IMPROVEMENTS IN CALCULATING MACHINES
Year: 1878

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company,
Patent Solicitors, at Frankfort on the Main, in the Empire of Germany, for
the Invention of "IMPROVEMENTS IN CALCULATING MACHINES."
A com-
munication from Karl Königsberger, of St. Petersburg, in the Empire of
Russia
Sealed the 9th May 1879, and dated the 20th November 1878.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office
of the Commissioners of Patents on the 20th November 1878.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at Frank-
fort on the Main, in the Empire of Germany. "IMPROVEMENTS IN CALCULATING
MACHINES." [A communication from Karl Königsberger, of St. Petersburg, in
the Empire of Russia.]
This Invention relates to improvements in calculating machines, and comprises
various details of construction herein-after described.
A machine constructed according to this Invention comprises two departments,
the larger one being composed of a cast-iron box, in the lid or cover of which is cut
a channel, and an aperture for each figure; in this box lies a central shaft upon
which is a fixed wheel, a movable wheel being beside it. In the fixed wheel are
cut (with a division of 30th) nine channels in which movable teeth are placed ;
these teeth have an angular form, and fit close to channels provided in the aforesaid
loose or movable wheel. Each channel is formed by two circular cuts at different
radii, and joined together, so that when the movable wheel is turned round, the
aforesaid teeth rise or fall, according to the proportion between the radii of the two
circles. In the said fixed wheel a spring is situated which, pressing against interior
teeth in the movable wheel regulates the position of this wheel and keeps the
same in its place. On the surface of the movable wheel there are figures, and on

page_text: the same is also situated a peg which serves to assist in placing the required figure
in the aperture cut out in the lid or cover of the box for that purpose.
A series of wheels and parts connected therewith as above described will be on
the same shaft.
The aforesaid shaft is also connected with a handle by means of two toothed
wheels. This handle is provided at its centre with a joint which by the assistance
of a light spring is pressed into a catcli placed on the side of the aforesaid large
box when the machine is in its normal position, and the central shaft as well as
the wheels upon it remain then immovable. The figures on the said movable
wheel have then such a position that when all the teeth are drawn into the smallest
circle of the wheel the cypher 0 is visible in all the apertures in the lid or cover,
and when all the nine teeth are, on the other hand, drawn out, then figure 9 is seen
in the said apertures of the box. Supposing, for instance, that the sum 2703 is
required to be set up, then the relative number of teeth inust be drawn out in the
wheels belonging to each figure desired, that is to say, 2, 7, 6, 3. Besides the loose
teeth above described each of the fixed wheels has also two other teeth which are
placed one on each side of the aforesaid 9 teeth; these two teeth are secured to the
wheel by a solid pin upon which the movement of the tooth takes place, and around
which is placed a wire spring which continually keeps the tooth in its position;
these teeth, unlike the other teeth, move horizontally, and are so placed that the
first wheel has no tooth, but the second has such in a division of 3 from the first
and ninth of the other teeth. The teeth in the third wheel are situated at a
distance of from the first to the ninth tooth, the teeth in the fourth wheel at a
distance of 3, and so on, or in other words, these teeth are so placed that they
relatively form two converged lines, and serve as will be further shewn in carrying
over the tenths.
