102 GREENHOUSE CONSTRUCTION AND HEATING. 
Fig. 70 shows the section of a propagating house 12ft. 
in width, and fitted with beds as described above, 
recently erected by the writer, and which afforded excellent 
results. 
The old-fashioned hot- baa (in a house) was constructed 
with a hot-water tank beneath, the heat being obtained 
by running two or three rows of piping through a brick 
and cement or other tank, a covering of slate or the like 
being placed over, and a few inches of cocoa-nut fibre, 
Fig. 70. 
sand, fine ashes, or the like, on this in turn, in which to 
plunge the pots, etc.; a moist and genial bottom heat was 
thus secured, in which cuttings of soft wooded plants 
rooted readily, but the amount of moisture was sometimes 
found excessive, especially when the bed was covered in 
with glass. Another difficulty frequently met with in such 
cases is the liability of the tank to leak where the pipes 
enter and leave it, but this has been already treated of. 
