Abbort , charles Greely (1872-1961)
/ / / Abbort , charles Greely (1872-1961) / /
Diagonal
/ / / Diagonal / /
Advance of Perihelion
/ / / Advance of Perihelion / apsidal /
field rotation
/ / / field rotation / /
CARBON NITROGEN OXYGEN CYCLE
/ / / CARBON NITROGEN OXYGEN CYCLE / /
Orthoscopic eyepiece
/ / / Orthoscopic eyepiece / /
Plossl eyepiece
/ / / Plossl eyepiece / /
Ramsden eyepiece
/ / / Ramsden eyepiece / /
Kellner eyepiece
/ / / Kellner eyepiece / /
Huygens eyepiece
/ / / Huygens eyepiece / /
Chiron
/ / / Chiron / /