hostile gun. The shell must then be on the
target.

"The system works equally well by day or by night, in rain or in fog.
Its one enemy is a wind which blows towards the hostile gun and
prevents the sound reaching the recording apparatus. It can detect a
gun as easily if it is in a wood or in a building as if it were on a
hill-top.

"Simple as it appears, however, it is not so easy as one might think
to make a practical ally of sound ranging. We have succeeded. The
Germans failed. Towards the end of the war at least ninety per cent,
of the German artillery was marked down accurately by these means; and
the staff employed on sound-ranging and flash-spotting (the last a
kindred method depending on a mixture of observation and mathematics)
had grown from _four_ in 1914 _to four thousand five hundred_ in 1918.

"Casualties have been heavy, and the work arduous. But those
responsible for it have, at any rate, 'done their bit.'"

This is just one instance, such as we ignorant at home can more or
less follow, of that concentration of British wit and British
perseverance on the terrible business of war which carried us to our
goal. Germany prided herself, above all, on "scientific war." But the
nation she despised as slow-witted and effete has met her again and
again on her own boasted ground, and, brain for brain, has won.

With the ever-growing importance of artillery has gone, of course, a
constant increase in artillery _personnel_, and in the proportion of
gunners to infantry. The Third Battle of Ypres in the autumn of 1917
was "one of intense struggle for artillery supremacy," says the Field
Marshal. Germany had put out all her strength in guns, and was
determined to beat down the British artillery. The British Command met
the attack and defeated it, in a long-drawn battle, in which,
naturally, the proportion of artillery _personnel_ to infantry was
exceptionally high--at one time eighty-five per cent. Last spring, for
a short time, owing to the transference of batteries from the Russian
front, the enemy command succeeded in establishing "a definite local
artillery superiority." But it was soon over. Before the breakdown of
the March offensive "our guns had regained the upper hand," and in the
later battles of the year the German artillery was finally mastered.

But immense as was the growth of the artillery factor, the ultimate
problem was the old problem of co-operation and combination of _all
factors_. "Deep stu