Publication: The Telegrapher
New York, NY, United States
The Improvement in Telegraph Line Construction.-Theories
and Practical Results in the Past.
BY OLD TELEGRAPHER.
IN previous articles which have appeared in THE TELEGRAPHER the writer has referred incidentally to some of the peculiarities of the construction of telegraph lines in the early days of the electric telegraph in this country. It is a subject which might be followed out more fully than it is possible for me to do, with interest and perhaps profit to the present generation of telegraphers. In fact, I do not feel myself qualified to discuss the matter very elaborately, and will, therefore, confine myself to a general consideration of some of the theories of line construction which have found adherents and earnest advocates in the past, with the results of attempts to put them in practice, and of the improvements which have since been made in this direction.
As is familiar to most telegraphers, after the general idea of the electro-magnetic telegraph had been pretty well developed in theory, the first attempt to construct a line over which the signals were to be transmitted was made between Baltimore and Washington - Congress having finally, though reluctantly, and with little or no faith in its success, appropriated forty thousand dollars for the purpose. The original idea was to put the wire underground, in a lead pipe made for the purpose, and a machine for digging the trench into which it was to lie buried was devised by Mr. Ezra Cornell and Mr. F. O. J. Smith, both of whom are yet living, in the enjoyment of handsome fortunes, derived mainly from their connection with the development of the telegraph interest. On account of the lack of insulation of the wire encased in the lead pipe this plan was found to be impracticable, and after a few miles of it had been laid the machine was conveniently broken, aid operations necessarily suspended for the time. It was decided to put the experimental wire on poles, and the line was finally constructed in this manner, as have been all the long lines in this country since. The line thus constructed worked, it is true; but, owing to bad insulation and the crude character of the instruments employed, it would hardly be regarded as a first class line by the telegraphers of the present day.
In connection with the telegraph everything had to be learned, and line construction among the rest. Some of the ideas which were advanced from time to time, even by those most deeply interested in the success of the telegraph, would greatly amuse the telegraphers, who are now better informed as to what is necessary to constitute a decent telegraph line. Wooden poles or posts were, naturally, in a country abounding in timber, adopted as the support of the wires and insulators, and as they are yet cheaper than any substitute which has been proposed, they maintain their position in this respect to the present day, and are likely to do so for many years to conic. Almost every telegraph constructor and manager has his own idea as to the best size for the poles, though generally those of from twenty-five to thirty feet in length have been adopted. Many lines have been built, however, with poles which were comparatively mere pipe stems in appearance. It is not necessary to inform the reader that such lines were and are intended to last only long enough to enable the contractor and builder to get his pay and get out of that section of the country. One superintendent conceived the idea that very short poles were the proper ones to be used, and some years ago a line might be seen along the railroad between Springfield and Worcester suspended on twelve foot poles. The disadvantages of this system of construction, however, soon manifested themselves, and I believe this was the only line thus built.
The theories in regard to the wire conductors employed have been numerous, and not infrequently as ignorant as might be expected front those who originated them. The surface theory, as it was called-that is, that electricity was transmitted mainly upon the surface of the wire, and that, therefore, the more surface that could be obtained with a given quantity of metal the better would he the conducting properties or the wire--set one time had many believers.
Two or three lines were accordingly constructed with a twisted wire, composed of a number of small strands, and naturally in a comparatively short time became oxidized and very brittle from the exposure to the atmosphere and the alternations of wet and dry weather. Some believed that a small conductor, of No. 10 wire, for instance, was just as good, as it certainly was much less costly to purchase or handle than a larger wire, and not a few lines were built of this, and sometimes even smaller wire. Of course, they did not last long. Others believed in obtaining and using the largest sized conductor possible, and No. 6, and sometimes even No. 4 wire has been used for this purpose.
There is no doubt an advantage in the use of these very large conductors, and when properly put up, if inferior insulation is used they are decidedly preferable. The objections to the use of such large conductors consist in the first place of the greater cost of the wire, and secondly, of the much greater difficulty and expense of handling and putting it up. They necessitate, moreover, large and more numerous poles than relatively smaller wire, and the advantages derived from their superiority as conductors may be obtained in a different and less troublesome and expensive manner. The Western Union Company has used a good deal of this large wire on its new lines on the main telegraphic routes, and has undoubtedly found it advantageous in improving the capacity and reliability of its lines, with such conductors as that company, for reasons which it cannot be difficult to understand, persists in using.
In the first year or two of the construction of telegraph lines copper wire was regarded as essential to be used, and in a metallic circuit at that, requiring two wires in all cases to complete the circuit. The unsuitability of copper wire for the purpose, from its extreme ductility, was soon demonstrated, and also the discovery of the earth circuit obviated the supposed necessity of furnishing an expensive conductor to complete the electric circuit. The discovery of the earth circuit was unquestionably one of the most important which has ever been made as regards facilitating the rapid advance of the electric telegraph throughout the world.
