Page:EB1911 - Volume 21.djvu/614

Rh Italy, bounded N. by Switzerland, W. by France, S. by Liguria had been deemed sufficient when the roof was of timber only, and E. by Lombardy. Physically it may be briefly described as the upper gathering-ground and valley of the river Po, enclosed on all sides except towards the Lombard plain by the vast semicircle of the Pennine, Graian, Cottian, Maritime and Ligurian Alps. In 1859 it was divided into the four provinces of Alessandria, Cuneo, Novara and Torino (Turin). It has an area of 11,340 sq. m. The people are chiefly engaged in agriculture—growing wheat, maize and rice, chestnuts, wine and hemp, in the reeling and throwing of silk and in the manufact1ire of cotton, woollens and clothing, there are also considerable manufactures at Turin, Savigliano, &c. The Piedmontese dialect has been rather strongly influenced by French. The ch1ef towns in the several provinces are as follows, with their communal populations in 1901: Alessandria (72,109), Asti (39,251), Casale Monferrato (31,370), Novi Ligure (17,868), Tortona (17,419), Acqui (13,940), Valenza (10,956), Ovada (10,284), total of province 825,745, number of communes 343; Cuneo (26,879), Mondovi (18,982), Fossano (18,175), Savigliano (17,340), Saluzzo (16,028), Bra (15,821), Alba (13,637), Boves (10,137); total of province 670,504, number of communes 263, Novara (44,249), Vercelli (30,470), Biella (19,267) Trino (12,138), Borgomanero (10,131), total of province 763,830; number of sommunes, 437; Turin (329,691), Pinerolo (18,039), Carmagnola (11,721), Ivrea (11,696), Moncalieri (11,467); total of province 1,147,414; number of communes, 442. The total population of Piedmont was 2,738,814 in 1859, and in 1901 3,407,493. The large number of communes is noticeable, as in Lombardy, and points to a village life which, owing to greater insecurity and the character of the country, is not to be found in central and southern Italy as a whole There are numerous summer resorts in the Alpine valleys. The chief railway centres are Turin, communicating with the Mont Cenis line, and with the Riviera by the railway over the Col di Tenda (in process of construction), Novara, Vercelli, Asti, Alessandria, Novi. The communications with Liguria are difficult owing to the approach of the mountains to the coast, and the existing lines from Genoa to Turin and Milan are hardly sufficient to cope with the traffic.

Piedmont in Roman times until 49 B.C. formed a part of Gallia Transpadana, and in Augustus' division of Italy formed with what was later known as Lombardy the 11th region. It formed part of the Lombard kingdom, and it was not till about A.D. 1000 that the (q.v.) arose. The subsequent history of Piedmont is that of its dynasty.

PIENZA, a town of Tuscany, Italy, in the province of Siena, 9 m. west of the town of Montepulciano by road, 1611 ft. above sea-level. Pop. (1901), 2730 (town); 3836 (commune). The place was originally called Corsignano and owes its present name to (q.v.) who was born here in 1405. The buildings which he caused to be erected by Bernardo Rossellino in 1460–1463 form a noble group of early Renaissance architecture round the Piazza del Duomo. The latter retains Gothic details in the interior, but the façade is simple Renaissance work. The other three sides are occupied by the episcopal and municipal palaces, and the Palazzo Piccolomini, the last, resembling the Palazzo Rucellai at Florence, is the finest, and in front of it is a beautiful fountain. The episcopal palace contains a museum with some fine ecclesiastical vestments, enamels and other works of art.

PIER (older forms per or pere, from Med. Lat. pera; the word is of obscure origin, and the connexion with Fr. pierre, Lat. petra, stone, is doubtful; equivalents are Fr. piedroit, pilier, trumeau; Ital. pila, Ger. Pfeiler), the term given in architecture to a vertical support in masonry or brickwork, usually rectangular on plan, which carries an arch or superstructure. The term is also sometimes given to the great circular columns which in some English cathedrals and churches carry the nave arches. In early Christian churches, when antique columns, such as abounded in Rome, were not procurable, square piers took the place of columns and sometimes alternated with them. The introduction of vaulting, however, in the 11th century, necessitated a support of much greater dimensions than those which and led to the development of the compound or clustered pier. To give extra support to the subordinate arches of the nave arcade, semicircular shafts or pilasters were added, carried up to the transverse and diagonal ribs of the main vault. In Romanesque work the pier was generally square on plan with semicircular shafts attached, the angles of the pier being worked with smaller shafts. As the rings or orders of the nave arches increased in number, additional shafts were added to carry tnem, and the pilaster facing the nave had central and side shafts rising to carry the transverse and diagonal r1bs of the vault, this development of the compound pier obtains throughout Europe in all vaulted structures. In the Early English period the piers become loftier and lighter, and in most important buildings a series of clustered columns, frequently of marble, are placed side by side, sometimes set at intervals round a circular centre, and sometimes almost touching each other. These shafts are often wholly detached from the central pier, though grouped found it, in which case they are almost always of Purbeck or Bethersden marbles. In Decorated work the shafts on plan are very often placed round a square set angle-wise, or a lozenge, the long way down the nave; the centre or core itself is often worked into hollows or other mouldings, to show between the shafts, and to form part of the composition. In this and the latter part of the previous style there is generally a fillet on the outer part of the shaft, forming what has been called a (q.v.). They are also often tied together by bands, formed of rings of stone and sometimes of metal. About this period, too, these intermediate mouldings run up into and form part of the arch moulds, there being no impost. This arrangement became much more frequent in the Perpendicular period; in fact it was almost universal, the commonest section being a lozenge set with the long side from the nave to the aisle, and not towards the other arches, as in the Decorated period, with four shafts at the angles, between which were shallow mouldings, one of which was in general a wide hollow, sometimes with wave moulds. The small columns at the jambs of doors and windows, and in arcades, and also those attached to piers or standing detached, are generally called (q.v.).

The term pier is sometimes applied to the solid parts of a wall between windows or voids, and also to the isolated masses of brickwork or masonry to which gates are hung.

Piers of Bridges.—The piers of bridges and viaducts on land are constructed of masonry or brickwork and occasionally, in the case of high piers, of open braced ironwork, as exemplified by the old Crumlin viaduct in Wales and the Pecos viaduct in Texas. These piers, besides being proportioned in cross-section to the weight they have to support, are widened out at their base, so as to distribute the load over a sufficient area for it to be borne by the stratum on which it rests without risk of settlement. Special provisions have to be made for the foundations of piers where the ground is soft for some depth, or loose water-bearing strata are encotmtered, and especially where the piers of large bridges crossing rivers have to be constructed under water. In soft ground, bearing piles driven down to a firm stratum, and surmounted by a planked floor or a layer of concrete, provide a convenient foundation for a pier; and in places where timber is abundant, wooden cribs filled with rubble stone or concrete have been used in the United States for raising the foundations for piers out of water. For river piers, where a firm, watertight stratum is found at a moderate depth below the river-bed, the site is often enclosed within a coffer-dam or a plate iron caisson carried down into the stratum and raised out of water, and then, after the water has been pumped out and the surface layers removed, the pier is readily built within the enclosure in the open air. When, however, a river-bed consists of silt, sand or other soft materials extending down to a considerable depth, brickwork wells are gradually sunk to a firm stratum by removing the material within them with grabs, and on them the piers are built out of water; or bottomless caissons are carried down by excavating their interiors under compressed air, and the piers are built on top of them within a plate-iron enclosure, a system