Difference Engines

Calculating machines were sometimes used to compute and print the mathematical tables widely used by nineteenth century engineers, mathematicians and scientists. A small number of digital computing machines computed and printed mathematical tables by finding successive values of a function using a mathematical technique known as the method of finite differences. The Englishman Charles Babbage proposed such a “difference engine” in 1820, and built a small section of it. Difference engines actually were built by Georg and Edvard Scheutz in Sweden and by George B. Grant in the United States. These pioneering devices were not widely adopted.

This is a replica of the portion of a difference engine built by Charles Babbage in 1832. Babbage, an English mathematician, hoped to compute and to print astronomical tables by machine.
Description
This is a replica of the portion of a difference engine built by Charles Babbage in 1832. Babbage, an English mathematician, hoped to compute and to print astronomical tables by machine. He proposed to estimate the value of functions using polynomials, and to use the method of finite distances to compute results.
Babbage never completed either a difference engine or a more complex, programmable instrument he dubbed an analytical engine.
The machine has three columns of discs. The leftmost column has six discs, each with the numbers from 0 to 9. The middle column has seven discs. The six lower ones each have the digits from 0 to 9. The uppermost disc is marked as indicated. The rightmost column has five discs numbered from 0 to 9. Above these are four discs, similarly numbered, that are immediately adjacent to one another. On the top of the machine are a gear train and a handle. The machine has a metal framework and a wooden base. The replica has containers for springs, but no springs.
The overall dimensions include the handle. Without it, the dimensions are: 59 cm. w. x 43.5 cm. d. x 72 cm. h.
The replica was built for display in the first exhibition devoted to mathematics and computing at the Museum of History and Technology (now the National Museum of American History). A similar replica is in the collections of IBM Corporation.
The original on which this replica is based is at the Science Museum in London. That museum also displays a more recent attempt to build a working version of Babbage’s difference engine.
References:
Merzbach, Uta C., Georg Scheutz and the First Printing Calculator, Washington, D.C.: Smithsonian Institution Press, 1977.
D. Pantalony, “Collectors Displays and Replicas in Context What We Can Learn from Provenance Research in Science Museums,” in The Romance of Science: Essays in Honour of Trevor H. Levere, eds. Jed Buchwald and Larry Stewart, Cham: Springer, 2017, pp.257-275, esp. pp.268-273. This article discusses replicas of the Babbage difference engine, but not the one at the Smithsonian, which was by a different maker than other replicas provided by IBM.
Swade, Doron. The Difference Engine: Charles Babbage and the Quest to Build the First Computer, New York: Viking, 2000.
Location
Currently not on view
date made
ca 1963
date received
1963
maker
Daniel I. Hadley & Associates
ID Number
MA.323584
accession number
252309
catalog number
323584
This is the first printing calculator sold. From ancient times, scientists and mathematicians have calculated numerical tables. These tables were often rife with error, both from incorrect calculations and from errors in reproduction.
Description
This is the first printing calculator sold. From ancient times, scientists and mathematicians have calculated numerical tables. These tables were often rife with error, both from incorrect calculations and from errors in reproduction. In the early 1800s, the English mathematician Charles Babbage proposed a machine called a difference engine that would compute and print automatically a large class of tables. Although Babbage's machine was never completed, it inspired the Swedish publisher Georg Scheutz and his son Edvard to build this instrument. It was exhibited at the world's fair held in Paris in 1855 and sold to the Dudley Observatory in Schenectedy, New York. It also was the first computing machine to carry out computations under U.S. government contract.
For a related object, see 1988.0798.01.
References:
Merzbach, Uta C., Georg Scheutz and the First Printing Calculator, Washington, D.C.: Smithsonian Institution Press, 1977.
Lindgren, Michael, Glory and Failure: The Difference Engines of Johann Mueller, Charles Babbage and Georg and Edvard Scheutz, trans. Craig G. McKay. Linkoping, Sweden: Linkoping University, 1987. Reprinted by MIT Press, 1990.
Location
Currently not on view
date made
1853
maker
Georg and Edvard Scheutz
ID Number
MA.323659
catalog number
323659
accession number
250163
When the Scheutz difference engine was shipped to the Dudley Observatory in Albany, New York, in 1857, all the instructions provided for its use were this set of drawings and a letter explaining the procedure for converting the machine from operation in one number system to anoth
Description
When the Scheutz difference engine was shipped to the Dudley Observatory in Albany, New York, in 1857, all the instructions provided for its use were this set of drawings and a letter explaining the procedure for converting the machine from operation in one number system to another.
The frail tan paper sheet has a white cloth backing. On the sheet are 14 drawings labeled Fig. 1 through Figure 14. The figures are similar to but not identical with those in the final specifications for British Patent A.D. 1854, No. 2214, as reproduced in Merzbach. The numbering is somewhat different.
For a related object, see the Scheutz difference engine, MA.323659.
Reference:
Merzbach, Uta C., Georg Scheutz and the First Printing Calculator, Washington, D.C.: Smithsonian Institution Press, 1977.
Location
Currently not on view
date made
ca 1857
maker
Georg and Edvard Scheutz
ID Number
1988.0798.01
accession number
1988.0798
catalog number
1988.0798.01

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.