The two openings of the two stone-lined fire boxes are the arched structures at ground level. The two flue pipes run near the floor to the back of the barn, then rise slightly as they return to the front, and emerge as the two angled pipes that also exit at the front (with vertical pipes, and require a rain cap).Killebrew said:BUILDING AN INEXPENSIVE FLUE-CURING SHED
A diagram of a cheap, efficient, and durable flue is given in Plate I, showing the ground plan of a tobacco barn 20 by 20 feet and the arrangement of the flues therein- Plate II shows the elevation.
To construct flues on the plan given, it is first necessary to cut out two or three logs from the end of the barn; then build the walls of the flues 12 or 13 inches distant from the sills or walls of the barn, as at EEEE, in Plate I, and projecting outside the walls at AA 18 inches. Build the walls of flues 18 inches apart, and 18 to 20 inches in height at the openings AA, decreasing in height as they run back to 14 inches at CC. Put in sheet-iron pipes at CC, 10 or 12 inches in diameter, equidistant from the flues and from each other, and carry them through the body of the barn, out at DD, with the ends elevated at DD 3 feet higher than at CC. The flues should be arched with brick or covered with flat fire-proof stone for about 5 feet from AA to BB; then cover the flues from BB to CO with sheet-iron. Use No. 16 iron nearest the fire, commencing at BB, and thinner iron, No. 18 or 20, for the remainder of the covering.
A cheap flue is constructed by cutting ditches in the floor of the barn from 15 to 18 inches wide and as deep as necessary and covering them with sheet-iron, as recommended for the stone or brick flue. A better one is made of mud walls, covered with sheet-iron. The mud walls are built by placing two wide boards I; from 12 to 14 inches apart and packing moist clay between them, beating it down hard, in position and arrangement similar to the walls of stone, and covering with sheet-iron. Upon firing the flues the boards are burned away and the dirt walls are hardened. If the clay is of proper quality, such as is fit for making tolerably good bricks, these walls will last a long time. It is necessary with the ditch or mud-wall flue to attach furnaces of stone, brick, or iron.
Killebrew's wonderful book, Report on the Culture..., is available for free download from www.archive.org. Search for "Killebrew tobacco".
Bob
