Improvements in or relating to Calculating Devices.
Year: 1896

page_text: Improvements in or relating to Calculating Devices.
I The Honourable GILBERT JAMES DUKE COLERIDGE of 11 Roland Gardens,
in the County of Middlesex, Barrister, do hereby declare the nature of this
invention to be as follows:-
This invention relates to a calculating device by means of which sums of money
or other numbers may be added or subtracted.
The device differs slightly in construction according to whether it is meant for
addition or subtraction. It consists essentially of a flat piece of wood or other
suitable substance, preferably oblong in shape, and provided with several shallow
grooves running lengthwise across its surface. The number of these grooves will
vary in accordance with the requirements of the device. In each of these grooves
lies a strip of cardboard or other suitable material with the edges serrated and
perforated in a manner hereinafter more fully described.
Covering the face of the board in such a manner as to retain the strips of
cardboard in the grooves while leaving them free to slide lengthways, is a piece
of cardboard or other suitable material, which is perforated by specially shaped
slots and holes corresponding to the several grooves in the board.
Taking by way of example a device constructed for adding sums from one
farthing to two hundred pounds, the board will be provided with five grooves
three of which are for the farthings, pence and shillings, respectively, while two
are for the pounds, one for the units and the second for the tens and hundreds.
The cover of the board is perforated at one end with five holes running
transversely across the board, each of which corresponds to a groove. At these
openings appear the sums which are the result of the calculation, and above each
is indicated the value of the sum appearing thereat, whether pounds shillings pence
or farthings. The farthings being on the right hand side while the pounds are on
the left. The slots in the cover are five in number and run longitudinally over one
side of each groove. The length of these slots varies, each starting from a
a transverse line about the centre of the board, formed by a transverse slot
which unites the ends of the farthings pence shillings and unit pounds slots, and
continues to half-way between the unit-pounds and ten-pounds slots, ending in
a small notch in the direction of the base of the board. Similar notches in
the same direction are formed in the transverse slot half-way between the other
longitudinal slots.
All the slots and notches are of equal width which is such as to allow of the
free passage therein of a peg or pencil-point. The strips lying in the grooves are
constructed of suitable material such as ivory, bone, celluloid, wood, metal, or the
like, and have the following appearance. Taking as an example that for the
pence column, it has printed upon it at one end in a column, the numbers
from 0 to 11, the 0 being the lowest; these numbers are so placed and spaced that
they may appear one at a time at the pence indicating opening in the cover of the
board. About the centre of the length of the strip its left hand edge is pierced
by eleven equidistant holes; at the end remote from the printed numbers each
edge has eleven equidistant notches or serrations, those on one edge being
individually opposite the corresponding notches on the other edge. The notches

page_text: are the same distance apart as are the holes, and the figures, those on the left hand
side forming with the holes a continuous series of equidistant openings in the strip
of sufficient size to receive the above mentioned peg or pencil-point. That portion
of the left hand edge of the strip in which the notches are cut is coloured differently
to the remainder of the strip, preferably red or blue, the strip itself being white.
By the side of the longitudinal pence-slot in the cover of the board, the numbers
from 1-11 are printed in a column in a manner similar to that on the strip, the
number 1 being the lowest or that which is nearest to the indicating opening. Thus
if the strip be in the groove in such a position that the 0 appears at the indicating
opening, the perforations in the edge of the strip will appear in the slot, one opposite
each number on the edge of the slot, while the first notch on each side of the strip
will appear in the transverse slot, the remainder being concealed beneath the cover
of the board. Three of the cther strips are marked coloured perforated and notched
on the same principle.
That for the farthings is marked . . . and has three holes and three notches
on the left hand edge, no notches however being cut on the right hand edge.
The strip for the shillings has the numbers from 1-19, and nineteen holes and
nineteen notches, a similar number of the latter being cut on each edge, as in the
pence strip.
The unit-pounds strip is marked 1-9 and has nine holes, and in each edge nine.
potches.
The edges of the slots corresponding to the farthings shillings and unit-pounds
columns are marked respectively with the numbers ; 1-19, and 1-9.1
The ten-pounds strip is marked with the numbers from 1-20 and has twenty
holes and in each edge twenty notches, but is not coloured differently in any
part.
The slot for the ten-pounds is isolated and marked at the side with the tens
from 10-90 in a manner similar to the other slots.
If now a peg be inserted in the hole opposite any number (say for example three)
and the strip by this means slid out until the peg reaches the end of the slot,
the number three will appear at the indicating opening; if to this number
it is desired to add 4 the peg is inserted in the hole which is now opposite the
number 4 and the strip again slid out when the number 7 will appear at the
opening.
If now to this 7 it is desired to add 8, the peg must be inserted opposite
the 8 as before but it will be found that the portion of the strip opposite the 8 is
coloured, which indicates that instead of moving the strip down until the peg
reaches the bottom of the slot, it must be pushed up until the peg reaches the
top when it must be moved to the left into the transverse slot until it engages
with a notch in shillings strip when it must be moved down into the intermediate
notch, when it will be found that the sum of 1 shilling and 3 pence is indicated at
the openings below.
The method of using the calculator for larger sums is as follows:-
Supposing for example it is required to add together the following sums,
£24 13s. 7 d., and £13 15s. 32d., first of all the peg is inserted in the hole in the
strip opposite the one half in the farthings slot, and the strip by its means pushed
down until the peg reaches the end of the slot, a half will then appear at the
indicating opening below. The peg is similarly inserted opposite the number 7 in
the pence slot and the strip pushed down, when a 7 will appear below. The peg
is then successively placed opposite the 13 in the shillings column, the 4 in the
unit-pounds column, and the 20 in the 10-pounds column, when the full sum
of £24 13s. 7 d. will appear below. The peg is now inserted opposite the in the
farthings column; it will be seen that this portion of the strip is coloured, indicating
that the peg must be moved up and not down and on reaching the end of the
longitudinal slut it must be moved transversely until it engages the notch in the
right-hand side of the pence strip when it must be moved downwards into the notch
in the cover, intermediate between the pence and farthings columns. The figures
below will then read, £24 13a. 8d.

