AN INSTRUMENT ⠀⠀ FOR THE SOLUTION OF TRIANGLES
Year: 1872

page_text: LETTERS PATENT to Walter Marsham Adams, B.A., late Fellow of
New College, Oxford, of the Arundel Club, Salisbury Street, Strand,
in the County of Middlesex, for- the Invention of "AN INSTRUMENT ⠀⠀
FOR THE SOLUTION OF TRIANGLES.”
*PROVISIONAL SPECIFICATION left by the said Walter Marsham Adams
at the Office of the Commissioners of Patents, with his Petition,
on the 9th August 1872.
I, WALTER MARSHAM ADAMS, B.A, late Fellow of New College,
5 Oxford, of the Arundel Club, Salisbury Street, Strand, in the County of
Middlesex, do hereby declare the nature of the said Invention for "AN
· INSTRUMENT FOR THE SOLUTION OF TRIANGLES,” to be as follows:—
This Invention has for its object the construction of an instrument for
the solution of triangles.
0- The instrument has three-graduated-rods-which-form the sides-of-the
humans of the necessary data.

page_text: triangle. The base of the instrument consists of an oblong frame which
carrics longitudinal horizontal bars, and also four columns at its corners
supporting two bars parallel to the bars in the base. At the centre of
one of the horizontal bars in the base is pivotted one of the graduated
bars which form the sides of the triangle. The other end of this gradu-
ated bar slides on a vertical semicircular graduated are fixed to the
ends of the horizontal bar in the base, and which shows the angle of
clevation of the side. This graduated bar also carries a slide, on which
are pivotted two other slides, one on the other side of the triangle,
and the other on a vertical graduated bar which can move parallel 3
to itself between one of the upper and one of the lower horizontal
bars. The lower end of this vertical graduated bar works along a
graduated bar in the base (graduated both ways from the centre), by
which its position may be determined.
The vertical graduated bar measures the altitude of the triangle.
The lower extremity of the second graduated side slides on another of
the horizontal bars in the base, and carries with it a quarter circle
graduated are, by which its angle of elevation is shewn. On the arc is
a slide fixed to the side. The upper corner of this arc slides on the
second upper horizontal bar, and its lower radius along one of the 2
horizontal bars.
The base of the triangle is another of the horizontal bars in the base
of the instrument. This bar is graduated from its centre.
The three slides pivotted together, as above mentioned, mark the vertex
of the triangle. All the slides in the instrument are fitted with set 2
screws to fix them in any desired position, and all the graduated bars and
arcs may be fitted with verniers, if necessary.
As an example of the working of the instrument suppose two sides of
a triangle and the included angle were given; in this case the lower end
of the second mentioned side would be slid along its horizontal bar until 3
it cut off the given length of base, and would then be fixed in that
position by its set screw. This side would then be turned up until it
was at the given inclination, and there set. Finally, the vertex slide
would be set so as to cut off the given length of side. The length and
inclination of the other side, and the length and position of the per- 3
pendicular from the vertex of the triangle could then be read off.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Walter Marsham Adams in the Great Seal Patent
Office on the 8th February 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WALTER
MARSHAM ADAMS, B.A., late Fellow of New College, Oxford, of the
Arundel Club, Salisbury Street, Strand, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of August, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
givo and grant unto me, the said Walter Marsham Adams, Her special
license that I, the said Walter Marsham Adams, my executors, admi-
nistrators, and assigns, or such others as I, the said Walter Marsham
Adams, my executors, administrators, 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 “Av
INSTRUMENT FOR THE SOLUTION OF TRIANGLES," upon the condition (amongst
others) that I, the said Walter Marsham Adams, my executors or admini-
strators, 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 Scal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Walter Marsham Adams, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :-
This Invention has for its object the construction of an instrument for
the solution of triangles.
The instrument has three graduated rods which form the sides of the
triangle, and two graduated arcs, which, by means of the necessary data
may be set so as to determine the dimensions of the other parts of any

