Physical description

Machined, assembled, cast, moulded. Plastic possibly stamped/painted with inscription.

Inscriptions & markings

Handwritten in what appears to be whiteout on top circular face: ½ watt. Dymo label adhered to front: PHYSICS PT2 F2 [Stamped] inscription on top: No 2470/ HARTMANN & BRAUN/ FRANKFURT ^/M /T.C.=+0,00002/10/OHM/bei 18oC. [Stamped] inscription centred on rim of top circular face in the front: 10hm=106, 3 cm/mm2 Hg. 0 oC. Medallion on top circular face: P.T.R. 38/ 1900. Handwritten on chipped paint dot on top: “2” (?)