Transferred from the Department of Commerce, Bureau of Standards.
Country of Origin: Germany
3-D Test: 6.4 x 25cm, 1.7kg (2 1/2 x 9 13/16 in., 3 3/4lb.)
Metal, and glass
Clock shaped instrument, with white luminous figures on black face. 250mm diameter, 60mm deep; c. 1925.