History of the Water Supply of the World / arranged in a comprehensive form from eminent authorities, containing a description of the various methods of water supply, pollution and purification of waters, and sanitary effects, with analyses of potable waters, also geology and water strata of Hamilton county, Ohio, statistics of the Ohio river, proposed water supply of Cincinnati.

by Thomas J. Bell

The direct system, commonly called the Holly Plan, does away with reservoir and stand pipe, and delivers the water directly into the mains under a pressure usually fifty pounds per square inch for domestic use, which is increased to one hundred pounds when fires occur. In the Holly Plan, a reserve power is used for fire purposes, besides mechanical device for regulating and controlling the variable pressure.

In either the stand pipe or direct system, a reserve power should be provided equal to the largest daily consumption.

From a compilation of general information concerning water-works of the United States and Canada, published by the Holly Manufacturing Company in 1878, we arrange the following:

188	cities and towns	use steam-power	for water supply.
104	“	have gravity works	“
32	“	use water-power	“
10	“	have gravity and steam works	“
27	“	use steam and water-works	“
2	“	have gravity, steam, and water-powers	“

Of the above number of pumping works—

139	have reservoir system.
98	have direct system.
16	have stand-pipe system.
4	have direct and reservoir combined.
1	has the three systems combined.
1	has stand-pipe and direct combined.

The expense of pumping water by steam and water-powers, also the practical yearly duties of various pumping engines, are given in the tables on [pages 61] and [64], compiled from annual reports for 1880:

PRACTICAL DUTIES (WITHOUT DEDUCTIONS) OF PUMPING ENGINES (YEARLY AVERAGE).

(From Annual Reports of 1880.)