386 EXPERIMENT STATION RECORD. 



iu sizes from 5 to 20 lioisepower when operating at i to full rated capacity, 

 followed in order by the superheated and saturated steam engines, the gas 

 engines, and the electric motors. It is stated, however, that utilization by the 

 mechanical means available of the waste heat will place the steam engines 

 ahead of the crude oil engines as regards economy. 



The possibilities of mixed fuels (Gas Engine, 16 (1914), No. 2, pp. 120, 

 121). — Tests on a 4-cylinder engine of 3.54 by 5.12 in. bore and stroke, using 

 gasoline, benzol, or mixtures of benzol and methylated spirits 1:1, 1:2, and 

 1 : 3 showed that on none of the mixtures of methylated spirits and benzol did 

 the engine run steadily under load unless the temperature of the jacket of the 

 induction pipe was at least 160° F. The benzol took less air than gasoline, and 

 the more methylated spirit in the mixtures the smaller was the quantity of air 

 required. 



The engine at 1,000 revolutions per minute gave 1.25 per cent less power and 

 used 15.5 per cent less benzol ; 1 per cent less power and used 3.7 per cent less 

 of the 1 : 1 benzol-methylated spirit mixture ; 8 per cent less power and used 

 S.9 per cent more of the 1 : 2 mixture : and 8.5 per cent less power and used 24.5 

 per cent more of the 1 : 3 mixture than when running on gasoline. Later experi- 

 ments using the 1 : 1 mixture in a high speed engine up to 2,000 revolutions per 

 minute " show that with the slightly increased compression obtained in this 

 engine, it was possible to get an explosive mixture which would burn rapidly 

 enough to exert at least as much power as gasoline with a piston speed of about 

 2.000 feet per minute." 



Fuel-briquetting investigations, July, 1904, to July, 1912, C. L. Wbight 

 (U. 8. Dcpt. Int., Bur. Mines Bui. 58 (1913), pp. lX+275, pis. 21, figs. 3).— 

 This bulletin reports briquet tests made with a large number of fuels from 

 different parts of the United States and also laboratory tests of briquet binders. 

 The advantages of briquetted fuel are noted as more regular, thorough, and 

 smokeless combustion, better draft, little clinkering, less need of care in firing, 

 greater evaporative power, better weather resisting qualities, higher rates of 

 combustion, less breakage during transportation, no spontaneous combustion, 

 less space required in storage, and higher heating values. 



Among a large number of other tests were tests of briquets in a kitchen range 

 and in a heating grate. The briquets ignited readily, making a hot fire, and 

 burned freely until consumed. Little shaking or poking of the fire was needed 

 to obtain maximum efficiency from the fuel, and the loss of unburned fuel 

 through the grates was not excessive and could be reduced by using step grates 

 or grates with narrow spaces between the bars. A grate measuring 8 by 24 in. 

 was big enough for heating a large room with briquets. Under the test condi- 

 tions little smoke was made. 



It is concluded that briquets should prove a satisfactory domestic fuel. 



Mechanics for builders, I, E. L. Bates and F. Charles ( New York, 1913, pp. 

 201; rev. in Sci. Amer., 110 (19U), No. 10, p. 212).— This book is meant for 

 students of building construction who desire to perfect themselves in the prin- 

 ciples of form and design. It selects from the larger study such subjects as 

 bear directly upon building problems and gives a thorough grounding in 

 strength of materials and theory of structure. 



The testing of sand for use in concrete, I, II, C. M. Chapman (Engin. 

 News, 11 (1914), Nos. 6, pp. 306-310, figs. 7; 11, pp. 554-558, figs. 2).— Part 1 

 of this article describes methods of sampling and testing sand for use in con- 

 crete, and part 2 gives methods of reducing to useful form the laboratory and 

 field data from such testing of samples. 



