Dialling

Dialling or dialing usually means to make a telephone call by operating its rotary dial.

Etymology

The word, dial, comes from the Latin dialis = "daily", because a sundial throws a shadow related to the time of day. It was also used to describe the gear in a medieval clock which turned once per day.

The word dialling originally referred to the creation of the mathematics required to create a sundial face to tell time based on the position of the sun. Those skilled in the art were referred to as dialists or gnomonists; taken from the word gnomon (a device using a shadow as an indicator).

The mathematician William Oughtred published a book, Easy Method of Mathematical Dialling, around 1600.^[1] Samuel Walker (1716–1782) was a Yorkshire mathematician and diallist.^[2] In his later years, Thomas Jefferson was known to practice dialling as a mental exercise.^[3] Professor of astronomy at Gresham College (London, UK), Samuel Foster (d. 1652), developed reflex dialling, which describes a device of his own invention: a sundial capable of reflecting a spot of light onto the ceiling of a room.^[4]

References

1. ^ Answers article about William Oughtred
2. ^ Index of British Mathematicians Part III 1701-1800 by Ruth V & Peter J Wallis (published by University of Newcastle upon Tyne?)
3. ^ a letter from Mr. Jefferson to Charles Clay in 1811
4. ^ Miscellanies: or, mathematical lucubrations by Samuel Foster, edited by John Twysden (1607-1688), published 1659 in London by R. & W. Leybourn