Probably the first successful direct multiplying machine was made by
Leon Bollee, a Frenchman, who patented his invention in France in 1889.
A patent on the Bollee machine was applied for in this country and was
issued March 17, 1896, some of the drawings of which are reproduced on
the opposite page.
[Sidenote: _Description of Bollee Machine_]
Instead of using eighty-one multiplying gear racks for each order as
in the Barbour patent, Bollee used but two gear racks for each order;
one for adding the units and the other for adding the tens; these racks
operate vertically and are marked respectively Bb and Bc. (See Fig. 3.)
The racks are frictionally held against gravity in the permanent
framework of the machine, and are moved up and down by contact at each
end, received from above by bar Ie, and from below by pins of varying
length set in the movable plates Ab.
The bar Ie forms part of a reciprocating frame which moves vertically
and in which are slidably mounted the pin plates Ab. These plates are
what Bollee called his “mechanical multiplication tables.”
The arrangement of the pins and their lengths are such as to give
degrees of additive movement to the units and tens gear racks equal to
the multiplying racks in the Barbour multiplier.
The pin plates are moved by the hand-knobs Ab², and the plate shown in
Fig. 3 is positioned for multiples of nine.
The means for setting the multiples correspond to the index hand-knob
of the Barbour machine, and consists of the crank Am, which, when
operated, shifts the whole series of plates laterally. A graduated dial
serves the operator to set the multiple that the multiplicand, set by
the positioning of the plates, is to be multiplied by.
The accumulator mechanism is mounted in a reciprocating frame which
moves horizontally, causing the gears of the numeral wheels to engage
first the units racks on their upstroke under action of the pins, and
then the tens racks on their down-stroke under the action of the top
bar of the vertically moving frame, the downward motion, of course,
being regulated by the upward movement it receives from the pin that
forces it up.
As may be noted in Fig. 1, the multiplying plates are held in a
laterally movable carriage that is shifted through the turning of the
multiplier factor setting hand crank Am, by means of the rack and
pinion action. This gearing is such that each revolution moves the
multiplying plates under a higher or lower series of orders, thus
allowing the multiples of a higher or lower order series to be added in
the process of multiplication or subtracted in division, as the case
may be.
Although the Bollee machine is reputed to be a practical machine, as
is attested from the models on exhibit in the Museum of Des Arts and
Metiers of Paris in France, it was never manufactured and placed on the
market.
[Sidenote: _Bollee’s principle commercialized_]
Bollee’s principle has, however, been commercialized by a Swiss
manufacturer in a machine made and sold under the trade name of “The
Millionaire,” the U. S. patents of which were applied for and issued to
Steiger.
Hopkins constructed his multiplying mechanism on the Bollee scheme of
using stepped controlling plates for his reciprocating racks to give
the multiples of the digits, but the ingenious method of application
shown in the Hopkins patent drawings illustrates well the American
foresight of simplicity of manufacture.
During the past ten years there have been a large number of patents
applied for on mechanism containing the same general scheme as that
of Bollee and Steiger, but up to the present writing no machines with
direct multiplying mechanism have been commercialized except “The
Millionaire,” which is non-recording, and “Moon-Hopkins Bookkeeping
Machine.”