Nuremburg type microscope with JFF branded in heart-shape on base, German, late 18th or early 19th century Nuremburg type microscope with JFF branded in heart-shape on base 1780-1820
Nuremburg type compound microscope, marked "JFF" in heart shape, German, late 18th or early 19th century Nuremburg type compound microscope 1780-1820
Nuremburg type microscope, with "iM" in oval branded on base, German, late 18th or early 19th century Nuremburg type microscope 1771-1820