The printing device disclosed in connection with the Barbour machine
for recording calculations was of the most simple nature, allowing only
for the printing of totals and sub-totals.
Its manipulation consisted of placing a piece of paper under a hinged
platen and depressing the platen by hand in the same manner that a time
stamp is used. The ink had to be daubed on the type by a hand operation
to make legible the impressions of the type.
[Sidenote: _Description of Barbour machine_]
The patent drawings of the Barbour machine are so fragmentary that it
is almost impossible to draw any conclusion as to its functions without
reading the specifications.
Fig. 1 represents the base of the machine, while Fig. 4 shows a
carriage which, when in place, is superimposed above the base as
illustrated in Figs. 3 and 5.
The operation of the machine is performed by first pulling out the
slides B (shown in Fig. 1), which set the digital degrees of actuation
of each order; and, second, by operating the hand-lever K, from its
normal position at 0 to 1, if it is desired to add, or to any of
the other numbers in accordance to the value of the multiplier if
multiplication is desired.
The movement of the handle K, from one figure to the other, gives a
reciprocation to the carriage, so that for each figure a reciprocation
will take place.
Each of the slides B, has a series of nine gear racks; each rack has a
number of teeth ranging progressively from 1 tooth for the first gear
rack to 9 teeth for the last rack, thus the pulling out of the slides B
will present one of the gear racks in line to act upon the accumulator
mechanism of the carriage as the carriage is moved back and forth over
it.
The accumulator mechanism consists of the register wheels M¹ and M²
and the type wheels M³ and M⁴ mounted on a common arbor and a carry
transfer device between the wheels of each order.
Operating between the accumulator wheels and the racks of plate B are
a pair of gears, one in the form of a lantern wheel loosely mounted on
the accumulator wheel shaft but connected thereto by a ratchet wheel
and pawl connection; the other, a small pinion meshing with the lantern
wheel on a separate axis, protrudes below the carriage into the path of
the racks.
Thus as the carriage is moved by the reciprocating device connected
with the hand-lever K, the pinions of the accumulator will engage
whatever racks have been set and the numeral wheels and type wheels
will be operated to give the result.
The numeral and type wheels have two sets of figures, one of which is
used for addition and multiplication, while the other set runs in the
opposite direction for negative computation or subtraction and division.
A plate arranged with sight apertures covers the numeral or register
wheels, while the type wheels are left uncovered to allow a hinged
platen F, mounted on the top of the carriage (see Fig. 3), to be swung
over on top of them and depressed.
Attached to the platen F, are a series of spring clips d, under which
strips of paper may be slipped (as shown by D, in Fig. 4), and which
serves to hold the paper while an impression is taken.
[Sidenote: _Barbour machine not practical_]
Thus the Barbour invention stands in the Art as something to show that
as early as 1872 an effort was made to provide means to preserve a
record of calculations by printing the totals of such calculations.