James Watt achieved lasting fame as an engineer and scientist with his improvement of Newcomen's steam engine. After years of experimentation, in 1775 he entered into a partnership with businessman Matthew Boulton to produce the improved engine. Their success led to the opening of a purpose-built steam engine factory in 1796, after which Watt gradually withdrew from active participation. By 1814, when he commissioned his bust from Chantrey, Watt was a national – if reluctant – celebrity. Following its exhibition in 1815 at the Royal Academy, the bust was frequently reproduced in full-scale marble and plaster replicas, miniature copies in ivory for the mass market and commemorative medals, which is why this particular depiction of Watt is so well known.