Assertion: reflecting telescope's mirror | /r/HasProperty | focuser
Facets:
Source sentences:
text: Like the refractor, there is a tube, but instead of lenses there are two mirrors (a primary at the bottom of the tube and a secondary flat diagonal mirror near the top), then a focuser and eyepiece, usualy on a dobsonian mount, but can be on a tripod, fork or other equatorial-type mount.