One of two glass positives:- Jupiter, J.H. Reynolds, Birmingham, 1917, December 13, 28-inch reflector, equivalent focal length, 160 ft, 8 1/2" x 6 1/2" One of two glass positives:- Jupiter 1917
One of two glass positives:- Jupiter, J.H. Reynolds, Birmingham, 1917, November 16, 28-inch reflector, equivalent focal length, 160ft One of two glass positives:- Jupiter 1917; 1929
One of of three platinotype prints of engravings in, 'Selenographia' by Johannes Hevelius, 1647 showing sunspots observed through a telescope. From page 519 and dated 3 May to 16 May 1644. Drawing of sunspots, German, 28 October 1642.
Telrad telescope finder, a naked eye sighting instrument using a magnified illuminated reticle projected onto an inclined glass plate Telrad telescope finder
One of of three platinotype prints of engravings in, 'Selenographia' by Johannes Hevelius, 1647 showing sunspots observed through a telescope. From page 525 and dated 27 August to 8 October 1644. Drawing of sunspots, German, 28 October 1642.