The ammunition for the heavy artillery is brought on railways of 60-centimetre gauge to the battery supply-shelters, whence 40-centimetre gauge tracks, equipped with small hand-trucks specially detailed to each battery, take it directly to the guns. These supply-shelters, solid enough to resist the enemy’s shell-fire, are constructed by each battery as soon as it has completed and occupied its allotted emplacement. During the preparation the transportation of supplies offers few difficulties so long as the fire of the enemy is not very severe. As soon as the ground begins to be torn up, construction-gangs must be summoned for the purpose of keeping in repair all the ways of communication. Each battery has its own organized reserve of munitions or supply-shelter, from which to draw the necessary shells during the first days of the operation, and the parks endeavour by all possible means to keep on feeding these reserves. Ammunition for the trench-guns is conveyed to the entrance of the trenches by similar little hand-operated railways, and cartridges and grenades for the infantry are distributed in the same manner. It is advisable, when time and means permit, to operate these small railways of 40-centimetre gauge in the trenches themselves, when they are sufficiently wide for the purpose. The small trucks, pushed by men, will bring the torpedoes and other munitions as far as possible, but when the narrowness of the excavations prevents this, supplies must be carried by hand to the most advanced lines. This work, which is very laborious, should be left, whenever possible, to men drawn from regiments in the rear which are not intended to take part in the impending attack. For the last year North African burros have been used for carrying the munitions through the communication trenches. They are hardy animals, easy to drive, and they save the troops a great deal of labour. =4. Importance of the munition supply.= To give our readers an idea of the enormous work involved in munition transportation, we append some figures obtained from a field battery operating in the first lines on the Aisne in March and April, 1917. On the 12th of April the reserve in munitions of that four-gun battery was 2000 shells per gun; _i. e._, 8000. From the 15th onward the battery received 1500 shells daily. On the 19th, in the evening, there remained only 1700 shells. The battery had therefore fired from the 12th to the 19th about 3600 shells per gun. This is a normal figure, and explains why millions of shells are fired on a large front in a few hours. PRECAUTIONS. The enormous quantity of projectiles and supplies of all kinds in the different parks prevents them from being sheltered or even concealed, and, in order to limit the accidents caused by explosions, the stacks of ammunition are far from one another. In an effort to hide them from the enemy aviation, painted cloths, or green or brown coloured grasses, are thrown over them, so as to deceive the eye.