IMPROVEMENT IN SET-SQUARES
Year: 1885

page_text: I, HENRY MARLE 220 Moseley Road Birmingham Superintendent Teacher of
Drawing Birmingham School Board do hereby declare the nature of my invention
for AN IMPROVEMENT IN SET-SQUARES to be as follows, viz. :-
The marking upon them-more particularly at the edges of graduated scales,
for the measurement and ad-measurement of lines and angles.

page_text: An improvement in Set-squares.
I, HENRY MARLE, of 220 Moseley Road, Birmingham, Superintendent Teacher of
Drawing to the Birmingham School-Board do hereby declare the nature of my
invention for AN IMPROVEMENT IN SET-SQUARES and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
This invention consists in marking the set-squares on one, or on both sides with
lines, straight or curved, so placed and arranged as to be useful for measuring
straight lines according to some scale or proportion; or for measuring or con-
structing angles; together with any description or explanation of such system of
lines, as may be deemed desirable.
For the measurement and admeasurement of straight lines, I mark the set-
squares 45° and 60°, or either of them, on either side, or on both sides-and more
particularly at the edge or edges of the set-square-with straight lines, longer or
shorter as may be determined, generally at right angles to such edge or edges, such
markings to extend either the whole length of the edge, or any portion of it, and
showing:-
i
(a) Inches, or parts of inches, or a combination of inches and parts of inches; or
(b) Any regular or equal divisions for any form of plain scale for linear
measurement, as may from time to time be determined—
Such markings to be accompanied or not by a line or lines parallel to the edge
or edges of the set-square; by words, letters, or numerals; or by all or any of them,
to complete or explain the scale.
For the measurement and admeasurement of angles, I mark the set-square 45°
on either side or on both sides, and more particularly at the edge or edges of the
set-square, with straight lines, longer or shorter as may be determined, radiating
at regular intervals of one or more degrees or parts of degrees:-
(a) from the right angle of the set-square to the hypotenuse or long edge
opposite to the right angle; or
(b) from a point at the centre of the hypotenuse or long edge, exactly opposite
to the right angle, and terminating in the two edges containing the right angle:
Such radiating lines to be accompanied or not:-
(a) by one or more arcs of circles, of any radius, described from the same centre
as the radiating lines;
(b) by a straight line or lines parallel to the marked edge or edges of the
set-square;
(c) by words, letters or numerals; or
(d) by all or any of them, as may be determined for the completion or the
explanation of such marking.
For the further measurement of straight lines-being the sides of inscribed
polygons in any of the above named circles-I draw chords of the required
length within the given arcs, and in any part of them; accompanied or not with
words, letters or numerals, or any combination of them, as may be deemed
desirable.

page_text: Also for the measurement and admeasurement of angles and sides of polygons,
he set-square 60° is to be marked-if so determined-in like manner to that
described herein for set-square 45°%; but with such modifications as are rendered
ecessary by the different shape of the set-squara.
In order that my said invention may be most fully understood, and readily
carried into effect, I will proceed to describe the drawings hereunto annexed.
Also for the measurement and admeasurement of angles and sides of polygons,
he set-square 60° is to be marked-if so determined-in like manner to that
described herein for set-square 45°; but with such modifications as are rendered
necessary by the different shape of the set-square.
In order that my said invention may be most fully understood, and readily
carried into effect, I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF DRAWINGS.
Fig. 1 of the accompanying drawings represents a large size set-square 45°,
marked as a protractor, together with sides of inscribed polygons in the inner
semi-circle.
Fig. 2 represents a large size set-square 60° marked with three plain scales to
measure 8ths, 10ths and 12ths of inches.
Fig. 3 represents a small set-square 45°, marked also with three plain scales of
inches and parts of inches.
Fig. 4 represents the other side of the set-square in Fig. 3, marked as an
elementary protractor, and with chords of inscribed polygons.
Fig. 5 represents a small size set-square 60° marked with three plain scales of
inches and parts of inches.
Having now particularly described and ascertained the nature of the said
invention, I declare that what I claim is
1. Constructing the set-square so as to combine the advantages and uses of the
set-square and one or more plain scales, substantially as described.
2. Constructing the set-square so as to combine the advantages and uses of the
set-square and protractor, substantially as described.
3. Constructing the set-square so as to combine and unite in one instrument,
the advantages and uses of the set-square, the protractor, and one or more plain
scales, substantially as described.
Dated this 25th day of November 1885.