[Illustration:  VIEW FROM TOP OF CHIMNEY SHOWING WATER FRONTAGE—­POWER HOUSE]

All cast iron used in the fittings is called air-furnace iron, which is a semi-steel and tougher than ordinary iron.  All line and bent pipe is of wrought iron, and the flanges are loose and made of wrought steel.  The shell of the pipe is bent over the face of the flange.  All the joints in the main steam line, above 2-1/2 inches in size, are ground joints, metal to metal, no gaskets being used.

Unlike the flanges ordinarily used in this country, special extra strong proportions have been adopted, and it may be said that all flanges and bolts used are 50 per cent. heavier than the so-called extra heavy proportions used in this country.

[Sidenote:  Water Piping]

The feed water will enter the building at three points, the largest water service being 12 inches in diameter, which enters the structure at its southeast corner.  The water first passes through fish traps and thence through meters, and from them to the main reservoir tanks, arranged along the center of the boiler house basement.  The water is allowed to flow into each tank by means of an automatic float valve.  The water will be partly heated in these reservoir tanks by means of hot water discharged from high-pressure steam traps.  In this way the heat contained in the drainage from the high-pressure steam is, for the most part, returned to the boilers.  From the reservoir tanks the water is conducted to the feed-water pumps, by which it is discharged through feed-water heaters where it is further heated by the exhaust steam from the condensing and feed-water pumps.  From the feed-water heaters the water will be carried direct to the boilers; or through the economizer system to be further heated by the waste gases from the boilers.

[Illustration:  PORTION OF MAIN STEAM PIPING IN PIPE AREA]

Like the steam-pipe system, the feed-water piping is laid out on the sectional plan, the piping for the several sections being identical, except for the connections from the street service to the reservoir tanks.  The feed-water piping is constructed wholly of cast iron, except the piping above the floor line to the boilers, which is of extra heavy semi-annealed brass with extra heavy cast-iron fittings.

[Sidenote:  Engine and Turbine Equipment]

The engine and turbine equipment under contract embraces nine 8,000 to 11,000 horse power main engines, direct-connected to 5,000 kilowatt generators, three steam turbines, direct-connected to 1,875 kilowatt lighting generators and two 400 horse power engines, direct-connected to 250 kilowatt exciter generators.

[Sidenote:  Main Engines]

The main engines are similar in type to those installed in the 74th Street power house of the Manhattan Division of the Interborough Rapid Transit Company, i. e., each consists of two component compound engines, both connected to a common shaft, with the generator placed between the two component engines.  The type of engine is now well known and will not be described in detail, but as a comparison of various dimensions and features of the Manhattan and Rapid Transit engines may be of interest, the accompanying tabulation is submitted: