Educational contact goniometer with fixed limbs
S.L. Penfield, New Haven, Conn., U.S.A.
Contact goniometer (cardboard 15 x 7.7 cm) with fixed
celluloid limbs, with instruction leaflet (12 x 20.2 cm)
in stiff paper envelope (16 x 8.7 cm).
Signed "CONTACT GONIOMETER | MODEL B. | Designed
by | S.L. Penfield | Professor in Yale University | Made
in New Haven, Conn., U.S.A. | Pat. July 31, 1900."