The American War of Independence – Artillery

Artillery had an almost parasitic relationship with the musket. Because muskets were individually so inefficient, they had to be massed in compensation, and it was this density of men that gave eighteenth-century artillery its raison d’être. Lacking accuracy itself, it was a beast of omnivorous and indiscriminate appetite, guzzling, like some Cyclops, the herds of men conveniently marching in dense formation toward its greedy muzzle.

The guns of the War of Independence were, like muskets, all smoothbore and, like muskets, lacked efficient aiming mechanisms. Although gunners thought of themselves as a cut above other branches of the army because their business carried with it the aura of “science,” it was as much a craft, even an art. The gunner’s “eye” and “feel” for his weapon mattered more than the complicated mathematical tables of barrel elevation, shot weights, and powder charges. The field gunner had recourse to three ammunition types. The first and most popular was simple round or solid shot: iron balls of different weights. Artillery firing round shot was graded by the weight of the ball rather than the caliber or diameter of the muzzle. The second was canister or case shot: tin cans filled with musket balls or any old pieces of iron junk. (The Prussian captain Johann Heinrichs described American case shot loaded with bits of “old burst shells, broken shovels, pickaxes, hatchets, flatirons, pistol barrels, broken locks etc etc.”). The case disintegrated as it emerged from the muzzle to spread its projectiles in a spray pattern, shotgun fashion. The third was spherical shell: hollow cast-iron globes filled with gunpowder and fitted with a fuse which, if cleverly adjusted, could be configured to explode just over the heads of advancing infantry. (In 1804, it would evolve into the famous shrapnel shell.)

Solid shot accounted for about 70 percent of the ammunition carried by the artillery and was used for medium-range fire. Ranges and lethality varied according to the size of ball and powder charge. William Müller, an officer in the King’s German Legion, made extensive tests of artillery accuracy which he published in The Elements of the Science of War (1811). Müller’s tests, although from a slightly later date than the War of Independence, would have been applicable to the earlier time frame. As with all such tests, there is some dislocation from the realities of the battlefield, but they are nevertheless useful as a range finder of lethality. For example, the 6-pounder (the workhorse of field artillery) firing at a cloth target six feet high by thirty feet wide (roughly representing a company of infantry) scored 100 percent hits at 520 yards and 31 percent hits at 950 yards. At 1,200 yards, however, it scored only 17 percent hits. Müller’s test does not quite tell the whole story because gunners firing a round shot tried to get two or even more bites at the cherry through ricochet: the effect of a cannonball bouncing before coming to rest. A 6-pounder might have a range of about 1,200 yards, but the ball had several phases of lethality over that distance. At zero degrees elevation (parallel with the ground) the first bounce (“graze”) would have been at about 400 yards; it would then travel for another 400 yards at shoulder height before making its second graze, and then on for a further 100 yards at about three feet from the ground before rolling to a halt. The knack was to pitch the ball just in front of the enemy’s first rank and have it skip and rise through the subsequent ranks. If the ground was hard and stony, each graze would kick up splinters, which, in their turn, became secondary projectiles. Even in its last phase, a rolling ball could be deceptively harmful. There are many instances of men being badly wounded, even killed, by trying to “catch” what seemed to be spent cannonballs, innocently rolling toward them. John Trumbull was with the American army besieging Boston when rewards were given for salvaged British cannonballs, but

it produced also a very unfortunate result; for when the soldiers saw a ball, after having struck and rebounded from the ground several times (en ricochet), roll sluggishly along, they would run and place a foot before it, to stop it, not aware that a heavy ball long retains sufficient impetus to overcome such an obstacle. The consequence was that several brave lads lost their feet, which were crushed by the weight of the rolling shot.

Private Edward Elley of Virginia described another incident, at the siege of Yorktown: “The works of the battery were thrown up by the militia soldiers, and whilst they were cutting brush a cannonball came bounding along on the ground, and a youngster put his heel against it and was thrown into lockjaw and expired in a short time.”

The most destructive potential for solid shot was when it was fired “in enfilade”: into the side of a rank of men. Müller estimated that one ball, fired in enfilade at effective range, would kill three men and wound four or five, but greater numbers were often recorded. The weight of the ball was an important factor in determining lethality because although the muzzle velocity of most field guns was about equal at approximately 900 feet per second, the heavier the ball, the more velocity it retained over longer distances. For example, at a 1,000-yard range, an eighteen-pound ball traveled at 840 feet per second, compared with 450 feet per second for a six-pound ball.

