CHE REFERENCE LIBRARY - ZetaTalk

84 THE NURSERY-MANUALare curious about such devices may consult the older Europeanwxks, and he will find brief descriptions in the previouseditions of the “ Nursery-Book.‘*Barnard’s propagating-tank,Fig. 83, is apracticable device forattachment to a commonstove. A similarapparatus may be connectedto the pipesof a greenhouse. Thetank consists of a longFIG. &I. Zinc propatgacing-tank.wooden box of matchedboards and put together with paint between the joints tomake it water-tight. The box should be about 3 feet wideand 10 inches deep, and 10 to 30 feet long, according to thespace required. In the middle of the box is a partition, extendingnearly the whole length, and on the inside, on eachside, is a ledge or piece of molding to support slate slabs tobe laid over the entire surface of the box. The slates are supportedby the ledges and by the central partition, and shouldbe fastened dower with cement to prevent the propagatingsa.ndfrom falling into the tank. One slate is left qut near theend, next the fire, to enable the operator to see the water and tokeep it at tile right level. Sand is spread on the slates, inwhich the cuttings may be struck, the sand nearly filling thebox. At .me end of the box is placed a common cylinder stove,with smoke-pipci to the chimney. Inside the stove is an ironpipe, bent in ii spiral. This coil, which is directly in the fire,is connected by pipes with the tank, one pipe leading to oneside of the partition and the other to the opposite side, asshown in the drawing. If water is placed in the tank, it wiliCl1 the pipes and form a continuous circulating systellr +,llrou&