DEMONSTRATION LENS PAIR, POSITIVE AND NEGATIVE
Stock Number: 9340
$295. the pair
For sale, antique lenses for, e.g., magnifying or diminishing a printed word. The lenses are double convex and double concave and the pair is in excellent condition.
Dimensions
3-3/4 inches overall
Circa
c. second half 19th century
Description
DEMONSTRATION LENS PAIR, POSITIVE AND NEGATIVE, c. second half 19th century, made of plated brass, 3-3/4″ (9.5 cm) tall with their curviform handles. One lens is double convex (positive) with a focal length of about 3-1/2″; the other lens double concave. In an exemplary demonstration, the former will magnify the printed word, the latter diminish it. An unusual pair, in excellent condition.
Ask the Dealer
Dealer information
TESSERACT
David and Yola Coffeen both have enjoyed academic careers, as planetary astronomer and as linguist/educator. But since 1982 (yes, 1982!) they have been full-time dealers in early scientific and medical instruments, under the name Tesseract. Selling primarily by catalogue (over 100 issued so far) they also have a web presence at www.etesseract.com, and can be contacted at [email protected].
