Recording the activities on the night of September 5-6, 1863, Colonel Lawrence M. Keitt, of the 20th South Carolina, commanding the Morris Island garrison, wrote, “Throughout the night, the enemy’s calcium light threw its bright, silvery rays upon our front.” The employment of this artificial light greatly aided Federal efforts in the closing days of the siege of Battery Wagner.
I mentioned the calcium lights briefly in relation to support of naval operations around Charleston. We know these devices as “limelights” today, even though they are long gone from the stage. Since this isn’t a science blog, I’m allowed to pull up a Wikipedia illustration and definition:
In brief, compressed hydrogen and oxygen feed a flame directed at a lime stick (or as the illustration indicates, “calcium oxide”). When heated to a point just before melting (4,662 °F), the line glowed brightly. Before the Civil War, Robert Grant, of New York City, promoted the use of these calcium lights to illuminate streets and other outdoor areas. Using a parabolic mirror, he demonstrated the ability to signal ships over ten miles out to sea. At the onset of the Civil War, Grant offered his calcium light as a means to enable night combat. Towards that end, in 1862 Company E, 102nd New York Infantry trained to operate with the light. But like many other fringe ideas, this one fell by the wayside. (John Lockwood offered a good summary of Grant and his light for the Washington Times in 2004.)
The idea of turning night into day came up again as the Federals contemplated operations on Morris Island in July 1863. Early on, Brigadier-General Quincy Gillmore and Rear-Admiral John Dahlgren hoped the lights would illuminate targets at night or give the engineers greater visibility while constructing the works. The lights proved less than perfect for these tasks. But with the siege lines closing on the battery in late August, the Federals turned on the calcium lights again. And this time, the intent was to place the Confederates directly in the limelight!
On September 3, Major Thomas Brooks reported placing a calcium light “on the left of the second parallel.” The Federals began using the light that night. At least two lights were used, thought it is unclear if these were both on the second parallel or in separate positions. On September 6, Brooks noted, “The whole of the superior and the upper portion of the exterior slopes of the south face of Wagner were plainly seen this night from the effect of the calcium light….” In addition to focusing on Battery Wagner, the calcium lights also illuminated the ironclads anchored off shore, to aid detection of spar torpedo craft.
In Battery Wagner, the effects of this light hindered operations. Any movement on the parapets, or even opening embrasures to fire, was visible from Federal lines. Not only did this hinder defensive fires, but also repairs to the battery. September 6, Colonel D.B. Harris, chief engineer, complained:
The covering to the bomb-proof and magazine also need repair. We have been thus far able not only to repair damages at night, but to add from day to day to the strength of the battery; but now that the enemy’s sap is in such close proximity to the battery, and he has contrived to throw a calcium light upon the parapets at night, it is impossible to do so without a heavy loss of men. In the efforts last night to repair damages, the commanding officer of the fort reports a loss in killed and wounded of 60 to 80 men of the working party alone. Without our ability to repair damages at night, the battery would become, under the incessant fire of the enemy’s land batteries and fleet, untenable, say, in two days. (Emphasis added)
In reaction, Confederates attempted to extinguish the lights with long range artillery fire. In the early morning hours of September 6, Major Edward Manigault commanding artillery at Legare’s Point on James Island directed fires from Battery Haskell, including an 8-inch columbiad, a 24-pdr rifle, a 24-pdr smoothbore, and a 4.62-inch rifle, on the calcium light on the second parallel. Neither Federal or Confederate accounts indicate Manigault’s gunners met with any success.
While there were plenty of examples where combatants had employed light to distract or disorient an enemy going back to ancient times, the use of calcium lights in September 1863 was novel to some degree. These were artificial lights, not reflected natural light, and to a higher magnitude. My pal XBradTC is likely composing a comment right now about how this foreshadowed the INTENDED use of the Canal Defense Lights in the European Theater during World War II.
I would add the use of calcium lights were a function of the night combat on Morris Island…unusually common night combat, for the Civil War, that is.
(Citations from OR, Series I, Volume 28, Part I, Serial 46, pages 90, 301, and 491.)