The second division of the machine consists of a slide which can be moved
forward and backward on the bottom of the larger box. This slide has for each
figure a vertical bracket between which is placed a figure wheel to which is
joined a toothed wheel. The said bracket has a channel in which is placed an
extractor; this piece has on the front a projecting rounded angle, while on the back
is placed a small pin which works in the hollow part of the said figure wheel. In
this wheel is placed a picker 11th part of the wheel's periphery, and in such a position
that it is ready to press out the said bracket when in the aperture of a plate 0 or 9
becomes visible, or rather the bracket springs out when the figure is altered direct
from 0 to 9, or vice versa." Supposing, for instance, that in the aperture of the
said plate the cypher 0 is shewn, and it is desired to add 9+1, it then becomes
necessary to place figure 9 in the first aperture of the larger box, that is to say,
nine teeth are drawn out on the wheel belonging to this aperture; if now the
handle is turned once in the right direction towards plus (+) the result will be that
these nine teeth turn the figure wheel a distance of the around, that is to say,
the figures in the aperture change from 0, 1, 2, 3, and so on to 9; if now, instead of
nine, one is placed in the aperture of the first larger wheel, and the handle is again
turned in the same direction, then the figure in the aperture of the small wheel
travels from 9 to 0, while the said extractor springs forward and retains such position
until the tooth comes forward and lays itself over the extractor's rounded angle, and
is pressed by it to the next toothed wheel; which wheel thereby turns its own
figure wheel round from 0 to 1, and 10 9+1 becomes visible in the aperture;
the handle is now placed in its normal position, and so presses the rounded forward
standing part of the fixed wheel that the extractor goes back to its place again.
Supposing now that in the aperture of the aforesaid plate the sum 100,000 is
seen, and from this sum 1 is to be substracted, then 1 must be placed in the last of
the higher apertures, and the handle turned in the direction marked "subtraction,"
division." The projecting tooth carries then the figure wheel around from 0 to 9,
and the said extractor communicating with this wheel moves out. The next
following tooth is now changed from its normal position (because, as herein before
mentioned these teeth have for each fixed wheel a different position), and carries
"
=

page_text: the approximating figure wheel from 0 to 9, and so on until coming to that figure
wheel upon which is shewn the figure 1; this wheel is now carried from 1 to 0, and
the extractor remains stationary while the said following tooth moves freely past.
If now the handle is moved around to its proper place then the projecting extractors
return back to their places, and the figures in the apertures shew, instead of 100,000,
099,999.
There is a small hook joined with a spring whose function is to retain the figure
and tooth wheel in the proper place, or this check motion may be modified to
effect the same object. In the aforesaid slide there is also an additional spindle ;
this spindle has a horizontal position, and there is secured to one end a small
ratchet wheel, while upon the other a button or stud is fastened, upon which are
stamped figures. Each time the handle is turned round, this spindle, by the
assistance of simple feed motion, is also turned roundth of its periphery, that is
to say, the figures in the apertures of the plate which partly cover these buttons
shew how many times the handle has been turned.
This last described division of the machine forms a movable box, which is kept in
its place by a spring situated in its slide; this spring works in holes situated in the
bottom of the larger box; these holes are placed at the same distance as the
distance from each other of the various systems of the machine, so that by pressing
upon a lever connected with this spring, and situated upon the left side of the slide-
box, this box can be moved or checked from one to more such distances.
By the turning a nut situated on the right end of the slide-box all the figure
wheels upon the shaft in that box case can be set to 0, while by pressing upwards
the lever situated on the front port of the box all the figures in the lower tier (or
the quotient) are placed at 0.
The operations of addition, subtraction, multiplication, and division may be
readily and quickly effected by the said machine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Wirth in the Great Seal Patent Office on the 19th May
1879.
st
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at Frank-
fort-on-the-Main, in the Empire of Germany. IMPROVEMENTS IN CALCULATING
MACHINES." A communication from Karl Königsberger, of St. Petersburg, in
the Empire of Russia.
This Invention relates to an instrument for assisting calculation, and is adapted
to add, subtract, multiply, and divide numbers without any other labor on the
part of the operator than that required to set and rotate certain numbered and
counting wheels, and to adjust a slide carrying a series of recording wheels.
The details of construction, arrangement, and operation of parts will be under-
stood from the description hereinafter following, and upon reference to the
accompanying Drawings, in which,-
Figure 1 is a front elevation of the machine with part of the case broken away to
show the interior mechanism; Figure 2 is a cross section of the machine; Figures 3
to 11 inclusive are detail views hereinafter described.
