THE MANUAL OF GARDENING. 71 
to its owner, the annual profit being, sometimes, $100,000 per 
annum. 
The tree is strong, hardy, vigorous, and though not so orna- 
mental as some other pines, fully merits a share of notice. There 
are some good specimens at McMahon’s Nursery. 
The Norway Fir ( Abies excelsa ), is the loftiest of European 
trees. Its widely extended branches spread out on every side, 
so as to form a cone-like or pyramidal shape, terminating in an 
arrow-like leading shoot. The branches, in young trees, are 
dispersed in regular whorls, from the base to the summit, and 
are nearly horizontal; but when old droop gradually at the 
extremities. On the whole it is a most desirable evergreen 
tree, and no lawn of sufficient extent should be without it. A 
noble specimen may be seen at Bartram’s. 
The black, red, and white, spruce firs (A. nigra, rubra, and 
alba), are quite ornamental, the latter particularly so. 
The Hemlock Spruce, A. Canadensis, is an elegant tree, from 
the symmetrical disposition of the branches, which droop grace- 
fully at their extremities, and also from its light and tufted foli- 
age. As it advances in age, the limbs become brittle, and readily 
broken by heavy snows ; but it is not liable to that disaster until 
30 or 40 years old. The Hemlock Spruce bears the shears well, 
and forms a handsome inside hedge. 
The Silver Fir, Picea pectinata, or comb-like leaved silver fir, 
has been termed the noblest tree of its genus, rising to an eleva- 
tion of 180 feet, with an erect stem, regularly furnished with 
whorls of candelabrum-like branches. The leaves are of a dark 
green on the upper surface, and silvery beneath ; hence its com- 
mon name. The cones are large, and have a fine appearance, 
both before and after they are mature. It is indigenous to the 
mountains of central Europe, and the west and north of Asia; 
and is found in France, Italy, Greece, and south of Germany. 
The finest specimens in the neighbourhood of Philadelphia are 
at Landreth’s, (south 5th street,) imported many years since, and 
now 40 feet high, and regularly formed. It likes a deep rich 
loam, not too moist. 
The Balm of Gilead Fir, Picea balsamea, or American silver 
fir, is a pyramidal tree, in general appearance resembling the 
European silver fir ; when standing alone it forms a symmetrical 
tree, abundantly furnished with leaves, and is certainly a beauti- 
ful object when young; but it declines in old age, and from the 
brittle nature of the wood frequently exhibits a branchless, muti- 
lated trunk. The true silver fir, on the contrary, retains its 
elasticity, and is magnificent when old. 
Rhododendron — This is one of the most showy and beautiful 
■shrubs produced in our gardens, and as such deserve assiduous care : 
