Improvements in Arithmetical Calculators.
Year: 1898

page_text: Date of Application, 29th Nov., 1898-Accepted, 15th Apr., 1899
COME CELESTECIFICATION.
Improvements in Arithmetical Calculators.
I, WARREN ALLEN DRAKE, of Riverside, in the County of Cook and State of
Illinois, United States of America, Expert in Handwriting, 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:-
The general object of my invention is to simplify arithmetical calculations
by providing certain means or instrumentalities to be used in connection with
tables or figures.
My improvements are applicable to the decimal system of notation and the
apparatus which I have employed I have designed generally as the "autodeci-
graph." The principle of my invention is adapted to a variety of uses and the
apparatus used in connection therewith may be embodied in a variety of struc-
tural forms. I have selected in the first place for the purpose of illustration
certain tables which are employed in extending taxes and the apparatus shown
in the accompanying drawings is well adapted for use in the carrying out of this
work. I will first explain briefly the method commonly employed in extending
taxes and then by reference to the accompanying drawings, show the applica-
bility of my improvements thereto and, by comparison, the saving in labor
which my invention accomplishes.
In the levying of taxes there are two prime factors namely, the total amount
of tax to be raised and the total value of the property subject to taxation. Ob-
viously, the percentage which the amount of tax required bears to the total
valuation of the taxable property gives the tax rate, but as in most systems of
government, the total amount of tax is sub-divided and specifically appropriated
for different uses, such as state, county, town, city, school, park, library, and
the like, repeated applications of the rate to the valuation of the several parcels
of property must be made and the amounts separately noted, in order to keep
each item of taxation separate.
A tax roll or warrant therefore usually consists of a sheet transversely lined
and vertically ruled into columns, at the left of the sheet the name of the owner
and description of the property being entered, and following the description are
columns with proper headings for the "assessed valuations, both as originally
laid by the assessor and by the county or other board of equalization and the
equalized valuation as fixed by the state board of equalization, and the remain-
ing columns being headed with the different divisions or items for which taxes
are levied. The rate being determined, the amounts of the several items are
ascertained by applying this rate to the valuation of each specific item of pro-
perty.
To assist in this work, it is common to employ tables which are made up
similar to interest tables, except that usually some of the sheets, as for example,
in the higher numbers, running by thousands-say from 10,000 to 1,000,000 are
provided with blank columns in which the percentages are written down for
each separate item of tax, these percentages being erased when the table is to
be used for computing the tax for another or different purpose. Thus there

page_text: may be as many as ten different items found upon the same tax roll or warrant
and the table must be revised for each item. In using these tables, a series of
additions must be gone through with, in order to ascertain the exact amount
of the tax upon any given piece of property for each particular item, as for
example, if the valuation of a parcel is $21,762, the rate must be applied to
this valuation and the tables are used by taking the amount first of $20,000;
next of $1,700; next of $60; and last of $2.00, and these four separate amounts
being added together give the amount of tax for one specific purpose. Obviously,
the same operation must be repeated to ascertain the respective amounts charge-
able against this one parcel for the various purposes for which taxes are laid
and the total amount of the tax must be ascertained by adding together the
several items. This same operation is repeated for each parcel of land and each
valuation must be returned to as many times as there are distinct items of
taxation. Thus in brief to extend the taxes on a single page of the tax roll
may require the making of several thousand figures, the performance of a large
number of additions and the re-construction or revision of the tables used as
many times as there are distinct items of taxation.
I will next proceed to describe the manner in which my invention may be
employed to shorten the labor and to avoid the numerous errors which fre-
quently creep into the work. The instrumentalities which I employ comprise
a table of figures and an indicator hereinafter called a decimal bar, said table
and said bar being capable of relative movement so that any line of the table
may be brought adjacent to the bar and the table and bar having also a trans-
verse relative movement so as to vary upon a decimal scale, the values expressed
by their juxtaposition.
In the accompanying drawings,
Figure 1 is a perspective view of one of my calculators adapted to the purpose
of the extension of taxes;
Figure 2 is a detail sectional view of a portion of the same;
Figure 3 is a plan view of a modified form of calculator adapted for use in the
calculation of interest;
Figure 4 is a side elevation of the same;
Figure 5 is a front elevation;
Figure 6, a side elevation, and
Figure 7, a vertical sectional view of another modified form of apparatus ;
Figure 8 is a front elevation of a modified form of apparatus adapted for use
in the calculation of interest;
Figure 9 is a similar view of the decimal bar and its pointers and a portion
of the cylinder which carries the table.
