Wood-Framed Mechanical Lantern Slide of the Orbits of Earth and Venus, Oxford{??}, c.1880

Wood-framed lantern slide with brass alloy cog wheel winding mechanism attached with 4 screws. 4 pins hold the frame in place. Labelled: " This to the Condensor. Top side in Lantern. Handle on the right. Turn quickly." Another label : "13". A label on the top edge of the frame "U". On the other side of the frame is hand written " Earth 8 to Venus 13 Takes about 1& 1/2 months to do .(?).." A handwritten note on the bottom edge of the frame "University Observatory Oxford". A yellow circle of glass in the centre represents the sun.