FORMATION OF ROCK-WORK. 251 



purpose of climbing are the now popular species of Vir- 

 ginia creepers, Ampelopsis quinquefolia, A. Veitchii, 

 and A. RoyalUi. The latter two are particularly valu- 

 able for climbing on rocks, and are now becoming much 

 used by the principal railroad companies, not only to 

 ornament but to ''lace up " shaley rocks through which 

 cuts are made. We sold a few years ago, to one of our 

 leading railroad companies in one season five thousand 

 plants of Ampelopsis Veitchii, which now in many 

 places have attained a height of thirty feet, giving 

 to slipping rocks not only great support, but covering 

 them with glittering green leaves in the summer and 

 tinting them in autumn with crimson and gold. 



For drooping and the general covering of rocks the 

 following list will be found useful : 



Achilleas, of creeping growth, Sempervivums, of all kinds, 



Campanulas, of creeping growth, Linnaea borealis, 



Crucianella stylosa, Lychnis grandiflora, 



Cerastium tomentosum, Lysimachia nummularia, 



Phloxes, of creeping growth, Orobus vernus, 



Polemonium reptans, Soldanella alpina, 



Saxifragas, Vinca major variegata, 



Sedums, of all kinds, Thymus vulgaris variegata, 

 Violas of sorts. 



All these are hardy. 



Artificial rock-works are often formed thus : The shape 

 aud dimensions of the work being determined on, the 

 clinkers from furnaces are collected, and dipped in hot 

 lime wash, which gives a coloring of pure white to their 

 fantastic shapes. With these the "rock- work" mound 

 is formed of the height and shape desired, leaving at 

 suitable distances cavities of six or eight inches deep, to 

 be filled with soil in which to place the creeping plants. 

 For this kind of rock-work a different class of plants is 

 more appropriate, such as are of bright colors and will 

 contrast with the ground work of white. Scarlet or 

 other high-colored Verbenas, Coleus, Gazanias, Scarlet 



