Cubic black box with ten brass contacts over which a rotary contact wiper moves; the wiper is rotated by a black knob.
Inscriptions & markings
Inscribed on top: “INDUCTANCE Type 17-C”, “10 x 0.01H”, “Muirhead & Co. Ltd No. 126967”, “PI 111”. On front: “MUIRHEAD”. Label: “Purchased by UNIVERSITIES COMMISSION”
