Editing Difference engine (section)

{{Short description|Automatic mechanical calculator}}
{{For|the novel by William Gibson and Bruce Sterling|The Difference Engine}}
[[File:Babbage Difference Engine.jpg|thumb|The London [[Science Museum (London)|Science Museum]]'s difference engine, the first one built from Babbage's design. It has the same precision on all columns, except in calculating polynomials, the precision on the higher-order columns could be lower.]]

A '''difference engine''' is an automatic [[mechanical calculator]] designed to tabulate [[polynomial]] functions. It was designed in the 1820s, and was created by [[Charles Babbage]]. The name ''difference engine'' is derived from the method of [[finite differences]], a way to interpolate or tabulate functions by using a small set of polynomial co-efficients. Some of the most common [[mathematical function]]s used in engineering, science and navigation are built from [[logarithm]]ic and [[trigonometric functions]], which can be [[Taylor series|approximated]] by polynomials, so a difference engine can compute many useful [[Mathematical table|tables]].