that IBM boss Thomas Watson had not been interested in the new machines initially, and when the first commercial calculation behemoths appeared in the early 1950s, filling whole floors with thousands of heat generating vacuum tubes, he estimated the demand by the US economy at a maximum of five. Later attributions may be found in The Experts Speak, a book written by Christopher Cerf and Victor S. Navasky in 1984, however Cerf and Navasky just quote from a book written by Morgan and Langford, Facts and Fallacies. Another early article source (May 15, 1985) is a column by Neil Morgan, a San Diego Evening Tribune writer who wrote: "Forrest Shumway, chairman of The Signal Cos., doesn't make predictions. His role model is Tom Watson, then IBM chairman, who said in 1958: 'I think there is a world market for about five computers. The earliest known citation on the Internet is from 1986 on Usenet in the signature of a poster from Convex Computer Corporation as I think there is a world market for about five computers' —Remark attributed to Thomas J. Watson (Chairman of the Board of International Business Machines), 1943". All these early quotes are questioned by Eric Weiss, an editor of the Annals of the History of Computing in ACS letters in 1985. There are documented versions of similar quotes by other people in the early history of the computer. In 1946 Sir Charles Darwin (grandson of the famous naturalist), head of Britain's NPL (National Physical Laboratory), where research into computers was taking place, wrote: it is very possible that ... one machine would suffice to solve all the problems that are demanded of it from the whole country. In 1985 the story was discussed on Usenet (in net.misc), without Watson's name being attached. The original discussion has not survived, but an explanation has; it attributes a very similar quote to the Cambridge mathematician Professor Douglas Hartree, around 1951: I went to see Professor Douglas Hartree, who had built the first differential analyzers in England and had more experience in using these very specialized computers than anyone else. He told me that, in his opinion, all the calculations that would ever be needed in this country could be done on the three digital computers which were then being built—one in Cambridge, one in Teddington, and one in Manchester. No one else, he said, would ever need machines of