86 THE MAGAZINE OF HORTICULTURE. 



ing man would probably never have thought of any other 

 plan than that of piling on the manure ; but with a desire to 

 do away with the great expense of this plan, which we 

 think Mr. Allen has estimated at about $700 for a border of 

 similar size, Mr. Simpson began to reflect upon the matter, 

 and then the happy thought occurred to him about the 

 warmth of a blanket, and next how he should give it a prac- 

 tical application. He has himself explained this, and given 

 the results of the fortunate suggestion which occurred to him. 

 To keep the heat in the ground he found far less difficult 

 than to force it in after it had already been exhausted. This 

 is the real secret of his success ; for without a warm border, 

 it would be an impossibility to ripen a crop of grapes in the 

 winter months. 



Mr. Simpson's remarks on ventilation are worthy of atten- 

 tion ; we do not doubt his plan, which is a modification of 

 the Polmaise and Penn systems so much talked about a few 

 years ago, is valuable, but we do not think this of material 

 consequence. In the way in which grape houses are gener- 

 ally built, there are crevices enough to admit drafts of fresh 

 air to take off" all foul air. But a warm border and a proper 

 temperature, evenly kept, are the important points to be at- 

 tended to in such early forcing. 



The vine is one of the most excitable of all fruit trees ; 

 some English writer has remarked that if the border is kept 

 at a temperature of A2°, there will be no movement of the 

 sap; but if raised to 45°, (only three degrees,) the vine will 

 at once bleed upon being cut, and at 50 to 55, it will soon 

 commence growing. This accounts for the tardiness with 

 which vines in early graperies push their buds, and the diffi- 

 culty of forcing in winter unless some provision has been 

 made to keep up the warmth of the border. A high internal 

 temperature of the grapery, without a corresponding warmth 

 of the border, only tends to injure the vines ; for if, after a 

 time, they begin to break, they will grow so weakly that the 

 clusters of flowers will be likely to prove abortive. To en- 

 sure success, therefore, in all early forcing, a vigorous root 

 action should be first secured, as Mr. Simpson's experiment 



