150 



GARDENING FOR PLEASURE. 



CHAPTER XLVIL 



THE HOT-HOUSE OR FORCING GRAPERY. 



When grapes are forced by artificial heat, probably the 

 best plan is that of the "lean-to" structure shown by 

 the illustrations, figs. 61, 62, and 63. Fig. 61 gives the 

 plan, which, as in some former engravings, it is not prac- 

 ticable to show on the page at full length; it is accord- 

 ingly "fractured" portions, as shown by the irregular 

 lines, being taken out of each compartment ; the figures 

 give the proper proportion. Fig. 62 is a part of the front 

 elevation, and fig. 63, a section at the division between 

 the two houses. The house is 100 feet long by 16 feet 

 wide, divided into two compartments for early and late 

 forcing, each 50 x16 feet, and both heated by one boiler 

 with valves in the furnace pit to shut off and taps to draw 

 the water from the pipes not in use ; a matter to be looked 

 to when vineries are not in use, for if the water is not drawn 

 out of the pipes it may freeze and burst them. When grapes 

 are to be forced, it is essential that a sufficient covering 

 of manure or leaves be placed on the border to prevent 

 frost from reaching the roots, as to apply heat to the vines 

 inside w^hile the roots are frozen, would seriously in- 

 jure them. For very early forcing, when the vines are 

 started as early as January, it is usual not only to put 

 covering enough to secure from frost, but also to 

 slightly ferment, so as to throw some warmth into the 

 border. Xo matter at what season the grapery is started 

 for forcing, the temperature should not run over 50° or 

 55° at night, with a day temperature of 10° or 15° higher, 

 increasing 10° when the buds have opened, which will be 

 in four or five weeks from the time of starting. In five 

 or six weeks the fruit will be set and the temperature is to 

 be raised 10° more. In forcing, moisture is of equal im- 



