ON AQUATIC PLANTS. 901 



disfiguring the plants. Ventilation should be amply provided, 

 both in the sides of the house and in the roof, for Aquatics 

 generally, and Nymphaeas in particular, when in full growth 

 require abundance of air on hot, sunny days. Around the 

 inside of the house, abutting on the walls, benches or borders 

 may be formed for the accommodation of ornamental plants ; or 

 small tanks or beds may be constructed for the culture of 

 Aquatics, or moisture-loving plants. For heating the house, suffi- 

 cient piping should be introduced to ensure a minimum 

 temperature of from 65deg. to yodeg. Fahr., and this will provide 

 for the maintenance of a higher temperature when desired, and 

 will minimise the amount of piping necessary to be employed 

 for heating the tank. 



Tank. — A tank for the reception of the Aquatics should be 

 constructed in the centre of the house, and whatever the 

 desired shape may be, whether entirely sunk in the ground, 

 or partly above the ground-level, a firm foundation must be 

 first secured. The bottom should be made perfectly solid with 

 a layer of bricks well bedded in cement and sand, and on the 

 top of this course a good thickness of stone or brick rubble 

 concrete should be added. The walls may be built with either 

 brick, concrete, or stone, the thickness of which will largely 

 depend upon the size of the tank. If it be desired to have 

 a tank from 20ft. to 30ft. in diameter and about 2ft. 6in. in 

 depth, walls i2in. thick to within loin. of the top, and from 

 that point sloping outwardly, with the masonry set in cement, 

 would be sufficiently strong. The tank should afterwards be 

 faced both inside and out with about lin. coating of good 

 cement, and the surface smoothly finished off to make it 

 watertight. On the inside, formed against the walls, a few 

 beds, enclosed in brickwork, may be introduced for the ac- 

 commodation of strong, erect-growing Aquatics ; these should 

 reach to about 6in. below the top of the tank, so as to admit 

 of their being submerged to a depth of 3in. or 4in. when the 

 water is at its normal height. A raised tank has the advantage 

 of bringing the Lilies and dwarf-growing Aquatic plants closer 

 to the eye ; but the formal appearance of plain external 

 masonry may in some instances be objectionable. It might, 

 however, be made interesting and pretty by forming a little 

 rockwork close against the wall, which might be furnished 

 with a variety of trailing and other dwarf - growing plants 

 adapted for the purpose. In favour of a tank sunk in the 

 ground, it may be urged that a better view of the tall-growing 

 Aquatic and sub-Aquatic plants is obtained, and if the top of the 

 masonry be surmounted with a stout, ornamental iron rail, on 

 which a selection of choice plants of climbing habit might be 

 trained, it would present a very effective appearance and at the 

 same time afford protection. 



