Cumberland Caverns

Cumberland Caverns. Saltpeter Mine. Even before Tennessee joined the Confederacy in 1861, officials examined the state’s caves for the nitrogen-containing compound called saltpeter, an essential ingredient in gunpowder. The soil at Cumberland Caverns was ideal, saltpeter had been mined there in Henshaw Cave during the War of 18 12. Nashville’s Sycamore Powder Mills, the larger of two major gunpowder mills in the South, used saltpeter, charcoal, and sulfur to make gunpowder., Soon, Henshaw Cave was producing saltpeter for the Confederacy., To make saltpeter, workers in the cave leached nitrates from the soil using water from the cave (also rich in nitrates), then poured the resulting solution into 80-gallon cast-iron crucibles outside the cave. Lye, made by leaching water through oak and hickory charcoal or ashes, was added to the crucibles. Wood fires built under the crucibles boiled down the liquid and produced the correct type of saltpeter crystals need for gunpowder. The saltpeter made here and at other nearby caverns was then transported to Nashville until the Federals occupied the city in 1862, when it was taken to other mills., As with other rare raw materials, saltpeter’s price rose sharply with increased demand. In 1864, near the end of the war, the price had risen from $.25 to $1.50 a pound., Postwar explorations in the cave have uncovered numerous saltpeter-industry artifacts, including wooden logs hollowed out to form water pipes, wooden paddles to stir the nitrate solution, leaching pits, and assorted tools. Some of these artifacts are on display in the cave shop. The leaching pits, hollowed out log water pipes, and the iron crucible may be viewed during the cave tour.