A sixth satellite was proposed for Uranus in 1797 by William Herschel to provide us with a terminus post quem for the orrery.
The youngest child of George Adams senior (1709-1772) by his second marriage, Dudley Adams was apprenticed to his brother George to train as a mathematical instrument maker. On his marriage ten years later, his mother gave him the globe plates and tools that had belonged to his father, and in 1788 he opened his own shop at 53 Charing Cross. In 1794, possibly as a result of supplying 28 inch globes for Lord Macartney's mission to China, he was appointed globemaker to George III, a prestigious post previously held by his father. However, he lived well beyond his means, and his bankruptcy in 1817 ended the Adams instrument business, founded in 1734.