Assertion: reflecting telescope's mirror | /r/HasProperty | consider
Facets:
value: to buying a new 74-inch
type: PURPOSE
Source sentences:
text: Typically a secondary mirror that is 20% of the diameter of the primary mirror is consider to incur minimal contrast loss.
text: The mirror was ground by Grubb in the 1950s, although until 1956, according to Observatories and Telescopes of Modern Times, there was some consideration to buying a new 74-inch from Grubb.