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were required to guarantee a speed of 26 knots; and it will be seen that in the thirteen instances this has been achieved on the six hours' run, As with their destroyers, Messrs. White, of Cowes, have been especially suc- cessful with torpedo-boats, their speed averaging 2614 knots. Messrs, Thorny- croft have also succeeded in averaging over 2634 knots, and in most other instances the rate was 26.2 knots. The conditions as to load and oil consump- tion were severe, and the Admiralty and the contractors alike are to be congratulated on the results. RECIPROCATING ENGINE IN . MARINE PRACTICE, A paper by Mr. D. Gibson was read before the Manchester Association of Engineers recently, the subject being "The Reciprocating Engine in Marine Practice, and Its Probable Puturc. This paper reviewed the types of ma- rine reciprocating engines, drawing attention to the most modern features of each, and to the considerations de- termining the choice of type.. The types are classified as triple-expansion three-crank engines, quadruple-expan- sion four crank engines, and triple- expansion four-crank engines. After discussing various points with regard to these, the author dealt with steam- jacketing, superheating, etc., conclud- ing by forecasting, as far as present indications render this possible, the future means of propulsion for the different classes of water-borne traffic. The author stated that about 70 per cent. of the world's commerce is carried on in three-crank triple-expan- sion engined ships. Such engines are suitable for all powers up to 4000 in- dicated horse-power per set, but the majority of these engines in use do not exceed 3,000 indicated horsepower per set. These vessels were driven at a speed of about 12 knots or so. The author suggested that if some speed- reducing gear could be devised capable of efficiently transmitting 1500 horse- power and upwards, turbines might ultimately be adopted for slow freight- carrying ships. Where vessels require 4000 indicated horse power and up- wards per set, and trade to long dis- tances, the quadruple-expansion four- crank engine finds most favor, with boiler pressure from 210 Ib. to 220 Ib. per square inch. The weight of such engines, with boilers, etc., com- pared with three-crank triple-expan- sion engines with 180 lb. boiler pres- sure, runs out about 8.to 10 per cent. heavier per indicated horse-power with the same revolutions, although the boiler proportions may be 5 per cent. less. The saving in fuel aver- THe Marine Review ages 6 to 7 per cent in favor of the quadruple type. In the cross-Channel L. and Y. railway steamers, fitied with triple-expansion four-crank engines, the weight per indicated horse-power -of boilers, water, and all machinery was 254 lb. The author advocated the steam-jacketing of the intermedi- ate cylinder. With regard to super- heating, the author stated that with a superheat of 150 deg. Fahr. the econ- omy gained was 12 to 15 per cent., and even 25 to 30 per cent. in the case of steamers which prime badly. As to the future, the author suggested that for fast cross-Channel service the saving in machinery weights of 20 per cent 1s.in favor .Of the. turbine, and other factors will probably tend to make this class of propulsion stand- ard for this traffic. For fast Atlantic service the future seems to be with the turbine. For very large freight carriers the combination system of turbines and. reciprocating engines seems to promise best, while for tramps and slow vessels using com- paratively small power the three-crank tripe-expansion engine seems likely to hold its own against any other form of steam propulsion as yet devised. WATER SHEEP? Most engineers can recall amusing experiences in connection with the translation of foreign engineering terms into English or vice versa by foreign correspondents who possess little knowledge of technical terms used in the profession. The case quoted below from the Manchester Guardian is worthy of a_ place amongst curiosities of this descrip- tion. A business communication in Arabic recently reached a Manchester firm, and when translated-by a Syrian interpreter proved to contain a re- quest for the price of coppering "two water sheep" of certain given dimen- sions. The translator was confident of his version, but admitted that he did not know what water sheep could be. For the moment even the prin- cipals of the firm to whom the com- munication was addressed were puz- zled, until it struck someone that this was the nearest synonym in the vo- cabulary of a pastoral people for "hydraulic rams." A MOTOR DRIVEN TABLE SAW. A tool for woodworking establish- ments which is to be especially com- mended on account of its convenience, and efficiency is the neat motor-driven table saw illustrated herewith. It is built by the Crescent Machine Ca; Leetonia, Ohio. The saw table proper and the saw £9 itself. are supported upon a_ pedestal which also furnishes a frame upon which the mechanism for adjusting the saw and table, and the starting rheostat are mounted. This adjusting mechanism consists of means for tilting the table and raising or lowering the saw. The former is accomplished by means of a hand wheel whose shaft bears a worm, with a grad- uated brass scale and pointer to show exactly the amount the table is tilted, up to 45 degrees. By means of the other hand wheel the saw is adjustable in a vertical direction, making the ma- chine adapted for cutting boards of dif- ferent thickness up to 4 inch. The saw itself may be as large as 14 inches, but no larger. The motor equipment consists of a SAW. CRESCENT MOTOR-DRIVEN TABLE 334-horsepower, totally enclosed West- inghouse type "R"' motor and a start- ing rheostat. The motor is shunt- wound, and runs at a constant speed of 1,800 revolutions per minute on a direct current line voltage of 220 volts. The type "D" rheostat is equipped with an automatic low voltage release, and is used for starting only. The motor is mounted on the extend- ed base of the saw table proper. It is connected to the saw mandrel, by a belt which passes through an opening at the back of the pedestal. A reference to the illustration shows the extreme ease of operation brought about by the motor equipment. The five operating handles are all within a radius of about one foot. The table can 'be adjusted and the saw started or stopped without the operator moving a step. The motor is behind the ma- chine out of the way, and takes up no space that would otherwise be use- ful, being beneath the overhanging ta- ble. The machine can be located in any position desired, being independent of line shafts.