The tribesmen of the North West Frontier are brave, and inured to fatigue and hardship, a considerable number have been trained in our Indian army, and these have some knowledge of tactics, and acquaintance with British methods. The clansmen possess no artillery, but in other respects are fairly well armed, and owing to the cheap sale of rifles and ammunition in Afghanistan, are daily becoming more formidable in this respect. They suffer, however, from two grave military faults, lack of discipline and cohesion, and at present would, it is believed, be unable to mass against any one of several columns invading their fastnesses. They would, more probably, be content merely to defend their own valleys and homesteads, rather than attempt to defeat, in detail, the divided forces of an invader operating from exterior lines. It would seem, then, that in a campaign in the Indian borderland, British troops would be justified in undertaking a concentric invasion from several localities. Certain advantages may also be claimed for this policy. The road space occupied, in these pathless regions, by a large force moving on one line, is so great, that, as was demonstrated in Sir W. Lockhart's advance from Shinawari, in 1897, the rear of the column will be several days' march behind the leading troops. In these circumstances, not only will risk of defeat in detail be even greater than in the case of concentric invasion--for small columns can better exercise mutual support, than can a large force moving in a restricted valley--but the length of the convoy train, and the seeming strength of the force, will be a direct temptation to the tribesmen to avoid battle, and have recourse to guerilla warfare. Besides, if small columns are employed, the whole country will be, in the first instance, over-run, and the enemy may, on account of the apparent weakness of the various detachments, take heart of grace and fight. This, after all, is what is most desired, for the aim is always to attain rapid and decisive victory, and so end the campaign. An argument against convergent invasion is, that since it may be necessary to use more than one line of communication, not only will the employment of larger numbers be necessary, but more transport animals, the provision and care of which really constitutes the main difficulty in frontier warfare, will be required. This drawback may, however, be mitigated by opening only one line of communication, along the easiest route, the other detachments moving as flying columns, until the heart of the district is reached, when their surplus animals can be transferred to line of communication duties. STRENGTH AND ORGANISATION OF COLUMNS.