A six-or nine-pound ball of iron traveling at anything up to 900 feet per second could do terrible damage to human flesh. Peter Brown, a patriot soldier crossing the Neck onto Charlestown Peninsula during the battle of Bunker’s Hill, described the effect of British gunships firing in enfilade: “One cannon [ball] cut off 3 men in two [cut them in half] on the neck of land.” James Duncan of the Pennsylvania Line at Yorktown recorded that on 3 October 1781 “four men of [his] regiment…were unfortunately killed…by one ball.” Even small-caliber guns like the three-pound ball from a “grasshopper” (a mobile gun sometimes referred to as a “galloper”) could pack a punch. For example, at Monmouth in June 1778 Joseph Plumb Martin described how the British “occupied a much higher piece of ground than we did and had a small piece of artillery, which the soldiers called a ‘grasshopper.’ We had no artillery with us. The first shot they gave us from this piece cut off the thigh bone of a captain, just above the knee, and the whole heel of a private in the rear of him.”

Even near misses could be fatal. A large ball created potentially devastating shock waves, with sometimes macabre results, as Joseph Martin witnessed at Yorktown.

I was sitting on the side of the trench, when some of the New York troops coming in, one of the sergeants stepped up to the breastwork to look about him…at that instant a shot from the enemy (which doubtless was aimed at him in particular, as none others were in sight of them) passed just by his face without touching him at all; he fell dead into the trench; I put my hand on his forehead and found his skull was shattered all to pieces, and the blood flowing from his nose and mouth, but not a particle of skin was broken.

A gun crew loading with ball could get off two or three rounds a minute; the heavier the ball, the slower the process (firing canister speeded up the rate). A six-or nine-pound gun would normally have a specialist crew of a minimum of five men (often supplemented by infantrymen to help move the gun and fetch ammunition). One man stood to the right of the muzzle with a combination rammer-sponger; the man to the left of the muzzle was the ammunition loader; a man to the left of the vent hole at the rear of the barrel carried a slow-burning match on a forked rod (“linstock”); opposite him stood the “ventsman.” At the rear stood the gun chief, who aimed the piece and gave the order to fire.

The loading sequence for the first discharge started with the crew chief directing aim (“laying” the gun) and moving it on the horizontal plane by having it manhandled with poles (“handspikes”). The elevation of the barrel was controlled by a screw mechanism at the rear of the barrel (or perhaps on older pieces by inserting a wooden wedge, the “quoin”). The loader now slid a cartridge consisting of a flannel or paper bag of powder and ball into the muzzle, and the rammer pushed it down the length of the barrel. (On larger pieces, the powder charge and ball were more often separate.) If the barrel was depressed below the horizontal, a wad (of straw, hay, a coil of rope, even turf) was rammed down to prevent the ball from rolling out. The ventsman now inserted a “pricker” into the vent to puncture the powder bag. He then inserted a quill or paper tube filled with “quick match” (cotton strands soaked in saltpeter and alcohol). When the order to fire came and the men had stood clear, the firer extended his linstock across to the vent (being careful to keep clear of the wheel when it recoiled) and lit the quick match.

Before the next shot could be loaded, the gun had to be relaid because the recoil would have thrown it back several feet. (Not until 1897 would the recoil problem be solved by the hydraulic “antirecoil” mechanism of the famous French 75.) The rammer reversed his pole and used the end covered in sheepskin and soaked in water to swab out the barrel. When the loader inserted the next powder bag, the ventsman covered the vent with his thumb (protected by a leather “thumb stall”) to prevent any accidental discharge. If a smoldering piece of the powder bag or wadding remained, the rammer would use a pole with a corkscrewlike end (the “wormer”) to extricate so it too wouldn’t create an accidental discharge. But, of course, in the heat of battle accidents did happen. At the siege of Charleston in May 1780 Lieutenant John Peebles of the Royal Highland Regiment (42nd Foot) recorded, “An artillery man lost an arm and an assistant killed by one of our own guns hanging fire and going off when they put in the spunge.”