Figure 10 is a transverse sectional view of the apparatus. illustrating a modi-
fication thereof wherein a plurality of cylinders is employed:
Figure 11 is a longitudinal sectional view, partly in elevation, of the struc-
ture shown in Figure 10;
Figure 12 is an enlarged detail plan view of a portion of the decimal bar
employed in the construction shown in Figures 8 to 11, the supplementary
cylinder being indicated in dotted lines: and
Figure 13 is a detail elevation, partly in section, of the supplementary cylinder
and one of its bearings.
Like figures of reference indicate corresponding parts in the several figures.
In carrying out my invention in one form, I place upon a revolving cylinder 15
Figure 1 a compilation or tabulation of numbers, these numbers being arranged
in vertical columns and transverse parallel lines. This cylinder is mounted
within a suitable casing, as 16, having a cover 17, whose front edges terminates
above the shelf 18, so as to provide a sight opening as at 19. Mounted to slide
in ways upon said shelf is a bar 20, which is hereinafter designated the decimal
bar, having pointers 21, one for each vertical column of numbers. A milled
wheel 22 affords means for shifting the decimal bar in its ways, while a similar

page_text: contrivance 23, exterior to the casing, affords means for rotating the cylinder
upon its axis. Upon the front of the hinged cover and arranged in line with
the several columns of numbers upon the cylinder are marked appropriate head-
ings, as for example, the words assessed," equalized," and the like these
words being adjacent to and immediately above the sight openings.
"
The above is a brief description of all the apparatus required for carrying out
my invention. In the compilation of the table, the left hand column of figures
contains the assessed valuation of the property and will appear opposite the
sight opening underneath the word "assessed,' said column of figures being
carried entirely around the periphery of the cylinder and including a series of
numbers beginning with 1 and foliowed by a series of ciphers. In the next
column, the equalized valuation is shown, while in successive columns are indi-
cated the tax upon one dollar for the several purposes for which the taxes are
levied, and in the right hand column the total amount of tax appears. Now,
assuming that the decimal bar is placed so that the pointer 21 indicates one unit
in the first column, it is a matter of calculation to determine the amounts to be
placed in the succeeding columns in line with this unit, while in the next line
below, which begins with two, will appear the several items, the amounts being
respectively twice as large as in the first line and so on throughout the table.
Now assuming that the apparatus be set so as to show $1.00 under the heading
assessed," this amount will be understood to mean the original valuation of
the parcel in question, while the pointer under the column" equalized" will
indicate a different amount, showing the equalized valuation, and in successive
columns will appear the tax upon $1.00 at the equalized valuation for each
specific purpose and in the right hand column the total amount of tax on $1.00
for all purposes. If now, the assessed valuation of the parcel be $10,000, as
indicated in Figure 1 of the drawings, and the equalized valuation $11,700,
the tax for state purposes at the assumed rate of $.55 on $100 will be $64.35;
county $90.558; town, $4.68; city, $286.65; library, $21.06; sanitary dis-
trict, $175.50; South Park, $51.48; school, $281.97; and the total amount of
the tax $976.248. Obviously by simply shifting the decimal bar, the amount
of tax for each of the several purposes on $1, $10, $100, $1,000, $10,000 or
$100,000 may be instantly ascertained. Suppose, however, that the assessed
valuation were represented by some number beginning with three, the cylinder
would then be rotated so as to bring the third row of figures opposite the sight
opening, whereupon would appear under the heading "assessed," the numeral 3
followed by a series of ciphers and by shifting the decimal bar as before, the
amount of tax for each particular item on $3, $30, $3,000, etc., could be readily
ascertained. The same principle, of course, would apply to the extension of the
tax upon any sum beginning with any of the numbers between 1 and 999, assum-
ing the table to be so constructed, and by shifting the decimal bar the amounts
might be readily found upon the numbers which are multiples of 10, running
from 1 to 99, 900,000, and without any additions or calculations. Taking now
for example, the same number which was used in illustrating the common method
of extending taxes, namely, $21,762.00, as the equalized valuation of a piece of
property, the cylinder would be turned until the number beginning with 217
appears. Then by shifting the decimal bar two places to the right, the num-
ber 21,700 is indicated and the amounts of the several items of tax thereon
appears under appropriate headings in line with the said number properly
pointed off, as the several pointers perform equal movements, and these amounts
are noted. Then by turning the cylinder to the number beginning with 62,
the amounts of the tax for the several items on $62 will be likewise indicated
and by addition of these amounts with those previously noted, each item of
tax is ascertained, thus saving two additions under each item of tax as compared
with the common method first explained. It will be observed from the foregoing
statements that the use of the apparatus with the particular number taken for
illustration saves two additions; but requires one addition, thus failing to indicate

page_text: mechanically the ultimate or desired sums. I have above used the headings "assessed"
and "equalized "and will now briefly explain in what manner my apparatus
may be used to find the equalized valuation and the proper amount of taxes under
each item. The assessed valuation is that which is fixed by the assessor or tax
levying officer. The equalized valuation is the amount of the assessed valuation
plus or minus a certain percentage, generally fixed by a governing board or
body. As assessed valuations are almost invariably made in even tens of dollars,
fractional parts of a dollar and sums less than $10 being omitted in the estimate,
the addition or subtraction of a certain percentage from these assessed valuations
necessarily results in producing odd numbers and numbers ending in digits.
