Created: 1999-06-03
Last Modified: 1999-06-03
Go to
Brad DeLong's Home Page

Teaching | Writing | Career | Politics | Book Reviews | Information Economy | Economists | Multimedia | Students | Fine Print | Other | My Jobs

Feedback is always very welcome...

Computing Before Charles Babbage


from Martin Campbell-Kelly and William Aspray (1996), Computer: A History of the Information Age (New York: Basic Books: 0465029906).

New Economy Master Page

pp. 11-13: "... in 1819 Babbage made the first of several visits to Paris.... It was probably during this visit that Babbage learned of the great French [mathematical] table-making project organized by Baron Gaspard de Prony. This project would show Babbage a vision that would determine the future course of his life.

"Du Prony began the project in 1790.... De Prony was... appointed head of the Bureau du Cadastre, the French ordnance survey office. His task was made more complex... by... the new, rational metric system. This created within the Bureau the job of making a complete new set of decimal tables to be known as the Tables du Cadastre. It was by far the largest table-making project the world had ever known, and de Prony decided to organize it much as one would organize a factory.

"De Prony took as his starting point the most famous economics text of his day, Adam Smith's Wealth of Nations, published in 1776. It was Smith who first advocated the principle of division of labor, which he illustrated by means of an imaginary pin-making factory. In this famous example, Smith explained how the making of a pin could be divided into several distinct operations.... If a worker specialized, the output would be vastly greater.... De Prony 'conceived all of a sudden the idea of applying the same method to the immense work with which I had been burdened, and to manufacture logarithms as one would manufactures pins'.

"De Prony organized his table-making 'factory' into three sections. The first section consisted of half a dozen eminent mathematicians--including Adrien Legendre and Lazare Carnot--who decided on the mathematical formulas to be used in the calculations. Beneath them was another small section--a kind of middle management--that, given the mathematical formulas to be used, organized the computations and compiled the results ready for printing. Finally, the third and largest section, which consisted of sixty to eighty human computers, did the actual computation. The computers used the 'method of differences', which required only the two basic operations of addition and subtraction.... Hence the computers were not and did not need to be educated beyond basic numeracy and literacy. In fact, most of them were hairdressers who had lost their jobs because 'one of the most hated symbols of the ancient regime was the hairstyles of the aristocracy'.

"Although the Bureau was producing mathematical tables, the operation was not itself mathematical. It was fundamentally the application of an organizational technology, probably for the first time outside a manufacturing or military context, to the production of information. Its like would not be seen again for another forty years.

"The whole project lasted about a decade...

"Babbage's unique role in nineteenth-century information processing was due to the fact that he was in equal measure a mathematician and an economist. The mathematician in him recognized the need for reliable tables and knew how to make them, but it was the economist in him that saw the significance of de Prony's organizational technology and had the ability to carry the idea further.

"De Prony had devised his table-making operation using the principles of mass production at a time when factory organization involved manual labor using very simple tools. But in the thirty years [between] de Prony's project [and Babbage], best practice in factories had itself moved on, and a new age of mass-production machinery was beginning to dawn. The laborers in Adam Smith's imaginary pin-making factory would soon be replaced by a pin-making machine. Babbage decided that rather than emulate de Prony's labor-intensive and expensive manual table-making organization, he woul dride the wave of the emerging mass-production technology and invent a machine for making tables.

"Babbage called his machine a Difference Engine..."

I'm not sure how reliable the source is. The authors appear to believe that Napoleon was Emperor of France in 1790, and that makes me skeptical of everything else they say. So I have to dig deeper into primary sources...

New Economy Master Page

Professor of Economics J. Bradford DeLong, 601 Evans Hall, #3880
University of California at Berkeley
Berkeley, CA 94720-3880
(510) 643-4027 phone (510) 642-6615 fax

This document:

Search This Website

Feedback is always very welcome...