The chief duty of the artillery is to support the infantry. It does this in three ways: 1st, By firing at the hostile infantry. 2d, By putting out of action the hostile artillery so that it cannot fire at the infantry. 3d, By demolishing the obstacles in front of the enemy's works. It smothers the enemy with a curtain of fire, so that the infantry can move forward without ruinous losses. Coöperation with the infantry is essential. If the infantry is defeated the artillery covers its withdrawal; if the infantry is successful the artillery moves forward and assists in reaping the full reward of victory by firing on the fleeing enemy. The present European War has greatly increased the prestige and importance of this arm of the service. The amount of artillery on the Western front and the amount of ammunition consumed daily is appalling. CAVALRY This very important arm is the eye with which the general sees for many miles to the front and flank. In an advance it pushes ahead, combs the country for the enemy, disperses his cavalry, and thus protects the infantry in the rear. It locates the enemy, and occupies his attention until the infantry comes up. It protects the flanks and rear of the infantry and artillery during the fight. If needed, it joins in the fight. If the infantry is defeated it covers the withdrawal, and if the infantry wins it pursues and pounces upon the enemy. MACHINE GUNS Before the present European War, machine guns were classified as emergency weapons. It was not believed that they could remain long in action, because they would soon be silenced by hostile fire (artillery and infantry). It was recommended, therefore, that a favorable opportunity be awaited before opening fire which was to be delivered with their utmost effectiveness. They were believed to possess very limited possibilities in an attacking line, hut as being most valuable in defensive works where protection and concealment could be found. During this war they have lost, as a defensive weapon, no prestige. They have also proved of great value to the attacking side. They are being made light and portable to accompany the firing line in an attack. The supply of ammunition alone limits the number that can be used. Each side in the present war has used them by the thousands with effectiveness. Machine guns are more worthy of consideration to-day than heretofore. BOMBS AND HAND GRENADES The present European War has revived the use of hand grenades and bombs. A certain number of soldiers in each British and French battalion are trained as grenade throwers. Their principal weapon is a bucket or bag of grenades or bombs. They operate not only from trenches but accompany the firing line in an attack and dispose of sheltered or isolated group of the enemy by smothering their position with a shower of hand grenades or bombs.