of Plate, 16th–18th Centuries (1883); Greco and Emanuel, Arts of the Goldsmith and Jeweller (1883); I. F Sick, Notice sur les ouvrages en or et argent des rots de Denmark (1884); Julius Lessing, "Der Silber Altar in Rügenwalde," König preuss. Kunstsammlungen Jahrbuch (1885), vi. 58; Gold und Silber (1907); C. Pulsky, E. Radisics and E. Molinier, Chefs-d'oeuvre d'orfèvrerie ayant figuré à l'exposition de Budapest (2 vols., 1886); R. von Kulmer, Handbuch für Gold u. Silberarbeiter u. Juweliere (1887); E. Molinier, "Le Trésor de Saint Marc à Venise," Gaz. des beaux-arts, 2nd series, vols. xxxv., xxxvii, xxxviii., 3rd series, vol i. (1887–1889); Le Trésor de la cathédrale de Coire (1895); Catalogue of Baron Adolphe de Rothschild's collection of Objects of Art (1902); A. Darcel, "Les Collections Spitzer," Gaz. des beaux-arts, 2nd series, xxxviii. 225 (1888); L. Gmelin, Alte Handzeichnungen nach dem verlorenen Kirchenschatz der St-Michaels-Hofkirche zu München (1888); A. Ilg, Kunsthistorisches Hofmuseum, &c. (1891); Arbeiten der Goldschmiede- u. Steinschlifftechnik (1895); Kunsthistorische Sammlungen des allerhöchsten Kaiserhauses: Arbeiten der Goldschmiede- und Steinschlifftechnik (1895); E. Marchal, La Sculpture et les chefs-d'oeuvre de l'orfèvrerie belges (1895); B. Czobor, Les Insignes royaux de Hongrie (1896); W. Froehner, Collections de château de Goluchów l'orfèvrerie (1897); R. Hausmann, Der Silberschatz der St Nickolaikirche zu Reval (1899); Warner Silfersparres nya grafiska aktiebolag (Stockholm, 1900); F. R. Martin, Schwedische königliche Geschenke an russische Zaren, 1647–1699 (1900); Dänische Silberschätze aus der Zeit Christians IV. aufbewahrt in der kaiserlichen Schatzkammer zu Moskau (1900); J. Starkie Gardner, Catalogue of the Collection of Silversmiths' work of European Origin (Burlington Fine Arts Club, 1901); A. Pit, Het goud en zilverwerk in het Nederlandsch Museum, &c. (1901); Kaiserliche Ermitage, St Petersburg, Führer durch die Peter-Gallerie (1901); Illustrated Catalogue of the Waddesdon Bequest, British Museum (1902); H. L. Tilly, The Silver Work of Burma (1902); P. Eudel, L'Orfèvrerie algerienne et tunisienne (1902); H. Barth, Das Geschmiede (1903); H. Wilson, Silverwork and Jewellery (1903); H. P. Mitchell, "A Medieval Silver Chalice from Iceland," Burlington Mag. (1903) ii. 70, 357; E. Ducharne and P. Vialettes, Manuel de l'orfèvre: la garantie du titre des ouvrages d'or et d'argent (1904); W. Stengel, Formalikonographie (Detailaufnahmen) der Gefässe auf den Bildern der Anbetung der Könige (1904); "Le Musée Willet-Holthuysen: l'orfèvrerie et l'argenterie," Art flamand er hollandais (1905), iv. 29; O. M. Dalton, Treasure of the Oxus (1905); H. H. Cunynghame, European Enamels (1906), Rosenberg, Geschichte der Goldschmiedekunst auf technischer Grundlage, Abteilung: Niello (1907); ibid. Abteilung: Aushängebogen (1908); Nelson Dawson, Goldsmiths' and Silversmiths' Work (1907); "Ecclesiastical Goldsmiths' Work in the Coast Towns of Istria and Dalmatia," The Builder, xciii. nos. 3384 and 3385; L. Forrer, Dictionary of Medallists, &c. (in progress), 8 vols.; T. Olrik, Drikkehorn (wassail horns), in progress; Thieme and Becker, Allgemeines Lexikon der bildenden Künstler von der Antike bis zur Gegenwart. (E. A. J.)
