The code or alphabet employed in this mul tiplex printing telegraph system is virtually similar to the Baudot alphabet. It is known as a five equal unit alphabet, that is, five im pulses of positive or negative current are com bined to form a given letter. Thus the letter A is assigned two positive and three negative impulses, B one positive, two negative and two positive units. Each current impulse in the Baudot code is of equal length and by different combinations of the five impulses it is possible to form 31 letters or characters. In the Morse code the dots and dashes representing letters and figures are of varying lengths, and hence a letter of the Morse code may consist of from 1 to 12 units. The average number of units in a letter of the continental Morse code is prac tically nine units per letter. It has been cal culated that this disparity in the two codes results in an advantage for the Baudot alphabet in practice of about 65 per cent over the Conti nental Morse alphabet in the rate of transmis sion over circuits of equal length.
This multiplex printer rendered most efficient service in France under the direction of the United States Signal Corps.
Miscellaneous Telegraph Systems.— In ad dition to the telegraph systems referred to herein, many others have been in actual op eration during the past century, either ex perimentally or commercially, among which may be mentioned the electrostatic systems of Lomond, Rensse, Reizen, Don Silva, Be tancourt, Cavallo; Ronald's synchronous sys tem; the electrolytic systems of Soemmering and Coxe; the chemical facsimile systems of Bakewell, Denison and Bonelli's chem ical printer; the chemical dot and dash systems of Bain, Morse, Anderson, Delany, Dyar; the electromagnetic systems of Alexander, Gauss and Weber, Steinheil, Schweiger; the needle systems of Wheatstone and Cooke, Davy; the dial systems of Siemens, Breguet, Kramer; the printers of House, Hughes, Phelp,s; the Meyer multiplex; the Mercadier multiplex and the Alteneck mechanical automatic system.
Telegraph System; in Practical Opera tion.— Wherever the electric telegraph is em ployed the Morse system is the one most gener ally utilized. In some countries such as the United States and Canada, Sweden, Portugal, Switzerland, Egypt, Bulgaria, New Zealand, India, Australia and South America, the Morse system is used almost exclusively. In Great Britain, Italy, Russia, France, China, Japan, the Morse and the Wheatstone automatic, which is simply a fast Morse system, are largely employed. In Austria, Belgium, Great Britain, Hungary, Sweden, Russia, France, the Hughes printer is in extensive use. In France the Baudot printer is utilized; also in Italy, Holland and Switzer land to a limited extent. In Great Britain, about 750 Morse ink recorders; 925 Bright's Bell; 5,000 A B C telegraph, 30 Delany multi plex and 4,700 single needle apparatus are in operation. All told there are approximately 70,000 Morse sets in operation in the United States and Canada, and 45,000 in all other parts of the world. There are in Europe about 1,700 Hughes apparatus, and in Europe and else where about 530 Wheatstone automatic sets in operation. Needle systems; A B C and Bell
apparatus are quite largely used in Europe on the railroad and commercial telegraph lines. A page printing telegraph system, termed Mork rum Printer, is also in extensive use in the United States.
It may be remarked that there is a desire on the part of the telegraphing public in all countries to receive telegrams in type and in page form, and as far as practicable the vari ous telegraph administrations are endeavoring to comply therewith. In the United States, as already intimated, the Morse operators in nu merous instances transcribe messages by the typewriter as received. In Great Britain the Murray page printer has been adopted by the government, and in Europe generally, where messages are received on paper strips as by the Hughes and Baudot systems, the strips are pasted on blanks in page form, for delivery.
Speed of Different Systems.— The average speed of transmission by the Morse manual telegraph may be placed at about 20 to 25 words per minute, although skilful operators attain a speed of 45 and 50 words per minute. The Reed by the Wheatstone system on short lines is about 500 to 600 words per minute. By the Hughes an average of about 30 words per minute in one direction is obtained. This sys tem may be duplexed, giving 50 words per min. ute on one wire. By the Baudot system, oper ating as a quadruidex, 120 words per minute; as a sextuples, 180 words per minute. By the Buckingham and the Barclay systems a speed of 80 words per minute, in each direction, may be obtained on circuits from New York to Chi cago, with repeaters midway. By the Murray printer, about 80 to 100 words per minute in each direction may be obtained.
Mileage of Telegraph Lines, Wires and Submarine Cables.— In the United States the total amount of pole lines is about 238,000 on which about 1,270,000 miles of copper and iron wire are erected. In Canada there are about 35,000 miles of lines and 84,500 miles of wire. In both cases the various railroad companies also operate a considerable amount of telegraph line (about 250,000 miles of wire) for the movement of trains, etc. In all other parts of the world there are approximately 435,000 miles of telegraph pole line and 1,450,000 miles of wire, exclusive of about 48,000 miles of pole lines and 216000 miles of wire con: trolled by railroads. The average size of the copper wire used on telegraph pole lines is No. 12 or 14 B. & S. gauge; that of iron wire, No. 6 or 8. The nature and size of the poles varies in different countries. Cedar is largely used in the United States and Canada; fir in Europe. Poles 30 to 40 feet long and set five feet in the earth are used. Thirty to 40 poles to the mile has been common practice, but the tendency in this country is toward the use of 45, 50 and more poles per mile to obtain greater security against sleet and wind storms. Iron telegraph poles are used in some countries.