Early Telescope Designers: James Gregory (1638 – 1675)

Gregory and Cassegrain: The Fathers of Compound Telescopes

In the space of just 10 years a Scottish mathametician by the name of James Gregory and Laurent Cassegrain, a French priest and science teacher, both proposed ideas for an optical configuration they hoped would improve upon Newton's reflector by eliminating the obstruction of the primary mirror.

Nether man was able to construct a working model of the design, but their ideas were not forgotten. Some 250 years later their ideas became the basis for nearly every compound scope that followed.