Publication: The Telegrapher
New York, NY, United States
The Centenary Insulator. — Little's Dry Zone Inverted Cup,
or Umbrella insulator, Universally Used.
BY RIP VAN WINKLE.
IT has been said that, among the impossibilities cited to convince Job of his weakness and impotence, the Almighty asks, "Canst thou send lightnings that they may go and say unto thee, here we are?" It is not to be inferred that the Almighty, in propounding this question, which at that time could not be affirmatively answered by mortals, intended to suggest an impossibility, the removal of which was not to be at a future time vouchsafed to his creatures.
Just about one century had elapsed since Watson, in 1747, erected at Shooter's Hill, Kent, England, his telegraph line of nearly two miles in length, down to 1846, when George Little came into the telegraphic field. In the interval telegraph engineers had been greatly exercised and troubled to discover a means of confining the electric current to the wires suspended in the air, which of course was and is an essential prerequisite of successful telegraphy. This problem appeared to the pioneer telegraphers and electricians almost insurmountable. They had resorted to the use of baked wood, cloth saturated with gum-lac, glass knobs and double cones of earthenware (with the wire threaded through the centre), and other devices, all of which proved insufficient and fallacious.
In 1846 Kimber, of London, a maker of moulds for glassware, was employed to make suitable moulds for the manufacture of Mr. Little's dry inverted cup zone, or umbrella insulator. This was fully described and illustrated in THE TELEGRAPHER for December 5, 1868. At the same time that the moulds were made for the manufacture of glass insulators of this pattern, the stoneware pottery at Lambeth, and the porcelain pottery at Staffordshire were also turning out the dry zone insulators in stoneware and porcelain. These came into extensive use at once, and was really the first practical step made in a hundred years towards the proper method of insulating land lines, now universal throughout the world.
By means of this valuable discovery, which solved one of the most difficult problems in practical telegraphy, it is possible to transmit signals over a circuit of live hundred miles, in weather which would, without this form of insulator, render it impossible to do so for fifty, and not unfrequently for five miles even.
It is left to the practical telegrapher what could be done in telegraphy, especially with the rapidity of transmission now indispensable, without Little's dry zone inverted cup, or umbrella form of insulator.