[Trade Journal] Publication: Transactions of the American Institute of Electrical Engineers New York, NY, United States |
AMERICAN TELEGRAPH ENGINEERING—NOTES ON HISTORY AND PRACTICE BY WILLIAM MAVER, JR., AND DONALD MCNICOL Although there may not be any startling technical announcements to make relative to recent progress in American telegraph engineering practice, yet within the twenty-five years past, in common with the progress in other lines of engineering, substantial developments have been also made in the telegraphic art along numerous lines, such as the standardization of equipment, and the adoption of improved apparatus and methods of operation which have generally resulted in increased efficiency of the plant, greater reliability of operation, a more rapid handling of the traffic, and consequent improvement in the service rendered the public; and which developments have, in fact, been adequate to meet the demands made upon the telegraph. The time has been deemed opportune to record some of the salient features of present telegraph engineering practice in this country, but first in order more clearly to illustrate the differences between past and modern practice a resume of the early history of telegraph practice in this country will be essayed in which resume certain more or less interesting items of information relating to that history perhaps not hitherto published, or in any event not readily available, may be recounted. The first electric telegraph line in this country was constructed by Morse in 1844 between Washington and Baltimore. The progress of this art into public favor was slow; due mainly to the high rates for service and to more or less imperfect service, the latter due mainly to poorly constructed lines and the former largely to heavy legal expense incurred in the effort to maintain for the Morse interests a monopoly of the telegraphic art. Morse endeavored to obtain a British patent for his electro-magnetic telegraph, but failed on the score of previous publication. Bain of Edinburgh came to the United States in 1848 to obtain a patent covering his chemical telegraph which was refused on the allegation that his device infringed the patents of Morse. Bain's telegraph consisted of a device for perforating long and short holes in a strip of paper, which were used to transmit long and short impulses of current over a wire. At the receiving end he used a sheet or strip of paper saturated with a chemical solution consisting of nitric acid 2 parts, prussiate of potash 20 parts and pure liquid ammonia 2 parts, which solution was decomposed by an electric current from the sending station thereby leaving long and short marks on the receiving paper sheet or strip. Bain pressed his claims in the United States Supreme Court and in the year 1849 a patent was finally allowed. A British patent to Morse would have been of doubtful value at that time, as during the life of the United States patent the Morse telegraph was but sparingly used in Great Britain, various needle and dial telegraph systems having obtained a strong foot-hold in that country. The maximum speed claimed for the Bain system was about 1000 words per minute, but as a writer of that day remarked (1)"The process of preparing the message to be transmitted, took quite as long as to transmit it" by the Morse method, and while "Mr. Bain's plan was entirely successful as far as it went it was found that after the quick receipt of a long dispatch, it would take about as long to copy it into manuscript as it would have taken to transmit it in the ordinary manner in the first place." Following the granting of the U. S. patent to Bain, numerous telegraph companies were organized and lines built on which the Bain automatic chemical system was employed, in opposition to the Morse Companies, but in 18.r)0 an injunction was obtained, based on the charge that Bain's apparatus infringed the Morse telegraph patent of 1840. A consolidation of many of the chemical automatic companies with the existing Morse lines soon followed, and subsequently the Morse manual system (in which the Morse stylus recorder, or register was used) went into almost general use. (2) The Morse register was gradually displaced by the reading sounder, but not without opposition on the part of the superintendents of telegraph who were apprehensive, needlessly as experience proved, of the introduction of errors thereby. The first printing telegraph was that due to Royal E. House the use of which was begun in 1847-1848 and continued for many years in this country. This system employed a key-board the depression of a key of which resulted in the printing of a given letter on a strip of paper at the receiving station. The speed of transmission by this system was about 50 words per minute. It was operated on lines 1000 miles in length. The Morse interests endeavored to bring this telegraph printer within the scope of the Morse patents but were overruled by the courts. In the early days of the electric telegraph the methods of line construction were naturally crude, but every year saw improvements in the direction of workmanship and materials used. Wooden poles were used from the first in this country, but the forms of insulators and the materials used in their construction were multitudinous, and it was not until much bitter experience was had with various "improvements" in