But to go back to bombs. All through France and Belgium, and wherever the Prussian soldiers found their way, there was evidence of the use of hand grenades which were thrown against the sides of or into buildings to set them in flames. Some of these devices, made of sheet metal, were in their action similar to the "Fourth of July torpedoes" familiar to every American school boy. When thrown they exploded throwing oil and chemicals over walls and floors. Some of them seem to have been loaded with bullets and were in effect hand shrapnel. Then there developed from the primary use of these nefarious weapons the recognized hand grenade, which is actually hand-shrapnel, plied by men at close quarters. Thousands of these have been thrown by the armies in their charges on the trenches. And then, to offset the use of these devices in the offensive, there came into being also the smoke bombs. These when exploding throw up great clouds of black smoke which hang over everything. EFFECTIVE IN A HUNDRED WAYS. The use of such bombs has proved effective in a hundred ways. They have been used to create a perfect shield of smoke to conceal the movements of troops, or prevent the enemy from finding the range with their long distance guns. Similarly bombs which contained burning chemicals have been used to hold in check the approaching enemy forces. Half way between the great gun and the hand grenade stand among war weapons the trench mortars. The first of these were used by the Japanese in their war with Russia. The Japanese mortars were mere logs hollowed out and strengthened by wrappings of bamboo rope. The projectiles fired from these were empty provision tins filled with high explosives, scraps of metal, bits of stone or whatever, in the emergency, could be found to fill them. The mortars are pitched at an angle and the projectiles are shot with a skyrocket effect, to land in the trenches or camp of the enemy. The Germans developed the idea and the perfected mortars are of steel, and capable of throwing bombs weighing several hundred pounds. And then the great moving fort which has been called "the tank!" Those snorting, fire-spitting dragons which were depicted for us in childhood can scarcely bring to our mind a greater element of the fanciful, the horrible, and the powerful than the steel hulks which came into being in this war under the name of "tanks."