282 ANNUAL REPORT SMITHSONIAN INSTITUTION, 196 



puters for solving very complicated mathematical problems, and 

 businessmen use them for the clerical operations associated with the 

 processing of their data. 



HISTORY 



Mechanical aids to computation go back to the abacus, an ancient 

 device still widely used in many parts of the world. The number 

 representation system of a form of the abacus, with two beads above 

 a bar and five below for each decimal digit, is now widely used in an 

 electronic equivalent form, biquinary^ in many modern computers. 

 The adding machine was invented in 1642 by Blaise Pascal. This 

 type of calculator was developed esx^ecially in the last century and 

 is now widely used. Automatic multiplication and division by cal- 

 culators was invented in 1902. 



The man who had the original concept of what is now known as a 

 digital computer was Charles Babbage, 1792--1871. Babbage was a 

 professor of mathematics at Cambridge University but engaged in 

 many activities outside the field of mathematics.^ Bab1)age first con- 

 ceived of a "difference engine" in 1822. This mechanical device would 

 permit the automatic production of mathematical tables such as 

 logaritlims, sine, cosine, and other numerical functions. However, 

 before he had completed this project he conceived of a much more 

 general computing device called an "analytical engine." It contained 

 most of the concepts now considered to be essential in a digital com- 

 puter. He drew up elaborate detailed drawings for the device. How- 

 ever, it was mechanical and required skills not then available. Only 

 part of the machine was built ; it is now in the British Science Museum. 



Despite the fact that it was never built, the significance and impli- 

 cations of such a device were miderstood by a number of people at 

 that time. Lady Ada Augustus Lovelace, 1815-52, daughter of Lord 

 Byron, was quite familiar with the analytical engine and its potential- 

 ities. Much of what we know about the device is due to her writings 

 on the subject. 



About 100 years after Babbage, circumstances made it possible to 

 build a digital computer. During World War II tecliniques were 

 developed which were used for building the first electromechanical 

 computers using electrical relays. Mark I was built at Harvard in 

 1944. Electronic techniques, however, permitted much higher rates of 

 operation. The first electronic computer, ENIAC, was built at the 

 University of Pennsylvania in 1946. It used 18,000 tubes, and with 

 the unreliability of tubes at that time it was easy to "prove" that tubes 



1 As Indicated In Bowden (see blblloprapbyl, I?abbn?re Invented the cowcatcher, the 

 speedometer, suggested a fixed fee for posting letters, made an operations research analysis 

 of the pin Industry, was the first to eall across a railroad viaduct In a handcar, among 

 other Interesting activities. 