Thus for example, take the illustration shown in Figure 1, showing
the assessed valuation to be $10,000, the equalized valuation, 17 per
cent. being added, shows $11,700 and the rate for each item of
taxation I increase by 17 per cent. and then extend the taxes or make the com
putation upon the assessed instead of the equalized valuation, thus dealing with
the column of figures which ends in even tens. For example, if the assessed
valuation be $18.600, the equalized valuation (17 per cent. added) will be
$21,762. If the taxes be extended on the latter amount according to the fore-
going illustration by the old method, four additions are necessary. If extended
by iny apparatus, according to the later illustration, one addition would be
necessary, but if extended on $18,600, the original valuation at the rate, in-
creased by 17 per cent, ro addition whatever is necessary because by turning the
cylinder to the number beginning with the digits 186, the equalized valuation
appears in its appropriate column and the amounts of the several items are
extended in line requiring only to be transcribed upon the roll. Thus it will
be seen that this method of tabulation, whereby the percentage for equalization
is applied to the rate of multiplier, instead of to the amount of multiplicand.
co-ordinates with the system of decimal notation carried out by the aid of the
apparatus, and the amounts of the several items of taxation upon any number
of dollars are equalized. To sum up, with my apparatus, any assessed valuation
having not more than three successive digits, followed by any number of naughts
or ciphers, may be equalized and the amounts of the several items of tax indi-
cated without any addition whatever.
To give a further idea of the saving effected by my apparatus, I may say that
the calculator shown in Figure 1, has a cylinder ten inches in length, and five
inches in diameter and is adapted for use in the extension of eight distinct items
of taxation, showing also the assessed and equalized valuations and the total
amount of tax on amounts commencing with the numbers from 1 to 150 inclusive
and will by the aid of the shifting decimal bar, show the like items on any
number of even tens from 10 to 100,000.
In Figures 3 to 7 inclusive I have shown certain modifications of the form of
instrumentalities employed in carrying out my invention. For example, in
Figure 3, let 24 represent a sheet of card board having delineated thereon three
columns of figures, which may be taken to represent principal interest and
amount. 25 represent a decimal har having pointers and its central portion cut
away so as to expose a single row of figures. To the ends of the bar are pivotally
connected swinging parallel links or arms 26, provided with longitudinal slots 21,
these links being pivotally connected together at one end and pivotally
mounted upon the sheet at the opposite end. Obviously with this
simple mechanism, the numbers in the first column
to represent the principal; the numbers in the second column, interest, and the
may be taken
numbers in the third column, the amount or the principal plus the interest.
The table, of course, in this case would be calculated with reference to a definite
rate and time and the interest and amount of any number of dollars represented
by a single significant figure and any number of ciphers may be found by the
mere shifting of the decimal bar; thus in the example shown in Figure 3, the
table is computed to, show the interest accruing monthly at the rate of 2 per cent.

page_text: per annum and the interest on $4.00 for one month at that rate is represented by
the decimal $.0006 plus and the amount $4.006 plus.
constant.
A simple apparatus of this kind would be available for use in computing
interest in savings banks and in other instances where the rate and time are
Of course, it will be seen that where a large number of figures are
to be handled, the sheet might be made movable and the decimal bar also mov-
able, but only transversely with reference to the sheet.
In the form of construction shown in Figures 5, 6 and 7, I show a casing
marked 28, having a sight opening 29 with a sliding decimal bar arranged with
its edge adjacent and parallel thereto and provided with the usual pointers.
Within the casing are mounted a series of cylinders or rollers 30, which may be
spring actuated, and mounted upon said rollers a series of flexible curtains 31,
having delineated thereon, tables or portions of tables. Within the casing is
a curved plate 32, so arranged as to hold the several curtains in convenient rela-
tion to the sight opening. Said curtains have rods 33 in their lower ends and
said rods are guided by grooves 34, so that each curtain may be drawn down
between the curved plate 32 and the sight opening, so as to expose the numbers
of the tables thereon. In this simple form of apparatus an extended surface is
provided in a simple and inexpensive form.
