ARMOURED MOTOR-CARS. On some armoured motor-cars small cannon are used; on others, machine-guns are placed. They are intended to throw the enemy lines into confusion at certain points. Their action must be swift, sudden, and brief. Their mobility enables them to dodge the fire of the enemy’s artillery. These cars can be much more useful in open field operations than in trench warfare. They will be especially useful as a help to cavalry when the latter can once more be used. Every regiment of infantry is now provided with a section of three 37 mm. guns which being light, easy to move, and very accurate are employed principally, either all together or in the proportion of one to each battalion, against machine-guns. They have been greatly appreciated by the regiment commanders; a large number will probably be distributed as soon as they can be manufactured. =5. Advance or withdrawal of the artillery.= One of the most interesting questions for an army in the making, such as the American Army, is that of the rapid moving of the heavy artillery, at a given moment. We do not hesitate to say that this problem is far from being entirely solved on the Western Front, and that its study and organization will be a very hard task for the engineers entrusted with its solution. American engineers will have to go to the Western Front and see for themselves all the difficulties to be surmounted. ADVANCE. During the spring of 1917, the French Army had to pursue on a large front an enemy who had not only devastated the country behind them to a depth of from 30 to 35 kilometres, but had also accumulated in this wilderness all the obstacles their fertile imagination could suggest. The 75 mm. field artillery alone, at the cost of great efforts and tremendous loss of horses, managed to overtake, though somewhat late, the advance of our infantry, which had succeeded in going forward everywhere. The sections for the supply of munitions followed their batteries, but more slowly; and some batteries, which at the cost of great and continuous efforts, had come into position, had no munitions. The only way to guard against such delays, in the future, will be to keep in reserve complementary teams of horses, to replace those that are killed, or to help the batteries and their ammunition sections through the worst passages. We have not the right to give here in detail the difficulties encountered in the advance of the heavy artillery. We were informed of them by a confidential note from the High Command. However, while this confidential note sets forth in detail all the difficulties encountered, it makes no recommendation whatever as to what should be done on such occasions in the future.