Charles Piazzi Smyth (1819-1900)

Professor of Astronomy

The astronomer Charles Piazzi Smyth was born in Naples on 3 January 1819. He was educated in Bedford and in 1835 became an Assistant at the Royal Observatory, Cape of Good Hope, South Africa. There he observed Halley's Comet in 1836 and co-operated with Sir Thomas Maclear (1794-1879) in the re-measurement and extension of Lacaille's arc.

In 1846 he was appointed Astronomer Royal for Scotland, based at the Calton Hill Observatory in Edinburgh, and Professor of Practical Astronomy in the University of Edinburgh In 1852 he organised time-signalling by the dropping of a ball on the Nelson Monument on Calton Hill in Edinburgh, improved in 1861 to a time-gun fired from Edinburgh Castle. It involved a signal being sent along a 4,000-foot steel cable - laid by sailors from Leith in just two days - to the gun at Edinburgh Castle. (Today, simultaneous with the firing of the gun, a signal ball still drops from the mast atop the Nelson Monument).

In 1851, Smyth was in Sweden to witness a total eclipse of the sun, and 1856 he was on Tenerife experimenting with a telescope. In 1857 he was elected as a Fellow of the Royal Society. A visit to Russia - visiting observatories - followed in 1859, and in the 1860s he visited Egypt and surveyed the Pyramids. Other activities included: work in spectroscopy; the study of telluric absorption; the construction of a map of the solar spectrum; work with Professor Alexander Herschel on the harmonic character of the carbonic-oxide spectrum; the measuring of the 'citron-ray' of the aurora; gathering meteorological data; the construction of a large solar chart; and, the study of cloud forms using photography.

Charles Piazzi Smyth died on 21 February 1900.