Crystal Palace International Electric Exhibition 1881-82

22 v. South. Devon invert insulator ("brown). w. „ „ „ (white). x. Andrew’s invert with, ebonite inner shed. y. „ „ bolt tube „ z. „ ,, bolt tube and shed. A. Ebonite insulator, single shed. B. Old form of shackle. 0. Bright’s shackle. D. Modern terminal insulator. E. Cordeaux’s screw insulator (1877). F. „ „ single insulator. [33.] Head of Pole, showing mode of leading in and terminating. [34.] Old Form of Testing Tablet. [35.] COLLECTION OF BATTERIES. a. 1844. Sand Battery in wooden trough. This battery was in general use in England on the lines of the Electric Telegraph Company from. 1844 till 1854. b. Sand Battery in Gutta-percha Trough. c. 1853. Troiufh form of Daniell’s Battery. This superseded the sand battery and was modified and introduced by Mr. John Fuller. d. Chamber Daniell Battery. A modified form of trough, battery introduced by Mr. John Muirhead in 1857. e. Small-size ditto. f. Daniell’s Battery. As used by the Postal Telegraph Department. g. h. Bichromate Battery (large and medium sizes'). As used by the Post Office Telegraph. Department, introduced by Mr. John Fuller, 1876. 1. Gravity Leclanche Battery. As used by the Post Office Telegraph. Department. h. 1862. Varley’s Secondary Battery. Used for some years in connection with, the time signals at the central station. It was charged by an ordinary battery for about half an hour previous to giving the time signal. [36.] SPECIMEN'S OF SUBMARINE CABLES IN USE BY THE P.O. TELEGRAPH DEPARTMENT. a. Isle of Man (shore end). b. Wexford, old (deep sea). c. Reuter's (shore end). d. Belfast. e. Seven-wire, shore end. Modern type. f. On© ditto ditto.