insulators that practice converged on the glass petticoat form now universally employed in overhead electric telegraph work in this country. One of the so-called improvements termed the "brimstone" insulator was especially defective and nearly ruined several of the competing companies that employed it. This insulator consisted of an iron arm which screwed into an augur hole in the pole, the outer end of the arm carried a hollow pendant filled with sulphur into which an iron hook that upheld the line wire was inserted. The civil war in this country, 1861-1865, again directed the attention of the world to the great utility of the electric telegraph in war and while its use at this time did not perhaps materially aid in the advancement of telegraph engineering it emphasized the value of the Morse telegraph system for this purpose because of its simplicity and reliability in operation. The source of electromotive force for telegraph purposes in the United States up to the year 1855 was the Grove cell, which was displaced by a modification of the Smee cell known as the Chester battery, and this battery in turn gave way to the Callaud or gravity battery, of which up to the introduction of the dynamo machine in the year 1882, many thousands were in use. In some of the main telegraph offices 5,000 to 15,000 such cells were employed; entire floors of large office buildings being set aside for their occupation. To meet the increasing demand for additional telegraph facilities in the decade 1870-1880, without resorting to the continual construction of additional line wires, the thoughts of inventors were directed to means for increasing the capacity of existing wires. To this end the chemical automatic telegraph, and the duplex and quadruplex systems of telegraphy were called into service. Thus in 1870 a compound wire of steel core and copper was erected between New York and Washington a distance of 275 miles on which a chemical automatic system due to Mr. George Little was employed. This system was a modification of the Bain chemical telegraph previously mentioned herein. Originally, adequate means were not provided in the Little system for diminishing the "tailings," or prolonged currents, due to the static capacity of the line, at the receiving instrument, in consequence of which the speed of signaling was low. Subsequently Little introduced a plain resistance in shunt around the receiver with beneficial results. The Varley devices consisting of electro magnets in shunt with the receiver, and of condensers in series with the receiver (4) for the purpose of eliminating the tailings were subsequently employed, (the electro-magnets probably first by H. Grace,) to great advantage in this and certain other later automatic chemical systems in which a single row of holes in the perforated paper (and a uni-directional current) was employed; the condenser as thus employed virtually giving the equivalent of the double current method. Still later the speed of transmission on this New York-Washington line was increased to 900 words per minute by the substitution of an iodine solution and by using a platinum needle in place of a nitric acid solution and iron needle. An important contribution to the art of chemical automatic telegraphy at this stage was the Edison key-board perforator, which by the depression of a key perforated in a moving paper tape the characters necessary for any given letter. By the Little method of preparing the perforated tape not more than 7 or 8 words per minute was feasible, while with the Edison keyboard perforator the tape could be prepared at a maximum rate of 40 words per minute, the average being about 25 words per minute. This key-board perforator while highly ingenious from a mechanical point of view was somewhat cumbersome in operation. The key board was about 18 inches in length, and the keys had a drop of about 2 inches requiring strong pressure to carry them down. As a writer of the period remarked "An hours work on one of these punches is a severe strain on the muscles of a strong man." (5) An important test of this system was made between Washington and New York, January 27, 1874 when the President's message on the Spanish "Protocol" consisting of 11,130 words was transmitted. This matter was prepared for transmission by ten perforators in 45-1/2 minutes. The message was transmitted in 59 minutes. Time from the beginning of perforation until message received at distant end of the wire, 53 minutes. The time consumed in translating the characters by ten operators in New York was about 45-1/2 minutes, or roughly it required 72 minutes for the entire operation. Four Morse operators on 4 single wires, it may be remarked, are capable of transmitting a message of this length in 55 minutes. In the practical operation of this system by the Automatic Telegraph Company on its single wire from New York to Washington, D. C., during 1873-1874 business was frequently badly delayed by the breaking of the wire, there being no emergency wire, or alternate route. This fact undoubtedly detrimentally affected the commercial success of this system, a result that must obviously follow in all cases where but one route or only a limited number of wires between the important business centers are available. This automatic system (6) was subsequently employed, more or less in combination with the Morse