Building Charles Babbage’s computer

Building Charles Babbage’s computer

Researchers are trying to build the Babbage Analytical Engine,a room-size machine designed by Charles Babbage in the 1830s that uses primitive punch card


Researchers in Britain are about to embark on a 10-year,multimillion-dollar project to build a computer—but their goal is neither dazzling analytical power nor lightning speed.

Indeed,if they succeed,their machine will have only a tiny fraction of the computing power of today’s microprocessors. It will rely not on software and silicon but on metal gears and a primitive version of the quaint old IBM punch card.

What it may do,though,is answer a question that has tantalised historians for decades: Did an eccentric mathematician named Charles Babbage conceive of the first programmable computer in the 1830s,a hundred years before the idea was put forth in its modern form by Alan Turing?


The machine on the drawing boards at the Science Museum in London is the Babbage Analytical Engine,a room-size mechanical behemoth that its inventor envisioned but never built.

The effort—led by John Graham-Cumming,a programmer,and Doron Swade,a former curator at the museum—has already digitised Babbage’s surviving blueprints for the Analytical Engine. But the challenges of building it are daunting.

The Analytical Engine was a work in progress,as Babbage continually refined his thinking in a series of blueprints. Thus,the hope is to “crowd-source” the analysis of what should be built; plans will be posted online next year,and the public will be invited to offer suggestions.

“There is no single set of plans that design a single machine.” said Tim Robinson,a docent at the Computer History Museum in Mountain View,Calif. “It was constantly in a state of flux.”

The project is significant in part because there has been a heated debate over whether—given time and resources—Babbage would have been able to build the machine he foresaw.

The idea was proposed last year by Graham-Cumming,who suggested a three-step project in which a decision would first be made on which blueprint to focus on,then a three-dimensional computer simulation would be created,and finally the machine would be built. “I hope that future generations of scientists will stand before the completed Analytical Engine,think of Babbage and be inspired to work on their own 100-year leaps,” he wrote.

Babbage,who lived from 1791 to 1871,is rightfully known as the “father of computing.” But it would be left to a fellow scientist,Augusta Ada King,Countess of Lovelace,to fully appreciate that his inventions were more than just tools for automatically tabulating logarithms and trigonometric functions.

Lovelace—daughter of the poet Lord Byron—recognised that the Analytical Engine could be a more generalized media machine,capable of making music and manipulating symbols. And 113 years before John McCarthy coined the term “artificial intelligence,” she considered—and then rejected—the notion that computers might exhibit creativity or even thought.

While Babbage was driven by the desire to automate tabular data for military and related applications,Lovelace wrote a lengthy commentary on the design that would prove deeply influential when it was rediscovered in the middle of the 20th century.

Lovelace is known as the first programmer,because she designed a program for the unbuilt machine. The algorithm appears in a series of notes written by Lovelace after a friend of Babbage asked her to translate an Italian professor’s write-up of a lecture Babbage had given at the University of Turin.

The Lovelace notes are remarkable both for her algorithm for calculating the sequence known as Bernoulli numbers and for what would become known as the “Lovelace objection.” In passing,she commented that the Babbage computer would not originate anything,but rather could do only what it had been instructed. The implication was that machines would not be creative,and thus not intelligent.

The consensus of computer historians is that while Babbage was clearly the first to conceive of the flexible machine that foreshadowed the modern computer,his work was forgotten and was then conceptually recreated by Turing a century later.

In 1936,Turing reformulated and advanced ideas first put forward by Kurt Gödel in 1931,positing the existence of what would be called “Turing machines”—an abstract computing device that was intended as an aid to exploring the limitations of what could be computed—and demonstrating that such devices could in principle perform any mathematical computation that was represented as an algorithm.


“The pioneers of electronic computing reinvented the fundamental principles largely in ignorance of the details of Babbage’s work,” said Dr Swade,the former museum curator. “They knew of him,there was a continuity of influence,but his drawings were not the DNA of modern computing.”