Page:Popular Science Monthly Volume 88.djvu/861

 Popular Science Monthly

��833

��Madison Square Garden

��Metropol.lan Tov

��FlatironBuMdIng

��Cotikill Water v^lll a/ss wUhovt ^;?.i.g' pumpino to thiS hc'ioht.

����\

��PRCSSURE TUNNEL

��VAL.VE

��Water supplied to the city of New York from the Catskills rises two hundred and eighty five

feet under its own pressure

��Water Rises to Three Hundred Feet in New York Sky Scrapers

A CITY possessing a pressure system capable of elevating water a vertical distance of nearly three hundred feet above street level without pumping is unusual. Yet New York's new Catskill supply system will accomplish this feat. Contrasted with the thirty or forty-foot heights which the average city system can attain, the performance is out of the ordinary, to say the least.

The artificial lakes supplying the water to New York are high up among the Catskill mountains, one hundred to one hundred and twenty-five miles north. In the case of the Metropolitan tower, for instance, this height to the supply enables the water to rise unaided two hundred and eighty-five feet above the ground level, or four hundred and eighty-five feet above the pressure mains, which are themselves two hun- dred feet below the street surface. The two hundred and eighty-five feet are more than two-thirds of the way up the occupied portion of the tower, so that but comparatively little pumping is necessary in order to reach the highest offices. The case is typical of all the large buildings in the city.

Heads such as that mentioned mean that pressures over two hundred pounds

��to the square inch have to be contended with in the huge mains so far below the surface. This condition necessitates unusual construction. In fact, the whole length of the mains from the Catskills to the city is made up of diffi- cult engineering feats. Over much of the distance they are made of steel tubing, lined and re-enforced with con- crete. In places they bore through solid-rock mountains, tunnel under rivers and lakes, burrow far beneath city streets and skyscrapers, all that the city may be reached by the shortest route consistent with engineering econo- my. Smaller mains near the surface care for the work of local distribution.

��War and Trade

BECAUSE many foreign-owned ves- sels, which formerly traded between the United States and South American ports, have been withdrawn for war purposes, trade is thereby increased in proportion for American vessels. It is estimated that seventy per cent of our commerce with Brazil, the Argentine and other South American countries is now being carried under the American, Brazilian and Argentine flags. Of the remaining thirty per cent only about fifteen per cent is still carried in vessels of the nations at war.

�� �