PLATEAU, JOSEPH ANTOINE FERDINAND (1801–1883), Belgian physicist, was born at Brussels on the 14th of October 1801, and died on the 15th of September 1883 at Ghent, where he had been professor from 1835. He was a pupil and friend of L. A. J. Quetelet, who had much influence on the early part of his character. The more original investigations of Plateau refer chiefly to portions of one or another of two branches of science—physiological optics and molecular forces. We owe to him the "stroboscopic" method of studying the motion of a vibrating body, by looking at it through equidistant radial slits in a revolving disk. In 1829 he imprudently gazed at the midday sun for twenty seconds, with a view of studying the after effects. The result was blindness for some days, succeeded by a temporary recovery; but for the next fourteen years his sight gradually deteriorated, and in 1843 he became permanently blind. This calamity did not interrupt his scientific activity. Aided by his wife and son, and afterwards by his son-in-law G. L. van der Mensbrugghe, he continued to the end of his life his researches on vision—directing the course of his experiments which they made for him, and interpreting the bearing of the results. He also published a valuable analytical catalogue of all the more important memoirs which had been written, from the earliest times to the end of the 18th century, on his favourite theme of subjective visual phenomena. But even more extraordinary were this blind man's investigations about molecular forces, embracing hundreds of novel experiments whose results he saw only with others' eyes. These form the subject of his great work Statique expérimentale et théorique des liquides soumis aux seules forces moleculaires (2 vols., 1873), a valuable contribution to our knowledge of capillary phenomena. His son, Félix Auguste Joseph Plateau (b. 1841), became professor of zoology and comparative anatomy at Ghent in 1870.
PLATEAU (a French term, older platel, for a flat piece of wood, metal, &c., from plat, flat), in physical geography, an elevated region of level or gently undulating land-surface, the term being synonymous with "table-land." The most clearly defined plateaus have steep flanks in contrast with their level summits, but the term does not necessarily connote a steep ascent from the surrounding country. Indeed, it is applied to such diverse forms as the high-lying plains encircled by the higher elevations of the Andes, and to those of the west of North America, which rise almost imperceptibly from the low central plains. A plateau may have its origin either in the upheaval of strata which preserve their original horizontal position during the process, or in the prolonged denudation of an originally broken surface. The two forms are distinguished respectively as Plateaus of Deposition and Plateaus of Erosion.
PLATED WARE, articles chiefly intended for table use consisting of an inferior metal or alloy covered by one of the precious metals, with the object of giving them the appearance of gold or silver. Before the introduction of electro-plating the method employed for silver-plating (the invention of which in 1742 is associated with the name of Thomas Bolsover, of Sheffield) was to fuse or burn together, by a flux of borax, a thin sheet of silver on each side of an ingot of base metal, generally copper, or German silver, which is an alloy of copper. The silver plates were firmly wired to the ingot, which was then placed in a heated furnace and brought nearly to the fusing point of the silver. The artisan knew the exact moment to withdraw the ingot. When cold it was rolled down to a sheet, and from such sheets "silver-plated" articles were made. Articles like dish-covers were originally only silver-plated on one side, and after being worked into shape were tinned inside with pure tin. In Birmingham bar-copper was the base metal used, when bare of silver this showed blood-red. The Sheffield manufacturers, on the other hand, used shot-copper mixed with brass (an alloy of copper and zinc) in the proportion of 4 or 6 to 1. In this way they got rid of the redness of the copper and rendered it harder, and their product is the "old Sheffield plate" (q.v.) that has become famous all over the world. This method of plating rapidly declined with the introduction of the newer process of electro-plating (q.v.), by which it has been superseded. Plating with nickel is extensively used for bedsteads and other articles of upholstery, and for various parts of bicycles, steamships, railway carriages, &c. Steel sheets are also plated with nickel for cooking purposes, and iron is plated with brass.
PLATEN-HALLERMUND, AUGUST, Graf von (1796-1835), German poet and dramatist, was born on the 24th of October 1796 at Ansbach, the son of the Oberforstmeister in the little principality of that name. The latter, together with other Franconian principalities, having shortly after his birth become incorporated with Bavaria, he entered the school of cadets (Kadettenhaus) in Munich, where he showed early promise of poetical talent. In 1810 he passed into the royal school of pages (königliche Pagerie), and in 1814 was appointed lieutenant in the regiment of Bavarian life-guards. With it he took part in the short campaign in France of 1815, being in bivouac for several months near Mannheim and in the department of the Yonne. He saw no fighting, however, and returned home with his regiment towards the close of the same year. Possessed of an intense desire for study, and finding garrison life distasteful and irksome, he obtained a long leave of absence, and after a tour in Switzerland and the Bavarian Alps, entered the university of Würzburg in 1818 as a student of philosophy and philology. In the following year he migrated to that of Erlangen, where he sat at the feet of F. W. J. von Schelling, and became one of his most enthusiastic admirers. As a result of his Oriental studies he published a little volume of poems—Ghaselen (1821), each consisting of ten to twenty verses, in which he imitates the style of Rückert; Lyrische Blätter (1821); Spiegel der Hasis (1822); Vermischte Schriften (1822); and Neue Ghaselen (1823). These productions attracted the attention of eminent men of letters, among them Goethe, both by reason of their contents, which breathe the spirit of the East, and also of the purity and elegance
