John Hadley
1682-1744
English mathematician and inventor who built the first working reflector telescope. Hadley built his Gregorian reflector telescope in 1721. The device contained a 6-inch (15.2-cm...
Read more
John Hadley
1682-1744
English mathematician and instrument maker whose new grinding techniques made it possible for him to construct high quality reflecting telescopes. His first such instrument was c...
Read more
John Hadley