ON AQUATIC PLANTS. 873 



presenting a natural, . and therefore more pleasing, appearance 

 when completed. In making the pond the ground should be 

 excavated to the depth of about 3ft, afterwards covering the 

 interior throughout with a 9m. course of brick, stone, or well- 

 made concrete. The surface should be smoothly finished off with 

 about an inch in thickness of good cement, so as to ensure 

 it being perfectly watertight. This would when finished afford 

 a depth of from 2ft. to z^ft., which would be sufficient for 

 the accommodation of Aquatics suitable for introducing into a 

 pond of this description. The margin should be constructed 

 so as to appear as a part of the rockery, and by the' 

 careful concealment of all artificial work its effect would be 

 the more satisfactory. Permanent beds formed of brick or stone, 

 about 2ft. 6in. square and i2in. deep, might be built in the pond 

 at equal distances apart, in which to plant Water Lilies ; and 

 around the inside against the wall other beds might be constructed 

 for the reception of some of the smaller-growing ornamental 

 Aquatics. Water is frequently associated with a rock-garden in 

 some shape or form, and where it is adjacently present would 

 form the source from which a supply might be obtained ; but 

 providing this is not the case, or the supply be inadequate, it 

 will be necessary to introduce it through water-pipes from 

 another source, the inlet being masked by rockwork, presenting a 

 natural appearance. At the lowest end of the pond the overflow 

 might be allowed to escape in such a manner that in its course it 

 would permeate the ground, and so afford a favourable situation 

 for planting some of the many choice bog-loving plants. 



Tanks. — In^ gardens of limited space brick, stone, or concrete 

 tanks about 2^ft. in depth might be constructed, and these, if built 

 entirely in the ground with the walls gradually sloping outwardly 

 at the top, will minimise the risk of their being damaged during 

 a long spell of severe frosty weather. The thickness of the walls 

 would largely depend on the size of the tank, but for those from 

 25ft. to 30ft. in diameter, walls of the same thickness as recom- 

 mended for the pond in the rock-garden would be sufficiently 

 strong, and the beds for the reception of the plants might be of 

 a corresponding size to those described in that instance. As 

 previously stated, a sunny position should be selected, and the 

 site and formation of a tank of this description should he carefully 

 considered in connection with the surroundings. In its con- 

 struction a natural effect should be aimed at as far as possible-, 

 so' that it will not present a too formal appearance. For example, 

 a suitable position in the flower-garden might be available for 

 the purpose, and if a border of some ornamental, compact, 

 dwarf-growing plants were formed around the outside, or a 

 little low rockwork substituted as an edging, upon which plants 

 adapted for such a position might be grown, this would greatly 

 add to its effect. 



