Improvements in Apparatus for Facilitating Arithmetical Calcu- lations, Chiefly Designed for Use in Teaching Arithmetic.
Year: 1888

page_text: Improvements in Apparatus for Facilitating Arithmetical Calcu-
lations, Chiefly Designed for Use in Teaching Arithmetic.
I GEORGE HENRY ANGUS, of Hutton Lowcross, near Guisborough in the County
of York, Schoolmaster, do hereby declare the nature of this invention to be as
follows:-
--
My invention relates to abacus, or to apparatas for teaching arithmetic, or
facilitating arithmetical calculations."
Apparatus of this kind or class has been hitherto constructed in such a manner that
the balls or discs are all visible at the same time, and without the means of showing
the numerical value of the digits 1 to 9, or vice versa, or of showing the representative
digit for any number of discs or other, objects.
The object of my invention is to provide means whereby the said discs are normally
concealed by means of shutters working in slides hereinafter described. so that the
value of any digit can be conveniently shown in discs, by moving the said slides or
shutters.
According to my said invention I provide an apparatus with a suitable frame having
at the left hand side, figures marked upon the same from 1 to 9. The said frame is
moreover provided with nine or other suitable number of slides in which are adapted
to move shutters which run from side to side of the apparatus. When the said
shutters are so operated, that is to say, moved from left to right, they display through
suitable apertures at the left hand side of the said slides, any digit from one to nine,
and in the slides above described its numerical value in discs. The said discs are
normally concealed underneath the said shutters.
The value of every figure in a vertical column of any addition sum up to nine deep
can be shown, thus imparting an intelligent appreciation of the numbers added
together.
The discs can be moreover colored red and black, so that complementary addition
can be readily taught.

page_text: By moving one of the shutters the side figure of which represents the units of the
number to be added to another, the discs colored red make up the next ten, and the
black ones beyond the said red discs represent the units over.
In the case of substraction by using any two consecutive slides ocular demonstration
can be given of the difference in value of any two numbers.
By beginning with the bottom slide, the side figures acting as multipliers, the
multiplication table can be pleasantly and thoroughly taught.
It is obvious moreover that I can somewhat modify the construction of my
apparatus without in any way departing from the nature of my said invention.
Dated this 17th day of March 1888.

page_text: Improvements in Apparatus for Facilitating Arithmetical Calcu-
lations Chiefly Designed for Use in Teaching Arithmetic.
I, GEORGE HENRY ANGUS, of Hutton, Lowcross, near Guisborough, in the County
of York, Schoolmaster 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 :-
My invention relates to an improved abacus or apparatus for teaching arithmetic
or facilitating arithmetical calculations.
In apparatus of this kind or class as hitherto constructed, beads, balls, or discs
have been employed, but such beads, balls, or discs have been so arranged that they
are all visible at the same time, no means being provided for concealing some of
them whilst leaving the remainder exposed. Moreover in such apparatus no provision
has been made for showing the numerical value of the digits 1 to 9 or for showing
the representative digit for any number of the discs or other objects.
One important feature of my said invention is the provision of means whereby the
discs may be concealed. For this purpose I prefer to employ shutters or slides as
hereinafter described. By means of the said slides the value of any digit can be
conveniently shown in discs by moving the said slides or shutters. I may, however,
employ other suitable means for concealing the said discs.
In the accompanying drawings I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a front elevation of the apparatus with all the slides or shutters herein-
after described, in the closed position.
Figure 2 is a similar view with all the said slides or shutters open to their full
extent.
Figure 3 is a transverse section on the line a Figure 1.
Figure 4 is a horizontal section on the line y y Figures 1 and 3.
Figure 5 shows a portion of Figure 3 drawn to an enlarged scale.
Figure 6 is a rear elevation with the slides or shutters in the same position as in
Figure 1, the back cover being removed to show the said slides.
Like letters of reference indicate corresponding parts throughout the drawings.
a is the frame, bare strips of wood or other suitable material fixed in the
said frame and having the discs painted thereon.
It is convenient, for certain calculations or operations hereinafter described, to
make the discs of two different colours as indicated in Figure 2, those discs for
example that are left blank being, say red, and the remainder black as shown.
ccare the slides or shutters which consist of bands of paper, cloth or other
suitable material passed around rollers d mounted at each side of the frame a so as
to be free to rotate when the shutters c are operated. The slides or shutters are
provided with handles by which the said shutters are moved to and fro for the
purpose hereinafter explained, and the said shutters are attached at each end to

