PRINCIPATO ULTERIORE mineral springs. The province is divided into the districts of Salerno, Campagna, Vallo della Lucania, and Sala Consilina. Capital, Salerno. PRINCIPATO ULTERIORE, or Avellino, a prov- ince of S. Italy, in Campania, bordering on Benevento, Foggia, Basilicata, Principato Cite- riore, and Terra di Lavoro ; area, 1,409 sq. m.; pop. in 1872, 375,691. It is traversed by lofty ridges of the Apennines, and watered by the Ofanto and several tributaries of the Volturno. Near Ariano are marble quarries. There is fine pasturage, wine and olives are produced in fair quantities, and the produc- tions generally suffice for local consumption. The province is divided into the districts of Avellino, Ariano, and Sant' Angelo de' Lom- bardi, corresponding to three natural divisions formed by the Apennines. Capital, Avellino. PRINGLE, Thomas, a Scottish author, born at Blaiklaw, Teviotdale, Jan. 5, 1789, died Dec. 5, 1834. He graduated at the university of Edinburgh, and became clerk to the commis- sioners on the public records of Scotland, which post he held till 1817, when he com- menced the " Edinburgh Monthly Magazine," which was the germ of " Black wood's Maga- zine." At the same time he was editor of the "Edinburgh Star" newspaper, and joint editor of "Constable's Magazine." He soon quarrelled with Blackwood, and, his other publications being unprofitable, went out to the Cape of Good Hope in 1820, and became government librarian at Cape Town. He es- tablished a private academy, founded the " South African Journal," and edited the " South African Commercial Advertiser," both of which were discontinued in consequence of the censorship of the colonial governor. He returned to Great Britain in 1826, and became secretary to the anti-slavery society. His " Nar- rative of a Residence in South Africa" ap- peared in 1835. A collection of his poems was published by Leitch Ritchie (1838). PRINGSHEIM, Nathanael, a German botanist, of Jewish parentage, born near Landsberg, Silesia, Nov. 30, 1823. He studied in several German universities and in Paris, went to Ber- lin in 1851, and in 1857 commenced the pub- lication of the Jahrbudier fur wissenschaftliche Botanilc, which he still edits (1875). He was professor of botany at Jena from 1864 to 1868. He has chiefly distinguished himself by his minute researches into the anatomy and phys- iology of cryptogamous plants, demonstrating the presence of antheridia or male organs in various algae, and establishing the fact of a true bisexual reproduction in several genera. Accounts of some of these discoveries are con- tained in his work Ueber die BefrucJitung und Keimung der Algen und das Wesen des Zeu- gungsactes (1855). Among his other works are : G-rundlinien einer Theorie der Pflanzen- zelle (Berlin, 1854) ; Beitrdge zur Morphologie der Meeresalgen (1862) ; and Ueber den^ Gang der morpJiologiscJien Differenzirung in der SpJiacelarien-Reihe (1873). 684 VOL. xin. 54 PRINTING 845 PRINTING (abbreviated from imprinting, from Lat. imprimere, to press in or on), the art of producing in a pigment reversed copies of characters engraved upon types, stamps, or plates. The essential feature is that the copy is produced in some color by means of pressure. Printing is applied to various ornamental pur- poses, such as the production of calicoes, tech- nically called " prints," wall paper, and some kinds of carpets (see CALICO PBINTING, CAB- PET, and PAPEE HANGINGS), but more espe- cially to the production of books and engra- vings. There are three methods of printing : 1, lithography, in which the lines and char- acters are drawn upon stone with a kind of oily ink or crayon, to which printers' ink will adhere while it is repelled from the moistened surface of the stone, and is transferred by the pressure of a roller or scraper to the pa- per (see LITHOGEAPHY) ; 2, copperplate print- ing, in which the lines and characters are cut into a plate, which being filled with ink, and the surface of the plate wiped clean, the color is taken up on the paper, also by the pressure of a roller (see ENGEAVING) ; 3, letterpress printing or typography, which alone will be treated in this article, in which the characters, whether upon separate types or on a plate, are raised above the surface, or rather all except the characters is cut away, leaving them stand- ing in relief. Printing was probably practised by the Chinese as early as the 6th century, but does not appear to have come into general use until the 10th. In 932 two ministers of the emperor presented a memorial that the " Nine Classics," which had hitherto existed only in manuscripts, should be revised and printed; this was done, and in about 20 years copies were in circulation ; and by the end of the 13th century most of the literature of former ages had been printed. Since that time the printed literature has become very voluminous, single collections often containing several thousand volumes. In the original Chinese method, which is still the most usual, a written sheet of paper is laid face downward upon a board of hard wood, to the smooth surface of which the ink is transferred, and then all except the inked lines is cut away, as in our process of wood engraving, leaving the letters, or rather words, in relief. The Chinese characters are composed mainly of a combination of simple lines, usually straight or slightly curved or hooked, which greatly facilitates the process of cutting. Each plate forms a page. In printing from this page the workman applies the ink with a soft brush, then lays the sheet of paper upon the plate, and passes another soft brush over<the back, thus giving the im- pression. Usually only one side of the sheet is printed, the other being left blank. Two pages are commonly printed at once, divided by a line down the middle, upon which line they are folded back to back, and fastened together so that the folded edge is in front, the single edges being included in the binding.
