From The Lincoln Nobody Knows by Richard N. Current:

In the loft of a carriage shop across the street from Willard's Hotel he was shown a queer field gun with a hopper and a crank. He turned the crank and, in the words of Robert V. Bruce, the authority on Lincoln and the tools of war, "delightedly watched the cartridge cases drop one by one into the grooves of a revolving cylinder, while the mechanism automatically tripped the firing pin." He named this the "Coffee Mill Gun" and gave McClellan a most enthusiastic account of it as a "wonderful new repeating battery of rifled guns, shooting fifty balls a minute." He thought it would enable McClellan at last to advance, and he even suggested going out, himself, and standing or falling with the army. Actually the Coffee Mill Gun was to have little use in the Civil War. Yet it was the ancestor of the machine gun of later wars, and Lincoln's order for its purchase gave rise to what has been called the first known sale of machine guns in all history. "And like the breechloading rifle," says Bruce, "the machine gun owed its first chance to a man who would 'take the responsibility' when others flinched."

Grimly, during the winter of 1861-62, Lincoln pushed the development of mortars for Halleck's and Foote's Mississippi River campaign. "Now," he said, "I am going to devote a part of every day to these mortars and I won't leave off until it fairly rains bombs." Foote was told that the President wished him to be sure, when he opened fire, to "rain the rebels out:' to "treat them to a refreshing shower of sulphur and brimstone." Foote was told also that the President "is evidently a practical man, understands precisely what he wants, and is not turned aside by anyone when he has his work before him."

Not only in the opening of the Mississippi but throughout the war the mortars, which owed so much to Lincoln's determination, served with telling effect. In the trenches around Petersburg, at the beginning of the long siege in July, 1864, a. North Carolina trooper in a letter to his wife noted the deathdealing efficiency of the mortar-equipped Yankees. "They kill and wound more men with Morter Shell than any other way for the last few weeks," this Tarheel wrote. "They throw them up and Drop them Right into the trenches when they Explode and tare to pieces all around them."

Lincoln played a part in the decision to use another kind of ammunition that would tear to pieces-an explosive bullet, or rifle shell. A New Yorker by the name of Samuel Gardiner, Jr., had invented what he considered an improved bullet of that kind, one that was exploded by a time fuse rather than the usual percussion fuse. Some bullets of the percussion type already were being employed here and there. Supposedly they were well adapted to penetrating and blowing up ammunition boxes, but they also had the effect of penetrating and bursting within human flesh. The Confederates occasionally used them. "To my dying day," a New York Tribune correspondent reported, "I shall have in my ears the wailing shrieks of a private of the 1st Long Island, shot dead beside my horse with a percussion musket-ball, whose explosion within its wound I distinctly heard."

Just three days after that explosion the inventor Gardiner called at the White House with samples of his supposedly more effective musket shell. Carefully looking over the bullets, Lincoln seemed to think they constituted an improvement on solid shot. He penned a note for James W. Ripley, the Army Chief of Ordnance: "Will Gen. Ripley please consider whether this musket-shell, would be a valuable missile in battle?" Ripley felt that the bullet had impracticable features and that, in any case, an ordinary Minie ball would put a man out of action just as effectively and far less brutally.

Nevertheless, Gardiner secured from the War Department an order for more than 100,000 of his bullets.

Ten thousand of these fell into rebel hands. At Gettysburg some Confederates as well as Federals fired them. And the' Federals occasionally employed them on Sherman's march and in Grant's Richmond campaign.

Apparently unaware of the whole story, Grant accused the rebels of using explosive bullets at Vicksburg; he protested that such bullets were "barbarous" because they produced "increased suffering without any corresponding advantage to those using them." After the war a new chief of ordnance condemned them as "inexcusable among any people above the grade of ignorant savages." European nations outlawed them as inhumane. But Lincoln did not forbid their use.

Nor did he have any scruples against making war with fire and flame, though General McClellan believed that "such means of destruction" were "hardly within the category of those recognized in civilized warfare." Recommending the inventor of an incendiary shell, Lincoln wrote a note for army ordnance: "He thinks he can make a very destructive missile, and, if not too much trouble to you, I shall be obliged, if you can accommodate him." Lincoln arranged for several demonstrations of Greek fire, one of them (which turned out to be a fizzle) on the snow-covered lawn of the White House. In April 1862 he telegraphed to McClellan on the peninsula and offered to send him a batch of "fire shells." These were sent but failed to reach McClellan, and ten barrels of incendiary fluid arrived too late for him to try out. In the spring of 1863 Lincoln personally took charge of plans for General Hooker to experiment with 100-pounder shells of liquid fire in battle use. He started for Hooker's camp to see for himself, then changed his mind when Lee undertook to invade the North. Still, though the Army's Chief of Ordnance was reluctant, Lincoln insisted upon an order for 1,000 incendiary shells.

Such shells, he thought, would be especially valuable in siege operations, as at Vicksburg and Charleston. Accordingly, from gunboats on the Mississippi, Admiral Porter threw a few shells filled with one brand of Greek fire into the sky above Vicksburg and started fires that burned a number of houses and quantities of military stores.

Vicksburg surrendered before a thorough test could be made, but behind Fort Sumter the city of Charleston remained exasperatingly out of reach. After a long-range, 200-pounder Parrott gun (the "Swamp Angel") had been set up on Morris Island, Lincoln himself gave the order to shoot into the city with incendiary shells. Charlestonians awoke to a rain of fire in the middle of the night. Promptly General Beauregard, in command of the local defenses, denounced the Federals for throwing "a number of the most destructive missiles ever used in war into the midst of a city, taken unawares and filled with sleeping women and children."

Only after these missiles had proved ineffective in reducing Charleston - and extremely dangerous to the Union soldiers manning the guns - did Lincoln lose interest in the tactics of conflagration.