


Pair of Clark standard cells in one case

Profs. Ayrton and Perry standard inductance

Clark standard element (cell) no. 142
1872

Clark standard cell

Electrically maintained tuning fork, by Muirhead

Standard resistor no. 4644

Standard air capacitor

Pair of Clark standard cells in one case

1/3 microfarad standard condenser
1892

Clark standard cell no. 1297 by Nalder Brothers and Co.

Standard condenser no. 30510
1911
Pair of turned wooden standards
1880-1920