Engraving by James Watson. Thomas Phelps (1718-1776) and John Bartlett (b 1724) were employed by George Parker, the second Earl of Macclesfield (1697-1764) as Observer and Asistant Observer at the observatory he had built at his Oxfordshire property, Shirburn Castle, in Tetsworth in around 1740. Parker was a notable astronomer and President of the Royal Society from 1752 to 1764, and equipped the observatory with the finest instruments posible. Thomas Phelps had started as a stable boy and John Bartlett was originally a shepherd and both were promoted to their positions by virtue of their outstanding abilities.
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