Canister or case shot (sometimes referred to as grapeshot, which was made up of larger three-ounce balls and was primarily a naval warfare munition) was reserved for relatively close-up work. It made, said the American artillery sergeant White at the battle of Princeton, “a terrible squeaking noise” as it flew. Characteristically, each canister contained 85 balls. Tests carried out in 1810 indicated that 55 of those balls (65 percent) would make hits at 200 yards; 36 (42 percent) at 400 yards, but only 6 (7 percent) at 600 yards. These are hit patterns that one would expect from a shotgun spread. (The balls spread to thirty-two feet over the first 100 yards.) At 80–100 yards (the effective range of a musket) it would be reasonable to assume that the hit rate of canister might have risen to at least 80 percent (44 balls). Theoretically, a standard battery of six guns firing at this range would have delivered 264 balls on target, compared with the 188 of a 500-musket battalion (the guns being 71 percent more effective). Even if we take into account men hit by multiple balls, no such level of casualties was inflicted by canister in any American battle (perhaps because there were few such concentrations of guns on the battlefield). The effect of concentrated case shot, however, could be withering. In 1793 near Tournai (in what is now Belgium) the Coldstream Guards were caught unawares by a French battery firing case at close range: “The fire was so sudden that almost every man by one impulse fell to the ground—but immediately got up again and began a confused fire without orders—The second discharge of the French knocked down whole ranks.” At Waterloo men and horses fell “like that of grass before the mower’s scythe.” An artillery officer at Waterloo described “four or five men and horses piled up on each other like cards, the men not even having been displaced from the saddle, the effect of canister.”

Spherical shell was the lob shot of eighteenth-century warfare. It was usually fired from short-barreled howitzers and mortars. (Regular cannons could not elevate their barrels sufficiently.) The skill of the gunner lay both in setting the trajectory and in trimming the fuse (which was lit automatically by the cannon’s flash) to achieve either an airburst just above enemy troops or an explosion as the ball bounced into the enemy’s lines. If the fuse or trajectory was miscalculated, the shell would fizz on the ground and could be extinguished by an intrepid soldier, but it was a hair-raising business. Tolstoy in War and Peace describes the (highly) disconcerting effect of a fizzing shell, pregnant with destruction, “whirring like a bird in flight…spinning like a top.” When it went off it made “a splintering sound like a window-frame being smashed” followed by “a suffocating smell of powder.” Some gunners firing shell were true master-craftsmen and could place their projectile with unnerving accuracy. The Continental army regimental surgeon Dr. James Thacher reported from Yorktown in October 1781:

It is astonishing with what accuracy an experienced gunner will make his calculations, that a shell shall fall within a few feet of a given point, and burst at the precise time, though at a great distance. When a shell falls, it whirls round, burrows, and excavates the earth to a considerable extent, and, bursting, makes dreadful havoc around. I have more than once witnessed fragments of the mangled bodies and limbs of the British soldiers thrown into the air by our bursting shells.

Attacking infantry typically had to pass through three killing zones, characterized by the three types of artillery ammunition usually employed. When the enemy was about 1,000 yards out, the medium guns (mainly 6 and 9-pounders) would engage, as would the howitzers with their shells. It would take the infantry about four to five minutes to make it to the 400-yard mark, during which time each gun could have fired about twelve to fifteen times. At 400 yards the attackers would also start to receive canister in addition to solid shot. It would take about three minutes for the attackers to get to the 100-yard mark, the start of the final and most intense killing zone, which would bring them into musket range as well as more canister and shot.

The patriot cause had few artillery pieces at the beginning of hostilities: forty-one cannons of various calibers, fourteen mortars, and three howitzers. A substantial number of guns, particularly of the larger sizes, had fallen into American hands with the capture of Ticonderoga and Crown Point in May 1775. They remained there until Henry Knox, that extraordinary autodidact bookseller who became the head of Continental artillery, managed to transport thirty-nine brass and iron cannons, fourteen mortars (three of which weighed over a ton), and two howitzers by sled through the wild winter terrain in one of the most extraordinary efforts of the war. (It ranks alongside Arnold’s march to Canada as a feat of staggering endurance.) More pieces were picked up when the British evacuated Boston, and another forty-nine guns when Burgoyne surrendered in October 1777. On the debit side, however, many guns were lost with the defeat at Long Island and the subsequent surrender of Forts Washington and Lee, where 146 pieces were taken by the British.

Even though colonial America manufactured 30,000 tons of pig iron a year, making it the seventh largest producer in the world, there had been little call before the war to create domestic cannon-foundries, and those guns that were made tended to be of heavier caliber, more suited to defense installations rather than smaller and mobile infantry support weapons. In early 1776 congresses began to encourage and finance foundries in Pennsylvania, New Jersey, New York, and Connecticut, but it proved slow going. Many of the cannons were substandard (due mainly to inferior metallurgy) and had to be rejected, and then there was the old monkey-on-the-back of a depreciating Continental dollar, which quenched the mettle of even the most patriotic ironmasters.

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