moved a similar distance, and
so on until the whole line is divided. The divisions so marked off will be
seventeenths of the line g h.
It is obvious that other methods of using the instrument may be adopted and
lines may be measured and divided with great nicety and in a speedy manner.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed I declare that what
I claim is =
The manufacture and use of mathematical dividing instruments consisting of
two limbs united by a rule hinge or joint, and the attached rule f with the sliding
joint de substantially as and for the purpose described and shewn on the Drawing.
Date Orth Mauch 1001