138 DESCRIPTION OF HOTHOUSES. 



glass roof is directly facing the south, or as 

 nearly so as circumstances will permit ; neverthe- 

 less, there are situations where a double glass- 

 roofed hothouse may be erected, and not con- 

 venient or desirable to build one facing the 

 south, in such cases it is by no means to be 

 rejected. 



Some pineries are built of a circular form, 

 with a wall all round, two or three feet high, 

 with upright sashes and sloping roofs, in the 

 same proportion as described in the last plan, 

 having the flues for fire-heat, or pipes for water, 

 or steam heat, carried round the inside walls, 

 with a circular pit, or two semi- circular pits, if 

 the house be large enough, with a walk round 

 between the pits and the outside walls. 



However much persons' taste or their ideas 

 may differ, as to the form of the hothouse to be 

 constructed, I would strongly recommend them 

 them to be raised only of a moderate height for 

 pines, as the internal heat will have much better 

 effects, and the plants will grow much stronger 

 than when the glasses are lofty ; the latter often 

 makes the plants weak, with long leaves, leaving 



