CHAPTER XI.
OPERATIONS AT ISLAND NUMBER TEN.
Commodore Foote, having repaired the gunboats disabled at Fort Donelson, sailed from Cairo the day that New Madrid fell into the hands of General Pope. He had seven gunboats and ten mortars, besides several tugs and transports. Colonel Buford, with fifteen hundred troops, accompanied the expedition.
The mortars were untried. They were the largest ever brought into use at that time, weighing nineteen thousand pounds, and throwing a shell thirteen inches in diameter. The accompanying diagram will perhaps give you an idea of their appearance. You see the mortar mounted on its carriage, or bed as it is called. The figures 1, 1 represent one cheek of the bed, a thick wrought-iron plate. The figures 2, 2 represent the heads of the bolts which connect the cheek in view to the one on the other side. The bed stands on thick timbers, represented by 3, and the timbers rest on heavy sleepers, 4. Figure 5 represents a thick strap of iron which clasps the trunion or axis of the mortar, and holds it in its place. This strap is held by two other straps, 6, 6, all iron, and very strong. The figure 7 represents what is called a bolster. You see it is in the shape of a wedge. It is used to raise or depress the muzzle of the mortar. The figure 8 represents what is called a quoin, and keeps the bolster in its place. The figure 9 represents one of the many bolts by which the whole is kept in place on the boat.
A Mortar.
The boat is built like a raft, of thick timbers, laid crosswise and bolted firmly together. It is about thirty feet long and twelve wide, and has iron plates around its sides to screen the men from Rebel sharpshooters. The mortar is more than four feet in diameter. It is thicker than it is long. To fire a mortar accurately requires a good knowledge of mathematics, of the relations of curves to straight lines, for the shell is fired into the air at an angle of thirty or forty degrees. The gunner must calculate the distance from the mortar to the enemy in a straight line, and then elevate or lower the muzzle to drop his shell not too near, neither too far away. He must calculate the time it will take for the shell to describe the curve through the air. Then he must make his fuses of the right length to have the shell explode at the proper time, either high in the air, that its fragments may rain down on the encampment of the enemy, or close down to the ground among the men working the guns. It requires skill and a great deal of practice to do all this.
The mortar flotilla was commanded by Captain Henry E. Maynadier, assisted by Captain E. B. Pike of the engineers. There were four Masters of Ordnance, who commanded each four mortars. Each mortar-boat had a crew of fifteen men; three of them were Mississippi flatboatmen, who understood all about the river, the currents and the sand-bars.
Commodore Foote’s flotilla consisted of the Benton, 16 guns, which was his flag-ship, covered all over with iron plates, and commanded by Captain Phelps; the Mound City, 13 guns, commanded by Captain Kelty; the Carondelet, 13 guns, Lieutenant Walke; the Cincinnati, 13 guns, Captain Stemble; the St. Louis, 13 guns, Captain Dove; the Louisville, 13 guns, Lieutenant Paulding; the Pittsburg, 13 guns, Lieutenant Thompson; the Conestoga, 9 guns, Lieutenant Blodgett; in all, 103 guns and 10 mortars. The Conestoga was used to guard the ammunition-boats, and took no part in the active operations. Commodore Foote had several small steam-tugs, which were used as tenders, to carry orders from boat to boat.