Six and a half inch concave mirror of enamel (white glass or Tassies compound), by William Herschel, England, 1780-1820. Prescribed at back:- "no.8, 7 feet enamel mirror (F)" in cardboard round box ("Pl ) without lid, exact focal length 7ft, 3.25 in Concave enamel mirror, 1780-1820 1780-1820
