Book excerpt: 2015 Reprint of 1931 Edition. Full Facsimile of the original edition. Not reproduced with Optical Recognition Software. The father of modern quality control, Walter A. Shewhart brought together the disciplines of statistics, engineering, and economics in a simple but highly effective tool: the control chart. This technique, and the principles behind it, has played a key role in economic development from the 1940's through to the present day. Most of Shewhart's professional career was spent at Western Electric as an engineer from 1918 to 1924 and at Bell Telephone Laboratories from 1925 until his retirement in 1956. In addition, he served for more than 20 years as the first editor of the Mathematical Statistics Series published by John Wiley & Sons.