To illustrate this: let us suppose the table to be computed to be that
of the fifth powers of the natural numbers, and the computation to have
already proceeded so far as the fifth power of 6, which is 7776. This
number appears, accordingly, in the highest row, being the place
appropriated to the number of the table to be calculated. The several
differences as far as the fifth, which is in this case constant, are
exhibited on the successive rows of dials in such a manner, as to be
adapted to the process of addition by alternate rows, in the manner
already explained. The process of addition will commence by the motion
of the dials in the first, third, and fifth rows, in the following
manner: The dial A, fig. 1, must turn through one division, which will
bring the number 7 to the index; the dial B must turn through three
divisions, which will 0 bring to the index; this will render a carriage
necessary, but that carriage will not take place during the present
motion of the dial. The dial C will remain unmoved, since 0 is at the
index below it; the dial D must turn through nine divisions; and as, in
doing so, the division between 9 and 0 must pass under the index, a
carriage must subsequently take place upon the dial to the left; the
remaining dials of the row T, fig. 1, will remain unmoved. In the row D^2
the dial A^2 will remain unmoved, since 0 is at the index below it; the
dial B^2 will be moved through five divisions, and will render a
subsequent carriage on the dial to the left necessary; the dial C^2 will
be moved through five divisions; the dial D^2 will be moved through three
divisions, and the remaining dials of this row will remain unmoved. The
dials of the row D^4 will be moved according to the same rules; and the
whole scheme will undergo a change exhibited in fig. 2; a mark (*) being
introduced on those dials to which a carriage is rendered necessary by
the addition which has just taken place.
Fig. 2.
The second quarter of a turn of the moving axis, will move forward
through one division all the dials which in fig. 2 are marked (*), and
the scheme will be converted into the scheme expressed in fig. 3.
Fig. 3.
In the third quarter of a turn, the dial A^1, fig. 3, will remain
unmoved, since 0 is at the index below it; the dial B^1 will be moved
forward through three divisions; C^1 through nine divisions, and so
on; and in like manner the dials of the row D^3 will be moved forward
through the number of divisions expressed at the indices in the row D^4.
This change will convert the arrangement into that expressed in fig. 4,
the dials to which a carriage is due, being distinguished as before by
(*).
Fig. 4.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account