This northernmost kiln in the group, once owned by Thomas Risteau Jenifer, is a continuous-burn vertical shaft kiln built in 1883. It measures 14 feet square for its full 25-foot height, with walls at least 4 feet thick around a circular center stack. Arched poke holes on either side were used to monitor the burning of Cockeysville Marble and, when the time was right, to stoke or push the mass of marble and ash down to the cooling chamber below. Its stack top opening measures about 4 feet in diameter, compared with the adjoining Risteau Kiln opening of 13 feet in diameter, illustrating the technological difference between the intermittent-burn Risteau Kiln, first developed in the Middle Ages, and the Jenifer Kiln, which became popular in the United States around the 1850s. The Jenifer Kiln could produce up to 6000 bushels of quicklime per year. A 10- to 15-foot-high chimney once stood atop it, helping create an updraft for hot-air baking of the marble and carrying away smoke and toxic fumes from lime making. After the kiln went out of use, the chimney was collapsed into the stack to prevent possible injury to people and dairy cows. During 2015 stabilization work, some of those chimney bricks were recovered, and several bear the names of manufacturers including Baltimore Brick Co., Savage Brick, and Union Brick Co. A timber bracing system with large timbers held against the stonework by original iron tie rods remains visible, reinforcing the kiln walls against the outward pressure of hot gases and expanding stones. Also visible below the kiln is the original stone patio in front, which most likely protected the ground from wagon-wheel damage and allowed continued use in bad weather.