scope, optical telescope, stenometer, speculum, monoscope, telephoto lens, telespectroscope, spotting scope, telephotometer, magnascope, more...

microscope

refracting, reflecting, radio, infrared, X-ray, gamma ray, neutrino, radio telescope, more...

inch, small, large, astronomical, powerful, great, refracting, good, optical, foot, ray

galileo used one,   using a spyglass,   long binoculars,   hubble component,   a scope,   observatory feature,   celestial glasses,   astrometric glasses,   looking tool