While the comparatively simple forms of my apparatus shown in Figures 3
to 7, inclusive, may be successfully employed for the purpose of calculating
interest, I prefer to employ for this purpose a machine of a character similar
to those shown in Figures 8 to 13 of the drawings, inclusive, which machine is
particularly adapted for use as an interest calculator.
In these figures I have illustrated my invention as embodied in an apparatus
Tor computing simple interest and the table used in connection therewith is
based on six per cent. per annum. The apparatus consists essentially of a mov-
able, cylinder or support upon the periphery of which is delineated a table con-
structed to show the interest upon $1.00 at six per cent. for various periods of
time and in tabular and progressive form, the interest on multiples of $1.00 for
equal times. The table may be extended to include any desired number of
dollars within practicable limits and in order to enable this extension to be
conveniently made, I may employ a plurality of cylinders or other devices, whereby
extended surfaces may be provided and brought into convenient position so that
the characters thereon may be read. These cylinders, supports or carriers for
the tables are used in combination with a sliding decimal bar, arranged trans-
versely of the columns and parallel with the rows of figures therein, this decima
bar having a series of pointers thereon, one for each period of time, each such
period having its appropriate column, and by shifting this bar with its pointers
the value of the numbers under each heading may be increased or diminished in
a ten fold ratio, the pointers indicating the carrying or removal of the decimal
point to the right or left as the case may be. In order to still further multiply
the power of the apparatus, each one of these pointers is made independently
movable, being preferably pivoted between its ends and, by its movement, made
to expose a figure or character indicating an additional period of time and also
moving the decimal point, thus introducing an additional multiplication or divi-
sion of the amount in question.
In the construction shown, the casing 16 contains either a single cylinder 15,
as in the construction shown in Figures and 9, or a plurality of eylinders, as
in the construction shown in Figures 10 and 11, and which will be hereinafter
more particularly referred to. The decimal bar 20 has mounted upon it a series
of pivoted pointers 21, and the rear ends of these pointers behind their pivots
work under a cover plate 35 Figure 12 which has segmental slots 36 therein,
one for each pointer, while upon the upper surface of the rear ends of the pointers
numbers are delineated. These numbers, as I have shown them, may be arranged
in series from 1 to 30, inclusive, with two ciphers annexed to each number
These numbers represent time and stand for days, while at the extreme right of

page_text: the machine I have repeated the numbers 100 and 200, said numbers repre-
senting years. The rear ends of the pointers have thumb pieces 37, by means of
which they may be moved upon their pivots, and the cover plate 35 has slots 38,
through which these thumb pieces extend. On the front of the hinged top 17
of the casing are arranged a series of sliding shutters 39 Figures 8 and 10 whose
lower ends depend below the plane of the pointers and cover the slot or sight
opening 19, when depressed. The cylinder 15 is provided with an operating
nand wheel 23, which, in this case, may be provided with a series of radial
arms 40, having terminal indicator buttons 41 marked with numbers bearing
a certain relation to the numbers carried by the cylinder 15.
In addition to the pivoted pointers 21 the decimal bar is provided with a fixed
pointer 42 at its extreme left hand.
Upon the periphery of the cylinder may be delineated in the first column or at
the left hand side of the machine, a series of numbers commencing with 1 and
extending to the capacity of the cylinder, preferably dropping out the numbers
expressed by even tens. Each of these numbers will have affixed thereto, by pre-
ference, a series of ciphers. For example, the first number appearing on the
cylinder will be 1 succeeded by five or six ciphers, so that assuming the decimal
point to be moved with relation to this number, it may be made to express 10,
100, 1,000 and so on up to 100,000. In the next row in the same column, the
Figure 2 will appear, followed by five ciphers and so on to the end of the column.
By calculation, the interest on the amounts represented by the digits in the first
column are computed for the several periods of time represented in succeeding
columns and the results appropriately placed. The time will be represented most
conveniently in days up to 30 days or one month and then the computation may
be made in months, days or years, as desired.
Let it be assumed now that the interest is required on $720. The cylinder will
be turned until the number 72 appears. The decimal bar will be shifted so that
the fixed pointer 42 carried thereby will point off from the number the three
figures on the left, namely 720. The shifting of the decimal bar to include these
three figures will carry the several pointers, representing time, to corresponding
positions below the numbers representing the interest computed for those times.
Thus the interest for one day will be $0.12 for two days, $0.24; for 30 days, $3.60;
for one year $43.20 and for 2 years, $86.40. But suppose the interest is required
for 70 days, then the pointer for indicating 7 days time is swung upon its pivot
to expose a cipher following the number 7 on the pointer and 70 days is thus read,
while at the same time the extremity or tip of the pointer has moved one place
to the right, thus effecting the multiplication of the former interest by ten and
reading from the table we find that the interest for 70 days is $8.40 or ten
times $.84, the interest for seven days.
