Standardization in Schematic Representation of Telephoneand Telegraph-Installations.-A. A. OOSTING.-De Ingenieur, The Hague, 1915, vol. 30, pp. 226-228.-The Author gives a list of schematic symbols to be used as standards in drawings and schemes of telephone- and telegraph-installations. This list is drawn up on analogous lines to those symbolizing electric plants and accessories. -H. C. A. T.

Printing-Telegraph System for Long Distances.-P. M. RAINEY. -Electrical World, New York, 1915, vol. 65, pp. 848-857.—This is a general description of the printing-telegraph apparatus designed and constructed by the Western Electric Company for the Western Union Telegraph Company of the United States. It includes methods of operation standardized on single and multiplex principles; alphabet used; synchronism; description of the apparatus in detail, with photographs. The system is designed to meet the requirements of operating over long distances.-P. T. P.

Improvements in Wireless - Telegraphy Apparatus : The Ultraudion Detector for Undamped Wireless-Signals.-L. DE FOREST. Electrical World, New York, 1915, vol. 65, pp. 465466.-This article describes a slight modification of the circuits of the "Audion" detector, used in wireless telegraphy, whereby it becomes a very sensitive detector of undamped oscillations. The principle, discovered by the Author, is embodied in an instrument to which the name "Ultraudion" detector is given. This method offers considerable possibilities for high-speed recording of wireless signals.-P. T. P.

Improvements in Wireless-Telegraphy Apparatus: The DoubleAudion Type of Receiver.2-R. H. TAYLOR.--Electrical World, New York, 1915, vol. 65, pp. 652–655.-This article describes a method of using two audions as an amplifying electrical "beats-receiver " for continuous radiotelegraphic waves. This method is a modification of the principle of the "Ultraudion" detector of Mr. de Forest. The Author gives data as to results actually obtained in his experiments and details of the arrangement and adjustment of the apparatus used.-P. T. P.

Efficient Radio-Stations. - RICHARD PFUND. Journal of the American Society of Naval Engineers, Washington, 1915, vol. 27, pp. 164–170.—Emphasizing the extreme importance of first-rate earth-connection, preferably on the seashore, for long-range wireless telegraphy. Also advocating the use of a metallic tower for the support of the antennæ, the transmitter being preferably at the top, or near the top, of the tower. By this means losses due to a too-close approach of the antennæ and the ground are limited to those between the tower-end of the antennæ and the top of the tower, and are comparatively small.-C. H. W.

1 See following Abstract.
2 See preceding Abstract.

Continuous Waves in Long-Distance Radio - Telegraphy. L. F. FULLER.-Proceedings of the American Institute of Electrical Engineers, New York, 1915, vol. 34, pp. 567-585.-A theoretical expression is obtained for the current at the base of an aerial, the actual current, however, being shown to be somewhat larger. Tests made between San Francisco and Honolulu in 1914, using the Poulsen arc, are described, together with a full account of the measurements made. The results are plotted in a series of curves, showing the effect of wave-length under various conditions. In many cases current received increases directly with the wavelength, but in others distinct maxima and minima are shown. An empirical formula is established, similar to the theoretical, and has been confirmed by tests made between Tuckerton and Honolulu, and also by the Goldschmidt alternator.-H. R. S.

Report of the U.S. Naval Radio-Telegraphic Laboratory.— L. W. AUSTIN.—Journal of the American Society of Naval Engineers, Washington, 1915, vol. 27, pp. 345-364.-This account of the work done by the Laboratory since 1912 includes investigation of the relation of resistance to wave-length in glass condensers, the highfrequency resistance of inductances, antenna-resistances with different wave-lengths, efficiency of different antenna-types, the quantitative study of long-distance transmission, the transmissionefficiency of damped and undamped or continuous waves, improved receiving-apparatus, and means of prevention of atmospheric disturbances.-C. H. W.

Long-Distance Telephony.- Electrical World, New York, 1915, vol. 65, pp. 279-280.-Details are given of the telephone-service between New York and San Francisco, which was inaugurated in January, 1915. The lines run via Pittsburg, Chicago, Omaha, Denver, Salt Lake City, to the Atlantic Coast, a circuit of 3,400 miles, and the voice was heard with greater clearness than over the first " long-distance" line of 2 miles laid down in 1876. Particulars are given of the lines and the Bell system under which they are operated.-P. T. P.

