Educational contact goniometer with fixed arms

Ward's Natural Science Establishment, Inc. Rochester, N.Y.
Contact goniometer (aluminium 10.8 x 6.2 cm) with an instruction leaflet (12.6 x 15.2 cm) in transparent plastic envelope (14.2 x 8.6 cm) .
Signed "WARD'S ALL-METAL | CONTACT GONIOMETER | WARD'S NATURAL SCIENCE ESTAB., Inc. | Rochester, N.Y. Monterey, Calif. | Cat # 13W0560 Made In U.S.A."
Ca. 1970.

private collection