NEWS OF 150 YEARS AGO
January/February 1861
From The Missouri Democrat, Tuesday, January 8, 1861.
Is Fort Sumpter Impregnable?—Fortifications and Gunnery.
A correspondent of the Boston Courier argues that Fort Sumpter is not impregnable, “because an impregnable fortification was never yet constructed, and probably never will be.” This proposition the writer proposes to demonstrate. As the seceders may soon attempt to take possession of Fort Sumpter, an intelligent discussion of its competency to resist an attack, becomes interesting. The Courier’s correspondent says:
Fort Sumpter has been built since the last war with England, and is situated on a little sandy island, about half way between Sullivan’s Island and James Island, on which old Fort Johnson stands; the main ship channel, which is from three quarters to a mile in width, running between Forts Sumpter and Moultrie. The distance from Forts Sumpter to Castle Pinckney, at the mouth of Cooper river, is between two and three miles. Surrounded by deep water, having a good foundation, Fort Sumpter has many natural advantages, and could alone offer a successful opposition, for a considerable time at least, to a large naval force.
It is constructed of solid masonry, octagonal in form, with a double row of port holes on all sides for heavy ordnance, and is said to be bomb proof withal…The armament of the fort consists of 140 guns, 16 of them being 10 inch “Columbiads,” which have a wide range, and throw either shot or shell. But with all its perfection of bomb proof casemates, improved guns and natural advantages of position, it is not impregnable, especially to attach from the land side. It can be successfully shelled from temporary batteries on Sullivan’s Island; and Mount Pleasant even, which is about two miles distant, and where the besiegers would have the advantage of elevation. With the heaviest ordnance, it could be successfully breached by batteries on James Island, and then easily carried by storm. Here, then, are three points of attack.
It is well known by military men that, by a combined, direct, vertical and enfilade fire, the guns on the faces of defensive works, even when well traversed, can be silenced from a distance; for, in the attack, the besieger occupied the great arc of a circle, and the besieged a small are[a] within it; so that, as the former has a choice of position, he can aline [sic] himself on the prolongations of the faces of the ravelins and bastions, where he can erect his enfilade batteries, and establish his direct and mortar batteries in situations best suited to assist them; so that guns on the terre-plains (top or platform) of the defensive works, are exposed to a combined fire, that soon produces the effect of slackening their fire. Engineers have endeavored to remedy this serious disadvantage, by making vaulted apartments of masonry for the guns, covered on top so as to be proof against the bursting of shells. There are two kinds of bomb proof buildings; one being isolated, that is, covering detached buildings, powder-magazines of hospitals; and the other covering the whole mass of ramparts; in the latter case they are called casemates. To this class belongs Fort Sumpter. Now, although the theory that such fortifications are impregnable is very good, practice had shown serious objections. In the first place, the casemated batteries weaken the ramparts under which they are constructed; and when their arches are ruined by the breaching batteries of the assailants, the whole mass of the rampart and parapet sinks down into the casements and exposes the interior of the works. In the second place, if casemated guns can command the country, they can also be seen from a distance; and as the choice of position is with the assailant, he can readily find situations for batteries, whence his guns can see the cheeks of the casemated embrasures, though the guns in these casemates cannot be brought to bear upon him; the assailant can thus batter the cheeks with shot that will bound or deflect from the embrasures into the casement to the destruction of the gunners. This evil was especially noticed by military men in the capture of the castle of Scylla, in Spain, in 1804. On examining the interior of these casemates, after the surrender of the castle, the English officers were surprised to observe the mischief which had been produced by shot that had deflected from the cheeks of the embrasures, and entered the casemates. It showed that a direct fire into a casemated embrasure must render such batteries untenable. The only remedy for this is to place the batteries in such a situation that the embrasures can only be seen in the direction in which the guns they shelter cn be pointed. It is only necessary to give some examples of the effects of shells and the force of heavy balls, in order to show that the roofs of blinded batteries cannot resist them for any great length of time. In low situations, however, on a river or the coast, they are sufficient to protect the gunners against the fire from ships, tops in passing the battery.
