COPYING MACHINES. 397 COPYRIGHT. newspaper copy, and telegraph messages. The blackened ])aper is prepared by saturatinf; it with a uiixtiire of lard and lampblack. The iiitiiiifijld irritcr of W'edgewood, invented in ISOO, was on this plan. The first sugj;estion for a copying )iress is said to have been made by Benjamin Franklin, who sanded the yet wet ink of his nuuuiscript with emery and then passed the manuscript between rollers in contact with a soft, highly polished pewter plate. This received the impression from the emery, from which nvnnerons copies could be made by the eopper-plate printing process. In 1780. .Tames 'att adopted the simple plan of copying by pressing transparent, bibidous paper against the damp manuscript, so that the writ- ing would be transferred as on a blotter and then read from the other side. In the pnyiyrofiniph a specially prepared paper is used, tipon which words are written with a common pen. but with a special ink. The sheet is then soaked in water, and the ink corrodes the fabric of the wet paper, leaving open lines in place of the writing. The sheet is then used as a stencil, like that prepared by the electric pen. The mimeotjraph is an apparatus invented by Thomas A. Edison, by which stencils of written pages are obtained for the purpose of producing an indefinite number of copies. It consists of a fine-pointed steel stylus, moving over the sur- face of a sheet of tissue paper, coated on one side with a film of sensitive material. This paper is placed on a plate of steel, known as the base- board, upon which are cut intersecting corruga- tions, numbering 200 to the inch. As the stylus moves over the pa])er it presses it down upon the steel plate, and the fine sharp points puncture the paper from the imder side in the line of the writing. This paper, or stencil - plate, is then fastened into a frame, which stretches it tight and smooth, again placed upon the baseboard with a sheet of paper between, and an ink-roller of peculiar construction is passed over its sur- face, forcing the ink through the perforations upon the paper beneath, thus making a print. The patent for this instrument was applied for in 1878, and there have been numerous improve- ments since, the apparatus being used exten- sively in connection with the typewriter, where the stencil is made by the type bars striking a sheet of paper laid against a piece of gauze. The Blitj-Print Process is peculiarly adapt- ed to the reproduction of drawings and plans. and is used by architects, engineers, and mechan- ics. Two solutions are prepared: the first con- tains one part of citrate of iron in four parts of pure water; the second contains one part of red prussiate of potash in six parts of water. When ready for tise, equal parts of the solutions may be mixed in a shallow dish, and applied to sheets of paper with a sponge or a eamel's-hair brush. Any paper will serve, but that is best which has but little sizing. The solution should be applied and the paper should be dried and kept in the dark. The solutions themselves will keep, sepa- rately, in the dark as long as desired, but if mixed soon begin to deteriorate. The drawing or writing to be copied should be made with very black ink. upon paper or tracing-cloth. A pho- tographer's printing-frame, with a plain glass and a back easily removed, is used in the follow- ing manner: Place the drawing face down tipon the glass; the prepared paper with its face against (he back of the drawing; pnt the mov- able back in place, reverse the frame, and expose to light. In direct sunsliine. two to seven min- utes will be long enongh, the time to be ascer- tained by trial; in diiruse<l light, the exposure must be live to ten times as long, .fter expos- ure the print should be immediately washed in clear water; when the chemicals are removed, the sheet is fastened by its corners to a line to dry, and the surface may afterwards be finished by a hot iron, or by pressure. A little practice is needed to secure the best results, aiul in a good print the lines will be clear white, and the back- ground a deep blue. A light bhu' backgiound indicates a weak .solution, or insnllicient e.X]>os- ure ; over-exposure is shown by a grayish tint. Clear, quick sunshine will give sharper lines than can be obtained by slow, diffused light. The chemical change is evident ; the light causes a reaction between the prussiate of potash and the iron, of which Prussian blue is the product ; this occurs wherever the light has not been inter- cepted by the black lines of the drawing, which therefore appear in white upon an intensely blue and imfading background. Copies may he multiplied at will from negatives on glass or films, from engravings in books, from drawings, or from manuscripts. Black Prints on a white ground may be made in the same general way, by using the proper solution in preparing the paper, and sometimes the process is reversed, COPYRIGHT. The exclusive right of re- producing, by writing, printing, or otherwise, the language and form of a literary or artistic pro- duction, and of publishing and vending the same. In this broad sense the right is wholly modern, being based upon a series of statutes, beginning with 8 Anne, c. 19, in England, and with the first Federal Copyright Act passed by the Con- gress of the United States in 1700. Copyright in published works exists in Eng- land to-dav bv virtue of the Copvright Act of ,"5 and G Vict.', c. 4.5 (1842). With this must, however, be considered the following amend- ments: 1844, international provisions; 1847, Colonial act; 1850. designs and scul])ture: 1852. international and engravings: lSli2. line arts; 1875. international, for dramatic works; 187.5, Canada: 1882, musical compositions: 188fi, in- ternational; 1887. order in council (confinning the Bern convention) ; and 18SS. nuisical com- positions. In the United States, the matter is one for national and not for State regulation, the power "to promote the progress oif science and useful arts by securing for limited times to authors and inventors the exclusive right to their respective writings and discoveries" being vested in Congress by Art. I. Sec. 8 of the Constitution. The only effective restriction which this clause places upon the power of Congress to legislate concerning copyrights is the virtual prohibition of the grant of a perpetual right of this charac- ter. The a|)parent limitation of the power to a copyright for 'writinys' only, has been removed by judicial construction, the term 'writings' hav- ing been held to include maps, charts, music, prints, engravings, drawings, paintings, and photographs, as well as books, written and print- ed articles, and the like. The power to protect the author of a book in the richt to dramatize the same, and the author of a dramatic composi- tion in the right of publicly performing or repre-