page_text: triangle. The base plate of the instrument consists of an oblong frame
which carries longitudinal horizonta. bars or guides, and also four
columns at its corners supporting two bars or guides parallel to the bars
in the base. At the centre of one of the horizontal bars in the base is
pivotted one of the graduated bars which form the sides of the triangle.
The other end of this graduated bar slides on a vertical semicircular
graduated arc fixed to the ends of the horizontal bar in the base, and
which shews the angle of elevation of the side. This graduated bar also
carries a slide on which are pivotted two other slides, one on the other
side of the triangle and the other on a vertical graduated bar which can
move parallel to itself between one of the upper and one of the lower
liorizontal bars. The lower end of this vertical graduated bar works
alongside the graduated bar in the base (graduated both ways from the
centro), by which its position may be determined.
The vertical graduated bar measures the altitude of the triangle.
The lower extremity of the second graduated side slides on another
of the horizontal bars in the base and carries with it a quarter circle
graduated arc by which its angle of elevation is shewn. On the arc
is a slide fixed to the side. The upper corner of this arc slides on the
second. upper horizontal bar, and its lower radius along one of the
horizontal bars.
The base of the triangle is another of the horizontal bars in the base
of the instrument. This bar is graduated from its centre.
:
The three slides pivotted together as above-mentioned mark the vertex
of the triangle. All the slides in the instrument are fitted with set
screws to fix them in any desired position, and all the graduated bars
and arcs may be fitted with verniers, if necessary.
As an example of the working of the instrument suppose two sides
of a triangle and the included angle were given; in this case the lower
end of the second mentioned side would be slid along its horizontal bar
until it cut off the given length of base, and would then be fixed in that
position by its set screw. This side would then be turned up until it
was at the given inclination and there set. Finally the vertex slide
would be set so as to cut off the given length of side. The length and
inclination of the other side, and the length and position of the pcr-
pendicular from the vertex of the triangle could then be read off.

page_text: By means of this instrument all problems and calculations which may
be made to depend on the solution of triangles may be worked out. For
example, problems may be solved in the rule of three, extraction of
square roots, quadratic and simultaneous equations, and the like.
In order that my said Invention may be most fully understood and
carried into effect, I will proceed to describe the Drawings hereunto
Figure 1 is a front view of the instrument; Figure 2 is a horizontal
section taken on the line 1, 1, Figure 1; and Fig. 3 a vertical section
taken on the line 2, 2, Figure 1.
In Figure 1 A, B, C, is the triangle for which the instrument is sct;
a is the base plate of the instrument; b, 61, 62, are longitudinal
horizontal bars or guides; c, c, c, c, are the four columns at the corners
of the base plate which carry the two bars or guides d, d, which are
parallel to the bars 6, 61, 6³, on the base plate. At the centre C. of the
horizontal bar 6 which forms the base B, C, of the triangle is pivotted
the bar A, C, which forms one of the sides of the triangle, the other end
of this bar slides on the semicircular arc e. At A in the bar A, C, is
carried the slide f, on which are pivotted the slides f,f"; f¹ sliding on
the bar which forms the side A, B, of the triangle, and on the
bar which forms the perpendicular A, D, from the vertex to the bar.
This last mentioned bar has at its ends slides g³, g³, on the bar b¹ and on
the bar d, and is thus capable of moving parallel to itself.
The extremity B of the bar forming the side A, B, of the triangle
slides on the horizontal bar 63, and carries with it the quadrant & whose
lower radius slides on the bar 6, and the upper end of whose other
radius is fixed to a slide g³ on the horizontal bar d'. The bar forming
the side A, B, has fixed to it a slide working on the quadrant.
All the slides carry set screws to clamp them, as is plainly shewn in
the Drawings; the graduation of the rods forming the sides of the
triangle and of the arcs are not shewn in the Drawings, but the rod
forming the side A, B, would be graduated from B, and the rods forming
the sides A, C, B, C, would both be graduated from C. The quadrant /
would be graduated from B, C, as initial line, and the semicircular arc e
from C. B. as initial line.

page_text: Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that what I
claim is, the construction of an instrument for the solution of triangles,
substantially as described.
In witness whereof, I, the said Walter Marsham Adams, have here-
unto set my hand and scal, this Twenty-eighth day of January,
in the year of our Lord One thousand cight hundred and seventy-
threc.
W. MARSHAM ADAMS. (L.S.)