796 ARBORETUM AND FRUTICETUM. PART III. 
When a rosarium, the groups of which are disposed so as to form one 
symmetrical figure, is to be planted solely with dwarf roses, the walk 
which surrounds it ought always to be 2ft. or 3ft. above its level, in 
order that the spectator, after having studied the groups in detail, may be 
able to retire to the surrounding terrace walk, and get a birdseye view of the 
whole. This principle, indeed, is applicable to all symmetrical rosariums, cis- 
tetums, flower-gardens, American grounds, &c., which are to be planted with 
dwarfs. Where standards, whether roses or other shrubs, are used; either in 
groups alone, or interspersed with the dwarfs, as in fig. 525.,; a surrounding 
terrace walk, though almost always desirable, is not so essential for the dis- 
play of the beauty of the scene. 
Where a rosarium cannot be formed in one compact whole, as in the 
design, fig. 525., it may be laid out on each side of a leading walk, in various 
ways. The walk may be either straight, or regularly curved: in either case, 

the climbing varieties may be used to form a sort of open arcade, to separate 
each section, as indicated in figs. 526, and 527. In these figures, @ repre- 
