October 28, 1915] 



NATURE 



231 



familiar with the rhinoceros in the circus, did not 

 identify it with his fierce niono-ceros or unicorn. 



In connection with the use of rhinoceros hide as 

 armour, it is recalled that it is only when the skin 

 is dried and properly prepared that it becomes of 

 iron-like hardness; for the skin of the living- 

 animal, notwithstanding popular hunters' tales 

 to the contrary, is quite soft and can be readily 

 penetrated in any place by a bullet or easily 

 pierced by a hunting knife. 



We have not space here to follow the author in 

 his exhaustive account of the origin and develop- 

 ment of defensive armour. He treats of this in 

 long chapters devoted to " Defensive Armour of 

 the Archaic Period " (b.c. 1122-255), characterised 

 by hide cuirass and scale armour in which metal 

 was absent ; " Defensive Armour of the Han 

 Period " (beginning in the third century B.C.), 

 when metal (at first copper and latterly iron) scales 

 were introduced, from Persia, Dr. Laufer believes, 

 to form "plate" armour; "Chain and Ring Mail," 

 also from Persia, though this was confined to the 

 Arabs and Moghuls and Tibetans, and never 

 adopted by the Chinese ; " Plate " armour, which 

 was much more ancient and at first formed of 

 bone-plates ; " Sheet " armour, as in the medieval 

 West, first came into use in China in the Tang 

 period (a.d. 618-906), and from India, the author 

 seems to believe. A chapter is also devoted to 

 "Horse-Armour," shedding much new light upon 

 this interesting phase of protective armament. 



A word of high praise must also be given to 

 the illustrations, which are well chosen and signi- 

 ficant ; and the photographic plates, sixty-four in 

 number, are beautifully reproduced. 



L. A. Waddell. 



MODERN BULLETS IN WAR AND SPORT. 



FOUR interesting articles appeared in the 

 columns of Engineering in August of this 

 year, contributed by Fleet-Surgeon C. Marsh 

 Beadnell, and these have now been reprinted in 

 the form of a thin pamphlet. The articles are 

 full of information as to the weights and velocities 

 of different bullets and as to the effects of bullets 

 of different kinds when they strike various sub- 

 stances at different points in their trajectory. 

 The great experience of the author as a big-game 

 sportsman on the one hand and as having seen 

 many cases in the South African and Philippine 

 wars and the present war on the other give great 

 value to his observations on the destructive or at 

 times very slight effects produced by the modern 

 bullet; his treatment of the dynamical and especi- 

 ally of the aerodynamical principles affecting the 

 notion of projectiles is less satisfactory. 



In dealing with the effects of bullets the author 

 shows how the damage done depends on the 

 energy lost by the bullet ; how, for example, a 

 bullet at a high velocity and striking properly 

 nd-on may drill a clean hole, doing the minimum 

 nf damage and losing but little of its velocity, 

 while at a later stage of its flight when travelling 

 more slowly, and especially if in any degree in- 

 lined to its trajectory, the destruction is incom- 

 NO. 2400, VOL. 96] 



parably greater, and the loss of energy as repre- 

 sented by V" equally so. 



The following^ experiment will exemplify this fact : — 

 Two skulls were filled with a substance of a consist- 

 ency as near as possible to that of the brain. Against 

 the, one was fired a normal bullet at high velocity, 

 agamst the other a similar bullet at low velocity, this 

 being effected by using a quarter charge ; the range in 

 each case was 10 ft. The first skull was neatly per- 

 forated, and the bullet, unaltered in shape, was found 

 embedded 26 in. in the wood backing ; the second 

 skull was partly disarticulated, and was fractured 

 posteriorly, the bullet lying inside against its posterior 

 wall. In the case of the first skull the bullet parted 

 with but little of its energy, and that only at the 

 actual points of entry and emergence. In the case 

 of the second skull more of the bullet's energy, both 

 absolutely and relatively, was expended on it and its 

 contents. 



In an experiment of this sort a good deal 

 depends on the compressibility of the material 

 filling the envelope. As illustrating this point it 

 may be permitted to refer to an experiment made 

 by the writer of this notice at the time that he was 

 photographing bullets. In order to ascertain if it 

 would be practicable to photograph a bullet glanc- 

 ing off still water, he constructed a long trough of 

 thin wood open at the top, somewhere about 

 3 ft. long and 4 or 5 in. wide and deep, and 

 on to the water in this he fired a o'303 bullet at as 

 near a grazing incidence as he could. The water 

 was hit about two-thirds along the trough, and 

 was driven out as by an explosion. The front 

 iind sides of the trough in advance of the point of 

 striking were split into matchwood, and generally, 

 apart from the photographic difficulties, it seemed 

 desirable to experiment in other directions. 



The author has experimented on the inclination 

 at which the modern high-speed bullet will pene- 

 trate a skull, and found that at angles above 5° 

 or 6° he obtained penetration, whereas Snider and 

 Martini bullets would glance off at much greater 

 angles. Space does not allow of reference to the 

 numerous valuable observations of the author on 

 the curious effects of bullets both in big game 

 and in warfare. These will be read with the 

 greatest interest. It is not possible, however, to 

 follow the author in his excursions in the domain 

 of pure dynamics, and his treatment of the action 

 of the air on the projectile appears to the writer 

 to be very largely imaginary and incorrect. So 

 difficult a subject as the action of air upon a 

 rotating projectile, whether spherical or elongated, 

 and whether the axis of spin is in or across the 

 trajectory, scarcely admits of any but the most 

 rigid treatment, and in this the author might find 

 Mr. Crabtree's admirable book illuminating. 

 There is a statement which is new to the present 

 writer, and it would have been well to have given 

 the authority. 



Thus, up to speeds of 790 ft. per second resistance 

 varies as the square of the speed, between 790 and 

 990 ft. per second as the cube, between 990 and 

 1 120 ft. per second as the sixth power, between 1120 

 and 1-^30 ft. per second again as the cube, and above 

 1330 ft. per second again as the square of the speed ; 

 above 1500 ft. per second the relationship is not 

 known. C. V, BoYS. 



