The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1899-02-26

Tie practice. Fractions and denOmi-
nate qualities may be computed; num-
bers can be raised to the third. fourth
or fifth power and the square or cube
root extracted with equal facility. The
machine is also adapted for the per-
formance- of all logarithnic and trfg-
onometric computations.
Mistakes are not apt to occur. as
the mere placing of the stylus point in
any subdivision Of the chain board. or
even its depression, produces no change
in the Indicator. Therefore. If a mis-
take is noticed before the chain is
moved forward no attention need be
given to the same. This point repre-
sents a great advantage over other
computing machines. where the slight
est touch Of the operating mechanism
results in arrangement of the regis
ter.
GUARD AGAINST ERRORS.
In the arithmachine the chains are
locked. only set in motion by deliberate
effort Of the operator. so an error can
be corrected before it Is made" If
mistake has been made in placing a
figure and noticed at the time. it can
be speedily corrected by adding or de-
Quoting the difference between the cor
rect and wrong figures to or from the
figures to be registered in the same
column.
So little exertion is required to ma
nipulate the arithmachine that the use
brings rest and relaxation. while those
who strain the muscles Of the hand
and forearm by writing find relief in
bringing into action different sets of
muscles when using the machine. The
operation Of writing is also straining
to the eyes. being creative in its nature
and requiring close attention to direct
and control the movement of the hand.
The manipulation of the arithma chine,
as well as the reading Of the results
arrived at with it's use, is purely recep-
tive as far as the eyes are concerned.
and therefore restful. the forms being
plainly visible and all glare removed.
The machine is composed of a num-
Der of perfectly Identical sections, &C
cording to the number of columns pro-
viGed, which may be five, eight or elev-
en-. The operating mechanism IN each
section consists of an endless chain
composed of thirty-five uniform and
peculiarly shaped links, joined so per-
fectly that the connections are invis-
ible when seen from above, yet per-
hitting the free movement Of the chain
The transverse teeth which form a part
of the chain links serve to actuate the
mineral wheels when thrown in con-
tact with them, furnish a hole for the
stylus when operating the chain, and
also lock it by means of a barr and
roller lock at the forward end of the
machine. The endless chain passes in
its movement. over two pentagonal roll
lers; between these two rollers and on
the underside of the chain board or
operating surface is a platform lever
This forms q solid foundation for the
movement Of the chain, with a foot
at one end causing, when depressed, an
immediate opening of the chain lock,
and connected with it near the other
end is a contact lever. This throws
the chain in tangentiaI contact with
the mineral wheel as soon as depressed
and moved by the stylus, and when at
rest assists in locking the chain by pre-
venting the turning Of the adjoining
pentagonal roller A slightly curved
spring presses the platform lever and
chain board upward against the bar
and roller lock, and joined to it is a
tension spring, which prevents any I'M
desirable loOSeneSs of the chain.
INDICATING MECHANISM.
The indicating mechanism is compos-
ed of a ratchet wheel, bearing on its
face the ten figures and having within
two circular depressions, the one con-
tanning ten circumferentiaI ratchets,
and the other the, carrying and return
levers and springs ring or collar
between the mineral wheel and the
central arbor serves to hold the return
disks in position.
A resetting wheel on the outside Of
the case, fastened to the neck Of the
central arbor and held in position by
the release pin and spring; comb
wheel behind the ratchet wheels, which
regulates their movement and insures
the alignment of the figures in the in
dicator opening; partitions which sep
arate the sections hold the lever pins
in position and through a larger open
ing between the mineral wheels form
a part of the carrying device, and the
two outside frame plates, which hold
the inner mechanism together and per
nit it to be removed from its case like
a watch, complete the mechanical con-
struction of the arith-machine the to-
tai number of working parts being 40,
with 80 screws and rivets. The arith-
metic is made entirely of metal; every
working part is properly strengthened
and every wearing part made of steel
or other suitable material, and capable
of performing about ten times the work
expected of it. In this way the ma
chine is guaranteed absolutely and
with proper care is likely to last a
lifetime.