Abstract :
This article discusses the significance of a letter from Charles Babbage to L. A. J. Quetelet, the Belgian statistician and astronomer, written in the spring of 1835, describing the earliest concept of the Analytical Engine. Quetelet caused the major portion of the letter to be printed, but it has never been fully translated into English. The article includes a modern translation of the full letter and compares it, where appropriate, with the partial translation printed in Taylor\´s "Scientific Memoirs" in 1843.