Dr. Howard McClenahan, Secretary of The Franklin Institute and Director of the Museum; Samuel Fels; and Dr. James Stokley, the Institute's Associate Director for Astronomy, admire the Mark Zeiss II planetarium instrument in the Fels Planetarium, circa 1933
http://www.rittenhouseastronomicalsociety.org/Pages/rasmedalrecipients.htm
The lattice-like projector support is designed to be a lightweight as possible to minimize vibration while the instrument is in motion. The construction of the planetary projector cages is similarly constructed.
http://www.savethebuhl.org/jake.html型號是Zeiss II星象儀.
