Astronomy: a 40-foot telescope constructed by William Herschel, in use outdoors. Coloured etching, 18--.

Apparently copied in reverse from an earlier (ca. 179-?) etching with lettering "View of Dr Herschel's forty feet telescope", which shows the same two figures in 18th-century costume, and some variations in the depiction of the telescope, e.g. the earlier print shows the base of the telescope housed in a wooden shed. The telescope was constructed at Slough for King George III