page_text: The peg is now inserted opposite the 3-in the pence column which portion of the
strip being uncoloured indicates that it must be moved downwards; the figures will
now read £24 13s. 11td.
The peg is next placed in the hole opposite the 15 in the shillings column,
the strip being here coloured indicating that it is to be moved up to the end
of the slot and longitudinally to the left and down into the intermediate
notch in the same way as when dealing with the farthings. The figures now
read £25 8s. 11d.
The peg is now inserted at the 3 in the units-pounds column and moved down
since this portion of the strip is uncoloured, and then inserted opposite the 10 in
the ten-pounds column, and similarly moved down, when the final total will appear
below as £38 8s. 11d.
If further sums are required to be added the strips are moved by means of the
peg in a similar manner, always remembering that where that portion of the
strip in which is the opening opposite the required number is coloured, the peg
must be moved up, to the left and down to the intermediate slot, whereas if
the portion of the strip is uncoloured it must be moved down to the end, of
the slot. .
The details of the device differ somewhat when it is constructed for subtracting
instead of adding. These differences are as follows. The farthings pence
shillings and unit-pounds-slots instead of being connected at their upper ends by a
transverse slot, have no connection with each other, but the lower end of each
terminates in a small slot at right angles and with a notch directed upwards at the
end of it, the shape of the slots resembling an L but turned to the left instead of
to the right.
The numbers beside each slot are arranged to run in the opposite direction the
highest instead of the lowest number being nearest the indicating openings at the
bottom of the board.
The strips are also formed differently, the numbers running as before but notches
are cut on either side of that portion of the strips where the holes were previously
cut, namely towards the lower end in the uncoloured portion, while holes are made
on the coloured left hand edge at the upper end where the notches were before..
The operation will then be as follows:-
Supposing it is required to subtract £13 15s. 3 d. from £24 13s. 7td. First the
strips are so adjusted until the latter sum appears at the indicating openings ;.
the peg is then inserted in the farthings slot into the opening in the strips opposite
to the, this being in the uncoloured portion indicates that the strip must be.
pushed downwards the peg on reaching the end of the longitudinal slot being
carried along the transverse slot and up into the notch; when the figures below
will read £24 13s. 64d.; the peg is next inserted in the pence slot into the hole
opposite the number 3 which being in the coloured portion of the strip indicates
that it must be pushed upwards to the end of the slot when the figures will
read £24 13s. 3d. The peg is now placed in the shilling column opposite
the 15 and the strip moved downwards (the required hole being in the uncoloured
portion) till the peg reaches the end of the slot, when it is moved to the left and up
into the notch as in the farthings column, when the figures will read £23 18s. 34d.
The peg is then inserted opposite the 3 in the unit-pounds column and the strip moved
upwards. The figures now reading £20 18s. 34d. Finally the peg is inserted at
the I in the tens-pounds slot and moved up, the figures then showing the full required
result namely £10 18s. 3 d.
If required the calculator may be modified in construction so as to be capable
of use either for the addition or subtraction of simple numbers, or calculations
based upon other monetary systems, the various weights and measures and other
data.
There may be occasions in using the addition device when an intermediate strip
will be found to have been so far pushed down that in moving the peg to the left
from the notch in the strip on the right the intermediate strip will be passed over