Most of the movable parts of the machine are enclosed and protected by a case A,
which has an inclined or rounded side to facilitate reading the numbers on the
different wheels as they appear through the upper row a, middle row b, or lower
row c of apertures. The shaft B has its bearings in the ends of case A and is
rotated by the crank C, and to it are firmly attached a series of wheels D, one third
of the periphery of each of which is constructed with radial recesses or sockets to
receive nine (9) teeth d, one or more of which may be caused to project so as to
mesh with the teeth of the smaller toothed wheels e that are rigidly connected with
the recording-wheel E placed on the shaft F, which traverses the box or slide H
made separate from the body of the case A.
The fixed wheels D may be termed the “counting-wheels," and always partake
of the rotation of the shaft B. Hence, if the first one of the teeth d of such a wheel
be caused to project or stand out from its periphery, and the shaft B be rotated
once, said tooth will engage one of the ten teeth of the opposite wheel e mounted
loosely on the shaft F, and turn the wheel e through the space occupied by its tooth.
Each recording-wheel is composed of three parts which rotate together; one e, a
toothed wheel, with which the teeth of the counting-wheels D engage; another the
toothed or scalloped edged locking-disc f which is slightly separated from the part e;
and the third part E, the recording-wheel proper, whose broad periphery has the
cipher (0) and the nine digits arranged in regular numerical order, the cipher
being placed between the 1 and 9 the same as on the counting-wheels D. The
composite or three-part recording-wheel E, e, f, is held fixed in any adjustment by
an automatic friction device consisting of a spring-lever G which presses against
the periphery of the disc f, as shown in Figure 2. The form of this holding or
locking device may be varied and another form is shown in Figure 10. The stress
of the spring will overcome the inertia of the composite recording-wheel, but is not
sufficient to prevent the easy operation of it by the counting-wheels D.
The effect of turning the recording-wheel E the distance of one tooth is to cause
the number 1 to appear in the opposite lower aperture c. If now instead of one
tooth, two (or more) of the teeth d of a counting-wheel D be caused to project from
its periphery, the recording-wheel E will be moved correspondingly, that is to say,
a distance of two or more teeth, and the corresponding number 2 (or a higher
number) will appear in the aperture c.
It will thus be apparent that the mechanical function of the several counting-
wheels D is to rotate the recording-wheels E which are placed with their peripheries
opposite, and that the wheels E will be rotated a peripheral distance corresponding
to the number of teeth that may project from the counting-wheels D. The first

page_text: counting and recording wheels on the right are for units, the next for tens, the
third, hundreds, the fourth, thousands, and so on. Between each two of the
counting-wheels D is a pivoted movable tooth I for effecting the operation of
carrying ten," as will be hereinafter described.
СС
The means for moving the nine teeth d of the several counting-wheels D, and
thus causing them to project or to recede, as may be required, consist of setting-
wheels K, one of which is placed close alongside each counting-wheel D, but is not
like the latter, fast on the shaft B. There are a series of pairs of counting and
setting wheels. Each setting-wheel K has the cipher (0) and the nine digits
inscribed on its periphery, the linear distance occupied being one-third of the cir-
cumference of the wheel. Each setting-wheel K has also a lug or thumb-piece g
by which it is turned on the shaft B and set at the required place. The rim of the
several setting-wheels K has a transverse slot L which extends about two-thirds
around the wheel. This slot is composed of two parts or slots of equal length,
which are concentric with the axis B but describe arcs having radii of different
length. Hence at the point where the two parts of the slot join there is an
angular projection constituting a cam h.
The several teeth d of the counting-wheels D have lateral nibs i, Figure 4,
which enter the slot L, and hence when a setting-wheel K is adjusted peripherally
that counting-wheel D which is paired with it being meanwhile held fixed, the
angular projection or cam h will so act on the nibs i of the teeth d as to cause the
latter to project or retract. If the setting-wheel K be moved through one-
third of a revolution in one direction then all the teeth d will project, because their
nibs will have all passed into that part of the slot L having the greater radius.
