September 30, 191 5J 



NATURE 



115 



TKEO'RY AND PRACTICE OF FLYING.^ 

 "T'HE present notice refers to three new books 

 -^ on the theory and practice of flying. Al- 

 though dealing with the same general subject, the 

 ground covered by each is almost entirely different 

 from that of the other two, and each has its own 

 special interest. 



"Aeroplanes and Dirigibles of War" deals 

 with the uses of aircraft in the present war and 

 with the methods of repelling aircraft attack by 

 lire from the ground ; the work contains very 

 little technical matter, no attempt having 

 been made to enter into details of construc- 

 tion. As showing the part which aircraft is 

 playing in the world-war, the book can be 

 read and appreciated with or without techni- 

 cal knowledge of aeronautics. 



The other books under notice are largely 

 technical, referring to aero-engines and to 

 aeroplanes respectively. In the first of these, 

 details of engines suitable for use in aero- 

 nautical work are" shown with numerous illus- 

 trations; there is little theoretical matter, and 

 scarcely any aerodynamics. The book on 

 aeroplanes is, however, almost entirely de- 

 bited to aerodynamics, and summarises the 

 important features as affecting the aeroplane 

 so far as they lie within present knowledge. 

 Having said so much generally, the further 

 more particular notes may be of interest : — 

 * (i) The book opens with interesting chap- 

 ters on the history and development of free 

 ballooning, tracing the military use of bal- 

 loons back to 1884 and incidentally claiming 

 for the British Government "superiority and 

 initiative." In spite of more recent develop- 

 ments the author says that the use of balloons 

 is still so important that no one of the belli- 

 gerents will seriously consider their disuse. 

 Passing from balloons to dirigibles, the early 

 struggles of Count Zeppelin with his enor- 

 mous rigid airships naturally receive much 

 attention. Other types, including the Par- 

 5eval and Astra-Torres non-rigid airships, 

 come under review, but the author says of the 

 Zeppelins that they have given airship supre- 

 macy to Germany. As a somewhat curious 

 offset to this, the author quotes with approval 

 a decision of the American military authori- 

 ties that "dirigibles are not worth their cost 

 as offensive machines," a decision which may *'' 

 after all prove to have been too sweeping. 



After reading these early chapters, the section 

 on aeroplanes is disappointing. In respect to 

 British military machines in particular the author 

 appears to have been singularly misinformed. As 

 an instance of this, it is stated that the BE type 

 of aeroplane has a maximum speed of 40-50 

 m.p.h., and to anyone acquainted with the tech- 

 nical flight journals such a statement is patently 



1 (1) " Aeroplanes and DirigibUs of War." By F. A. Talbot. Pp. xi+ 

 283. (f-ond >n : W. Heinemann, 1915.) Price yt. M. net: 



ByT'! A. Burls. Pp. X-+196. (London: C. 



wrong. As a matter of fact, the lowest flight 

 speeds are of the order of those mentioned, whilst 

 the highest were more nearly 70-80 m.p.h. at the 

 beginning of the war. 



Coming to anti-aircraft guns and bomb- 

 dropping the book again becomes interesting. 

 One of the illustrations reproduced in Fig. i 

 shows a mobile anti-aircraft gun as manufactured 

 by Krupp. Some of these guns are said to throw 

 a shell weighing 40 lb. to a height of 6000-8000 

 ft., forcing the ayiator to similar heights for 

 safety. From such heights the accurate drop- 



(3) "A'ro Eneines. 

 Griffin and Co , Ltd., 1915.) Price &s. M. net. 



(a) "The Aeroplane." By A. Fage. Pp. vii 

 and Co., Ltd., 19.15.) Price 6s. net. 



NO. 2396, VOL. 96] 



[36. (London: C. Griffin 



I. — The latest Krupp auti-airrraft gun, fthowiiig novel disposition of wb«cls. 

 From "Aeroplanes and Dirigibles of War," by F, A. lalbot. 



ping of bombs is a task of some difficulty, and 

 success is often attained only by the pilot running 

 the risk of destruction by shell-fire at much lower 

 altitudes. 



The author concludes with an expression of his 

 opinion that aerial activity will increase with the 

 duration of the war, a prediction which is already 

 being justified by events. 



(2) The most interesting and useful part of this 

 book is the description in detail of a number of 

 engines used in flight. The descriptions occupy 

 about three-quarters of the whole and range from 



