He developed the first reflecting telescope, which featured a concave mirror, a flat mirrow & an eyepiece
Newton's first reflecting telescope was completed in 
1668 and is the earliest ... Newton built his reflecting telescope because he 
suspected it could prove... [DOC] [TLE] Reflecting telescope - Wikipedia [PAR] A reflecting telescope (also called a reflector) is an optical telescope which uses 
a single or combination of curved mirrors that reflect light and form an image.