Beginning in 1897, a new system of defenses was built outside the fort proper. A concrete battery was built into the hill under Walbach Tower, which was equiped with two 8-inch breach-loading rifles, Model 1888MII, serials 38, 43 (Watervliet Arsenal), on disappearing carriages, Model 1894, serials 23, 22 (Providence Steam Engine Co.), with hand-operated platform ammunition hoists. The battery was armed and operational in 1898 during the Spanish-American War, but was not fully completed until 1899. It was named Battery Elon Farnsworth (in honor of Brigadier General Elon John Farnsworth, killed in action in Pennsylvania in 1863). The battery continually suffered from extreme dampness, and was never electrified. Due to structural problems that were never completely fixed, it was also never modernized prior to World War I. This area is currently fenced off from the public, due to its deteriorating condition. In 1898, during the Spanish-American War, the harbor was planted with 21 underwater mines, each loaded with 101 pounds of gun-cotton, and anchored by 1000-pound anchors. The U.S. Lightship Lilac laid buoys to mark the locations of the mines. The buoys served as daymarkers to warn local boaters. The Lighthouse Board then ordered that all lights and fog signals at Fort Constitution and on Seavey’s Island be turned off at night. The minefield was electrified at night from 8PM to 4AM. The crisis ended after about two months, but the mines remained in place until 1899. A small concrete mine casemate was completed in 1898 under the left flank of Battery Farnsworth to control the detonation of the mines in the harbor. However, this casemate was never afterwards used due to wetness problems. (NOTE: This casemate may or may not have been actually used in 1898 for mining operations. Sources are not clear as to if there was a temporary casemate built during the war, because of the stated wetness problems.) Harbor mining operations were conducted by the U.S. Army Corps of Engineers, not the Coast Artillery, until about 1901. A new mine casemate was later built at Fort Stark in 1907. Battery K, 2nd U.S. Artillery, commanded by Captain Curtis, was posted here from 1898 to 1900, then replaced by a 20-man detachment from Battery M, 4th U.S. Artillery, which was based at Fort Strong in Boston, Mass.