|Thomas Fowler Calculator - 1840|
utilizes a simple mechanism to multiply or divide two numbers. The
machine uses signed ternary, a variation of base three where each
digit is represented by either "-", "0" or
"+". This model is only a small portion of the machine
Fowler envisioned. The capacity of this machine is seven places in the
product, equivalent to a decimal value of 1093. Fowler planned a
machine with 55 places, equivalent to a decimal capacity of 8.72 x 1025.
Fowler never documented his machine. He built a model of it, but it did not survive"
Glusker - Reconstruction
of Thomas Fowler's calculating machine