Thus by a single operation and observation, the interest may be ascertained
for any number of days from 1 to 30 inclusive upon the said principal, and by
swinging any one of the pointers upon its pivot, the time and the amount of interest
may be multiplied ten fold, one hundred fold, etc., according to the number of
ciphers employed. Of course, the multiplication of the interest ten fold is
equivalent to the multiplication of the time ten fold and the operation may be
expressed or explained by reference either to time or amount of interest. For
any number of days exceeding 30 and represented by a number ending in a signifi-
cant figure, the interest would be found for the nearest number of days ending
with a cipher and then the number of days in excess thereof would be shown by
observing the amount opposite the pointer corresponding to that number and the
two sums added to obtain the total interest. Thus for 229 days, the pointer
bearing the number 22 followed by 2 ciphers would be shifted to expose one cipher
and the number of days would read 220 and the pointer would indicate $26.40,
while the pointer marked 9 would indicate $1.08, and the sum of these amounts,
or $27.48, would represent the interest for the required time. Now if it was

page_text: desired to find the interest on $7200, the decimal bar would be shifted to the right
to include an additional cipher.
I have shown the shutters as being capable of sliding movement and normally
so disposed as to conceal all of the tabulation work upon the cylinder, but it may
be desired to expose an entire row of numbers simultaneously, particularly if the
computation require the reading and addition of two sums to find the interest
for the required time. To enable all of the shutters to be raised and lowered
simultaneously, they may be mounted upon the sliding plate 43 having rack
bars 44, in which are engaged small pinions 45 Figure 10 on the operating rod 46,
the latter extending longitudinally through the casing and being provided with
milled heads 47 on its ends exterior to the casing.
In the apparatus heretofore described, whether employed as an interest calculator
or as an arithmetical calculator of any other kind, specific reference has been had
only to those forms of apparatus in which, when a cylinder is employed, only one
such cylinder is embodied in the machine. I may, however, for the purpose of
giving an increased capacity to the apparatus, without materially increasing its
size, employ a plurality of cylinders upon which the tables or section of table are
mounted, and such an apparatus is shown in Figures 10 and 11 of the drawings.
In this construction I employ an external cylinder 48, which is hollow inter-
nally and which is provided with hollow trunnions 49 having bearings in the ends
of the casing and provided with hand wheels 50 Figure 11 by means of which the
cylinder 48 may be rotated. The cylinder 48 is also provided with a plurality of
longitudinal slots or sight openings 51 corresponding in number with the internal
cylinders and located adjacent to the same. Within the cylinder 48 and mounted
upon suitable axes in the spider heads or arms 52 thereof are located a plurality of
cylinders 53, four being shown in the present instance, although this number mav
be varied as desired. Each cylinder 53 has a gear 54 upon one of its journals, and
all of said gears 54 mesh with a central gear 55, which is secured on the inner
end of a shaft 56 which passes loosely through the hollow trunnion 49 and is
provided at its outer end with a hand wheel 57. By rotating the hand wheel 50
the main or outer cylinder may be so rotated as to bring either any row of numbers
on said cylinder or any one of the slots 51 thereof to a point where it will be
visible through the sight opening 19. When the two slots or sight openings 19
and 51 coincide the surface of that one of the cylinders 53 which is then opposite
said sight openings is rendered visible, and by means of the hand wheel 57,
shaft 56 and intermediate gearing, said internal cylinder may be so rotated upon
its axis as to bring any row of numbers thereon into proper relation to the sight
opening so as to permit inspection thereof. In order to lock the external cylinder
when one of the internal cylinders is in use, I provide a plurality of apertures 58
Figures 10 and 11 in one end of the said external evlinder and I employ in con-
junction therewith a sliding locking holt 59, carried upon one end of a lever 60
pivoted between its ends at 61 on the inner face of the end of the casing and
having at its other end a stem 62 extending through the casing and provided
with a head or button 63. A spring 64 serves to normally press the locking bolt
into engagement with the external cylinder. The locking bolt, by its engagement
with one of the apertures 58 of the outer cvlinder, will hold the same stationary
with the proper cylinder 53 opposite the sight opening, but said locking bolt may
be readily disengaged by pressure upon the head or button 63 to permit the
external cylinder to be rotated, and if desired a retaining catch or latch
may be provided to lock the bolt in a position in which it will be normally dis-
engaged from the cylinder 48. By employing a plurality of cylinders the surface
or area for the delineation of numbers is materially increased without increasing
the size of the apparatus, and thus the capacity of the apparatus may be enlarged
and made adequate to a vast range of computations without involving an undue
demand for space owing to an undue increase in the size of the apparatus.
