Assertion: positive eyepiece | /r/HasProperty | constructed by c. huygens
Facets:
value: in the mid-17th century
type: TEMPORAL
value: by the english scientist
type: OTHER
Source sentences:
text: Positive eyepieces of a type still used today were constructed by C. Huygens in the mid-17th century and by the English scientist J. Ramsden in the late 18th century.
text: Positive eyepieces of a type still used today were constructed by C. Huygens in the mid-17th century and by the English scientist J. Ramsden in the late 18th century.