Image: BabbageDifferenceEngine

Description: Part of Charles Babbage's Difference Engine assembled after his death by Babbage's son, using parts found in his laboratory. The brass parts were machined by the toolmaker Joseph Clement. Babbage never completed his difference engine, partly due to problems with friction and machining accuracy, but also because he kept changing the design. Henry Provost Babbage inherited the pieces following his father's death in 1871, and some years later in 1879 he assembled several working sections of the full machine. Possibly as many as seven assembled sections exist. This portion, in the Whipple Museum of the History of Science of the University of Cambridge, demonstrates how the addition and carry mechanism works. In the photograph, part of the left hand side is obscured by reflections from the glass display case.
Title: BabbageDifferenceEngine
Credit: Own work
Author: Photograph © Andrew Dunn, 5 November 2004. Website: http://www.andrewdunnphoto.com/
Permission: CC-BY-SA-2.0
Usage Terms: Creative Commons Attribution-Share Alike 2.0
License: CC BY-SA 2.0
License Link: http://creativecommons.org/licenses/by-sa/2.0
Attribution Required?: Yes