Details
A Crookes' pattern vacuum tube with two electrodes,
the elongated bulb containing phosphorescent mineral substances, on wood stand -- 9in. (23.5cm.) high; a Crookes' tube, the pear-shaped bulb with centre butterfly; and a double radiometer with amber knop, shaped stand with spreading foot -- 13in. (33.6cm.) high (A) (3)
the elongated bulb containing phosphorescent mineral substances, on wood stand -- 9in. (23.5cm.) high; a Crookes' tube, the pear-shaped bulb with centre butterfly; and a double radiometer with amber knop, shaped stand with spreading foot -- 13in. (33.6cm.) high (A) (3)