Whatever this fateful war may bring to us and to others, the defenceless bridge will have to be reconsidered; and for this reason its evolution attracts me even now, despite the darkling uncertainty that encompasses every hour of the day. The Forth Bridge, all shatterable bulk and no beauty and grace, does full justice to our industrialism, but yet he belongs, not to the public spirit of Great Britain, but to the spirit of the age everywhere; for in other lands he has a great many rivals not a whit less huge and vulnerable. As an example, we will take the Illinois and St. Louis Bridge, really a fine work of his kind, dating from 1873. He crosses the Mississippi, which at St. Louis flows in a single channel 534 yards wide and 8 feet deep at extreme low water. The greatest range between high and low water is 41 feet. There are three ribbed arches of cast steel, the middle one with a span of 520 feet, while the others are 18 feet narrower. If it was worth while for the sake of public convenience to erect this great highway above a wide and dangerous river, it was also worth while for the sake of public convenience that the width of the arches should be determined by the probable dangers to which the bridge would be exposed in commercial strikes and in other wars. Human gunpowder is not a rare thing in the United States of America. The black race there has a population that increases rapidly, and some day it may breed a great soldier, a dark Napoleon, who will find it no difficult task to organise a widespread society of bridge-wreckers. No truisms are more common than unexpected events. Let us then ask whether it would be possible swiftly to repair a metal arch having a span of 520 feet. If not, why build a huge and costly structure with steel-ribbed arches which are much too wide? What if one of them was destroyed at a time when the double railway track over the river, and the wide roadway above for other traffic, were necessary to bring reinforcements to a stricken army? [Illustration: ON THE TARN AT MILLAU IN SOUTHERN FRANCE. THIS DRAWING, A COMPANION PICTURE TO GIRTIN’S “BRIDGNORTH,” REPRESENTS THE BROKEN END OF AN OLD BRIDGE WITH A MILL BUILT ON IT; BEHIND IS AN ARCH OF THE NEW BRIDGE] These questions were too unmercantile to be considered by the chief engineer, Captain James B. Eads, a very scientific person, who was entirely of a piece with our European pontists. Not a scrap of attention did he pay to military matters. Every account of Captain Eads and his bridge bombards us with technical details. We are expected to gape with admiration because £60 per ton of 2000 lbs. was the price paid for 2500 tons of cast-steel. Wrought-iron in a ton of 2000 lbs. cost £40, and 500 tons at this price were used. Rolled-iron in a ton of 2000 lbs. cost £28, and 1000 tons at this price were employed, together with 200 tons of cast-iron at £16 per ton, the ton in this case being 2240 lbs. Here indeed is a golden target for bombs and for modern artillery!