page_text: Each handle c' is constructed in
the form of a clip which engages with the corresponding strip which strips are
supported only at their ends, to permit the requisite movement of the shutters. One
end of each shutter c is attached to its handle c in front of the strip b, while the
other end of the said shutter is attached to the said handle behind the said strip, so
that the discs will be uncovered or covered successively and in order by the move-
ment of the said shutters, and, at the same time, the said shutters form continuous
bands. The handles e are, moreover, attached to slides working in guide-grooves e
in the frame a. Numerical figures from 1 to 9 are printed or otherwise formed on
the face of the shutters c, which will appear consecutively in the apertures or spaces f
formed in the frame of the apparatus, as the said shutters are opened, and thus
indicate the number of discs that are exposed to view in the corresponding row of
discs, that is to say, the number displayed in one of the apertures or spaces f by the
movement of the corresponding shutter will always correspond to the number of discs
uncovered by such movement of the shutter.
the handles so as to form continuous bands.
By means of the apparatus above described, the value of every digit in a vertical
column of any addition sum may be shown by the displayed vertical row of figures in
the apertures, and the values of these digits will be indicated by the discs uncovered
in a manner that will impart an intelligent appreciation of the numbers which are
to be added together, thus obviating the necessity for finger-counting.
By colouring the discs in the manner herein before described, that is to say, some
of them being coloured, say red, and the remainder black, I provide for readily
teaching complementary addition. For this purpose the number of discs coloured
red in any row, added to the number printed or stamped or otherwise formed on
the side of the frame opposite the end of such row in each case makes 10 that is to
say the numbers on the side of the said frame and the number of red dises in the
corresponding rows of discs are always complementary to each other as regards the
number 10. So that, in adding two numbers which together make more than 10,
the shutter opposite to the side figure which represents the units of one of the
numbers to be added is moved until the second of the two numbers is displayed in
the space then the discs coloured red make up the next ten, and the black discs
For example, in
beyond the said red discs represent the units over and above ten.
adding together say 6 and 7, the shutter of the sixth row of discs is moved until
the figure 7 is displayed, when it will be seen that four red discs and three black
ones are discovered in the row of discs. The four red discs with the number 6 on
the frame make up ten, and the three black discs give three units over, i. e. thirteen
in all.
-For the purposes of subtraction, by using any two consecutive slides the exposed
discs in which correspond to the numbers to be operated on, ocular demonstration can
he given of the difference in value of any two digits.
Multiplication may also be thoroughly and pleasantly taught by beginning at the
lowest slide and opening out as many shutters as correspond to one of the numbers
to be operated on, i. e. the multiplier until the figure is displayed in each case in the
space that corresponds to the second number to be operated on, and the total
number of discs discovered or displayed will represent the result of multiplying the
said digits.
It is obvious that the construction of the apparatus may be somewhat modified
without departing from the nature of my said invention.
Having now particularly described and ascertained the nature of my said inven
tion and in what manner the same is to be performed I declare that what
claim is:
First. An abacus or apparatus for teaching arithmetic or facilitating arithmetical
calculations, provided with suitable means whereby all or any of the discs or equivalent
objects may be concealed or exposed, as, and for the purposes, above specified.
Second. An abacus or apparatus for teaching arithmetic or facilitating arithmetical
calculations, wherein provision is made for concealing all or any of the discs or

page_text: equivalent objects and for simultaneously exhibiting a numerical figure or digit and
showing the value thereof by means of the said discs or other objects as, and for the
purposes, above specified.
Third. An apparatus such as is hereinbefore described, wherein provision is made for
teaching complementary addition, as above specified.
Fourth. The combination, in an abacus or apparatus for teaching arithmetic or
facilitating arithmetical calculations, of a fixed strip of wood or other suitable material
having thereon discs or other objects, and a movable slide or shutter having numerical
figures printed or otherwise formed thereon, substantially as, and for the purposes,
above specified.
Fifth. The improved apparatus consisting of the parts constructed and combined
substantially as described with reference to the accompanying drawings and arranged
to be operated as, and for the purposes above specified.
11111
171 1
CT
י
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.