From Dr. Hutton’s experiments in the parabolic theory of gunnery, the following prominent facts appeared: An eighteen pounder discharged successively with 3½, 3 and 2½ pounds of powder, at a butt formed of English oak planks bolted firmly together, forming a solid mass of 32½ inches in thickness, perforated the butt each time, driving great quantities of splinters before it. The lowest charge, 2½ pounds, occasioned the greatest destruction, for it separated the planks and broke the inside one short in two. Another butt formed in the same manner, firmly bolted with iron bolts 1½ inches in diameter, forming a mass 4½ feet thick, was penetrated by balls from an 18 pounder, fired with six pounds of powder from 37 to 46 inches. With 3 pounds of powder the penetration was 36 inches, and with 2½ pounds, 23 inches. To gain an increase of range or penetration, or to augment the force of heavier matter may be used with advantage. A shell filled with lead will produce a greater blow than an iron shot of the same diameter, discharged with the same quantity of powder; it may also be made to range further, from being better able to overcome resistance to the air. At the siege of Cadiz, the French used shells filled with lead, which, discharged with a velocity of 2,000 feet per second from howitzers, ranged to a distance of three miles. An instance of the rapid and terrific effects of bombardment took place in India, in the reduction of the strong fortress of Hattrass. The Bengal Artillery had thirty-two mortars in battery, and expended upwards of 3,000 shells. They opened fire at 9 o’clock and scarcely ten minutes had elapsed when several fires were discovered in the fort. At 5 o’clock, the great magazine, containing 200,000 pounds of powder, blew up, with an awful explosion. The lofty and massive walls, in comparison with which the walls of our forts are mere shells, ceased to be impregnable in less than twelve hours, and the garrison sought safety in flight that night. The more recent siege of Moultan, in the Punjaub [sic], in 1849, is another example of the power of artillery in reducing strong places.
In breaching, no gun of less caliber than 24-pounders should be used. The best method of forming a breach is, first, to cut the outer wall (revetment) which supports the embankment toward the bottom by a horizontal line, and at various distances by vertical lines; to shake afterwards each portion of the walls between two of the vertical lines, to cause it to crumble into the ditch or water at the foot. The destruction of the outer wall being thus prepared, it is only necessary to break the mass between the vertical lines—to shake these parts and disunite them—and the tumbling to pieces will soon take place. Batteries, to breach, fire as quickly as they can with precision—about 25 or 30 rounds per hour.
At the siege of St. Sebastian, 3,500 rounds were fired from 10 guns in 5½ hours, great accuracy of range being at the same time observed. An exposed wall may be breached with certainty at distances from 500 to 1,000 yards, even when elevated 100 feet above the breaching battery. At the siege of Badajoz, a breach of 180 feet was made with 9,500 shot, at a distance of 520 yards, through a casemated wall. At the siege of Ciudad Rodrigo, the main breach of 109 feet was created by 6,700 shot, at a distance of 560 yards, through good masonry. It appears, from a series of nine years’ experiments made at Metz, Strausbourg and La Fere, from 1816 to 1825, that, at a range of 1,400 yards, the probability of hitting with twelve pounter and six-pounder is as 8 to 3; of the eight pounder and six pounder about the proportion of 3 to 2. This practice shows the superiority of the heavier guns in point of accuracy.
We have endeavored to show in the foregoing that fortifications, however scientifically constructed, or of whatever material or coat, cannot withstand, for any considerable time, the effects of the shot or shell. There are times, however, when these forces cannot be brought to bear except at the expense of great labor and time; but even a fortification so situated has not been found able to hold out against the desperate valor of disciplined troops. Fortresses perched on almost inaccessible heights, have been stormed repeatedly; surrounded by water, they have been scaled from boats. The sacrifice of life is sometimes awful in such cases, whole companies, and regiments even, being swept away in the discharges from the fort; but the dead bodies of the advance serve as a bridge for the reserve, over which they rush to victory. The Peninsular war, and later, our own troops in Mexico, especially at Chepultepec [sic], the English and French in the Crimea and in India, furnish many examples of the weakness of the most powerful fortifications when assailed by determined men. It was one of Napoleon’s maxims that a fortified place could only protect a garrison and arrest an enemy a certain length of time. Gibraltar and Cronsdadt will one day be added to the examples of this rule.
The improvements in the science of gunnery, especially during the last twenty years, has been more than commensurate with the improvements in the construction of fortifications. Whereas, in the Peninsular war, it was never attempted to breach a wall at a distance of more than eight hundred yards, it could probably be successful breached now at a distance of more than a mile, with such guns as the Columbiads.
