Grape Culture. 7 



little heating power, as, when the low temperature comes, 

 heavy firing and waste of fuel will take place, and the saving 

 of the capital cost of two rows of 4-inch pipes is soon swallowed 

 up, not to speak of the trouble and anxiety when there are 

 20 or 30 degrees of frost. 



It need hardly be mentioned that where two or more 

 houses are heated from the same boiler, provision must be made 

 for heating each house separately. 



THE HALF-SPAN VINERY. 



When the aspect is south, or nearly south, the semi-span 

 vinery is considered to be preferable to the lean-to. Especially 

 is this the case with a late house. The morning and evening 

 sun shining through the back roof is supposed to aid the 

 ripening and colouring very considerably. The mode of con- 

 structing a semi-span vinery is practically similar to the 

 lean-to already described. Probably even greater care should 

 be exercised in very thoroughly binding the roof so that there 

 should be no outward thrust on the walls, which is the true 

 principle of roof construction. The roof ventilator on a 

 semi-span roof should always be on the south side ; on no 

 account, unless where exceptional reasons exist, should the 

 ventilator be on the north side. In dealing with these two types 

 of vinery construction, an assumed width is taken and an 

 assumed slope, but it is by no means to be inferred that the very 

 best grapes cannot be grown in houses of a different width 

 and a different slope. There is no fixed rule the wide house 

 will grow more, but it may not follow, better grapes. In short, 

 a good gardener will grow good grapes in a very poor house. 



SPAN- ROOF VINERY. 



For market purposes, and where very large quantities of 

 grapes are required, or where there are no high walls, the span- 

 roofed form should be adopted, and there must be a radical 

 change in aspect. In the case of the lean-to and semi-span the 

 vinery should face the south with as little east or west aspect 

 as may be practicable, but the span-roofed structure should 

 run north and south as evenly as possible, so that each side may 



