*Post by h***@bbs.cpcn.com*I believe Bush invented the analog computer.

That depends on how you define 'analog computer', since some would dignify the

Gunter scale and William Oughtred's invention by that name. However, the

differential analyzer of Vannevar Bush, unlike, say, a mechanical tide predictor

(another much earlier device sometimes called an analog computer) was very much

a mechanical device that had the same functionality as an electronic analog

computer: through feedback between functions, functions of those functions, adn

integrals or differentials of those functions, it could produce an analog

solution to a differential equation.

A tide predictor, on the other hand, just cranks out numerical values for a

Fourier series that is already known; the differential analyzer solved problems

where the solution was not known.

So there is definitely a sense in which the Bush differential analyzer was the

first 'real' analog computer.

John Savard