If in the other direction then all the teeth d will be retracted, because their nibs i
will pass into that part of the slot L having the less radius. Correspondingly a less-
movement or adjustment of a setting wheel K will cause the projection or retraction
of a less number of teeth d. The figures on the periphery of the setting-wheels K
appear successively through the upper apertures a in the case A, and serve to indicate
the number of teeth d that project from the counting-wheels D. Thus when all the
teeth d are retracted the cipher (0) will appear on the setting-wheels K in all the
apertures a, but when all are projected the highest number, 9, inscribed on the setting-
wheels will appear in the slots a. The wheels K are accordingly said to be set on zero
or on 9. If a setting-wheel K be adjusted so that the figure 2 appears in the
aperture a, it is an indication that two teeth d have been made to project from the
adjoining counting-wheel D. If figure 4 appears then four teeth d project; if 7
then seven teeth d project, and so on.
It will be apparent therefore that if I wish to move a recording-wheel E to
cause any particular number (say 2) to appear in a middle aperture b, then the
setting-wheel K opposite said recording-wheel must be rotated till that number (2).
appears in the upper aperture a. Then by rotating the shaft B the series of
counting and setting wheels D, K, will be carried round and the two teeth d that
have just been set, and hence project from the counting-wheel D will engage the
same number (two) of the teeth of the part e of the opposite recording-wheel, and
rotate it a corresponding distance (two-tenths) so that the desired number (2) will
appear in the middle aperture b. If now I desire to double that number (2) we
have but to rotate the shaft B again and the recording-wheel E will be moved the
same distance farther and the number (4) expressing the addition will appear
in the aperture b. Thus any number of additions can be made and to any
amount.
To subtract, it is obviously only necessary to reverse the rotation of the shaft B, and
thereby cause the projecting teeth d of the counting-wheels D to rotate the recording-
wheels E backward. Multiplication being but a form of addition, the operation is
substantially the same; but a particular manipulation is necessary, as will be pre-
sently explained, where the multiplier is above a unit in value. That manipulation
consists in adjusting all the recording wheels E one decimal place to the right for

page_text: hundreds, two for thousands, and so on, the recording-wheels E being attached
to the slide H for that purpose.
I will now describe the devices for holding the setting-wheels K in any adjust-
ment, and for carrying the tenths.
The holding device is a spring-stop, which is placed in a radial position in a
socket formed on the left side of each counting-wheel D, diametrically opposite the
middle one of the nine teeth d.
The adjacent portion of the inner periphery of the next setting-wheel K is
provided with the notches , and the stop k works in frictional contact with such
notched section of the wheel. When a setting-wheel K is adjusted peripherally,
the stop moves over a corresponding number of notches l. If one or two or nine
teeth be caused to project from a counting-wheel D, then the stop will enter the
first or second or ninth notch of the setting-wheel correspondingly. Thus each
setting-wheel K is locked in the desired adjustment with relation to a counting-
wheel D, so that the pairs of such wheels appear and act when rotating as one
double wheel.
The tenths are carried by the long pivoted teeth I, there being two for each pair
of counting and setting-wheels D, K, except the units-wheel. These teeth I are
pivoted to arms of the counting-wheels D, one at each end of the peripheral row of
adjustable teeth d, before described. A spring m is so connected with each of the
teeth I that the latter are pressed laterally to the right in the open notches formed
in the periphery of the wheel D, Figures 1 and 6. Each tooth 1 projects from the
periphery of the wheels D, and its outer end is thrown laterally (to the left) at the
proper time to cause it to move the next recording-wheel E on the left, that is to
say, that wheel which is next to or on the left of the recording-wheel K, which is
opposite the counting-wheel D, with which the teeth-carrying tooth I is connected
and with which it rotates. The lateral movement is effected by a slide M, Figures
3, 4, 7, having a semicircular head n, and a lateral semicircular projection or rib o.
