THE GRAPE VINE. 57 



termed the " hot-air ventilator/' and consists of a sheath 

 of " copper placed over or incasing a row of the front 

 pipes. The diameter of the sheath is one inch more 

 than the hot pipe it encloses, consequently there is an 

 open space of half an inch all round the pipe inside the 

 sheath. This cavity is fed with fresh air from the 

 exterior of the house, by a pipe 5 inches in diameter, 

 vi^hich springs from the lower surface of the sheath and 

 passes through the front wall of the house to the ex- 

 ternal air. There is a valve in this feed-pipe to modify 

 the supply of fresh air at pleasure. In the upper sur- 

 face of the sheath is a double row of holes, so that the 

 moment the cold air comes into the chamber round the 

 pipe and gets hot, expanded, and lighter, it makes its 

 exit through these holes into the general atmosphere of 

 the house." 



VINEEY FOR LATE GKAPES. 



Having shown that a lean-to vinery facing due 

 south is the best form for early forcing, iinder this head 

 I have no hesitation in saying that for the same reasons 

 that I have recommended the lean-to for winter forc- 

 ing, when the sun is only a short time above the horizon, 

 the span-roofed- vinery running north and south is best 

 for the ripening of grapes, say after the middle of July. 

 A span-roofed house in this position gets the benefit 

 of sunshine longer in summer than does the lean-to. 

 The east side gets the morning sun, at noon the whole 

 roof is exposed to it, and on tiU late in the evening 

 the west side is exposed to the sun, when it would 



omit the vine — it -would he like the play of Hamlet with Hamlet 

 omitted. 



