The process of carrying, which takes place when the moving power is describing the second and fourth quadrants of its revolution, is accomplished thus :—A bar or finger revolves on the axle of the lowest cylinder n, for example, in the first vertical column on the left ; and, at a proper time comes against the extremity of a claw which then engages itself between the teeth of a ratchet-wheel connected with the next cylinder above it : both the wheel and cylinder are thus made tc turn, but the length and position of the claw are such that the cylinder can only make one-tenth of a revolution, and thus bring to the front a figure greater by unity than that which was there before. When a cylinder has made the movement just indicated, a projecting pin, called a thumb, on the axle of the lower cylinder, touches a trigger which raises, out of a notch in the claw, a hook which retained the latter : a spiral spring then draws back the claw and allows it to fall between the next teeth of the ratchet-wheel without creating any movement in the cylinder ; and the apparatus is thus prepared for the next carrying operation which is to take place.
It was proposed by the inventor to apply to the machine an apparatus by which the numbers obtained from the cylinders in the left-hand column might he immediately transferred, by the operation of punch ing, to plates of copper, in order that the results given by the machine might be printed without a possibility of error. To effect this, a curvilinear bar of metal was to act on an arm of a lever so as to raise it to ten different heights corresponding to the ten figures on the surface of a cylinder ; and the opposite arm of the lever was to move au arch carrying ten punches having on them the characters 1, 2, 3, &c. in relief. The plate of copper being below, a bent lever was to press the punch upon the plate, and produce the impression of the figure. The different figures in front of the first column of cylinders would thus be successively transferred to the copper-plate ; and the arch and plate being shifted, the set of figures brought in front of the cylinders in the same column, at the next operation with the machine, would be trans ferred in like manner.
If Mr. Babbage's plan had ever been fully carried out, the machine would perform the several operations of simple arithmetic ou any numbers whatever. It would combine the quantities algebraically or arithmetically in an unlimited variety of relations. It would use algebraic signs according to their proper laws, and develops the con sequences of those laws. It would arbitrarily substitute any formula for any other, effacing the first from the columns on which it is repre sented and making the second appear in its stead. It would effect
processes of differentiation and integration on functions in which the operations take place by successive steps. The inventor further asserts that the engine would be particularly fitted for the operations of the combinatory analysis, for computing the numbers of Bernoulli, &c.
This machine embodies the principles of all the calculating machines yet proposed. A few words concerning other contrivances may, how ever, be desirable.
Staffers arithmetical machine is about 18 inches In length, 9 in breadth, and 4 in height. It contains- three rows of small cylinders, thirteen in the first row, and seven in each of the others ; upon each cylinder are ten numerals, from 0 to 9. These cylinders act upon each other by means of small wheels, levers, sliders, and other delicate appa ratus. The upper surface of the machine presents seven small holes, with moveable plates beneath them, marked by numerals, seven similar holes over the peripheries of seven little vertical wheels, and thirteen number-holes in a distinct row. Each set of seven holes has a traversing movement, but the longer row is immovable. Every one of the twenty seven holes has ten numerals, from 0 to 9, belonging to it. In per forming any sum, the conditions of the question are arranged on the two smaller rows ; and then, by turning a handle, the result males its apps trance at the holes of the larger row. By different modes of adjusting the two smaller rows of holes, and of turning the handle, the machine performs addition, subtraction, multiplication, division, and evolution. It can multiply seven digits by seven, or millions by A very beautiful part of the apparatus is a little bell, which rings when ever the operator attempts to perform an impossible operation, such as subtracting a larger number from a smaller, or dividing a smaller by a larger ; the machine refuses to work, rings a bell, and stops.
Colmar 's anthuaometer is rather larger than Staffers machine. It has as many slides, each working in a groove, as there are digits in the quantity which it is capable of calculating; and each groove is num bered with ten figures, from 0 to 9. There are as many round boles in a brass plate as there are possible places of figures in the result to be produced; and beneath each hole may appear any one of the ten numerals. The machine is adjusted to any particular problem or sum in addition, subtraction, multiplication, division, or evolution, by moving some among the many slides ; these slides work upon certfin wheel. and levers underneath, which cause the proper figures for the result to make their appearance at the row of holes in the brass plate.