This second period merges very gradually into the third, or final, period, which is that of the last effort possible to the belligerents.  There comes a moment before the end of the first year when, in the case of most of the belligerents, every man who is available at all has been equipped, trained, and put forward, and after which there is nothing left but the successive batches of yearly recruits growing up from boyhood to manhood.

Although Britain is in a peculiar position, and Russia, through her tardiness in equipment, in a peculiar position of another kind, yet one may fairly say that the vague margin between the second period of growth and the third period of finality appears roughly somewhere round the month of June.  It will fall earlier with Germany, a good deal earlier with France; but from the middle of May at earliest to the end of June at latest may be said to mark the entry of the numerical factor into its third and final phase.

Let us take these three periods one by one.

The first period is by far the most important to our judgment of the campaign; a misapprehension of it has warped most political statements made in this country, and most contemporary judgments of the war as a whole.  It is impossible to get our view of the great European struggle—­of its nature in the bulk—­other than fantastically wrong, if we misapprehend the opening numbers with which it was waged.

There are three ways of getting at those numbers.

The first and worst way is the consulting of general statistics published before the war broke out.  Thus we may see in almanacs the French army put down as a little over four million, the German at the same amount, the Russian at about five million, and so forth.

These figures have no relation to reality, because they omit a hundred modifying considerations—­such as the age of the reserves, the degree of training of the reserves, the organization prepared for the enrolment of untrained men, etc.  The only element in them which is of real value is the statistics—­when we can obtain them—­of men actually present with the colours before mobilization, to which one may add, perhaps—­or at any rate in the case of France and Germany—­the numbers of the active reserve immediately behind the conscript army in peace.

The second method, which is better, but imperfect, is that which has particularly appealed to technical writers.  It consists in numbering units; in noting the headquarters and the tale of army corps and of independent divisions.

The fault of this method is twofold.  First, that only actual experience can tell one whether units are really being maintained during peace at full strength; and secondly, that only actual experience discovers how many new units can and will be created when war is joined.  In other words, the fault of this method (necessary though it is as an adjunct to all military calculations) lies in its divorce from the reality of numbers.