10. Hand-held Camera Obscura, c. 1700
Two boxwood, pasteboard and green vellum tubes, with gold tooling, one sliding within the other. At end of the drawtube is a convex lens, 50 mm in diameter and focusing at 160 mm, with a clear glass cover mounted in a boxwood ring screwed in front of the lens, while at the further end of the inner tube there is a ground glass screen on which the image is focused. The gold tooling is of the pattern found on English microscopes and telescopes during the period 1700-1720.
Length 190 mm, diameter 70 mm (closed).
Inventory no. 83,805.