Sciothericum telescopicum
Sciothericum telescopicum was a sundial (sciothericum) that incorporated a telescope (telescopicum) for greater accuracy in determining exactly when noon occurred. It was invented by William Molyneux in Ireland in 1686.[1] The device used a telescopic site to determine the position of the center of the sun relative to a double gnomon and could thus determine the time of noon to within 15 seconds. The improved accuracy was important for geography, navigation and astronomy calculations.[2][3]
References
- ^ William Molyneux, “A New Contrivance of Adapting a Telescope to an Horizontal Dial for Observing the moment of Time by Day or Night”, printed by Andrew Cook and Samuel Helsham, 1686
- ^ Philosophical Transactions of the Royal Society of London, October 1686, No. 184 p. 213 et seq.
- ^ Dn. Johanni Georgio IV, Acta eruditorum, 1687, p 623 et. Seq.