Early history of British insulators and when first used

32. INSULATORS.

A selection of insulators as used in England at different periods.

a. Iron wire.

b. Three-strand copper (W. F. Cooke's original goose-quill insulator, which was used on the line between Paddington and West Drayton in 1838.

c. Cooke & Wheatstone's original ring insulator (1840).

d. Cone insulator, original form (1845).

e. ..."........."......, later........"

f. ...".........."....., form for repairing broken insulators.

g. Walker's double-cone insulator (brown). (1850.)

h. ....."..........."........."........"...... (white).

i. Physick's insulator (1847), in which the bolt by which the wire is suspended is insulated by mastic cement in the cavity at the top of the insulator

j. Edwin Clark's brown earthenware insulator, with zinc cap (1850).

k. Do., with groove for wire.

l. Do., glass instead of earthenware.

m. (1851) brown earthenware.

n. ....."....glass.

o. Latimer Clark's invert insulator, corrugated (1856).

p. Varley's double-cup insulator, fitted.

q. Ditto, in separate parts, 1862.

r. Varley's No. 11 wire double-cup insulator.

s. Brown earthenware insulator called (Z).

t. Jobson's invert white, double shed.

u. .....".........."...... "... single ....."

v. South Devon invert insulator (brown).

w. ..."........ ".......".........."       (white).

x. Andrews' invert with ebonite inner shed.

y. ......."..........."....bolt tube........"

z. ......."..........."....bolt tube and shed.

A. Ebonite insulator, single shed.

B. Old form of shackle.

C. Bright's shackle.

D. Modern terminal insulator.

E. Cordeaux's screw insulator (1877).