It has been in the insulation of telegraph conductors or wires that the most numerous theories, and the most remarkable displays of genius have been made from time to time. It was understood front the first that some method of insulating the wires was indispensable, but the ideas, as regarded the means of accomplishing this, were exceedingly crude, and as various as the persons prepounding them. Glass in some form was employed on all the early lines of telegraph, but some of those who were regarded as bright and shining lights in the telegraphic galaxy of the day regarded glass insulators as too expensive, and one of them, the late Amos Kendall, I think, wrote a sharp letter to Mr. Henry O'Rielly, who was then engaged in constructing one of the earlier lines, for his extravagance in using glass insulators, and suggesting that it would be much cheaper to cut a notch in the top of the poles and wrap the wire with tarred hemp and place it in the notch! Mr. O'Rielly failed to realize the wisdom of this suggestion, and persisted in using the glass insulators, which were the best known at that time, in spite of the expense. The letter making the suggestion is still in existence, and has been deposited by Mr. O'Rielly in the library of the Historical Society, in this city, with a large number of other MSS., and publications, and dam, in reference to the early telegraphic history of the country, where they may be preserved, as their value and importance deserve, for present and future use.
For several years glass was regarded as the only practicable insulator for telegraph wires, the only difference being in the shape and method of supporting them so as to scene the best results. Experiments were made with other substances from time to time, but they resulted in the return to glass. Prof. Royal E. House, the inventor of the House Printing Telegraph Instrument, also invented an insulator, which was used to some extent on the House lines, so-called. It was irreverently styled "the dinner pot insulator" by telegraphers of that day on account of its size and peculiar shape. The insulator consisted of an outer shell of iron, cast with the thread of a screw on the inside. The interior of the insulator was coated with glass. A screw was cut upon the top of the pole and the insulator screwed into it. As long as the glass remained intact the insulator was a very good one, but unfortunately the expansion and contraction of the iron from the effects of heat and cold had not been taken into account, and the glass was soon fractured from this cause. Again, the insulator furnished an excellent object upon which amateur sportsmen could exercise their skill with rifles, pistols, etc., and as at that time the wires, especially in the Western part, of the country, ran for hundreds of miles through the forests, many of the House insulators were soon decorated with bullet holes, which seriously interfered with their insulating properties, Thee were quite expensive, also, costing some fifty or sixty cents apiece, and they did not long remain in use on any line.
It would require too much time and space to recall the many modifications of this idea of Prof. House, of an iron shell, with glass insulation inside, which have made their appearance from time to time, only to be discarded in their turn for the same cause, the impossibility of keeping unfractured the glass coating. Some of these were of such a shape and manufacture that, outwardly they appeared to be perfect, while, in fact, they afforded no insulation at all, and, consequently, caused much annoyance and trouble to the operators and line repairers, and great loss and damage to the companies. The Lefferts insulator, so called from having been designed by Gen. Marshall Lefferts, was for some time very popular and quite extensively used. This consisted of a wooden plug, some 16 to 18 inches long, with a knob on the end in which a hole was bored, and in this a glass insulator with an iron hook cast in it was placed, and secured from falling out by a wooden pin, which fastened the insulator in the aperture prepared fur it. These have gone out of fashion now, however, and none have been made for some years past.
The different styles of fancy insulators which have appeared from time to time have mostly ceased to be made, and the insulators now used are various forms of glass-the best and most generally used being that known as the screw glass insulator-the poorest, that manufactured specially fur the Western Union Company and known as the Western Union insulator; the Kenosha or Carbon insulator, and the Brooks improved parafine insulator. The latter is considered the best, and although its original cost is greater than either of the others, it has shown itself to be in fact the cheapest and most economical.
When we contrast the best lines now built with those which sonic years ago were regarded as first class, it must be conceded that there has been a decided improvement in their construction. It is true that a good deal of poorly constructed line is still put up, but this is generally the fault either of the contractor, who in this way seeks to increase unduly the profits of his job, or from the parsimony and ill-judged attempted economy or poverty of the company or parties for whom they are built. The use of very large iron wires for conductors, especially by the Western Union Company, has been referred to in this article. The necessity of this for increasing the capacity of the wires may be avoided, either by employing the equivalents of such wires manufactured by the American Compound Telegraph Wire Co., of this city, or by using a more perfect insulation for smaller wires, such as is furnished by Mr. Brooks in his improved parafine insulator, with which he guarantees, for a small annual payment, to maintain a No. 9 iron wire in continual wet or foggy weather at the same conductivity and capacity as the larger wire under ordinary atmospheric conditions.
The compound telegraph wire manufactured under the patents of Messrs. Farmer and Milliken of Boston, if proper care is taken in putting it up originally, is guaranteed to give the best results. Combining as it does lightness and strength, the conductivity of copper with the strength of steel, it is easily handled, and when once in place should last in effective service for many years. It is essential, however, that care should be taken that it is properly handled, and the patent joint which is furnished with it should be used, as joints and splices made carelessly and in the ordinary way are apt to interfere with the copper coating of the interior steel wire and impair its conductivity. From such careless and improper handling discredit has at times been east upon this wire which it does not deserve. It is destined eventually to occupy an important and leading position as a telegraphic conductor, and will be extensively used. The smaller number of poles and insulators required when this wire is used really reduces the first cost of a line, especially if the Brooks insulators are employed, to very nearly that when ordinary iron line wire is employed.
Marked as has been the improvement in the construction of telegraph lines heretofore, there is still much room for further improvement. The progress in that direction from year to year is encouraging, and telegraph managers are coming to understand that inferior material and careless construction will not pay in the long run. With such lines as can be built with the material and insulation now available, and with the improved systems of working telegraph lines which are coming into use, the capacity of such lines for business will be largely increased, and the relative cost of the service reduced, so that with them the telegraph, at even lower rates than are now charged, may he made profitable to investors, and afford a better remuneration to intelligent and competent employes.