The slide M is held in a suitable guide-frame and slotted to receive the shaft F, on
which the recording-wheels E are mounted, and is also set inclined, see Figure 3,
with the head n pointing to the shaft B of the counting and setting wheels. The
lower ends of the slides M are beveled to an angle, and in each complete revolution
of the adjacent recording-wheels they come in contact with an angular projection or
cam p, Figure 3, formed on the inner periphery of the inscribed recording-wheels.
The consequence of this construction and arrangement of parts is that, when the
shaft B is rotated and the number of figures to be added or multiplied exceeds nine
units, the camp will come in contact with the beveled end of the slide M connected
with the units-recording wheel, and push up the slide so that it will project toward
shaft B, as shown in dotted lines in Figure 3. Then the tenth carrying tooth I of the
units-counting wheel will strike the lateral ribo on the head of the slide M and pass
around it to the left, in doing which it will enter a notch, or what is the same thing,
engage a tooth of the part e of the next recording-wheel on the left, and thus move
such wheel the distance of one notch or tooth, thereby carrying ten. The function of
the slotted slide M. is then performed and it becomes necessary to force it back to
its original position until again required for the operation of carrying tenths. This
is effected by a cam or boss q, Figure 3, on the opposite counting-wheel D, as will
be readily understood on reference to Figure 3.
It is obvious that the operation is the same for carrying one between the tens and
hundreds, and hundreds and thousands, and thousands and tens of thousands
recording-wheels as between the units and tens wheels, and hence need not be
described.
The slotted slides M are held in the projected or retracted position by a small
friction spring-stop, as in Figure 3.
When the recording-wheels E have been moved or rotated from the zero-position,
and a new addition or other numerical operation is to be begun, it is necessary to
carry them back to zero, that is to say, back to such position that the zeros or

page_text: ciphers on their peripheries will appear through the apertures b. To do this I
arrango the shaft F so that it is capable of rotation by a thumb-piece N fixed on
its outer end. The shaft is provided with a series of radial fingers or lugs, Figure
4, which will engage corresponding fingers or lugs 8, projecting inwardly from the
hollow hubs of the recording-wheels E. The shaft F is pressed toward the left by
a spiral spring t, and is drawn toward the right so as to bring its lugs in engage-
ment with the lugs s of the recording-wheels E by a fixed cam or notched annular
boss O ou the end of the case A with which the thumb-piece N works in frictional
contact. When the edge of the thumb-piece N enters the notch in the boss O, it
allows the shaft F to be pushed end wise to the left by the spring t, and the recording-
wheels E are then free to rotate; but if the latter are not on zero, then the rotation
of the thumb-piece N will draw the respective lugs 7, 8, into engagement and cause
the recording-wheels E to turn back to zero.
I employ a series of small cylinders or cylindrical buttons P to indicate for addition,
subtraction, and multiplication, the number of revolutions up to nine each made by
the counting and setting wheels D, K, and also for indicating the quotient in divi
sion. These cylinders P are inscribed with the cipher and nine digits, and one
cylinder is arranged for a pair of units, tens, hundreds, and other counting and
setting wheels, and each is fixed on a small shaft R, that is arranged in a horizontal
plane at right angles to the axis of the last named wheels. A ratchet S is fixed on
the inner end of each cylinder-shaft R, and with this a reciprocating bevel-nosed
push-pawl T, Figures 3, 5, engages at each rotation of the shaft B. Said pawl slides
in a suitable guide, is retracted by a spring w, and pushed forward by a pivoted
lever V, whose upper end works in contact with an eccentric W, Figures 3, 5, fixed
on the shaft B. Each time the shaft B rotates, and thus carries around the eccentric
W, the pawl T advances and moves the ratchet S one notch, thereby intermittently
rotating the cylinder P, fixed on the other end of the shaft R. The ratchet S is,
however, so constructed, one tooth being removed or absent from the regular series,
that when the ratchet has been moved nine-tenths of a complete rotation the pawl
T has no more effect on it. This construction and operation have a certain relation
to the number of teeth in the counting-wheels D and the recording-wheels E, both
of which only count up to nine. The means for locking the cylinders P in any
position or adjustment are friction spring-stops 2, Figure 2, substantially like those
employed in connection with the counting-wheels and recording-wheels, and pre-
viously described.
