The Charles Babbage (1791-1871) issue commemorates the 150th anniversary of his death.

Charles Babbage is considered the ‘father of the computer.’ The 1820s saw Babbage work on his Difference Engine, a calculator that prepares numerical tables, using a mathematical technique known as the method of finite differences, by arithmetical addition only. It consisted of two major parts — the calculating mechanism and the printing and control mechanism. It operated on digits 0–9, represented by positions on toothed wheels and was designed to stamp its output into soft metal, which could later be used to produce a printing plate. In 1832, a working part (one-seventh) of the calculating section was assembled, but it was limited to two orders of differences and five figures, suitable for demonstration purposes only. It was about 24” high, 19” wide, and 14” deep, and worked perfectly producing tables based on the quadratic n^{2}+n+41. The terms of this sequence are 41 (n=0), 43 (n=1), 47 (n=2), 53 (n=3), 61 (n=4) …, giving the differences of the terms as 2, 4, 6, 8 … and the second differences a constant value of 2, 2, 2 …