In the apparatus as heretofore described the computation of large amounts over

page_text: or
a certain sum, requires the shifting of the cylinder to first determine the interest
upon or derivative of a large amount, in either hundreds or thousands, and then
a separate shifting and examination to determine the interest upon
derivative of the small remainder, the two results thus obtained being
added together.
For instance, when the machine is used as an interest
calculator, if it be desired to compute the interest on $30,563 for 60 days at
6 per cent., the interest on $30,500 is first ascertained from the machine, the tables
giving this information readily and directly, and after the amount of interest as
been noted and written down, the cylinder or cylinders will be shifted until the
number 63 is exposed in the principal column, and the interest on that amount is
noted and added to the interest on the $30,500.
In practice it is customary in banks and other places where devices of this
character may be profitably employed, to verify, review or check the computations
made by referring back to them, and in the case of such computations as that
just referred to, where one result must be noted and the cylinder or cylinders then
turned to permit the determination of another result, it is obvious that with a
construction such as herein before described, the first result disappears from view
before the second result becomes visible, so that in reviewing or checking it is
necessary to again manipulate the instrument and to note in writing the results
in order that they may be added together.
To obviate these difficulties and to adapt the apparatus to present the results
of the computations to view at one time when such large numbers are being
computed, in order that said results may be reviewed or checked without further
manipulation of the apparatus, I provide for use in conjunction with the main
cylinder or group of cylinders, upon which the numbers with their derivatives are
tabulated, an auxiliary or supplementary cylinder, whereupon the numbers from 1
to 99 with their derivatives are tabulated, so that any given number within the
capacity of the machine may be made the subject of computations, and the results
upon which the final result is based will be simultaneously in full view, whereby
the computations may be reviewed or checked without further manipulation of
the apparatus.
To this end I provide a supplementary or auxiliary cylinder 65, which may be
conveniently mounted underneath the shelf or ledge 18, as shown in detail in
Figures 8 to 13 of the drawings, and which is supported in suitable bearings in
an extension 66 of the casing 16, being longitudinally movable in said bearings.
The cylinder 65 is connected with the decimal bar 20, so as to move longitudinally
in unison therewith, by any suitable means, as, for instance, an arm 67 secured
to the decimal bar at each end and having a terininal yoke 68, the arms of which
engage a grooved collar 69 secured on the shaft or axle 70 of the cylinder 65.
The shelf IS is provided with a slot 71 through which the figures on the cylinder 65
may be inspected. The decimal bar 20 is provided with a second series of
pointers 72 pivoted thereon and connected with the pointers 21 so as to move in
unison therewith and in the same direction relatively to the decimal bar. This
connection may be effected in the manner indicated by providing each pointer 21
with a pin or projection 73, whilst its companion pointer 72 is provided with a
slot 74 Figure 12 with which the pin 73 engages. Movement imparted to any
one of the pointers 21 will impart an equal movement to the corresponding
pointers 72 in the same direction. It will be understood, of course, that the
pointers 72 co-operate with the tabulated figures upon the supplementary
cylinder 65. Upon the shelf 18 there is provided a series of sliding shutters 75,
one for each pointer 72, which shutters may be projected over the slot 71 so as to
conceal the figures upon the cylinder 65. In order to cause, these; shutters to
retain their proper positions relatively to the cylinder 65 and pointers 72, they
are mounted upon a plate 76 which is secured at each end to an extension 77 of
the arm 67 and which moves in the slot 71 in the shelf 18.
There is provided at the left hand of the plate 76 an aperture 78, Figures 8

page_text: and 12 through which the figures of the column at the left of the cylinder 65 are
visible.
Upon the main cylinder or cylinders of the apparatus there is delineated in the
first column at the left hand side of the machine a series of numbers commencing
with 1 and extending to the capacity of the cylinder or cylinders, preferably
omitting the even tens and affixing to each of the numbers a series of ciphers.
In the succeeding columns on said cylinder or cylinders are represented the figures
indicating the interest on the amounts represented by the figures in the same row
of the first column, as herein before pointed out. Upon the cylinder 65 there are
delineated in the first column at the left a series of numbers commencing with 1
and extending to 99, and in the columns to the right thereof is represented the
interest for the various periods of time indicated by the corresponding pointers on
the amounts appearing in the corresponding rows of the left hand column.
