Hotbeds 353 



is given on the outside of the frame. The pipes should 

 run parallel at equal distances from the walls of the bed 

 and each other, with a slant upward from the furnace to 

 the chimney at the other end of the frame. They should 

 be covered with a layer of earth sufficiently deep to secure 

 as nearly as possible an equal distribution of the heat. 

 The heat secured from this apparatus is much more diffi- 

 cult to control than that from fermenting manure, but 

 the construction may be made permanent with only the 

 removal of the layer of earth, in which the seeds are sown 

 for each new crop." 



Substitutes for glass. 



It will be noted that the bed in Fig. 219 is covered 

 with muslin. On this poin't Ness writes : " Instead of 

 glass, the sashes may be covered with cotton cloth, satu- 

 rated with pure raw linseed oil. Before using such cloth, 

 care must be taken that the linseed oil is thoroughly 

 dried, as the fumes given" ofE by the too fresh oils are 

 liable to kill or severely injure the plants, when enclosed 

 in such an atmosphere." 



Various prepared papers and fabrics have been advised 

 from time to time to substitute for glass on late-started 

 hotbeds or in the Southern States, and on coldframes. 

 Some of them may give much satisfaction, reducing cost, 

 breakage, and labor of handling. For late work or warm 

 climates it may not be necessary to oil the cloth. 



"Most commercial growers in the South [writes F. S. 

 Earle, Bull. 108, Ala. Exp. Sta.] use cotton cloth for 

 covering coldframes, as it is much cheaper than glass, 

 and is much. easier to handle in opening and closing the 



