WAR-TIME TROPICS

North Otago Times, Volume CIII, Issue 13652, 21 August 1916, Page 4

WAR-TIME TROPICS

MATTERS OF INTEREST- PROM VARIOUS SOURCES. BULLET WOUNDS. Medical observation is exercised over the facts that in all bullet wounds it has been found that the aperture which the bullet has made increases in proportion to- the length of range of lire, and that when the bullet goes right through.body or limb the aperture at the exit is considerably larger than at the entrairce, A bullet at 200 to 400 yards makes,a passage smaller than itself. Over 1000 yards it exceeds the diameter of the bullet, and when the bullet is nearly at the. end of its range the wound is very large, The explanation is quite simple. The spiral rilling in the barrel causes the bullet to spin, and the spin is maintained throughout its course. But the resistance of the air pressing on the point of the bullet in front, tends to slow it, whilst the momentum of the back part of the projectile . pushes it forward. This causes a wobble in the bullet, the point of which soon begins to describe a small circle in the air. At short range there is little time for this aberration to develop appreciably, hence the bullet only makes way for its own cross section, but at long range the aperture has to be wide, enough to accommodate Hie bullet and its t irregular motion, ZEPPELIN BOMBS. German aircraft are known to have dropped on the British Isles four different patterns of bombs. Fnr-h varies in form, size and weight, although there are only two types or.classes—namely, the high explosive bomb and the incendiary bomb. Portions of all four have been picked up in different parls of flic country, and occasionally complete unexplodcd' bombs have been discovered. Several are reported to have been picked up in Scotland recently, and one at least was safely delivered to the proper 'authorities, who are charged with the destruction of such dangerous missiles. Asphyxiating bombs have not been traced, and although a sulphuric smell was detected after several explosions, that is accounted for by the presence of a limited and practically harmless—in anasphyxiatiug sense—quantity of phosphorous which the incendiary ibombs contain. The incendiary bombs are comparatively light missiles, They, are tor-pedo-shaped, have a cast iron casing, and their total weight is about fifteen pounds, while the radius of the danger area on explosion in Ihe open is nboul one hundred yards. Two kinds have been found. One containing a magnesium star mixture is two feet long, with a width tapering from Jive inches; Ihe nlher, containing soi)io phosphorus, but chiefly lilled with thermit and star composilipn, is only fifteen inches long, with a width tapering from leu inches, anil having at the narrow end a calico streamer. This latter type is more vicious, in its action than the other. When explosion occurs the liquid is scattered and scls lire to iiillatninable material wilhin reach. There are also two kinds of high explosive bombs, and they vary in weight from 1001b to MOIb, or from slightly under lo considerably over a hundredweight each. The commoner, and heavier of the two

is spherical in form and over a foot in diameter, -lit the open the radius of the danger area is (iOO yards. The rnsinjj■ is cither cast iron or cast, steel/ and if contains about ;10ll> of froytl. The dimensions of the lighter highexplosive bomb are approximately two feet in length by one foot, tapering lo about three inches, with a thin steel case and gunmotnl vanes on the fuse. It probably contains fiOlb of trotyl, and in the open the radius of danger area, has he'on estimated at 400 yards. The mechanism in .all these bombs may differ considerably, and they may be arranged to explode oir contact or a few seconds after contact. A bomb 'dropped from a height of SOOO feet, while the airship is travelling at sixty miles on'hour, would probably strike the. ground L'ooo .feet, or throe-eighths of a mile, in front of the spot vertically below the point from' which it was dropped. The possibility, therefore, of striking a definite object is' very remote.