page_text: and the strip beyond on the left hand will be moved. It will then be necessary
to push the intermediate strip back as far as it will go to 0. Or in using the
subtracting device it will be found occasionally that the peg will not move
to the left owing to there being no slot in the next strip when this strip must
be pulled out from 1 to its full length and the next strip which has a slot must
be moved up.
It may be taken as a rule for both the addition and subtracting device that
where the hole or notch opposite the required number happens to be in the
coloured portion of the edge of the strip this strip must be moved up, whereas if
the hole or notch occurs in the uncoloured portion of the strip the latter must be
moved down.
Dated this 30th day of June 1896.
BOULT & WADE,
Agents for the Applicant.
Improvements in or relating to Calculating Devices.
I The Honourable GILBERT JAMES DUKE COLERIDGE of 11 Roland Gardens
in the County of Middlesex, Barrister 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 :-
This invention relates to a calculating device by means of which figures repre-
senting sums of money or other quantities may be subtracted from each other.
In the accompanying drawings,
Figure 1 is an elevation showing the front of the device.
Figure 2 is an end view of the same.
Figure 3 is a front view showing the strips adjusted for use.
Figure 4 is an elevation of one of the improved strips.
Like letters indicate like parts throughout the drawings."
The apparatus comprises a frame composed of a flat piece of wood or other
suitable substance preferably oblong in shape provided with several shallow grooves
running lengthwise along its surface. The number of these grooves varies in
accordance with the requirements of the device. In each of these grooves lies a
slide formed of cardboard or other suitable material with the edges serrated and
perforated in a manner hereinafter more fully described.
Covering the frame in such a manner as to retain the slides in the grooves while
leaving them free to slide lengthways is a second frame which may be formed of a
piece of cardboard or other suitable material and is perforated by specially shaped
slots and holes corresponding to the several grooves in the board.
Taking by way of example a device constructed for subtracting figures repre-
senting sums of money from one farthing to one hundred pounds. The frame A
is provided with five grooves C, D, E, F, and G of which C,.D, & E, are for the
figures representing farthings, pence, and shillings, respectively, while F and G
are fer the pounds, the former (F) for the units and the latter (G) for the tens.
The frame B is perforated at one end with five holes H arranged transversely
across the board and each corresponding to one of the grooves. At these
openings H appear the numbers which are the result of the calculation, and above
each is indicated the value of the number appearing thereat, whether pounds,
shillings, pence or farthings, the farthings being at the right hand side while the
pounds are at the left. Five slots J, K, L, M, and N, are cut in the cover B
running longitudinally over one side of each of the grooves C, D, E, F, and G,
respectively.

page_text: The length of these slots varies but each starts from a point in a transverse line
about the centre of the board. The slots J, K, L, and M have short transverse
portions J, K, L, M', at their lower ends each of which terminates in an upwardly
directed notch J, K, L, M, the shape of the slots resembling the letter "L
turned to the left.
All the slots and notches in the frame B are of equal width, which is such as to
allow of the free passage therein of a peg or pencil point. The slides S lying in
the grooves C, D, E, F, and G are constructed of suitable material such as ivory,
bone, celluloid, wood metal or the like, and are shaped as hereinafter described.
Each slide is of suitable length and of such width as to lie and be easily movable
within its groove.
Taking the slides in order, that for the farthings C, at a suitable point in its
left hand edge, has three perforations and three notches, all at equal distances
apart, while towards the lower end are printed upon its surface .,, running
from below upwards, these numbers being in such a position.that when the slide C
is pushed right into the groove C in the position shown in Figure 1, no indication
will appear at the opening H above it, while in the slot J will be visible the three
notches and at the extreme top of the slot the first of the perforations in the edge
of the slide
The pence-slide D' is shown by itself in Figure 4 and as will be seen has eleven
notches and eleven perforations in its left hand edge and eleven notches in its right.
hand edge, the notches and perforations being all equi-distant and arranged as
shown. The numbers from 0 to 11 inclusive are printed upon the end of this slide
one above the other running from below upwards, the 0 appearing at the opening H
over the slide when the latter is pushed into the groove D as far as it will go as
shown in Figure 1.
The shilling slide E is similarly constructed but has nineteen notches and
nineteen perforations in its left hand edge and nineteen notches in its right hand
edge, the numbers printed upon it running from below upwards and being from
0 to 19 inclusive.
The next slide F¹ is that for the units of pounds and is provided with nine
notches and nine perforations in its left band edge and nine notches in its right
hand edge and has the numbers from 0 to 9 inclusive printed upon it.
The remaining slide G¹ is for the tens of pounds, that in the device illustrated
being intended to work up to one hundred pounds, and accordingly provided with
ten perforations on its left hand edge but no notches, and ten notches on its right
hand edge, the numbers upon it being from 1 to 10 inclusive. An extra perforation
is placed below the ten perforations before mentioned. This is not required for
calculating purposes, but is added to facilitate setting the device.
All the slides S have that portion of their left hand edge, in which are situated
the perforations coloured differently from the rest of the slide, as for example, red,
while the rest of the slide is white, the object of this being to aid the eye in using
the device. The extra perforation in the slide G' is not coloured, being only used
for setting the device.
By the side of each of the slots J, K, L, M, and N in the frame B are printed
numbers;,,, beside the slot J, 1 to 11 inclusive beside the slot K, 1 to 19
inclusive beside L, 1 to 9 inclusive and 10 to 90 inclusive beside the slots M and N
respectively. These numbers in each case are arranged one above the other with
the lowest number near the top of the slot that is to say at the end furthest away
from the opening H. It will be noted that the distance between each of the
numbers printed upon each slide between each of the notches and perforations, and
between each of the numbers printed upon the frame B beside each of the slots is.
arranged to be exactly equal.
It will be seen that the notches on the right hand edge of each of the slides D',
E', F, G, appear at the end of the transverse portions J, K, L, M, of the
slots J, K, L, and M. Thus after the slides have been adjusted to indicate a
certain sum, by inserting a peg or pencil into the notch in the left band edge, say,