The operating of the apparatus is as follows:
Assuming that the shutters are closed and the decimal bar and auxiliary
cylinder in a position at the extreme left and that it is desired to compute the
interest on $30,563 for 60 days at 6 per cent. being the percentage for which
the tables are calculated, the main cylinder or cylinders are rotated until the
number 305 followed by a series of ciphers appears in the column at the extreme
left of said main cylinder or cylinders. The decimal bar is then moved two
places to the right, so that the fixed pointer 42 indicates the sum 30500 at the
extreme left of the main cylinder or cylinders. This movement, of course, carries
along with it the pointers 21 and 72 and the auxiliary cylinder 65 with tits
shutters 75. By lifting the shutter 39 above the pointer 21 bearing the number 6,
the pointer 21 will indicate thereon, when its tip is in its normal, position to the
extreme left, the interest on $30,500 for 6 days, or $30.50. The pointer 21 is
moved so as to expose a cipher after the 6 and brings the indicating point one
place to the right, and we will read upon the corresponding column of the main
cylinder or cylinders the interest on $30,500 for 60 days, i.e., $305.
The movement of the pointer 21 has imparted a corresponding movement to the
pointer 72, so that when the auxiliary cylinder is rotated, as it may conveniently
be by a suitable handle 79 on its axis 70, so as to bring the number 63 in the
column at the left hand thereof into view through the aperture 78, the shutter 75
opposite the sixth pointer 72 may be opened, whereupon said pointer will indicate
the interest on $63 for 60 days, i.e., $63. This amount is readily added to
the $305 previously ascertained, thereby giving as the interest on $30563 for
60 days at 6 per cent. the sum of $305.63. Moreover, it will be seen that the
two partial results, to-wit, the $305.00 and the $.63, from which the main result
or total is obtained, both remain visible at the same time and in full view, so
that the calculation may be revised and checked without manipulating the appa-
ratus, as would be necessary if the two component figures from which the partial
results are obtained were on the same cylinder or on different cylinders which were
not both visible at the same time.
By reason of this mode of operation, calculations may be more quickly made
and more readily checked, thereby giving results productive of higher rapidity
and greater accuracy.
It is obvious that while I have described the apparatus as organized for com-
puting taxes and interest, these are only two applications of the principle involved,
and the machine is adapted for a wide application in the making of arithmetical
calculations of various kinds, such as complicated discount calculations involving
several discounts, or other accounts susceptible of tabulation and adapted for
calculation upon a percentage basis. It is also obvious from the preceding descrip-
tion that the structural details of the apparatus may be varied without departing
from the principle of my invention and I therefore do not wish to be understood
as limiting myself to the precise construction herein before described and shown
in the drawings.

page_text: 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 I
claim is:-
1. An arithmetical calculator comprising in combination, a suitable backing or
support having numbers arranged thereon with a decimal bar or pointer, said
support and said bar or pointer being capable of relative movements, whereby the
values expressed by the numbers may be increased or decreased, substantially as
described.
2. An arithmetical calculator, comprising in combination, a suitable backing
or support having arranged thereon a plurality of numbers, with a decimal bar
consisting of or having a plurality of pointers, said support and said bar or
pointers having relative movement, whereby the value of the numbers may be
increased or decreased in a ten fold ratio, substantially as described.
3. An arithmetical calculator, comprising in combination, a suitable backing
or support having delineated thereon, a plurality of columns of numbers and a
decimal bar or indicator having pointers arranged thereon and connected so as
to be movable simultaneously and through equal distances, whereby any number
or row of numbers may be brought adjacent to said bar and said pointers moved to
increase or decrease the value of the numbers expressed in a ten fold ratio, sub-
stantially as described.
4. An arithmetical calculator comprising in combination a movable backing
or support having numbers arranged thereon in parallel columns with a movable
decimal bar having a pointer for each column of figures, substantially as
described.
5. An arithmetical calculator comprising in combination a rotatable cylinder
having delineated and arranged thereon in tubular form, a series of numbers and
a decimal bar having pointers, one for each column, of figures, and whereby the
rotation of the cylinder may be made to being any row of numbers into juxta-
position to the decimal bar and by the movement of the latter along said row,
the value of the numbers expressed may be increased or diminished in a ten fold
ratio, substantially as described.
6. An arithmetical calculator, comprising in combination, a suitable casing or
support having a sight opening therein, a revoluble cylinder mounted within said
casing and having numbers delineated and arranged in parallel columns and
rows thereon, a decimal bar mounted to slide in suitable ways adjacent to said
sight openine and said bar having pointers thereon for each column of figures,
substantially as described.
7. An arithmetical calculator, comprising in combination, a suitable casing, a
cylinder rotatably mounted therein, a sight opening in the wall of said casing, a
shelf arranged upon the casing adjacent to said sight opening and having ways
thereon, a decimal bar mounted to slide in said ways, a series of headings arranged
upon the casing above the sight opening, and a series of numbers arranged upon
the cylinder in parallel circumferential columns and transverse rows, said decimal
bar having a plurality of pointers, one for each column, and whereby said numbers
may be indicated or pointed off, according to the decimal system of notation, sub-
stantially as described.
