An account of the Royal Society’s Newton telescope

Abstract

'THE FIRST REFLECTING TELESCOPE INUENTED BI S R ISAAC NEWTON AND MADE WITH HIS OWN HANDS IN THE YEAR 1671’ These words are engraved on a brass plate screwed to the base of the little telescope that has been revered by the Royal Society as the handiwork of its greatest Fellow, Isaac Newton (1642-1727), who was President of the Society from 1703 until his death. Newton is normally credited with the invention of the reflecting telescope, an invention widely and enthusiastically publicized by the Royal Society when Newton sent one of his instruments to London to be inspected by the Society’s Council in 1671. In spite of the confident message on this engraved plate (its eccentric orthography suggesting an enhanced antiquity), the original telescope presented by Newton in 1671 did not remain in the Society’s care. The surviving Newton telescope (figure 1) was presented to the Society in 1766 by the antiquary George Scott, F.R.S., on behalf of Heath & Wing, a firm of scientific instrument-makers in the Strand, London. Scott affirmed that it was ‘formerly belonging to Sir Isaac Newton, P.R.S., and made by himself’. But can this instrument properly be associated with Newton? This brief account looks at the history and provenance of Newton’s early reflecting telescopes and argues that at least part of the extant instrument may be Newton’s, making it possibly the world’s oldest surviving reflecting telescope.