A Londoner, whose addresses included Denmark Street, Soho (1776), Mr Gamble's near King's Arms Stairs, Lambeth (1777) and Constitution Row, Gray's Inn Road (1799-1802), Newton's copper-engraved plates provided many of the hand-coloured illustrations of Cornwall for Grose's Antiquities of England & Wales (1786).
His brother William (1735-90) was an architect, and son William John (1785- 1869) also became an engraver.
works and access
Works include: Pendennis Castle, Cornwall, the NW aspect (1786); Pengersick Castle, Cornwall (1768); Fowey Castle, plate 1 - the North side (1768); Fowey Outer or St Catherine's Castle, East aspect Plate 1 (1786); Mount's Bay (1786)
Access to Work: Hand-coloured original print illustrations from a copper engraved plate, Antiquities of England and Wales (Grose 1786); http://www.heatons-of-tisbury.co.uk/cornwall3.htm
misc further info
Thieme and Becker