8. An arithmetical calculator, comprising in combination, a plurality of rotat-
ably mounted cylinders or supports having numbers tabularly arranged thereon
and a decimal bar or pointer, said supports being independently rotatable upon
their axes and severally movable with relation to the decimal bar, whereby any
number on either or any of the supports may be brought into juxtaposition to the
bar and the value thereof increased or diminished, substantially as described.
9. An arithmetical calculator, comprising in combination, a decimal bar having
pointers thereon, a plurality of rotatable supports each having numbers serially
arranged in tabular form thereon, said supports being rotatable upon their own
axes and bodily movable, substantially as described.
10. An arithmetical calculator, comprising in combination, a decimal bar having

page_text: pointers thereon, a series of cylinders mounted upon axes parallel to said bar, each
of said cylinders having depicted thereon a series of numbers in tabular form,
said cylinders being mounted upon a suitable frame work revolving upon an axis
and each capable of independent rotation on its own axis, substantially as
described.
11. An arithmetical calculator, comprising in combination, a decimal bar having
pointers thereon, a hollow external cylinder having a series of numbers depicted
thereon in tabular form and provided with one or more transverse slots affording
a sight opening and one or more internal cylinders journalled upon and moving
with said external cylinder and with its periphery adjacent to said slot and
capable of rotation upon its own axis, substantially as described.
12. An arithmetical calculator, comprising in combination, a suitable casing, a
sliding decimal bar, and external cylinder capable of rotation about a fixed axis
and a plurality of interior cylinders rotatably mounted within said external
cylinder, suitable gearing for operating said cylinders and a locking mechanism
for the external cylinder, substantially as described.
13. An arithmetical calculator comprising in combination an interest table
delineated upon a suitable support and comprising, in parallel columns, numbers
representing the principal and numbers representing the interest calculated for
various times and a decimal bar or indicator, said table and said bar being movable
with relation to each other and said decimal bar having pivoted pointers, sub-
stantially as described.
14. An arithmetical calculator comprising in combination an interest table
mounted upon a suitable backing or support, a bar having pointers thereon, said
bar and said table being movable with relation to each other, whereby various
amounts may be indicated, and said pointers having each an independent move-
inent, whereby multiplication of one of the factors may be mechanically effected,
substantially as described.
15. An arithmetical calculator comprising in combination a rotatable cylinder
or support having delineated thereon, in parallel columns, numbers indicating
principal and interest, a bar having pointers thereon, one for the principal and one
for each of the several columns representing interest or time, said pointers being
pivoted upon said bar, and serially numbered, said serial numbers having each
arranged adjacent thereto, one or more ciphers normally concealed and capable of
being exposed by the manipulation of the pointer, whereby the time indicated by
any given pointer may be increased and the interest correspondingly increased
by such manipulation, substantially as described.
16. An arithmetical calculator comprising in combination a rotatable support
or cylinder adapted to receive thereon an interest table, a sliding decimal bar
having pointers pivoted thereon, said pointers being serially numbered and a
series of movable shutters, whereby any number delineated upon the cylinder may
be separately exposed, substantially as described.
17. In an arithmetical calculator, the combination with a rotatable cylinder or
support, of a sliding decimal bar having pivoted pointers and a series of movable
shutters mounted upon a common support capable of bodily movement, whereby
said shutters may be separately or simultaneously moved as desired, substantially as
described.
18. An arithmetical calculator comprising in combination one or more main
supports or cylinders having a main table or tables delineated thereon, a supple-
mentary rotatable support or cylinder having a table thereon computed with
relation to the small amounts which are adapted to furnish the terminal figures
of the amounts of the main table or tables, and a sliding decimal bar having
pointers thereon co-operating with said cylinder, substantially as described.
19. An arithmetical calculator comprising one or more main cylinders having
a main table or tables delineated thereon, a supplementary cylinder tabulated for
small amounts, and a sliding decimal bar having two series of pointers mounted

page_text: thereon, movable in relation to said bar and co-operating respectively with the
main and supplementary cylinders, substantially as described.
20. An arithmetical calculator comprising one or more main cylinders having
a main table or tables delineated thereon, a supplementary cylinder tabulated for
small amounts, a sliding decimal bar, and two series of pointers pivotally mounted
on said decimal bar and connected in pairs to move in unison, said series
co-operating respectively with the main and supplementary cylinders, substantially
as described.
יה זייד
0011
T
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.