Gregorian telescope
Type of astronomy magnifier / From Wikipedia, the free encyclopedia
The Gregorian telescope is a type of reflecting telescope designed by Scottish mathematician and astronomer James Gregory in the 17th century, and first built in 1673 by Robert Hooke. James Gregory was a contemporary of Isaac Newton, and both often worked simultaneously on similar projects. Gregory's design was published in 1663 and pre-dates the first practical reflecting telescope, the Newtonian telescope, built by Sir Isaac Newton in 1668.[1] However, Gregory's design was only a theoretical description, and he never actually constructed the telescope. It was not successfully built until five years after Newton's first reflecting telescope.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/2/23/Gregorian_telescope.svg/640px-Gregorian_telescope.svg.png)