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Rh treaties and prepared much material for the American Peace Commission in Paris. In March 1919 he was called to Paris to advise in the adjustment of commercial treaties, and in Nov., on invitation of President Wilson, attended the second industrial conference in Washington for promoting peace between capital and labour. He was a strong supporter of the Covenant of the League of Nations. He was the author of Principles of Economics (1911; 2nd ed. 1915); Some Phases of the Tariff Question (1915); Investors and Money-Makers (1915); and Free Trade, the Tariff, and Reciprocity (1919).

TEISSERENC DE BORT, LÉON PHILIPPE (1855-1913), French meteorologist, was born in Paris Nov. 5 1855, the son of an engineer. He began his scientific career in 1880, when he entered the meteorological department of the Bureau Central Météorologique in Paris under E. E. W. Mascart. In 1883, 1885 and 1887 he made journeys to N. Africa to study geology and terrestrial magnetism, and during this, period published some important charts of the distribution of pressure at a height of 4,000 metres. In 1892 he became chief meteorologist to the Bureau, but resigned in 1896 and founded a private meteorological observatory at Trappes, near Versailles, where he carried out investigations on clouds and the problems of the upper air. In 1898 he published an important paper in Comptes Rendus detailing his researches by means of balloons into the constitution of the atmosphere. His discovery of the so-called isothermal layer, or stratosphere as it is now generally called, will always stand out as one of the most important events in the study of the upper atmosphere. He also carried out investigations in Sweden and over the Zuider Zee, the Mediterranean and the tropical region of the Atlantic, and fitted out a special vessel in order to study the currents above the trade-winds. He was elected a fellow of the Royal Meteorological Society in 1903, hon. member in 1909, and was awarded the Symons gold medal of the society in 1908. He collaborated with Hugo Hildebrandsson in Les bases de la météorologie dynamique (1907). He died at Cannes Jan. 2 1913.

TELEGRAPH (see ).—Apart from the advances in Wireless Telegraphy (see ) and Cable Telegraphy (see ), progress since 1910 has been seen in various technical directions. The developments in the United Kingdom and in the United States in some respects have differed, and this article therefore considers them in two sections which differentiate not only certain technical and commercial aspects of the subject but also certain distinctive points of view.

One of the most important developments in type-printing telegraphy is the adaptation of the Baudot for duplex working by A. C. Booth in 1905. This forms the basis 9f all modern multiplex systems, and has led to a great increase in the output and flexibility of such systems with a consequent considerable extension of their use.



Booth-Baudot. The underlying principle of the Booth-Baudot will be understood by reference to fig. 1. It will be seen that the outgoing signals from the sending rings of the distributor at the home station divide differentially at the line relay and therefore do not affect the receiving apparatus which is connected in the local circuit via the receiving rings of the distributor. Installations of

double, triple, quadruple, quintuple, and sextuple duplex have given excellent results in the British Post Office service during a number of years. The method of driving the mechanism of the Baudot distributors and receivers has been changed from weight driven gear, to electric motor drive. In the case of the receivers, a small series motor with belt drive is used, while the distributors are driven by the La Cour phonic motor. In both cases a considerable saving is obtained in first cost and maintenance expenses with the advantages of more satisfactory working and greater facility in changing apparatus when necessary.

The Carpentier method of automatic transmission on Baudot circuits has recently been reintroduced in the British Post Office, but with several important improvements.

In offices where a large number of keyboard perforators are used, each having its own particular lay-out, the change from one instrument to another caused serious difficulty from an operating standpoint. This difficulty was much felt with the original Carpentier keyboard, in which, owing to the exigencies of the Baudot code, the keys for the numerals were spread over the keyboard instead of being arranged on the first row of letter keys as in most typewriters. Carpentier sought to minimize this difficulty by adding an extra row of keys for the numerals, and a similar arrangement was adopted in the Morse keyboard perforators such as the Gell and the Kleinschmidt.

Messrs. A. C. Booth and A. S. Willmott have now invented a device which enables the keyboard for any type of machine telegraph, whatever the code used, to be arranged exactly as in a typewriter, thus allowing the numerals to be placed in their standard positions without the extra row of keys.

The Booth-Willmott-Baudot keyboard perforator punches the 5-unit code transversely on a paper tape which is of the same size as that used in the Murray and Western Electric instrument (see hereafter), enabling the transmitters of either of these installations to be used in conjunction with it. Switches are provided on the instrument tables so that any particular arm of the multiplex may be worked automatically from a transmitter fed by a Booth-Willmott perforator or by direct-sending from an ordinary Baudot keyboard sender at will.

A. C. Booth, “Telegraph Keyboard Perforators,” I.P.O.E.E. Journal (vol. xiv., p. 72); A. C. Booth, The Baudot Printing Telegraph System (1907), I.P.O.E.E. paper; H. W. Pendry, The Baudot Printing Telegraph System; A. C. Booth, “The Baudot Duplexed,” I.P.O.E.E. Journal (vol. iii., p. 336); A. C. Booth, “Progress of Baudot System,” I.P.O.E.E. Journal (vol. vi., p. 324); “Duplex Baudot Tests,” I.P.O.E.E. Journal (vol. viii., p. 11); E. Montoriol, “Baudot System in France,” I.P.O.E.E. Journal (vol. x., p. 25); E. Lakey, “Progress of Baudot Duplex,” I.P.O.E.E. Journal (vol. xii., p. 216); Post Office Technical Pamphlet for Workmen, B6.

Murray Multiplex.—The difficulty experienced by Baudot operators in manipulating accurately the direct-sending keyboards in time with the cadence signal at speeds much in excess of 30 words per minute led Murray to adopt the Carpentier method of automatic transmission in his multiplex system. The main features of the Booth-Baudot system are utilized, but the operators perform on perforators which have keyboards similar to that of an ordinary typewriter and do not have to keep in time with a cadence signal. Each key of the perforator, when depressed, perforates in a paper tape, a particular combination of holes in accordance with the arrangement of the five-unit code adopted by Murray. The tape thus prepared has its perforations across the slip and not longitudinally as in the case of the Murray automatic system, the use of which has been abandoned, so that a great saving in the cost of paper results.



Fig. 2 shows a portion of the Murray multiplex transmitting tape perforated to represent the word “telegraph.” From the perforator, the tape passes directly into an automatic transmitter, which has five selecting needles, each controlling a contact lever resting