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Cost OF CONSTRUCTION.

Costs.

The total cost of a power station with a capacity

of 10 000 kilowatts, including coal storage, coalhandling apparatus, building, complete boiler plant equipment, engines, generators, switchboards, ready to deliver power to high-pressure feeders, interest during construction, but excluding real estate, will be...

$1 250 000 The total cost of high-pressure cables, sub-station

buildings, transformers, switchboards, arc lighting circuits, centres of distribution for incandescent lighting, lamp-posts, lamps, meters, and all appliances necessary to make a complete operative plant up to and including the lamps, including the cost of real estate, but excluding the cost of the main duct system, all for a capacity of 6,000— 450-watt arc lamps in Manhattan and The Bronx and for 250 000 sixteen candle-power incandescent lamp equivalents, will be..

$2 850 000

The total cost of the complete system will then be.. $4 100 000

COST OF OPERATION.
ARC LAMP--
We estimate that the total annual cost of operating

a 7.5 ampere inclosed, alternating-current arc
lamp, for 4,000 hours per year, including all costs
of generation, distribution of energy, lamp repairs,
carbons, trimming, inspection, giobes, fire and
boiler insurance, general expenses of management,
depreciation at 7.5 percent on the total invest-
ment, and interest at 3.5 percent on the total
investment, will be..

$75.40 INCANDESCENT LAMPThe total cost per kilowatt-hour at the lamp, includ

ing all charges of generation, distribution, inspection, lamp renewals, metering, general expenses, interest and depreciation, for the supply to the incandescent lamps, will be...

5.15 cents TOTAL Cost OF OPERATIONThe total annual cost of operating this plant for

6,000 arc lamps and 250,000 sixteen candle-power equivalents, including all operating expenses, depreciation at 7.5 percent and interest at 3.5 percent, will be.....

$906 000

The cost per arc light is higher than given in the report of Mr. Hutchinson, on account of the smaller number estimated on; on the other hand, the cost of incandescent lighting is lower on account of the greater number of lamps to be lighted.

These estimates include neither the cost of construction of ducts for cables, nor any rental charge for duct space.

These items have been omitted under instructions of yourself and the Corpora

tion Counsel, who have informed us that the City has the right to use all the duct space that it requires and free of all charges.

We annex to this report a copy of the report of Cary T. Hutchinson above referred to.

Very respectfully,
CARY T. HUTCHINSON,

Chairman.
GEORGE F. SEVER.
NELSON P. LEWIS.

OFFICE OF

CARY T. HUTCHINSON, CONSULTING ENGINEER,

No. 56 PINE STREET,

NEW YORK CITY, May 11, 1903. Hon. ROBERT GRIER MONROE,

Commissioner, Department of Water Supply,
Gas and Electricity,

Park Row Building, New York City:

Sir.--I hand you herewith my report on the cost of construction and operation of an electric plant for the public lighting of the Boroughs of Manhattan and Bronx of The City of New York.

There are now in service 5 000 arc lamps in the Boroughs of Manhattan and Bronx and a total equivalent connected capacity of 160 000 sixteen candle power incandescent lamps. There should be at least 10 000 arc lamps in these two boroughs and all the lighting of the public buildings should be done by electricity. I have, therefore, made my principal estimates on a plant to supply 10 000 arc lamps and to do all the lighting of public buildings by electricity--but have added a supplementary estimate for a plant to meet the present conditions only.

The cost per year for one arc light, including interest at 3.5 percent, and depreciation at 8 percent, will be $69.40, and for 10 000, 694 000.

The cost per kilowatt-hour for incandescent lighting will be 5.475 cents, and the annual cost for all this lighting will be $219 000, making a total of $913 000 for the two services.

For 5 000 arc lamps and the lighting of public buildings, the cost per year per arc light will be $80.80, and the total cost will be $623 000; at the present rates charged the City the annual cost is $1 130 000-an annual saving of $507 000.

The total cost of construction of a plant for 10 000 arc lights and the public building lighting, excluding the cost of subway ducts (which, you have informed me, the City has the right to use free of rental), will be $1 208 000; the annual saving of $947 000 with this plant amounts to 22.5 percent of its cost.

The total cost of construction of a plant for 5 000 arc lights and the public building lighting, excluding the cost of subway ducts, will be $3 000 000; the annual saving of $507 000 with this plant amount to 16.9 percent of its cost.

Ten thousand arcs and the present public building lighting can be supplied for $200 000 less than the City is now charged for 5 000 arcs and the public building lighting.

This lighting can be done at practically half the rates now charged to the City.

These estimates are all based upon economical construction and operation of the plant.

Very respectfully yours,

CARY T. HUTCHINSON.

REPORT ON ELECTRIC PLANT FOR THE LIGHTING OF

THE BOROUGHS OF MANHATTAN AND BRONX.

General
Conditions.

This report gives the cost of construction and operation of a plant to supply 10 000 480-watt arc lamps and about 150 000 incandescent lamps, in Manhattan and Bronx.

There are now in Manhattan 3 155 arc lamps and in The Bronx 1 822-a total for the two boroughs of 4 977. This number is insufficient-particularly for Manhattan. There should be at least twice as many in Manhattan; 10 000 is the mini-' mum now required, and more would be better.

The City now pays for lighting about 600 public buildings and places, such as markets, parks, school houses, police stations, engine houses, hospitals, repair shops and yards, public baths, etc.; about half of this lighting is by gas, the rest by electricity. All of this lighting should be electric; the equivalent connected capacity of all this public lighting is about 160 000 sixteen candle power electric lights; in the near future large extensions of this lighting will be required. There is no satisfactory way to estimate the future requirements; hence central station capacity has been provided only sufficient for all the present lighting of public buildings and places by electricity, eliminating gas entirely. The central station capacity can easily be increased as the demand increases.

The conditions in Manhattan and in The Bronx are very different. In Manhattan all circuits must be underground and the distribution of lighting is relatively dense. In The Bronx the problem is more that of a suburban town; all wires are overhead and the density of the distribution is low.

In order to get a close approximation to the distributing system required, every arc light now

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