Hence the phalanx or "preponderating mass formation." The Macedonian development of this depends (to reduce the matter to the simple algebraical formula to which all military problems are susceptible) on the fact that if _x_ equals the greatest efficiency of an army, and the rooted square of stability to the _n_th rank equals the phalanx, then the rooted square of stability to the _n_th rank equals _x_ minus the tangential curve of velocity of mobility. This should be plain even to the amateur student of tactics. Blending almost a military expert's appreciation of this cardinal doctrine with his natural selfishness as a leader of cavalry, PHILIP has given to this, the mobile arm, much of the striking power of the original phalanx. This is now placed in the centre, its business being mainly to force a salient in the enemy's line, the two resultant enclaves of which can then be shattered (at their re-entrants) by the cavalry squadrons, hurled forward on both phalanks. It should be noted, as a brilliant example of PHILIP'S staff work, that in the Macedonian Army, for the avoidance of confusion in the field, "phalanks" is now spelt "flanks." To the intelligent student who has followed me thus far in these articles it should not be necessary to explain again the terms "enclave," "salient," and "re-entrant." "Tactical" is a term used when one is not using the term "strategical," and _vice versâ_. * * * * * "In the words of Bacon, it should be 'read, marked, learned and inwardly digested.'"--_Financial Paper_. Our gay contemporary does not tell us whether it was before or after completing the works usually attributed to SHAKSPEARE that BACON compiled the Book of Common Prayer. * * * * * THE FLAPPER. [Dr. ARTHUR SHADWELL, in the January _Nineteenth Century_, in his article on "Ordeal by Fire," after denouncing idlers and loafers and shirkers, falls foul "above all" of the young girls called flappers, "with high heels, skirts up to their knees and blouses open to the diaphragm, painted, powdered, self-conscious, ogling: 'Allus adallacked and dizened oot and a 'unting arter the men.'"] Good Dr. ARTHUR SHADWELL, who lends lustre to a name Which DRYDEN in his satires oft endeavoured to defame, Has lately been discussing in a high-class magazine The trials that confront us in the year Nineteen Seventeen. He is not a smooth-tongued prophet; no, he takes a serious view; We must make tremendous efforts if we're going to win through; And though he's not unhopeful of the issue of the fray He finds abundant causes for misgiving and dismay. Our optimistic journals his exasperation fire, And the idlers and the loafers stimulate his righteous ire; But it is the flapper chiefly that in his gizzard sticks, And he's down upon her failings like a waggon-load of bricks.