In 1821, Charles Babbage set out to create a machine that would mechanize mathematical computations. Over the next two decades, Babbage designed three machines: Difference Engine No. 1 (Babbage completed a section of this machine in 1832), the Analytical Engine (for which Ada Lovelace wrote the first published computer algorithm) and Difference Engine No. 2. Alas, none of these machines came to fruition during Babbage's lifetime. In 1985, a team at Science Museum in London launched a project to build Difference Engine No. 2. To create this machine, the team used Babbage's original designs, which were created between 1847 and 1849. In 2002, the team successfully completed the project, at last making Babbage's computer a reality. The Computer History Museum has created this fascinating online exhibit about Charles Babbage and Difference Engine No. 2. The exhibit incorporates a number of fascinating primary documents, including a photograph of the portion of the Difference Engine that Babbage was able to complete in 1832 and portions of Babbage's plan for Difference Engine No. 2.