page_text: in the pence slide D' which appears through the slot K, this slide may be moved
downwards until the peg reaches the end of the slot K, when it is caused to move
to the left along the slot K into engagement with one of the notches in the
right hand edge of the slide El which may be then moved up the distance between.
two notches by carrying the peg up into the notch K².
To illustrate the method of operating the device it will be assumed that it is
required to subtract £13 15s. 3 d. from £24 13s. 7d. First the slides C', D', E',
F¹, and G, are drawn out until the numbers 2, 4, 13, 7 and appear at the
openings H, as shown in Figure 3. It will now be seen that a certain portion of
the coloured edge of each of the slides C, D, E, F & G', appears in the
slots J, K, L, M, and N. The peg for manipulating the strip is now inserted into
the farthing slot J into that notch in the edge of the slide C which happens to be
situated opposite the number "" this being the first number of the sum which we
wish to subtract. The peg is now moved downwards to the end of the slot J
carrying the slide with it, and is then passed along the slot J into engagement
with the notch in the right hand edge of the slide D and finally moved up into
the notch J, thus shifting the slide D' one point upwards. The numbers indicated
at the openings H will now read £24 13s. 6d. The next operation is to insert the
peg in the slot K opposite the number "3" where a perforation situated in the
culoured portion of the edge of the slide D will be found to be opposite the number.
The presence of the coloured portion must be taken as an indication that the peg
must be moved upwards in the slot K till it reaches the end instead of being moved
downwards as was the case when dealing with the faithing. The sum indicated at
the openings H will now read £24 13s. 3d. The peg is now placed in the slot L
opposite the "15" and the slide E' moved downwards (the notch appearing opposite
this number in the uncoloured portion) till the peg reaches the end of the slot and
then it is moved to the left along the slot L and up into the notch L²; the figures
will now be seen to read £23 18s. 34d. Next the peg is inserted opposite the "3"
in the unit pounds, slot M when, this part of the slide F being coloured, it is
moved upwards, the figures now reading £20 18. 3d. Finally the peg is inserted"
opposite the "10" in the tens of pounds slot N and moved up. The figures then
giving the full required result namely £10 18s. 3 d.
It will be seen from the above that it is to be taken as a rule that where the
opening in the edge of a slide situated opposite a required number happens to be
in a coloured part of that slide, the latter must be moved up, whereas if the opening
is in the white portion it must be moved down.
If required the calculator may be modified in construction so as to be capable of
use for the subtraction of simple numbers or calculations based upon other monetary
systems, the various weights and measures or other data.
There may be occasions when it will be found that the peg will not move to the
left to the end of the transverse slots J, K, L, M', owing to there being no notch
in the adjacent slide. Under these circumstances this slide must be pulled out to
its full length and the next adjacent slide, on the left hand of this one must be
moved up one notch.
It is obvious that in place of forming grooves in the frame A and attaching the
slotted frame B to its face, the frame B may be constructed of wood or other
material of sufficient thickness to have the grooves cut in its back as well as the
slots and openings in its face, the frame A being in this case merely employed as a
backing to retain the slides S in the grooves.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A calculating device substantially such as described for the subtraction of
figures representing sums of money or other quantities.
2. In a calculating device the combination with a grooved frame A of a slotted
and perforated frame B and movable slides with serrated and perforated edges

page_text: lying in the grooves in the frame and arranged to be manipulated substantially as
described to perform the operation of subtraction.
3. In a calculating device the combination with a frame B perforated slotted
and numbered as illustrated in Figures 1 and 3 of slides S serrated perforated and
numbered as described and illustrated in Figures 1, 3, and 4 of the accompanying
drawings.
4. The complete calculating device substantially as and for the purpose described
and illustrated in the accompanying drawings.
1007
BOULT & WADE,
Agents for the Applicant.