Telegraphic Insulation, Brooks and Kenosha mentioned

Telegraphic Insulation. — Common Sense and

Common Nonsense, as Displayed on

the Subject.

THERE has been some good sense, or rather common sense, and much common nonsense displayed in the consideration and practical treatment of the important matter of the insulation of telegraph wires. From its first issue, down to the last number of THE TELEGRAPHER which has appeared, I have been an attentive and interested reader, and have been especially interested in the subject of insulation of telegraph wires, upon which so much has appeared in its columns. Let it not be understood that the writer is the inventor or designer of a telegraph insulator. So far from it has the writer been, that he has never even bad such a design under consideration. Seeing the blunders which so many others have made in this specialty, it has been sufficient, and no doubt much safer for him to criticise [sic] criticize others than to offer anything of his own in that line to be criticised [sic] criticized, and most probably very properly condemned in its turn. Neither is he the special and interested advocate of any particular insulator or system of insulation. What is heartily desired is to get at facts and correct principles in the business, leaving to others the task and profit, if there be any, of successfully and practically applying them.

At the first view, the insulation of telegraph wires would seem to be a very simple matter. Experience has demonstrated the fact that it is far otherwise. It might be supposed, and was originally supposed, and by not a few practical telegraphers is still supposed that all that is necessary is to provide some substance of low electrical conductivity on which to support the wires, and the problem would be solved. Glass fulfils this condition, and in dry or very cold weather is as good an insulator as could be desired. The quantity of electricity which will pass through glass under ordinary conditions is nil, or infinitessimally [sic] infinitesimally small. The quantity which will pass over it when moisture condenses upon its surface, or is deposited by rain or melting snow and ice, as has been painfully realized from the construction and operation of the first to the latest telegraph line, by thousands of perplexed and bothered operators, is unknown, but by no means inappreciable. Notwithstanding this, the glass insulator is still the one most generally adopted and used in this country. This is what may be very appropriately termed the common nonsense on the subject of insulation. The great as well as the little telegraph companies of the country go on putting on the glass insulators by the tens of thousands and hundreds of thousands, although the exercise of a little common sense on the part of their managers would show them the nonsense of their action.

It may be that glass insulators are designed by an overruling Providence as a punishment for the moral and professional delinquencies of telegraph managers and operators, but why the innocent and ignorant investors in telegraph property should be punished with them, as they are by the loss of money and of business consequent upon their use, is one of those things which appear incomprehensible now, but which may be made plain to us hereafter. Were telegraphy a new enterprise, in which experience and investigation had not had time to teach wisdom, the continued manufacture and use of glass insulators would not, perhaps, deserve to rank among the popular and common absurdities of the age. The contrary, however, being the case, and science and experience having both demonstrated the unfitness of glass for telegraphic insulation, there is no excuse for the obtuseness and pigheadedness which retains them in the telegraphic service.

At an early period in telegraphy there were not wanting those who perceived that by glass alone the telegraphs could never be saved. Those wise individuals sought to overcome the difficulty by inclosing the glass in shells of iron of various forms and thicknesses. This worked very well for a short time, and it was thought that the desideratum in insulation had been found. But in a little while the electricity mysteriously disappeared from the wires soon after leaving the battery, and the latter were short circuited in a manner which was not only destructive of business but also of the batteries, which were greatly excited at the possibility of rapid action afforded by the excellent near ground connection and convenient absence of resistance to the speedy generation and discharge of the electricity which it was their province to supply. Careful examination of the line gave no indication of difficulty or cause for this untoward development. Finally, it occurred to some one who had studied the matter more carefully and comprehensively than his fellows, that iron was exceedingly susceptible to changes of temperature, and expanded and contracted materially with every increase and decrease of heat, and that glass was much less susceptible to the variations of temperature, and was therefore more rigid and unyielding, and being exceedingly brittle withal, the difficulty might perhaps be found in the fracture of the glass, which would, of course, be only apparent upon a close examination. Acting upon this idea some of the insulators were taken down and examined, and it was found that in nearly all of them the glass was fractured, and that they afforded practically but little, if any, insulation to the wire.

In due time the iron-glass insulators disappeared, and were replaced most generally by the previously rejected glass insulators, pure and simple. Various other combinations were experimented with, such as inclosing the glass insulator in a wooden pin, the use of rubber, flint and other similar substances, but still the ultimate result was, in most cases, a return to the glass, as previously used.

Almost every telegraph manager or superintendent had and has his own ideas of what proper insulation and the best insulator consists of, and such as were or are in a position where their experiments can be tried, have displayed their genius in this direction, almost invariably with one result-a practical failure of a more or less complete character. Some of these have been I improvements on glass insulators, but none of them of sufficient merit to secure anything more than a temporary and very limited use.

There are now two insulators presented for adoption, and only two which seem to be a very material improvement upon glass. The first of these, the Improved Paraffin Insulator, manufactured by Mr. David Brooks, of Philadelphia, has stood the test of several years' use, and has thoroughly demonstrated its right to be ranked as nearly a perfect insulator as can be made. The other is known as the Kenosha Carbon Insulator, which has the advantage of the Brooks, in that its first cost is much less. It is claimed to be an excellent insulator, but the writer is not sufficiently acquainted with its merits or demerits practically to speak definitely on the subject. It is being quite extensively used on the Western lines and in Canada, and its advantages or disadvantages will soon be fully demonstrated. If it should prove to be what its advocates claim for it, it and the paraffin insulator must become the insulators of the future.

To continue to use glass insulators when the superiority of other substances for insulating purposes has been fully demonstrated, merely on account of the cheapness of its original cost, would be something more than common nonsense; it would show that those who ire responsible therefor [sic] therefore were actuated either by an utter want of capacity and sense, or by motives even less creditable to them. The adoption of the improved insulators would be but an act of common sense, but one which ought not to be doubtful or tardy when the superiority of such an insulator is fully demonstrated.