manual system, on the lines of the Atlantic and Pacific Telegraph Company until the year 1871), when it was gradually displaced by the Morse manual method of transmission. (7) From about 1880 to 1884 the American Rapid Telegraph Company and its successors the Banker's and Merchants, and United Lines Telegraph Companies, operated a chemical automatic system known as the Foote & Randall system. These companies lines (compound copper coated wires) extended from Boston and New York to Washington, Pittsburgh, Buffalo, Cleveland and intermediate points. In this system the double-current method was employed. The prepared paper was perforated in two rows as indicated in Fig. 1. Dots were represented by one hole on either side of the strip, the dashes by two holes. Consecutive dots, and dashes, were perforated diagonally on alternate sides of the paper strip as shown in the figure. Two metal drums d, d' connected with the positive and negative poles, respectively, of the battery were placed side by side in such a manner that one drum came under the holes on one side of the paper, the other under the holes on the other side. Transmitting needles or brushes n, n' connected jointly to the line wire were arranged so that each was in line with one row of holes on the paper. By the arrangement of the holes as shown each consecutive character of a letter, and the first character of a following letter were made by a different polarity to that making the preceding character and consequently all letters containing more than one character were represented by dots and dashes on alternate sides of the received paper strip. · · W. J. Camp: I would say that the Canadian Pacific Railway used white porcelain insulators to a considerable extent in the years 1890 to 1898, but the cost increased so much that we reverted entirely to glass until three years ago. We found that the manufacture of glass insulators in Canada had deteriorated so greatly that the insulators turned out were altogether unsatisfactory, apparently they were not properly annealed, with the result that from a week to two months after being placed on the line they would go to pieces without being subjected to any mechanical injury. The price of porcelain insulators had also been so much reduced that for the past three years we have used nothing but white porcelain. · · (1.) "Electric Telegraph," (1852) Jones, pr. 110-150. (2.) In a personal letter to Mr. Maver dated August 22, 1890. Mr. D. H. Craig who was a prominent figure in the early annals of American telegraphy, writes: "I used Bain's system on lines between New York, Boston and Portland between 1850 and 1853 and was able often in stormy weather to send to the Boston press columns of news when the Morse lines would not telegraph a word. We frequently, however, had trouble with "tailings" when the dots and dashes all ran together and made the record partially or wholly unreliable, so that in a message or series of messages of 500 or 1000 words there would be yards of record that would have to be discarded and the messages repeated. The later use of artificial resistances or magnets largely eliminated this trouble. Bain used on his early lines (for his chemical solution) nitrate of ammonia, 2 pounds to a gallon of water, and muriate of ammonia one pound to a gallon of water, and one-half ounce of yellow prussiate of potassia. This makes a fair solution, but we discarded it, (date not given) and substituted one half ounce red prussiate of ammonia and one pound of muriate of ammonia dissolved in one gallon of pure rain, or distilled water—iron pins were used with this." (3.) Described in " Manual of the Telegraph," Shaffner, p. 391. (4.) British patent No. 3543. 1862. U. S. Patent 7S495. 1868. (6.) (Described in " The Electric Telegraph", Prescott, Vol. 11, p. 727.) (5.) "The Telegrapher," 1875, p. 109. (7.) About the years 1875-77, the widely advertised claims of the Atlantic and Pacific Telegraph Company relative to the advantages of the chemical automatic and Wheatstone automatic telegraph systems controlled by that company were having a depressing effect on the stock of the Western Union Telegraph Company. Presumably to offset this effect President Orton of the last named company contracted with Messrs. Craig, Randall and Foote to pay 0,000 for a chemical automatic telegraph system that would be superior in every respect to that operated by the rival company. Tests were made of the new automatic system and the experts reported that all the technical conditions of the contract were fully met. Upon the sudden death of President Orton shortly thereafter however complications arose, a compromise offer of 0,000 being declined, whereupon the contract was abrogated and the inventors' interests in this system were turned over to the American Rapid Telegraph Company. It may be added on the authority of Mr. C. A. Randall that the inventors finally received about ,000 as their portion of the amount received for the patents covering the automatic system bearing their name (W. M. Jr.)
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Keywords: | General : Brimstone Insulator : Canadian Pacific Railway Company |
Researcher notes: | Footnote (6) came before footnote (5) in the actual text. |
Supplemental information: | Patent: 6,779 |
Researcher: | Elton Gish |
Date completed: | February 9, 2008 by: Elton Gish; |