(41 ) 
surrounding landscape, and much would be gained by restoring 
the stream to a condition nearer its natural one. We, there- 
fore, recommend that, instead of simply lowering the dam, 
there be built up against it, in front of the fall, an irregular pile 
of rocks, the tops of some of them projecting above the upper 
water level, which would break up the even character of the 
present fall into a foaming cascade, which would be in har- 
mony with the forest and much more beautiful than the present 
unnatural mill dam. Above the ‘Blue Bridge” the banks of 
the river will require some attention from time to time, and a 
part of its reach through the northern meadow may ultimately 
be advantageously walled, but a judicious planting of trees and 
shrubs, in addition to those now in position, will probably pro- 
tect the banks at most points. A small amount of dredging 
is apparently indicated as desirable by the soundings at points 
above the ‘‘Blue Bridge,” but no great amount is evidenced. 
The lowering of the water will be beneficial to certain of 
the trees in the immediate vicinity of the banks, by relieving 
them from a surplus supply of moisture which they now en- 
dure. There have already been a number of trees, killed 
by drowning and by the action of ice on their roots, removed 
from the valley. 
Through the meadows at the northern end of the site the 
Bronx at high water now occupies two channels, and it is 
recommended that it be restricted to one, which will be feasible 
when the stream is lowered as above described. 
18. Economic Garden. 
A collection of plants selected on account of their useful 
products has usually found place in botanical gardens, and we 
regard the feature as a desirable one. The collection should 
be grouped as far as possible by the products, and this will be 
also largely in their relationships from a botanical standpoint ; 
the tract recommended for this collection lies within the de- 
ciduous arboretum, east of the Bronx, in a glade devoid of 
trees and with excellent soil; a maximum space of about one 
