,50 AERATION OF VINERIES. 



cliaiuber, and immediately below the flue,* are conducted the 

 cold air drains, both from the back of the house and also from 

 an air drain d running the length of the house underneatli the 

 vine border. This central drain communicates with the external 

 air by two drains h h, which are protected by a wire grating. 

 Both sets of drains are furnished with sliding valves made of 

 slate, working in a groove m n : to each valve is fixed an upright 

 wooden bar furnished with holes, and by means of a pin the 

 admission of air can be regulated as wished. In addition to these 

 drains there are five ventilators in the back wall of the house g. 

 These are made to slide in a frame, and are connected together 

 by an iron rod, having at each end a weiglit attached, by moving 

 wliich the whole of the ventilators are acted on simultaneously. 



It will be seen by the above description that when the valves 

 m and n are raised and the back ventilators opened, a current of 

 air is immediately admitted beneath the lieatiug medium, and 

 thus gets warmed before coming in contact with the foliage of 

 tiie vines. The general direction of the warmed air is naturally 

 towards the back ventilators. During the winter months and in 

 dull weather these valves recpiire only to be slightly raised, 

 keeping a continuous current through the house without lowering 

 the temperature : during bright sunnj' days I open the whole of 

 them, when of course a more rapid circulation of air takes place; 

 but I do not find it necessary to open tlie top sashes until the 

 weather becomes sufficiently warm that air may be admitted 

 witliout any fear of its injuring the foliage by direct exposure to 

 its influence, \\ hich often occurs to vines in leaf when the sashes 

 are lowered in cold though bright weather during winter and 

 early spring. I may mention that had I iiad the entire building 

 of the liouse in the first place, I should have preferred building 

 the back wall sufficiently higli to have left room for the back 

 ventilators to have opened above the wall plate and immediately 

 under the coping, to remedy the evil in the present case of a 

 direct current of cold air passing through. I have attached on 

 the nortli side a frame which prevents the air entering the house 

 directly from the outside. 



I need not advert to the beneficial effects a constant supply of 

 warm air in rapid motion must have on the health and fertility 

 of plants, particularly of vines and other exotic fruits forced 

 through our comparatively long and dull winters, as these facts 

 are sufficiently establislied by our higiiest autiiorities, and the 

 short though conclusive experience I have had with tlie mode I 

 have described convinces me that the above principles miglit be 

 carried out in nearly all our forcing-houses with the most ilecisive 



* Lest it may appear strange to speak of a flue here, while I have shown 

 hot-water pipes in the section, I may mention the flue is merely temporary, 

 and will be replaced by hot water when the vines are strong enough to force. 



