Some Essentials Thereto 



SI 



The Ideal Structure.— The nearest approach to the 

 ideal is that known as span-roofed. It should occupy 

 a position entirely in the open, with uninterrupted 

 access to light and air, and commanding a maximum 

 of winter sunlight. For convenience, a width of ten 

 feet or twelve feet should do quite well, with ridge 

 placed about seven feet high. Because of the greater 

 measure of dryness the arrangement affords the 

 structure on suitable foundations should be built 

 from ground level, and not partly sunk — pit-house 

 fashion. The most complete system of bottom, side 

 and top ventilation that can be devised should be 

 indulged in so that every part of the house may be 

 abundantly ventilated at all times. Internally the 

 staging should be raised to the level of the opening 

 side lights so that the plants are ev-er receiving fresh 

 supplies of air. If from any cause it is deemed neces- 

 sary to close the side ventilators, those below the 

 staging in the outside walls should be immediately 

 opened — if not already open — to act in conjunction 

 with the roof ventilators which should never be closed. 

 By these means, dryness and buoyancy are secured. 

 The plant stages should have solid bottoms, provided 

 either by strong sheets of corrugated iron, by slate 

 slabs, or by cement concrete with an inch or more of 

 granite chippings, Thames sand, or finely powdered 

 coke or shell to arrange the plants on. By reason of 

 their introduction into the alpine house, the natural 

 flowering period of the plants and their heights are 

 somewhat changed, hence a list only of the names of 

 the more suitable is given. The list might be indefi- 

 nitely increased. 



Achillea argentea 

 ,, Heuteri 

 Adonis amurensis 



fl-pl. 

 Anemone blanda (Fig. 29) 

 ,, ,, scythinica 



Pulsatilla 



S'lba 

 rosea 



Anemone Robinsoniana 

 Daphne Cneorum 

 Crocus asturicus 

 pulchellus 

 ,, sativus 

 Erythronium (Dog's 



Violets), any ' 

 Fritillaria aurea 

 ,, citrina 



Tooth 



