GAINING A FOOT OF GROUND PER HOUR.

Here a charge of explosive is placed and fired from a distance by an electric wire. At the same instant the men charge over the ground and occupy the ruined trench of the enemy. (Ill. L. News copr.)

This photograph shows a 16-inch coast defence gun made as part of the armament of the Panama Canal. It fires a projectile weighing 2,400 pounds which would pierce the armor of a battleship at a distance of 22 miles.

CHAPTER XXIV

HOW MODERN WARS ARE WAGED

All the Resources of Science Drafted into War - The Scope of Warfare Doubled - Directing a Modern Battle-Mathematics and Mechanics - Torpedoes and Submarines - Many Lethal Inventions High Power Firearms- The Hospital Service A Notable Change in the Garb of All Armies but One - Cryptic Coloration Learned from Animals - The Origin of “Khaki” Purpose of Such Colora

no respect, probably, is human progress more strikingly shown than in the ways and means of war. The contrast between the cave or the hut and the modern mansion or great office building, between the stage coach and the express train, between the candle and the electric light, between the stylus and the printing press-these contrasts are not more marked than that between the methods of warfare of early ages and those of today.

That is, of course, because many of the most advanced achievements of science, in chemistry, mechanics, engineering and what not have been applied to the arts of war; if indeed they have not, as many certainly have, been effected expressly for military purposes. Thus gunpowder was invented for use in war. It became of vast utility also in the arts of peace, but the improvements which have been made in it, and the development of other far more powerful explosives, have had their stimulus largely in the desire to increase the efficiency of military firearms. Steam navigation was of course applied to warships as well as to merchant vessels. Submarine navigation, which

Fulton undertook before he invented his steamboat, was meant almost exclusively for warlike purposes. The telegraph, the telephone, wireless telegraphy, and the electric light, have been made adjuncts to the army. most striking developments of the balloon and the aeroplane have been for military purposes. The automobile has been made a vehicle of war.

DOUBLING THE FIELD OF WAR

The

The present generation has seen the field of military operations doubled in extent, and more. Formerly war was waged on the surface of the earth and on the surface of the sea. Now it is waged with equal fury in the heavens above the earth and in the waters beneath the surface of the sea; to which we may add that it is also waged under ground to an extent never dreamed of in earlier wars. d

The ride of Paul Revere, and the beacon fires of the days of the Armada, are now supplanted by the telegraph and telephone as means of arousing the people and of summoning troops to the scene of conflict. Armies no longer march great distances to meet the foe, but are conveyed by trains, perhaps on railroads specially built for the purpose. Supplies of food and ammunition instead of being brought by mule wagon are conveyed by trains of automobile trucks.

BATTLEFIELD COMMUNICATIONS

A hundred or even fifty years ago, the commanding general of an army sought some coign of vantage from which he could survey the entire field of battle; or if that was impossible, he stationed himself as close to the firing line as might be prudent and kept himself informed of the progress of the battle and sent his orders to his lieutenants by relays of mounted messengers,

Now he may be miles from the scene of battle, seated in his tent or in a house, following the movements of the troops on a topographical map and transmitting orders and receiving reports by telephone to and from all parts of the field. Thus an army of hundreds of thousands, operating on a battle front of twenty or thirty miles, is as directly under control of the distant commander-in-chief as was a single regiment in olden times.

NAVAL MECHANICS AND MATHEMATICS

Equally striking has been the transformation of naval warfare. In Nelson's day, and even in Farragut's, the captain or the admiral stood on the quarter-deck, directing the navigation of the ship and the fighting of the crew, while the ammunition was brought to and placed in the guns by hand. Now the commander stands in his armored conning tower, giving commands by telephone, and the ammunition is handled and the guns are loaded by mechanical or electrical devices. The whole battleship is an intricate, elaborate engine or congeries of engines, operated by steam or electricity.

One great cause of the American naval victories in the War of 1812 was their use of sights on cannon. But now

a warship's guns are aimed by machinery, according to elaborate mathematical calculations. Instead of laying hostile ships side by side, gun-muzzles touching, as Paul Jones loved to do, the fighting is conducted at a distance of miles. The huge guns, loaded with smokeless explosives, hurl shells of half a ton weight each a distance of a dozen miles, with force sufficient to pierce the vitals of a ship at seven or eight miles, and with fuse gauged to explode the projectile within a second or two of the appointed time; while the mathematical and mechanical accuracy of the