THE DEBATE ON AERONAUTICS Sir,--It is not to be wondered at that the Chairman of Committees declined to allow yesterday's debate on aviation to diverge into an enquiry whether the Powers could be induced to prohibit, or limit, the dropping of high explosives from aerial machines in war time. The question is, however, one of great interest, and it may be desirable, with a view to future discussions, to state precisely, since little seems to be generally known upon the subject, what has already been attempted in this direction. In the _Règlement_ annexed to The Hague Convention of 1899, as to the "Laws and Customs of War on Land," Art. 23, which specifically prohibits certain "means of injuring the enemy," makes no mention of aerial methods; but Art. 25, which prohibits "the bombardment of towns, villages, habitations, or buildings, which are not defended," was strengthened, when the _Règlement_ was reissued in 1907 as an annexe to the, as yet not generally ratified, Hague Convention No. iv. of that year, by the insertion, after the word "bombardment," of the words "by any means whatever," with the expressed intention of including in the prohibition the throwing of projectiles from balloons. The Hague Convention No. ix. of 1907, also not yet generally ratified, purports to close a long controversy, in accordance with the view which you allowed me to advocate, with reference to the naval manoeuvres of 1888, by prohibiting the "naval bombardment of ports, towns, villages, habitations, or buildings, which are not defended." The words "by any means whatever" have not been here inserted, one would incline to think by inadvertence, having regard to what passed in Committee, and to the recital of the Convention, which sets out the propriety of extending to naval bombardments the principles of the _Règlement_ (cited, perhaps again by inadvertence, as that of 1899) as to the Laws and Customs of War on Land. But the topic was first squarely dealt with by the first of the three Hague Declarations of 1899, by which the Powers agreed to prohibit, for five years, "the throwing of projectiles and explosives from balloons, or by other analogous new methods." The Declaration was signed and ratified by almost all the Powers concerned; not, however, by Great Britain.