The cylinders P are provided with milled head or knobs, to enable them to be
individually rotated back to zero when desired; but one or all may be rotated back
by means of a sliding rack-bar, al, operated by loose pinions 3 on the shaft R, a
toothed segment-lever, Y, and a handle or small crank Z, Figures 1 and 11, which
is fixed on the same shaft as the segment-lever Y, but on the outside of the case A.
The rack-bar x' is constantly in mesh with the pinions y; but the latter have a
tooth, z, Figure 2, which at one point in their rotation come in contact with teeth
on the shaft R, and thus turn the latter so as to bring the cylinders P back to
zero.
When, however, the cylinders P are set on zero, the teeth or lugs do not engage,
and the movement of the rack-bar has no effect. Hence, if a part of the
cylinders P are not on zero, they may be rotated back by moving the crank Z to
the right without changing the position of those cylinders which are already on
zero.
As before intimated, the several recording-wheels E, e, f, and the devices directly
connected therewith, including the shaft F, numbered cylinders P, and rack-bar a¹,
and other parts are mounted in a portion of the case A, which is adapted to
slide endwise for the purpose of carrying on the process of multiplication when the
multiplier is some number having a value above units, also in certain cases of
division. Said portion H of the case A slides on a dovetailed rib b', and it is
locked in any adjustment by means of a lever A', Figure 1, and spring stop-pin c¹,
which latter enters holes in the base plate of the case A.

page_text: The crank C for rotating the axis B of the counting and setting wheels is jointed
near its middle, and its inner end pressed outward so that its outer end will retain
its place in the catch B' on the end of the case A when left free, see Figures 1
and 5. The crank rotates a gear wheel C¹ which meshes with another gear wheel
D' on the shaft B, see Figure 5.
To operate the arithmometer, the several inscribed or numbered wheels K
and E, and also the cylinders P, are all set on zero, and the crank C placed in the
catch B¹.
For addition, the first of the numbers to be added is brought down and made
visible in the upper apertures a of the case A by moving the proper setting-
wheels K. The crank C'is then rotated once to the left or downward, as indicated
by arrow pointing to "add" on the right-hand end of the case A, Figure 1, which
will move the recording wheels E, and cause them to exhibit the same number in
the middle apertures b. The setting-wheels K are then adjusted to show the
second number to be added, and the crank C turned as before, which will cause the
recording wheels E to rotate correspondingly, and thus exhibit the sum of the two
numbers in the apertures b, and so on till all the numbers to be added together have
been successively set up or caused to appear in apertures a, and merged in the sum
to be finally exbibited by the recording wheels in apertures b.
For example, to add 12 and 250, move by means of its lug g the first units-setting
wheel K two spaces, or until the number 2 appears in the first or right-hand
aperture of the row of apertures a. Then adjust the second or tens-setting wheel K
one space so that the Figure 1 will appear in the second aperture a. Then rotate
the crank C downward, and the number 12 will appear in the middle row of
apertures b. The first, second, and third (units, tens, hundreds), setting wheels are
then adjusted to exhibit 250 in apertures a, and the crank rotated once downward.
The sum of the two numbers, to wit, 262, will then appear in the middle row of
apertures, the first recording wheel E having been moved two spaces, the next six
spaces, and the third two spaces.
For subtraction the process is of course reversed. The wheels K, E, and cylinders
Pare first set on zero. Then the minuend is set up by adjusting the setting
wheels K, and the crank C is turned as for addition, thus causing the minuend to
appear also in the middle row b of apertures. The subtrakend is then set up in the
upper row a of apertures, and the crank C rotated backward or to the right as
indicated by the upper arrow pointing to "subt."
