The record-union., 1897-08-10
TO JUGGLE FIGURES.
1t Is Very Easy Matter When You
Know How to Do 1t.

Deen directed to the apparently mar
velous feats of so-calleds lightning CAL
culatorss" and not until now has any
one ventured to hint that, after all,
these men may not be such intellectual
prodigies as the public has been led to
believe Yet careful consideration
of their intellectual equipment and of
the work done by them seems to show
that their ability to juggle with figures
and to solve arithmetioal problems at
moments notice is by no means a
sign of genius, but is simply the result
of a few months hard work.
Among the best known of these
lightning calculators" are Inaudi.
NORTH Frankel, the hoy wonder" and
Professor Hainhaus. Frankel aston
ished the world a few years ago by his
wonderful skill in dealing with fig
ures, but his fame did not last and he
found it necessary to begin life anew
as a sailor. Hainhaus is at present a
salesman for a mercantile house, and
maud. it is said, has found so little
prophet in arithmetic that he has aban-
doned his curious profession and has
become a shepherd. Others, however,
both in this country and elsewhere,
have taken the places of these men,
and in like manner continue TO mystify
credulous audiences. A few words,
therefore. explaining how these men
work, will prove both timely and use
full
A lightning artist of this kind needs
four tools-adroitness a good memory,
tact and the ability to fool the public.
Constant or f0n ic
otherwise these professors" would be
more helpless before an audience than
any ordinary bank clerk or accountant
Assuming that a lightning calculator
has these tools, we may reckon on his
doing four kinds of tricks He will
multiply any number of figures by
any other number of figures; he will
substract any. number of figures from
any other number of figures; he will
be ready to tell at off-hand the day of
the week at any time in any given year,
and he will tell the cube root of almost
any number of &gures which may be
given to him.
All this seems very extraordinary, but
it is really simple enough. For pur-
poses of multiplication and substraction
the professor uses a black slate, on
which he writes the figures given to
him. He uses the slate for two rea-
sons; first, in order that he may not
burden his memory with the figures
given to him, and, second that he may
have time to solve the problem by
means of the weIl-known "one-times-
one" method. This is a very simple
method, which can be mastered by any
one of normal intelligence in six weeks
or two months. There are scores of
men in Europe who make a living by
going from house to house and doing
tricks with figures according to this
method. AS a rule they are either
tramps or discharged convicts, who
have utilized their time in prison in
learning how to juggle with figures.
In cases of subtraction the slate
proves very useful indeed, the an
swer can be told before the amount TO
be Subtracted has been fully written
down. In regard to the problem of
naming the week day on which any
date will fall, any one who takes the
trouble will find a very easy solution
in an almanac. This feat, indeed, has
been practically dropped from the pro-
grammes Of these professors, and is
only practiced now by bunglers. The
real artists, the lightning calculators'
par excellence, are satisfied if their au-
diences wonder at their skill in sub
tracing and multiplying, and especially
at their skill in telling the cube root
of any number of figures
Now, this seems an almost impossible
feat, but yet ii is simple enough when
one knows how to do it--so simple, in
deed, that any bright boy can learn to
do il in few weeks. First he must
know exactly what a cube is-namely,
that il is the result of multiplying one
number by itself, and then multiplying
the product by the original number
Thus, 8 multiplied by 3 equals and 8
multiplied by 3, the original number,
produces 21, which consequently, is
the cube of g. The cube root of 81 is
the original number g. and to find the
cube root is the reverse Of finding the
cube The would-be adept at this art
should first study carefully the follow
ing figures:
1x1x1x :: /; 2x2x2 :: s; 3x3x3 81.
4x4x4 :: 81; 5x5x5 :: 125; 6x6x6 !: 216
Tiki :: 343: SxSxS :: SO; 9x9x9 =: 729
A close study of these figures shows
that multiplied in this manner by
itself results in s, that multiplied by
itself has 2 as a final figure, that 3
multiplied by itself has Z as a final fig
ure, that Z multiplied by itself has
as a final figure and that 4, ). 6 and
multiplied by themselves have their
original figures as finals. Hence the
artist knows that any sum given to
him, the final figure of which is s,
must have as cube root-that, If the
final figure be 9, the cube root must be
| 8, and so on.
| For example. give him the figures
| "A, 0SS. and he can at once tell that A.
| is the cube root for the reason that "A
/ has as a cube root, as the cube of 4
| is Ga, while the cube of > is 125, much
more than "A, and 0SS has as a cube
root Or give him a more difficult
| problem, as. for example, the figures
| 324. .369 Then he will see at a glance
| that 324 is more than 216 which Is the
cube root of 6, but is less than 343, the
cube root of Z: therefore the cube root
/ of these three figures is 6, In like man.
ner the final figure Of 369 being 8, ii
| follows that the cube root of these three
| figures is g., and thus the cube root OF
/ the six figures has been shown to be
| 60 Any one can test this method for
/ himself, and a little practice IS all that
! is needed to make one as deft in such