IMPROVEMENTS IN APPARATUS FOR MAKING CALCULATIONS
Year: 1842

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
MARSTON, of Aston, in the Parish of Hopesay, and County of Salop, Esquire,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-seventh day of January, in the fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Francis Marston, Her especial licence, full power, solo privilege and
authority, that I, the said Francis Marston, my exors, adññiors, and assigns, or
such others as I, the said Francis Marston, my exors, adñiors, or assigns,
should at any time agree with, and no others, from time to time and at all
times during the term of years therein expressed, should and lawfully might
make, usc, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, my Invention of "IMPROVEMENTS IN APPARATUS FOR
MAKING CALCULATIONS;" in which said Letters Patent is contained a proviso,
that I, the said Francis Marston, shall cause a particular description of the
nature of my said Invention, and in what manner the same is to be per-
formed, to be inrolled in Her said Majesty's High Court of Chancery within
six calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.
:

page_text: cach of the figures of the circular row of figures c, c, c, in the same radius.
division of the table; the next row of figures indicate the value in pounds.
and shillings, supposing the numbers in the circular row of figures c, c, c, to
indicate shillings; the next row of figures indicate the value in shillings and
pence of the number in the same radius on the circular row of figures c, c, c,
combined with the additional index plate, the use of which I will hereafter
describe. In this manner the table is composed, and to such an extent, that
any number of pence up to 500 is on sight resolved in shillings and pounds,
and the value in pounds of any number of shillings up to 500 is in like.
manner ascertained at sight. f is a fixed point, fixed at o in the fixed circle of
figures a, a, a, and on the revolving board is fixed a projecting tooth g, which
at every revolution of the revolving circle c, c, moves the wheel h one tooth,
such wheel being affixed to the axis i, and the wheel is prevented turning,
excepting when driven by the tooth g, by means of the spring j. On the upper
end of the axis i is affixed a pointing hand, which points to the numbers on
the fixed dial plate k, and when commencing any calculation, the 0 of the
circular row of figures a, a, and the 0 of the circular revolving row of figures
c, c, are brought to the position shewn in Figure 1, that is, in a line with the
fixed point f, and then, the apparatus being used, will calculate up to (99); but:
on moving further, the tooth g will move the pointing hand one space, and thus
point to (1) on the dial plate k, which will.indicate (100), and then the revo--
lution of the circular row of figures c, c, will go on, and whatever figuro or
figures are brought up to the fixed point will read off with the addition of 100,
which is indicated by the pointing hand; and when the revolving circle of
figures c, c, has made another revolution, and the tooth 9 has actuated another
tooth on the wheel, the pointing hand will indicate that 200 is to be added to
the number indicated by the figure or figures on the circle c, c, at the fixed
point f.
Having thus explained the construction of the apparatus, a few examples of
the mode of using it will make the instrument still better understood.

page_text: and so on with tho remaining 5, 9, 11, 13, 6, when the disc c will show the
result, 54, at the stop.
Another example. First, observing that both dials are properly set at 0, let
the numbers to be added be 61, 10, 34, 56, 72, 35, 81, 96; place the pointer
in the holo opposite 61 ou the circle a, bring the disc c round till tho pointer
is caught by the stopf; repeat the operation till the remaining figures are
brought down, when the amount will be shewn on the calculator; thus, the
arrow on the small dial will point to the figure 4, signifying 400, and the stop
or index of the disc c at 45, giving the sum total 445..
Compound Addition. This rule is worked in the same manner as the
former, the figures opposite the stop shewing the number of pence added up,
and the next line the amount in shillings. For example, supposing 85 to be the
number added, on the next line will be found 73. 1d.; or should it amount to
185 (which 100 will be recorded on the dial), on the next line will be 15s. 5d.,
and so on, cach line giving an additional 100 up to 500, and in like manner
with shillings, the value of which will be found in the yellow colored
divisions. .
Subtraction. To ascertain the difference between certain figures; for ex-
ample, 7 from 15, what remains? Place the pointer in the hole opposite the
figure 7, bring it down to the stop f, and the figures 15 on the disc ▸ will
stand opposite to the figure 8 on the frame, which is the difference; 7 from
15, there remains 8.
Multiplication. To find the amount of 7 times 7, place the pointer in the
holo opposite the figure 7 on tho circle a, bring it down to the stop, and
repeat it seven times, and the number of the multiplicand and the product will
be seen at the inlar, videlicit, 49.
Division. To know how many times 16 will go in 100, place the pointer in
the holo opposito the figures 16 on the circle a, bring it down to the slopf,
and repeat the operation till 96 will stand at tho stop, which will shew that
16 will go 6 times in 100, because it has been moved so many times before it
came to 96, and there aro four over, as shown by the 100 on the disc standing
opposite the figuro on the circle a, a.
Having thus described the nature of my Invention, and the manner in
which the same is to be performed, I would have it understood. that ] make
no claim to any of the parts separately; but what I claim is, the mode of con-
structing an apparatus for making calculations by combining two circular rows
of figures, the one moving and the other fixed, together with the apparatus
for indicating the hundreds, by recording the number of revolutions made by the
revolving circle, as above described. And also claim the combining with