John Hadley John Hadley, a mathematician aged 49, presents a new instrument of navigation, the octant, also known as the reflecting quadrant, at the Royal Society. A member of the Royal Society, he is already and rightly famous as the inventor of the parabolic reflecting telescope which he presented ten years ago. Three other person at least are working on an instrument of the same sort these days : (1) Thomas Godfrey, 27, a glazier, likely ahead of the group by one or two y