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1022 WINGATE, SIR FRANCIS REGINALD (1861- ), British general and administrator in the Sudan (see 28.729). In Dec. 1916 he was appointed High Commissioner for Egypt and relinquished the governorship of the Anglo-Egyptian Sudan, after a successful administration during 16 years. At the beginning of 1919 Sir Reginald Wingate was summoned to London to report on the situation which had arisen in Egypt, and he remained there many months at the disposal of the Govern- ment until his resignation in Oct. 1919. He had received the G.B.E. in Jan. 1918, and was created a baronet in June 1920.

WINNIPEG (see 28.731), the capital of the Canadian province of Manitoba, had a pop. at the close of 1920 estimated at 198,000 (271,958 including suburbs). The Dominion census of 1911 gave a pop. of 136,035. Winnipeg is the great commercial metropolis of western Canada, its importance having been enhanced since 1911 by the completion of the Grand Trunk Pacific Railway (which later became a part of the Canadian National Railways system). The Hudson Bay railway, in* tended to link Winnipeg with Port Nelson on Hudson Bay and thus to provide an outlet by sea through the summer months for the produce of the west, was still under construction in 1921. Begun as a private enterprise, it had been taken over by the Canadian National Railways system: its completion was ex- pected to improve further Winnipeg's position as the trade outlet of the west. As the wholesale centre for the prairie provinces Winnipeg housed in 1920 5,000 commercial travellers representing an annual wholesale turnover that exceeded $300,000,000. The assessed value of property in'the city that year was $259,419, 520. After 191 1 Winnipeg grew in importance as a manufacturing centre, and in 1920 had 513 factories and in- dustrial plants, including flour mills, packing houses, structural steel works, rolling mills, tanneries, sugar refineries, clothing, harness, soap, jewellery and dye factories, etc. The output of its industries in 1917 amounted to $98,101,632. The almost unlimited power resources of the Winnipeg river, 100 m. away, led to a scheme for an extensive hydro-electric system, to develop 175,000 H.P., which was in course of construction in 1921. The Civic Power Electric Co. had developed 60,000 H.P., and the Winnipeg Electric Railways had developed 30,000 and had 50,000 under construction in 1921. The building of the Grand Trunk Pacific Railway, Canada's third trans-continental rail- way, in the years following 1911, opened an important phase in Winnipeg's history. The company's extensive railway shops were located at Winnipeg, and the Fort Garry Hotel was erected by the railway in the heart of the city.

WINTER, JOHN STRANGE (MRS. ARTHUR STANNARD) (1856- 1911), English writer (see 28.734), died in London Dec. 13 1911. WIRELESS TELEGRAPHY AND TELEPHONY (see 26.529). Wireless telegraphy and telephony (also called radiotelegraphy and radiotelephony) made enormous progress between 1910 and 1921. This was due chiefly to the improvements and advances, effected in three great inventions, viz.: the three-electrode thermionic tube developed out of the Fleming oscillation rectify- ing valve, the high frequency alternator, and the Poulsen arc generator of continuous waves. The first of these has given a means of detecting electric waves of immense sensitivity, and also a most effective and easily managed generator of continuous electric waves. The second has provided machines for creating high frequency electric currents, and therefore electric waves, of great power, enabling large long-distance radio stations to be equipped which can signal to any part of the world by day or night. The third has also given an alternative method of generat- ing high-power continuous waves. These generating and receiv- ing appliances quite revolutionized wireless telegraphy and made wireless telephony possible not merely as an experimental feat, but as a practically useful art. In addition to these inventions there have been others such as directive radiotelegraphy, and wire-guided high frequency telegraphy and telephony of immense utility. The application of the thermionic valve in ordinary wire telephony as a repeater is also bringing about improvements of very great importance. Contemporaneously with these achievements investigations have been made of a more scientific

character arising out of the study of the nature of electric wave propagation round our globe and of the causes of atmospheric disturbances, called " strays," which have always been the great obstacle to practical radiotelegraphy.

We shall consider briefly the nature of these improvements in turn.

High Frequency Alternators. It had become clear by 1904 or 1905 that the use of continuous waves in radiotelegraphy would have marked advantages over the then employed damped wave trains produced by condenser discharges, and would be essential for the accomplishment of radiotelephony. The most obvious method of producing such continuous waves (C.W.) was by some form of high frequency alternator. At that time, when wave lengths of 300 to 3,000 metres or 1,000 to 10,000 ft. were mostly in use, this meant the design of machines giving alternating currents having a frequency of 1,000,000 to 100,000,000, and such frequencies seemed unattainable by any ordinary alternator construction as long as the revolving part of the alternator had to carry coils of wire. In low frequency alternating current dynamos, generating currents, reversed 50 to 200 times a second, there is an electromagnet which provides a constant magnetic field through which field coils of wire arc moved so as to generate in the latter an alternating current. Either the field coils or the armature coils may be the rotating portion. In the case of alternators required to produce high frequency currents (20,000 to 100,000) it is impossible to rotate coil-wound armatures or fields at the necessary speed, and the most usual solution of the problem is to construct inductor alternators in which the moving part consists merely of a disk or drum of steel with teeth or ridges on its edge or surface, which serve to change the magnetic flux through stationary armature coils, the field coil also being fixed. We can then balance such a drum or disk and so fashion its edge that it can be rotated at a high speed safely. With the increase in capacity and wave length of the aerial wires or antennae requisite for long distance power stations, frequencies between 20,000 and 100,000 came into use, and attention was again directed to the design of alternators giving such frequencies.

M. Latour has classified these machines into: (i) alternators in cascade, (2) internal cascade alternators, (3) homopolar or inductor alternators, (4) variable reluctance alternators, and (5) alternators with partial utilization of periphery. Although Bethenod in France constructed in 1912 a small machine of type (i), the first alternators of type (2) of 100 kilowatt output, or so, were constructed by R. Goldschmidt about 1912.

In machines of types (i) and (2) we start with the production of a single-phase alternating current of some moderate frequency, say 10,000, and multiply it up to much higher frequencies by taking advantage of a well-known principle called Fresnel's theorem. If there be two equal vectors represented by lines of equal length, which are pivoted to one point and revolve with equal angular velocities in opposite directions, their resultant is a line of constant direction but periodically varying magnitude with amplitude twice the size of that of the revolving vectors. Hence an alternating magnetic field of constant direction may be resolved into two fields of constant magnitude but rotating in opposite directions, each of half the maximum amplitude of the alternating field. If then we pass a direct electric current through the field coils of an alternator and induce in the revolving armature an alternating current say of 10,000 frequency the field due to this armature current may be resolved into two oppositely rotating fields, one of which is stationary as regards the field magnets and the other cuts them with twice the angular velocity of the rotor. This gives rise to a current of twice the frequency in the field coils. The field due to this latter current can again be resolved into two oppositely rotating fields and these induce currents of still higher frequency in the rotor coils. We can so build up currents of frequencies in the ratio of 1, 2, 4, etc. The currents of intermediate frequency can be taken up in circuits comprising capacity and inductance tuned to these frequencies respectively. The current of the highest frequency can be put into an aerial wire and employed to radiate long electric waves of corresponding wave length.

High frequency alternators of the above description were built for the radio station established at Tuckerton, N.J., in correspondence with a similarly equipped one at Eilvese, near Hanover in Germany, and used for trans-Atlantic transmission from about 1912 up to the time of the entrance of the United States into the World War.