ABSALON

Telephone-Disturbance: its Cause and Remedy. LARSEN. Ingeniøren, Copenhagen, 1915, vol. 24, pp. 273-278.The Author describes in detail the means adopted for ascertaining the cause of an annoying disturbance of telephone-service which had for some time baffled all attempts at discovery. It turned out to be of an unusual character, but he eventually succeeded in remedying it by comparatively simple means. The article is accompanied by formulas and diagrams relating to electro-static and magnetic induction, etc.-L. S. Z.

Development of Marine Engineering in Germany.-Dipl. Ing. MOMBER.-Zeitschrift des Vereines deutscher Ingenieure, Berlin, 1914, vol. 58, pp. 1074-1084, 1121-1128.-Discussing fully the boiler and engine development of German marine engineering, the Author

deals in detail with the Scotch boiler, forced draught, feedwater and superheaters, water-tube boilers as used in the Navy, oil-firing, the 4-cylinder reciprocating-engine, turbines, combination of 3-cylinder engine and low-pressure turbine, high-speed turbine geared down to low-speed propellers, mechanical gearing, hydraulic gearing and turbo-electric drive. Illustrated examples and the results of practical experience are given.-H. C. A. T.

Largest Battleship Launched: the U.S.S. "Pennsylvania."Engineering News, New York, 1915, vol. 73, p. 556.-This ship, launched in March, 1915, is described as an oil-burning superDreadnought, having the following features:-Displacement, 31,000 tons; speed, 21 knots; main battery twelve 14-inch guns, effective range 13 miles, all firing on either broadside; secondary battery twenty-two 5-inch guns; main armour-belt, 14 inches thick and 18 feet deep; complement, 885 men. In a Table comparison is made with the leading battleships of other nations.-C. O. B.

Naval Repair-Ship "Vestal." L. J. CONNELLY. American Machinist, New York, 1915, vol. 42, pp. 45-52.-The "Vestal," originally a twin-screw collier of 7,720 tons, has been fitted up as a workshop comprising pattern-shop, foundry for cast-iron, steel and brass, machine-shop, forge, etc. Work is brought to her either in boats or by ships coming alongside. The foundry is located at the stern, and the largest casting made up to date weighed 1 ton. The machine-shop is placed in the hold, and there is a gallery on each side for smaller tools. The stores are fitted with steel bins, and there are racks for pipes, bars, etc. There is an optician's shop for the repair of telescopes, field-glasses, periscopes, etc. Plans and photographs are given. -H. R. S.

Motor-Craft for Special Services.-F. HOUMÖLLER.-Ingeniøren, Copenhagen, 1915, vol. 24, pp. 49-53.-A small screw-ferryboat for vehicles and passengers and a stern-wheel river passenger-boat are described and illustrated. The ferryboat is 62 feet long, 18 feet wide, and draws 5 feet 9 inches. It has a screw and rudder at each end, the bow-screw being used for reversing. The 57-HP. motor gives a speed of 7 knots per hour. The stern-wheeler is 61 feet long, 12 feet wide, and 18 inches draught, with a 16-HP. motor giving a speed of 6 knots.-L. S. Z.

Motor-Boat "Gallia.”—W. J. OUDEGEEST.-De Ingenieur, The Hague, 1914, vol. 29, pp. 320–323.-This 1,630-ton boat is fitted with two 340-B.HP. 4-cylinder direct-reversible 2-stroke Bolinder engines, running on crude oil, with hot-tube ignition and developing a speed of 9-3 knots. Special reversing-pumps fitted to cylinders 1 and 3 effect a saving of air-reservoir capacity. The auxiliary machinery is driven by a 10-B.HP. Bolinder engine. The fuelconsumption is 0.462 lb. per B.HP.-hour. A roller thrust-block and a "Cederall" stuffing-box are fitted to reduce friction-losses to a minimum.-H. C. A. T.

Submarine-Improvements.-C. N. HINKAMP, Lieutenant U.S.N. -Journal of the American Society of Naval Engineers, Washington, 1915, vol. 27, pp. 171, 185.-Improvements in engines, compasses, ballastpumps, auxiliary and main pumps, control of sparking in electric switches, speed of submergence, signalling under water, design and fitting up of periscopes, and heating and cooking arrangements are briefly described.-C. H. W.

Additional Notes on Submarines.-G. W. BAIRD, Rear-Admiral U.S.N. (ret.).—Journal of the American Society of Naval Engineers, Washington, 1915, vol. 27, pp. 186-191.-A history of some early submarines, from Bushnell's boat built and used in 1776, of which an illustration, compiled from descriptions, is given, to Mr. W. Scott Simms' boat, controlled from a distance, built in 1882, which is also illustrated.-C. H. W.