For example, to reverse the above process of addition, suppose the number 262 to
be exhibited by the recording-wheels E in the middle row b of apertures, and it is
desired to subtract 12 from it. Then set the tens and units recording wheels E to
exhibit 12. Then rotate the crank C once backward, and bring it to rest in the
notched catch B¹. Then the remainder 250 will appear in the middle row of
apertures. To subtract other numbers set them up and rotate the crank C back-
ward each time one is set up successively.
For multiplication the process is as follows:-Adjust the setting wheels K. so
that the multiplicand or number to be multiplied will appear in apertures a.
Then
if the multiplier be units, rotate the crank downward as many times as there are 4
units in the multiplier, and the product will appear in the middle row b of
apertures. If the multiplier be above units, first rotate the crank C to the left or
downward as many times as there are units, and adjust the tens-setting wheel K. to
show the second figure of the multiplier; then adjust the slide H one place to the
right to bring the hundreds' recording wheel E opposite the units'-setting wheel, 5
rotate the crank C as many times as there are hundreds in the multiplier, and so on,
the slide being adjusted to the right each time there is a multiplication by figures
of increasing value by the tens of hundreds, thousands, or tens of thousands, and
so on.
Thus, to multiply 8,654 by 3, set up 8,654 in the upper row a of apertures as 5
shewn in Figure 1. Then rotate the crank three times downward, and the product
25,962, will appear in the middle row of apertures (8,654×3=259-62). Suppose

page_text: this amount 8654 was to be multiplied by 33 instead of 3. Then having multiplied
by the 3 units and obtained the product 25,962, as just described, move the slide H
one place to the right (for the 3 hundreds) and rotate the crank again three times,
and the desired result will appear in its place (8,654 x 33=285,582.)
in
For division, the operation consists in setting up the dividend in upper row a
of apertures; then rotating the crank C forward or to left to cause the same
number to appear in the middle row of apertures b, the divisor is then set up
the same way, and the crank rotated backward or to the right until nothing
remains in the dividend's place, or else a remainder will remain which is less than
the divisor. The quotient will appear on the cylinders P, since they indicate the
number of times the crank C has been rotated, and thence, the number of times the
divisor has been subtracted from the dividend. (The principle that division is
merely a mode of subtraction is thus mechanically illustrated). If the dividend
exceed the divisor, or the latter will not evenly divide the former, the slide H
must be adjusted to the right as many places as there are to be decimals in the
quotient.
To divide 12 by 4 set up 12 in apertures a and turn crank C to left or downward
to cause 12 to appear in middle row of apertures. Then set up 4 in units' place
in upper row a of apertures and turn crank to right or backward till zero appears
in the place of the dividend. The quotient 3 will then appear on the first or units
cylinder P (124=3).
The
To reverse the former example of multiplication, suppose the number or former
product 285,582 appears as the dividend in the middle row b of apertures, then
set up the divisor 8,654, which was the former multiplicand, and adjust the slide H
one place to the right until the first figure (8) of the divisor is directly over the
second figure (8) of the dividend counting from the left. Then turn the crank C
backward or to the right until the first figure (8) of the divisor can no longer be sub-
tracted from the figures in the dividend which are under and to the left of it.
number 3, which is the first figure of the quotient, will then appear on the second
cylinder P and the dividend will be reduced to 25,962. The slide H is next moved
one place to the left, or back to its original position, as shown in full lines, Figure 1,
and the crank again rotated until the dividend disappears and a line of zeros stands
in its place: The figure 3 will then appear on the first cylinder P, making the second
figure of the quotient sought, to wit, 33. It will be seen that the result indicates
that the divisor 8,654 is contained three times in the first five figures 28,558 of the
dividend, and three times in the new or second dividend 25,962.
