It is a remarkable fact that, at least since the wars of the Austrian succession, the proportion of cavalry to infantry has changed very little, the variation being constantly between a fourth, a fifth or a sixth; this seems to indicate that those proportions meet the natural requirements of an army, and that these numbers give the solution which it is impossible to find in a direct manner. We doubt, however, if this is the case, and we find the principal instances of the employment of a numerous cavalry sufficiently accounted for by other causes.
Austria and Russia are states which have kept up a numerous cavalry, because they retain in their political condition the fragments of a Tartar organisation. Buonaparte for his purposes could never be strong enough in cavalry; when he had made use of the conscription as far as possible, he had no ways of strengthening his armies, but by increasing the auxiliary arms, as they cost him more in money than in men. Besides this, it stands to reason that in military enterprises of such enormous extent as his, cavalry must have a greater value than in ordinary cases.
Frederick the Great it is well known reckoned carefully every recruit that could be saved to his country; it was his great business to keep up the strength of his army, as far as possible at the expense of other countries. His reasons for this are easy to conceive, if we remember that his small dominions did not then include Prussia and the Westphalian provinces. Cavalry was kept complete by recruitment more easily than infantry, irrespective of fewer men being required; in addition to which, his system of war was completely founded on the mobility of his army, and thus it was, that while his infantry diminished in number, his cavalry was always increasing itself till the end of the Seven Years’ War. Still at the end of that war it was hardly more than a fourth of the number of infantry that he had in the field.