c. **Pascal's Adding Machine (1642). **Blaise Pascal, a French philosopher and

inventor, was only 19 when he began work on an adding machine in 1642. He was

inspired in the attempt by the computational drudgery of his father's job as regional tax

official. Pascal's machine, the "Pascaline," was a boxed wheel-and-cog device; he built

more than 50 versions of it over the course of a decade. The operator fed it the figures

to be added by dialing them on a series of wheels. Each wheel, marked with the digits

0 through 9, stood for a particular decimal column (is, 10s, 100s, and so on). A wheel

carried a total greater than nine by executing a complete turn and advancing the higher

order wheel to its left by one digit. Pascal's principal of interlocking wheels remained

central to the operation of most adding machines for the next 300 years. His machine

could perform simple addition by carrying over, with relative ease. It performed other

operations by a cumbersome system of repetitive additions. The machine was widely

praised and the young Pascal presented a copy to King Louis XIV. It never made him

rich.

Figure 1-10. Pascal's adding machine used interlocking wheels, which remained

central to most calculating devices for the next 300 years.

d. **The Von Leibniz Calculator (1673). **The next advance came in 1673, when

Gottfried Wilhelm Von Leibniz attached a multiplication/division device to Pascal's basic

machine. His was the first machine that could do subtraction, multiplication, and

division easily. The device actually multiplied and divided through a process of

successive adding and shifting, made automatic by a special component that speeded

up the repetitive additions and subtractions involved in multiplying or dividing. Von

Leibniz, an eccentric genius and mathematician, built the device as an aid to himself.

For, though he understood calculus, he could not multiply, having failed to learn the

multiplication tables. Of the tedious computations astronomers had to do, he wrote" it is

unworthy of excellent men to lose hours like slaves in the labor of calculation which

could be relegated to anyone else if machines were used."

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