Herschel Speculum metal blank for primary mirror

Model created for manufacturer to reproduce the blank speculum mirror used within the William Herschel 7ft replica telescope. Instead of glass, the mirrors are made from speculum metal which is an mixture of two thirds copper and one third tin. 4 blanks are to be reproduced for the William Herschel Society and ground and polished to a reflective surface. Source: Objaverse 1.0 / Sketchfab