Hand held electric vibrator, 1909.

Sargrove sprayed-circuit radio receiver (production prototype) c 1940s.

Sargrove sprayed-circuit radio receiver (experimental model) c 1940s.

Sargrove two valve radio receiver, 1947-1948.

Six-stage superheterodyne receiver procesed on the ECME system, c 1940s.

Sargrove sprayed-circuit radio receiver (experimental model) c 1940s.

Poulsen's Telegraphone, 1903.

Poulsen's Telegraphone, 1903.

Hoover washing machine with wringer, 1948.

Hoover washing machine with wringer, 1948.

Hoover washing machine with wringer, 1948.

Hoover washing machine with wringer, 1948.