October 17, 1919] 



SCIENCE 



357 



2,800 tons; while during the whole war 

 in France, on the British front alone, more 

 than 170,000,000 artillery rounds were 

 fired, weighing nearly 3,500,000 tons— 622 

 times the number of rounds, and about 

 1,250 times the weight of projectiles. 



However great these figures in con- 

 nection with modern land artillery may 

 be, they become almost insignificant when 

 compared with those in respect of a 

 modern naval battle squadron. The Queen 

 Elizabeth, when firing all her guns dis- 

 charges 18 tons of metal and develops 

 1,870,000 foot-tons of energy. She is 

 capable of repeating this discharge once 

 every minute, and when doing so develops 

 by her guns an average of 127,000 effective 

 h.p., or more than one and one half times 

 the power of her propelling machinery; 

 and this energy is five times greater than 

 the maximum average energy developed on 

 the western front by British guns. Fur- 

 thermore, if all her guns were fired simul- 

 taneously, they would for the instant be 

 ■developing energy at the rate of 13,132,000 

 h.p. From these figures we can form some 

 conception of the vast destructive energy 

 developed in a modern naval battle. 



"With regard to the many important 

 engineering developments made during the 

 war, several papers hy authorities are 

 announced in the syllabus of papers 

 constituting the sectional proceedings of 

 this year's meeting. Among them are 

 "Tanks," by Sir Eustace d'Eyncourt; 

 "Scientific Progress of Aviation during 

 the War," hy L. Bairstow; "Airships," 

 by Lieutenant-Colonel Gave-Brown-Cave ; 

 "Directional Wireless, with Special Refer- 

 ence to Aircraft, ' ' by Captain Robinson ; 

 "Wireless in Aircraft," 'by Major Erskine 

 Murray; "Wireless Telegraphy during the 

 First Three Years of the War," by Major 

 Vincent Smith; "Submai'ine Mining," by 

 Commander Gwynne; "Emergency Bridge 



Construction," by Professor Ingles; and 

 "The Paravane," 'by Commander Burney. 

 Accordingly, it is quite unnecessary here 

 to particularize further except in the few 

 following instances: 



Sound-ranging and Listening Devices. — 

 Probably the most interesting development 

 during the war has been the extensive ap- 

 plication of sound-listening devices for 

 detecting and localizing the enemy. The 

 Indian hunter puts his ear to the ground 

 to listen for the sound of the footsteps of 

 his enemy. So in modern warfare science 

 has placed in the hands of the sailor and 

 soldier elaborate instruments to aid the 

 ear in the detection of noises transmitted 

 through earth, water, air or ether, and also 

 in some cases to record these sounds graph- 

 ically or photographically, so that their 

 character and the time of their occurrence 

 may be tabulated. 



The sound-ranging apparatus developed 

 hj Professor Bragg and his son, by which 

 the position of an enemy gun can be deter- 

 mined from electrically recorded times at 

 which the sound-wave from the gun passes 

 over a number of receiving stations, has 

 enabled our artillery to concentrate their 

 fire on the enemy's guns, and often to 

 destroy them. 



The French began experimenting in 

 September, 1914, with methods of locating 

 enemy guns by sound. The English sec- 

 tion began work in October, 1915, adopting 

 the French methods in th« first instance. 

 By the end of 1916 the whole front was 

 covered, and sound-ranging began to play 

 an important part in the location of enemy 

 batteries. During 1917 locations by sound- 

 ranging reached about 30,000 for the whole 

 army, this number being greater than that 

 given by any other means of location. A 

 single good set of observations could be 

 relied upon to give the position of an 

 enemy gun to about 50 yards at 7,000 



