266 AMERICAN GRAPE CULTURE. 



raised at the top, bottom, or either of the sides, 

 according as it may be opposite the point whence 

 the wind comes. Water, also, must be faith- 

 fully applied, but only when it is wanted, and 

 no more than is wanted. The wants of the plants 

 in these two particulars must be carefully and 

 constantly watched and ministered to. 



No very precise rules can be given for shading 

 and ventilation. We have several times stated 

 the importance of having a uniform moist at- 

 mosphere for the young plants to grow in, and 

 it seems hardly necessary to repeat it here ; yet 

 it is a point that must be constantly borne in 

 mind. The importance of a strong light with- 

 out the direct rays of the sun has also been al- 

 luded to: it is the colorific and not calorific 

 rays that are wanted. Ventilation and shading 

 must have reference to these two points. If the 

 sashes face the south, as is almost universally 

 the case, the sun heats the frame early, and by 

 mid-day it becomes almost seething. The plants 

 would speedily die if left to such conditions, 

 and it therefore becomes necessary not only to 

 ventilate and shade early, but to exercise the ut- 

 most vigilance all through the day to regulate 

 the ventilation so as not to reduce either the 

 heat or the moisture below what is necessary 



