“What he wills, he does;
and does so much
That proof is called impossibility.”
MARY A. WARD.
A CHART OR DIAGRAM OF THE WAR PROM JANUARY, 1916, TO THE ARMISTICE, WITH AN EXPLANATION
 As I have already stated, in a footnote, I owe permission to publish this small reproduction of an interesting and unique document to the kindness of Lieut.-General the Hon. Sir Herbert Lawrence, K.C.B., etc., Chief of the General Staff.
EXPLANATION OF CHART
 [My readers will be as grateful as
I am to Captain W.O. Barton,
lately at work at G.H.Q., for this vivid explanation of the Chart.]
THE CHART.—This Chart is a small scale reproduction of one used and corrected from day to day at British G.H.Q. in France. It shows graphically the actual position at any given date of the British forces in FIGHTING STRENGTH, FRONT HELD, and HEAVY GUN POWER: when big operations are in progress it gives at a glance the number of CASUALTIES incurred and PRISONERS taken, perhaps the surest indication of the measure of success gained. Owing to the size of the reproduction, the horizontal scale lines of the original Chart cannot be given. To calculate a number at any particular date from the Chart as reproduced, it is only necessary to measure with a rule the height of the desired line at the given date. Reference to the appropriate numerical scale at the side will then give the number.
1916, STRENGTH AND FRONT.—Begin with the FRONT and FIGHTING STRENGTH lines. The Strength line tells the Commander his actual numbers (by reference to scale 2), but he needs more. He looks at the line representing Front and marks the proportion it bears to Fighting Strength. Measure these lines in mid-June, 1916. Since January, FRONT (scale 1) has expanded by about one-fifth—from 67 to 90 miles. The Chart shows the reason. But meanwhile Fighting Strength, then the vital factor for attack, has risen from 470,000 to 680,000, nearly one-half. The Army has been built up by new Divisions for the great Somme offensive.
CASUALTIES.—The battle opens. The red line of casualties leaps into prominence and, with its ascent, STRENGTH falls. Reinforcements are needed. They arrive to replace casualties, and STRENGTH goes up again. So through the long conflict these lines act and react. Ground is won, but hardly and at great cost: the ascent of the Front line is slow.
PRISONERS.—What are the enemy losses? How are his men fighting? The PRISONERS line (scale 5) tells best. Gradually the proportion of prisoners to (British) casualties increases: his casualties are growing, his resistance becoming less effective: the wearing-out process tells. Mark the concluding phases of the Somme battle. The PRISONERS line is nearer to that of casualties. The Tank has been introduced, and here is ocular evidence of its effectiveness. More tanks is one of the lessons of the lines.