Page:Aircraft in Warfare (1916).djvu/110

§ 45 § 45. The Question of Armament; Treaty Restrictions. In the specification of a fighting type of aeroplane the first and foremost consideration is its means of attack. These fall into two broadly distinct categories: fire-arms, chief amongst which for the purpose in question is the machine-gun or mitrailleuse; and gravitational weapons, including bombs, hand-grenades, steel darts, etc.; the latter being mainly useful when attacking a terrestrial objective. Except when dealing with a dirigible or airship, gravitational weapons are but ill suited to the conditions of attack on aircraft. Light artillery may certainly be mounted on an aeroplane, but only the very smallest calibre—namely, the "1-pounder"—can be considered suitable for machines such as are built at the present day; even the mounting of a gun of this size is a matter of great difficulty. The only advantage obtained by the employment of a weapon of this character is in the fact that it is permissible to throw shell, high-explosive or otherwise, the use of which for smaller sizes of projectiles is prohibited by treaty obligation. Any explosive projectile of less than 1 lb, weight (more exactly 400 grammes, or 14 oz., about) is banned by the Declaration of St. Petersburg, of 1868; the paragraph with which we are concerned reads:—"The contracting parties engage mutually to renounce in case of war amongst themselves the employment by their military or naval troops, of any projectile of a weight below 400 grammes which is either explosive or charged with fulminating or inflammable substances." This is reaffirmed in the text of an abortive declaration of the Brussels Conference of 1874. Article 13 (e): "The use of arms, projectiles, or material which may cause unnecessary suffering, as well as the use of