2. _Directing and correcting artillery fire._ Very many reports of the use of the aëroplane in this respect have come to hand during the present war. The Germans appear to be very keen on this particular use. Stories told by wounded soldiers graphically describe how with the appearance of the enemy’s aëroplane there comes accurate and deadly fire. The Germans appear to have several simple and ingenious means of indicating the instructions of the aërial observer in this respect. An interesting contribution to our knowledge has been supplied by Bombardier Smith, who was wounded by a bomb dropped from a German aëroplane. Writing to the _Times_ he describes how the Germans have special bombs for range-finding. Those bombs have proved a great success in the war, as they find the enemy’s ranges very accurately. The bomb when dropped leaves a thick, black, smoky line to enable their gunners to take the exact range. We were in a good position but suffered loss. The enemy could not find us until the aëroplane came on the scene. Then we had it rather hot. The gunners had to leave the guns, but later saved them all after being reinforced by other guns. Another method the Germans adopt is to drop a silver ball. Almost as the ball drops from the range-finding aëroplane, the shrapnel shell bursts over the lines of the opponent. They also sometimes pull up and down a little disc suspended beneath the aëroplane. A still further variety of signalling is accomplished by the use of lamps that are visible in daylight. Almost every method of signalling can be used for the purpose, such as flag signalling; wireless signals are no doubt especially effective. I will quote from a recent article by Mr. F. W. Lanchester in “Engineering” as to the German use of the aëroplane in this respect:-- The value of aëroplane work will be relatively greater the longer the range; in fact, it may in future be found possible to employ heavy artillery of long range under conditions in which without the help of the aëroplane it would be comparatively useless. As an illustration, there is nothing to-day to prevent a long-range battery, well served by its aëroplanes, from effectively shelling an enemy without knowing in the least the character of its objective--_i.e._, whether an infantry force or position, a body of cavalry, or the enemy’s guns. In the present war the aëroplane appears to have been utilised by the German army, as a matter of regular routine, as an auxiliary to the artillery in the manner indicated. It has been reported again and again that the appearance of an aëroplane overhead has been the immediate prelude to the bursting of shrapnel, frequently the very first shell being so accurately placed as to indicate that the method of signalling, and, in fact, the whole performance, must have been well thought out and equally well rehearsed. 3. _Offensive operations._