93 
CONSTRUCTING THE BROOK 
Reference has several times been made in the Rrcorp to the 
construction of an artificial brook through the Garden. The 
brook extends from the lake, in the northeast corner, southward, 
by a winding course, to near the southern boundary of the 
grounds. The construction of this brook was looked forward 
to as rather a difficult undertaking, but, though many obstacles 
have been encountered, the actual work was easier than had 
been anticipated. 
The first and most essential question to so 
— 
ve concerned the 
method of constructing the stream bed, so as to make it approxt- 
mately impervious to water. One engineer suggested merely 
turning on a large stream from a hose and allowing the water 
to mark out its own course through the meadow. ‘This, how- 
ever, was not practical, as proper consideration for the plans 
of the landscape architect, iz toto, made it necessary to determine 
the locus of the stream arbitrarily. 
Another engineer was of the opinion that the bed of the 
stream would have to be of concrete, but this, on brief considera- 
tion, was seen to be wholly impracticable, not only because the 
expense involved was prohibitive, but also because a concrete 
bed would have been subject to serious injury by frost each 
winter. 
It was finally decided to mark out an arbitrary stream- 
course, as mapped by the landscape architect, excavate below the 
desired final bottom of the stream, and line the bed with clay. 
After this plan was determined upon, a layer of blue clay was 
uncovered in excavating for the laboratory building, and this 
layer furnished enough clay to line the entire length of the 
stream-bed to a depth of one foot or more. 
Since a natural stream would, quite probably, not make just 
the curves and meanderings arbitrarily decided upon, it was con- 
sidered unwise to allow the water to flow as an uninterrupted 
stream from source to mouth, but to plan a succession of dams 
and quiet reaches, except for a short distance of more gradual 
fall. ‘This plan had the further advantage of adding to the scenic 
possibilities (fig. 13). As finally worked out, the stream con- 
tains nineteen dams, four pools, and one swamp, in addition to 