In the matter of carrying out for decimals, suppose the dividend is four cents to
be divided into six equal parts, set up 4 in units' place in upper aperture a and
move the slide H three (3) places to the right; then rotate crank C and bring
down the 4 in the thousands' place in the middle row b of apertures. The 4 will
then be directly under the 6, but since 4 is not divisible by 6 the slide H is moved
back one place to the left. The crank is then rotated backward so long as the first
two figures (40) can be divided by 6, and 6 will appear in the quotient. The
slide H is then again adjusted to the left and the operation repeated and another 6
will appear in the quotient. A third and last adjustment of the slide H is made
and a third 6 will appear in the quotient, with the remainder of 4 in the units'
place of middle row b of apertures. The decimal point is obviously to be placed
before the first figure of the quotient, thus, 666, since the slide was moved three
places to the right, or in other words because three ciphers were added to the
dividend.
Having thus fully described the said Invention and the manner of performing
the same, I wish it understood that I do not claim broadly setting the teeth of
counting wheels by means of an adjustable cam or cam-wheel, nor the use of a slide
for causing the lateral movement of tenth-carrying teeth, nor the combination of a
toothed counting and recording wheel, but I claim,-
First. In an arithmometer the series of teeth d having nibs or lateral projections
in combination with the loose setting-wheel having a continuous slot, whose two

page_text: equal parts are arcs of different radii, and the counting wheels fixed on the rotating
shaft, and the automatic spring stop attached to one wheel and acting on the other,
all constructed and arranged, as shown and described, whereby the adjustment of
the setting-wheels circunferentially causes the positive movement of the said teeth
out or in by the passage of the nibs from one part of the slot into the other, and
holds the teeth thus projected or retracted as specified.
Second. In an arithmometer the combination of the pairs of counting wheels
carrying adjustable teeth, and the setting-wheels having a toothed section and an
automatic or spring stop for locking the respective wheels together in any adjust-
ment, said stop being attached to a counting wheel and acting constantly on said
toothed section of a setting-wheel, so that when sufficient pressure is applied to the
setting wheel in the direction of its periphery the spring will yield instantly and
allow the desired adjustment as specified.
Third. The combination with a recording-wheel having the cam formed on its
inner periphery, and the slides having a fixed angle on the same shaft F of the
recording-wheels, all shown and described.
Fourth. The toothed part of the recording-wheels and the part having its periphery
inscribed with the cipher and nine digits, and the slides all placed side by side on
the same shaft F and the counting wheels on shaft B, all combined as shown and
described, for the purpose specified.
Fifth. In an arithmometer, the combination of the sliding rack bar, the inscribed
cylinders and their shafts, the pinion, mounted loose on the latter, and provided
with lugs to engage lugs on the shafts, all as shown and described, whereby the
reciprocation of said rack bar will rotate the cylinders back to zero, but will not
move or adjust them when standing on zero, as specified.
Sixth. In an arithmometer, the combination of the spring lever A¹ and stop c¹
with the toothed portion of the recording wheels and the toothed counting-wheels
for rotating said recording wheels, as shown and described.
Seventh. In an arithmometer, the combination of the spring-stop with the cylinders
having teeth formed on their inner ends, and the shafts R, ratchets, and push pawl,
as shown and described.
Eighth. In an arithmometer, the combination of the thumb-piece and fixed cam,
the shaft or rod F, the recording-wheels, and the lugs on said rod and wheels, as
described, whereby the rotation of the shaft will carry all the wheels back to the
zero position, as shown and described.
Ninth. In an arithmometer, the combination of the spiral spring t, thumb piece N,
fixed cam and the shaft and recording wheels, provided with lugs so located that
when the thumb piece is rotated the lugs will not engage when the recording-
wheels are standing on zero, as specified.
Tenth; In an arithmometer, the combination of the jointed crank having a spring
for throwing its outer end inward, the notched catch fixed on the case A, the gear
wheels C, D, the shaft B, and counting and recording wheels, all as shown and
described.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand
and seal, this Sixteenth day of May, in the year of our Lord One thousand
night hundred and savanto nina
FRANK WIRTH. (L.S.)