Submarines and Torpedoes.-C. N. HINKAMP, Lieutenant U.S.N. --Journal of the American Society of Naval Engineers, Washington, 1915, vol. 27, pp. 438-453.—Commencing with a brief history of their development, the Author gives many details of the management and peculiarities of behaviour of submarines, with notes on torpedoes and observations on the distance at which periscope-wash or submarines can be detected, the best time to attack, etc.-C. H. W.

1

Problems in Screw-Propulsion.-C. W. DYSON, Captain U.S.N.Journal of the American Society of Naval Engineers, Washington, 1914, vol. 26, pp. 1045-1098.-The Author shows how to use diagrams similar to those already published by him to predict the performance of newly-designed propellers. He explains how the revolutions per minute may be estimated from those of a screw of different pitch, diameter, and projected area, but absorbing the same power; also how to allow for the effect of fine or bluff hull-lines, and to predict the tip-speed at which cavitation will commence. Several fully-worked-out examples are given.-C. H. W.

Pendulum-Propeller.-H. C. VOGT.— Ingeniøren, Copenhagen, 1915, vol. 24, pp. 87-90.-The Author deals with the trial-trip of a vessel fitted with the pendulum-propeller, which is stated to possess advantages over the screw, particularly in cases where the propeller is used as an auxiliary to sails. Scale-drawings of the arrangement of the propeller also show the lines at the stern of the vessel, which, it is stated, can be made more favourable for sailing than is possible when designed for a screw, making this form of propeller suitable as an auxiliary in fishing- and other small sailing-craft.-L. S. Z.

Turbine-Electric Propulsion of a Battleship compared with other Means.— P. W. FOOTE, Lieutenant-Commander U.S.N.—Journal

1 Journal of the American Society of Naval Engineers, vol. 24, p. 574, vol. 25, pp. 169, 175, and Minutes of Proceedings Inst. C.E., vol. 192, p. 413, and vol. 194, pp. 506, 507.

of the American Society of Naval Engineers, Washington, 1915, vol. 27, pp. 54-82.-Reciprocating-engines are considered better for battleships than direct-driving turbines. When the latter are connected with the propeller, either electrically or by mechanical reducinggear, this relation is reversed. Reasons are given for preferring electric drive, and reference is made to the "Jupiter" as a satisfactory example.-C. H. W.

Stresses in Steam-balanced Valve-Gears.-E. N. JANSON.Journal of the American Society of Naval Engineers, Washington, 1914, vol. 26, pp. 1165–1181.--Giving inertia-diagrams and details of the mode of calculating the stresses, with a tabulated statement of the actual pressure per square inch on the rubbing-surfaces of eccentric sheaves on eight ships.-C. H. W.

Packing in the United States Navy for Steam-Joints and Glands.-ALEX. M. CHARLTON, Lieutenant U.S.N.-Journal of the American Society of Engineers, 1914, vol. 26, pp. 1099-1109.-This is a description of the tests adopted at the engineering experiment station for testing non-metallic packings for stuffing-boxes and jointing, with some of the recommendations of packings for use with steam at 300 lbs. per square inch pressure.-C. H. W.

Desirability of using High Mean Referred Pressures in SteamEngines.-E. M. BRAGG.-Journal of the American Society of Naval Engineers, Washington, 1914, vol. 26, pp. 1298-1302.-In supporting Mr. Royds' conclusions that a loss of economy results if the sum of the mean pressures, referred to the low-pressure cylinder, is less than a certain minimum, Mr. Bragg gives a diagram which shows that in the case of H.M.S." Argonaut," when the indicated horsepower of the starboard-engine was kept constant by adjusting the rate of expansion, the pounds of steam used per hour per horsepower, plotted over various initial pressures (by gauge), followed a straight-line law.-C. H. W.

Transporter-Cables for Loading Vessels at Sea.-R. BONNIN. -La Nature, Paris, 1915, part 1, pp. 306-308.-The possibility of taking in supplies of stores, coal and fuel-oil at sea, by the use of cables extending from the transport to the warship, was first demonstrated by the United States of America. An account, with illustrations, is given of the methods in use for supplying the navies of various countries. The special mode of supporting the coal-sacks and the flexible tubing for pumping the oil are shown by diagrams. G. R. R.

Extensometer-Tests on Board Ship. Dr. Ing. SIEMANN.Zeitschrift des Vereines deutscher Ingenieure, Berlin, 1914, vol. 58, pp. 1161–1169.—The shock of heavy seas washing against a ship sets up stresses higher than those statically allowed for. By fitting extensometers to different parts of a ship's hull, the Author obtained stress-diagrams for different weather-conditions. It is pointed out