380 PERNS : BRITISH AND FOREIGN. 



arranged in any part of the house., and are readily 

 detached and again fixed at another point when found 

 necessary. The first deposit for the rockery should 

 be rough and somewhat absorbent, such as irregular 

 brickbats, masses of stone, loosely disposed to admit 

 of a ready dissemination of the heat amongst its 

 parts, and then follow with the material proper. 

 Apertures for the escape of the heat should be con- 

 structed at frequent intervals, drain-pipes being very 

 suitable for this purpose, which, by the mass being kept 

 properly moist, will allow the heated air to circulate 

 in a congenial steamy condition throughout the house. 

 In the design and arrangement of the principal 

 mass of material composing the rockwork, it is, as in 

 the design of the house, a good deal a matter of taste 

 and convenience as regards size; whether in repre- 

 senting in miniature a rugged mountain side, or deep 

 glen, with its clear pool, reflecting the elegant forms 

 of the Ferns growing near it ; or may be a miniature 

 valley, with undulating surfaces gradually rising on 

 either side, with projecting rocks. There are nu- 

 merous kinds of material more or less suitable for 

 constructing a rockery either indoors or out, and but 

 a few localities where some of these may not be easily 

 procured. The chief desideratum is to have such that 

 is of porous consistence, and generally with rough 

 and ragged surfaces. It is useless to be particular in 

 the selection of various kinds of stone on account of 

 their fine quality, either in texture or colour ; for where 

 Ferns properly thrive all such will be speedily obscured 

 by their luxuriant growth ; consequently any brick- 

 field affords very good material that would contribute 

 largely in the general structure, in the way of con- 



