In comparing the slow with the rapid filter, it should
be borne in mind that any accidental disturbance in the
process of filtration is likely to interfere with the purifica-
tion of the water nearly in proportion to the rate of fil-
tration.
Projects Presented.
We present, for your consideration, several projects for
the radical improvement of the entire water supply of
the city, viz. :

A. — 200,000,000 gallons daily of mountain water, from



Digitized by



Google



69

the tributaries of the Upper Lehigh and from the Upper
Perkiomen, deUvered by gravity into Queen Lane reser-
voir.
An 8-foot aqueduct, extending from Big creek, on the
Lehigh river, to Treichlersville, on the Upper Perkiomen,
carries the impounded waters of the Upper Lehigh tribu-
taries into one of the reservoirs on the Perkiomen creek.
A dam at Green Lane, on the Perkiomen, impounds
the combined waters of the two streams, which are carried
thence by a 12-foot high-level aqueduct to the Queen
Lane reservoir.
B. — 200,000,000 gallons daily of mountain water, from
the tributaries of the Upper Delaware, near the Water
Gap, delivered by gravity into a new reservoir to be con-
structed near Twelfth street and Olney avenue.
A M-foot aqueduct extends from the Delaware Water
Gap to the proposed new reservoir at Twelfth street and
Olney avenue, conveying thereto the impounded waters of
the Upper Delaware tributaries, which it receives through
several feeders at the Water Gap.
C. — 450,000,000 gallons daily of mountain water, from
the tributaries of the Upper Lehigh, and from the Upper
Perkiomen, delivered by gravity into Queen Lane and
East !Park reservoirs.
