The Promptuary Papers

Introduction Napier’s bones was to be found in a Spanish museum. Tomash travelled to Spain and quickly deThe Annals of the History of Computing has been able to publish a number of items concerned with the very beginnings of the art of mechanized calculation. Included in these items are a few that make reference to the invention, by John Napier, of a device similar to, but more powerful than, the famous Napier’s bones. This modification of the Napier’s bones, known as the promptuary of multiplication, has remained little known for two basic reasons: Napier’s description of the device has not been readily available other than in the rather cryptic Latin original; and no physical example of the device was known to exist other than a cardboard replica, now in the Royal Scottish Museum in Edinburgh, that was made for exhibit during the Napier Tercentenary Celebration Conference held in Edinburgh in 1914. The first hindrance to the study of the promptuarium, as Napier called it, was removed when William F. Hawkins produced an English translation of Napier’s Rabdologiae in 1979. The portion of this translation which referred to the Promptuarium was printed in a supplement to the 16th volume of The New Zealand Mathematical Society Newsletter in December 1979. Hawkins not only translated Napier’s description, but also added some notes of his own to clarify the method of construction and use of the device. The second obstacle fell when Erwin Tomash, through contacts in the museum community, found out that a peculiar instrument similar to a set of