6 THE FORCING GARDEN. 
which they are heated to a good growing temperature 
The grapes swell, but do not often colour well, especi- 
ally the very early ones, and the reason is given 
above. 
Fic, 2.—SECTION OF TOP VENTILATORS, TWO FEET SQUARE. 
Reference to ventilators.—aaaa, openings in back wall of house close under wall 
plate at the top; BBBB, shutter and sliding venti:ators ; cc, the runs in which 
the ventilators slide, by means of connecting wires, DDD; and the cords and 
pulleys, EEEE; ff, stops. The runs must be fixed on the wall with stout hooks, 
aud the pulleys fixed firmly on the wall. All these shutters can be opened and 
shut at once the whole length of the house. 
It is difficult ordinarily to get air enough into 
very early graperies so as to colour the fruit. Houses 
for the early forcing of vines are not constructed for the 
safe admission of air in a sufficient quantity to colour 
Fid. 3.—SECTION OF FRONT AIR SLIDING SHUTTERS FOR AN EARLY FORCING HOUSE 
AND VINERY, 
Reference.—a aaa, openings, one foot square, in front wall, as shown in sectional 
plan of vinery (fig. 4), at ‘B.’ These optnings may be four feet apart, or less. 
BBEBBBB, sliding shutters, opened and shut all at once by the cords and 
pulleys, cc. As these shutters are fixed so low, the cords work upwards instead of 
pulling downwards, as in the case of the ventilators at the top of the house. They 
may be outside. 
the fruit well. The roofs are too flat for a brisk cir- 
culation, when it can be admitted, which is not often. 
It will be seen in fig. 4 what my plan is for meeting 
