nor is it advisable that I should do much towards indicating those on which we are in agreement.
There are two theories, however, evolved by Mr. Lanchester to which I may safely draw attention. The first he has called the N-square law, and it is, to my mind, a most valuable contribution to the art of war. It is the scientific statement of a truth which, although but dimly perceived, has been skilfully used by many great captains, both Naval and Military, but it is now for the first time stated in figures and logically proved. We can never be governed by the rules of exact science; there are too many conflicting factors, too many fortuitous circumstances; but there are certain rules, whether based on experience or calculation, which no commander may lightly transgress. Concentration of force is one of these rules, and a statement of the inevitable disadvantages of dispersion is valuable. The examples chosen from sea and land warfare illustrate the working of the law with admirable precision.
In the other case, Mr. Lanchester's calculations are less satisfactory. In considering the proportion of aircraft which is suitable for the requirements of an army in the field, the aircraft are compared with cavalry, and the aeroplane with a single trooper. This is no sound basis for calculation. To begin with, a single aeroplane absorbs, on the average, the services of some twelve officers and men, and its cost, which is not an immaterial factor, would provide more than a score of horses. But even the most accurate display of comparative figures will bring us no nearer to a correct result. The aeronautical arm is a new force in war, performing new functions, extending its activities every day and, at present, recognising but few limitations to its possible development. There is, as
