An Instrument for Readily Dividing a Straight Line of Given Length into any Number of Equal Parts and for Measuring with Precision any Portion of such Line.
Year: 1888

page_text: Date of Application, 26th Sept., 1888
Complete Specification Left, 16th May, 1889-Accepted, 22nd June, 1889
PROVISIONAL SPECIFICATION.
An Instrument for Readily Dividing a Straight Line of Given
Length into any Number of Equal Parts and for Measuring with
Precision any Portion of such Line.
I, EDWARD AYEARST REEVES, of the Royal Geographical Society, 1, Savile Row,
London, W. Assistant Map Curator to the above Society, do hereby declare the nature
of this invention to be as follows :-
A, B, ((on accompanying drawing) is a thin piece of metal wood, or some other
suitable material, cut so that A, B, shall be exactly at a right angle to B C. Attached
to A B, at the points D and F, are two thin, movable arms, DE and F G, of the
same length, and graduated into any required number of equal parts. A slot is cut
down the centre of these two arms, along which can be moved the two pivots, a and b,
(attached to a thin, straight, movable ruler, H 1) to any position on the arms DE,
and FG, and opposite any division on the same. The pivots a and b are permanently
fixed to the ruler H I, and are so placed that they are exactly in the same straight
line with the inner, bevelled edge of this ruler. In the same manner the pivots
joining D E and F G to A B are placed so that they are in the same straight line
with the inner edge of AB; the lower part of which is also bevelled. Attached
to A B, at the points J and L, are two other thin, movable arms, of equal length,
which, at their ends, K and M, carry another movable ruler, NO.
At P is a clamping screw, by means of which the ruler, H 1, is kept in any desired
position.
The Instrument is used in the following manner :-
(1) To divide a line of given length into any number of equal parts, say 56.
First slide the ruler H I along the arms D E and F G until the central marks on
the pivots, a and b, are exactly opposite the number on these graduated arms, corre-
sponding to the number of equal parts into which it is desired to divide the line,
which, in this case, will be 56.
Next bring the upper, bevelled edge of B C to coincide exactly with the continua-
tion of the line to be divided, towards the left, and make the point d on the inner,
bevelled edge of A B coincide with the left hand extremity of that line. Then
move the ruler H I, until its inner edge coincides with the other extremity of
the line.
Now move the ruler N O until its bevelled edge is exactly over the first of the
graduation marks on the arms D E and F G, and mark off on the line to be divided,
with a finely pointed pencil, the exact point where the ruler NO cuts that line.
Then move NO on to the next marks on D E and F G, and go through the same
operation; then to the next, and so on till the last is reached.
5 The line will the be found to have been divided into 56 equal parts.
from the left extremity, in towards the centre.
(2) To measure, with precision, any portion of a given straight line, say a portion
0 the upper edge of B C coincide with the continuation of the line of which a portion
100th division on the arms D E and F G. Then set the Instrument as before, making
Move the ruler H I until the centre of the pivots a and b are exactly opposite the
is to be measured, and place the inner edges of A B and HI on the two extremities
of the line.
the portion of the line to be measured, and see what division is then cut by the
Then move the ruler N O until its bevelled edge is exactly on the point marking
portion of the line in question will measure 0.64 of the whole line.
Dated this 25th day of September 1888.
EDWARD AYEARST REEVES.

page_text: COMPLETE SPECIFICATION.
An Instrument for Readily Dividing a Straight Line of Given
Length into any Number of Equal Parts and for Measuring with
Precision any Portion of such Line.
I EDWARD A YEARST REEVES of the Royal Geographical Society 1 Savile Row,
London, W. Assistant Map-Curator to the above Society 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 :-
The construction and mode of using this instrument will be understood by reference
to the accompanying drawing which represents a suitable form of it, but it must be
noted that I do not bind myself to the particular form of its parts nor to the
particular means for combining such parts, so long as the action or use remains
substantially as hereinafter described.
A B (on accompanying drawing) is what I call the main bar which may be
made of a piece of metal, wood, or some other suitable material, to which are
attached or jointed at such a distance as to be at least more than the length of the
scale bars so as to fold up, say at the points (and E, the two movable parallel
bars CD and E F, graduated into any required number of equal parts (say 120).
The free ends of these scale bars are adjustably connected to an outer bar G H so,
for instance, that along these arms can be moved the indicators a and b, which carry
the said outer bar G H, and to which they are fastened by pivots placed exactly under
the graduated central line of the scale bars C D and E F, and in the same straight
line with the inner bevelled edge of the outer bar G H, so as to form a parallelo-
gram of varying angles and with varying length of scale bar between the main
bar A B and the outer bar G H. At the points I and K, on the main bar AB,
are fastened two other movable arms 1 J and K L, which may be called the parallel
links, and which carry another straight bar, which may be called the intermediate
ruler M N, the outer edge of which is bevelled.
This ruler is arranged so that when it is closed up, and set at O on the graduated
arms or scale bars CD and E F, the part c N fits into the space c¹ N³, and its
outer bevelled edge and the points C and E (the commencement of the graduation)
are in the same straight line. In a similar manner, when the outer adjustable
bar G H is closed up, the points D, C, F and E will all be in the same
straight line.
The Instrument is used in the following manner :-
(1.) To divide a line of given length into any number of equal parts, say 56.
First, slide the outer bar G H along the scale bars C D and E F until the
bevelled edges of the indicators a and 8 are exactly opposite the number on these
scale bars corresponding to the number of equal parts into which it is desired to
divide the line, which, in this case, is 56. Next, keeping the ruler M N closed up
(set at O) make its bevelled edge, at its lower end, coincide with the commencement
of the line to be divided, and move the outer bar G H until its inner edge coincides
with the other extremity of the line.
Now move the ruler M. N until its bevelled edge is exactly over the first of the
graduation marks on the scale bars C D and E F, and mark off on the line to be
divided, with a finely pointed pencil, the exact point where the ruler M N cuts that
line. Then move this ruler M N on to the next marks on the scale bars C D and EF,
and go through the same operation, then to the next, and so on until the last is
reached. The line will then have been divided into 56 equal parts.
(2.) To measure, with precision, any portion of a given straight line, say a portion
from the left extremity on towards the centre.
Move the outer bar G H until the indicators a and b are exactly opposite the
100th division on the scale bars C D and E F. Then, with the ruler M N closed
of the 5
ruler M N and the outer bar G H on the two extremities of the line.

page_text: Now move the ruler M N until its bevelled edge is exactly on the point marking
the portion of the line to be measured, and see what division is then cut by the
ruler M N on the graduated bars CD and E F. Suppose it, in this case, to be 64,
then the portion of the line in question will measure 0.64 of the whole line; or,
taking this line to represent 100 yards on the scale of a plan, then the portion
measured will be 64 yards.
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 :-
1. A line dividing and measuring instrument consisting essentially of a main bar
to which are jointed at a suitable distance apart one end of two equally divided
parallel scale bars having their free ends so connected to an outer adjustable bar that
the latter can be moved relatively to the first named bar to form a parallelogram of
varying height and angles and with varying length or part of the scale bars between
the main bar and the adjustable bar, the main bar being also by parallel links con-
nected or jointed to a ruler to form a parallelogram of varying height and angles all
substantially as and for the purposes set forth.
2. The dividing and measuring instrument as shewn on the accompanying drawing
and hereinbefore described.
Dated this 16th day of May 1889
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.