PHILADELPHIA, the first city of the State of Pennsyl vania, and third in population and manufactures in the United States. It was planned by William Penn and other members of the Society of Friends partly, if not chiefly, as a haven of refuge for persecuted peoples, who like themselves, wished to be guided by the "inner light" of conscience. They called their town Phila delphia (from the Greek (13tXa30?4)Eta, brotherly love), borrow ing a place-name of sectarian significance in Lydia, Asia Minor, seat of one of the seven early churches.
Philadelphia was the Proprietary capital of the Province until 1776; capital of the State until 1799; capital of the United Col onies until 1781; capital of the United States under the Articles of Confederation from 1781 to 5789 and under the Constitution from 1790 to 1800.
Independence Hall, Philadelphia's most celebrated structure, which is a few squares east by south of the city-hall, is in lat.
57.54" N.; long. 75° 8' 57.5" W. Chestnut street pier is 101.6 m. from the Atlantic. An official tabulation of point-to point airline distances between the Philadelphia Municipal air port and five well-known places follows : New York, 79 m. ; Balti more, 81 m.; Washington, D.C., 119 m.; Pittsburgh, 26o m.; Boston, 283 miles.
Between the Delaware river and the nearest mountains, the Kittatinny range, is the 6o m. wide Philadelphia Piedmont plateau, invitingly fertile, and, in early days, heavily timbered with oak, hickory, chestnut, tulip-poplar, beech, dogwood and laurel. As the city has had much to do with the de velopment of its "back country" so, conversely, the Philadelphia Piedmont plateau, with its many cities, towns and rich townships has contributed greatly to the growth of Philadelphia. And as the Delaware comes down from the north-east, or Minisink coun try, so the lesser Schuylkill, with its numerous tributaries, comes down from the north-west, out of the anthracite coal-fields, bi secting the Piedmont diagonally, breaking over the last score or more of falls at tidewater and joining the greater stream at the obviously strategic point of the whole region—the Coaquannock of the Indians; the Ft. Beversrede of the fur-trading Dutch; the Tacony-Tinicum of the Swedes and the Philadelphia of to-day.
All of old Philadelphia, with the main part of the new, lies on the peninsula of dry land between the Delaware and Schuylkill—a Dutch word meaning hidden river, or, more literally, skulking creek; the Indian name was Manayunk. But
the city spreads south-westward beyond the Schuylkill, over the dike-protected Tinicum lowland (in places 5 ft. below high tide) to Darby and Muckinpalus creeks and extends westward across rising ground from zoo to 200 ft. high, as far as Karakung creek, now, Cobbs. Thus the city is both longer (241- m. from the ex treme south-west on Bow creek to the extreme north-east point of Poquessing creek and Frankford avenue) and broader (r5 m. from Northwestern avenue, and the Schuylkill, Roxborough, to Poquessing creek and Delaware river, Torresdale), than the penin sula, which has three levels—the lowland (Passyunk) section of mud, blue clay and gravels; the elevated section from Spring Garden street to the northern boundary; and the elevated west Philadelphia section to the western boundary.
Sewerage profits by the natural drainage of small valleys and their watersheds, which involve the utilization of many creeks. It comprises (1935) over 2,000 m. of sewers, of which ap proximately one-fourth are main sewers. Diameter measurements of them vary from i to 24 ft. So great is the volume of water in some of these creek-sewers (for instance, the Cohocksink and Mill creek) that costly blow-outs have occurred. A new oval shaped sewer in the bed of Mill creek, big side down, permits a freer flow. Subway building has caused much sewer reconstruc tion and metropolitan development in the old city has necessi tated great changes. Since 191o, two extensive sewerage disposal plants have been built. In the lowlands, sewers are clogged by mud brought in by flood tides. The part of the Schuylkill delta below its lowermost reach is cut into by tidal estuaries, forming numerous islands. In this section (4oth ward), the sewage prob lem presents difficulties. But in 1925 work was begun on the Mingo pumping system, by which the sewerage, drained into a central basin, is pumped at the rate of 1,000,000 gal. daily into the 40th ward disposal plant. Prior to the establishment of the Mingo system there were great numbers of unsewered houses in the 4oth ward. Throughout the city these now are less than ro,000, as against 60,939 on Jan. 1, 1911.