Editing Newtonian telescope (section)

{{Short description|Type of reflecting telescope}}
{{redirect|Newton telescope|the observatory at the Canary Islands|Isaac Newton Telescope}}
{{use British English|date=November 2013}}
[[File:Newtonian telescope with woman looking through it.png|thumb| Woman looking through a Newtonian telescope]]

The '''Newtonian telescope''', also called the '''Newtonian reflector''' or just a '''Newtonian''', is a type of [[reflecting telescope]] invented by the English scientist [[Sir Isaac Newton]], using a [[Curved mirror#Concave mirrors|concave]] [[primary mirror]] and a flat diagonal [[secondary mirror]]. Newton's [[Newton's reflector|first reflecting telescope]] was completed in 1668 and is the earliest known functional reflecting telescope.<ref name="books.google.com">{{cite book |url=https://books.google.com/books?id=7R8LsvMcUioC&pg=PA67|title=Isaac Newton: Adventurer in Thought |first=A. Rupert |last=Hall |page=67 |year=1992 |publisher=[[Cambridge University Press]]|isbn=9780521566698 }}</ref> The Newtonian telescope's simple design has made it very popular with [[amateur telescope making|amateur telescope makers]].<ref name="ingalls1935">{{cite book
 | title = [[Amateur Telescope Making]]
 | editor-last = Ingalls  | editor-first = Albert G. | editor-link = Albert Graham Ingalls
 | publisher = Munn and Co., Inc.
 | edition = 4th
 | year = 1935
}} [https://archive.org/details/in.ernet.dli.2015.37314] </ref>