Page:EB1911 - Volume 23.djvu/758

 intended for the core pass. This core is of such a size that the aggregate number of wires that are mounted in the machine exactly cover it in a spiral direction.

All the wires, including the centre core, are passed through their individual hollow spindles, then led to the nose or head of the machine, and finally passed through a stationary compression block to draw-off wheels. The speed of these wheels is regulated in proportion to the speed of the machine by means of suitable gearing. During the revolutions of the machine each bobbin and fork is kept in a vertical position, and floats thus, by means of an eccentric ring behind the back disk. This ring is connected to the spindles of the bobbin forks by means of small cranks, thus preventing any torsional movement that would otherwise be imparted to the individual wires.

Each bobbin is controlled by a brake which acts as a pensioning device so that equal strain can be applied to each, allowing the wires to unwind uniformly. The finished strands are wound in turn upon large bobbins, and mounted in the flyers or disks of the rope closing machine. These machines are similar in design to the stranding machine, but are naturally much heavier in construction, and, therefore revolve at a proportionate speed. The speed of the machines varies according to the weight of material, the size of the strands and the construction of the finished rope. The modern machine, or the type most generally used, makes about fifty revolutions per minute, whilst three times this speed is often obtained when spinning the strands.

The rapid strides made by electricity have furnished another large branch of what may be termed wire rope manufacture. The ropes used for electrical purposes are almost invariably termed cables, and there are many different kinds and sizes of them. The wire must necessarily possess good conducting power, and be comparatively cheap. Up to the present copper has proved to be the chief material possessing these two important properties in combination; hence it is the metal par excellence for electrical conduction. Aluminium and alloys have been tried with varying degrees of success.

The conductor itself consists of a strand of soft copper wires, around which the dielectric or non-conducting material is placed. The methods of forming the strands do not differ essentially from those described above. The dielectric is usually paper, spun jute fibre, vulcanized india-rubber or vulcanized bitumen. If the first two dielectrics are used, a lead sheath is necessary to enclose the insulated strand and so exclude moisture; if the cable is likely to (get damaged, it is further enclosed by steel tapes or steel wires, an finally covered with yarn or braid. Vulcanized bitumen is not only a dielectric, but is also absolutely impervious to moisture. Hence in many instances where paper or fibre is employed as the principal dielectric, a sheath of vulcanized bitumen is used instead of lead to exclude moisture. Cables are also made with a single central stand of copper wires in addition to one or more concentric layers of copper wires, the layers being separated by some dielectric material; or there may be two or more strands, separately insulated, and more or less elaborately clothed with the above-mentioned substances.

ROPES, JOHN CODMAN (1836–1899), American military historian and lawyer, was born at St Petersburg on the 28th of April 1836, the son of a leading merchant of Boston who was engaged in business in Russia. At the age of fourteen, his family having meantime returned to Massachusetts, he developed an affection of the spine which eventually became a permanent deformity. His courage and energy, however, did not allow him to yield to his affliction. He entered Harvard in 1853, and graduated in 1857. His interests as a young man were chiefly religious, legal and historical, and these remained with him throughout life, his career as a lawyer being conspicuous and successful. But it was the outbreak of the Civil War in 1861 which fixed his attention principally on military history. He ceaselessly assisted with business and personal help and friendship the officers and men of the 20th Massachusetts regiment, in which his brother, Henry Ropes, served up to his death at Gettysburg, and after the war he devoted himself to the collection and elucidation of all obtainable evidence as to its incidents and events. In this work his clear and unprejudiced legal mind enabled him to sift the truth from the innumerable public and private controversies, and the ill-informed allotment of praise and blame by the popular historians and biographers. The focus of his work was the Military Historical Society of Massachusetts, which he founded in 1876. The work of this society was the collection and discussion of evidence relating to the great conflict. Although practically every member of this society except himself had fought through the war, and many, such as Hancock and W. F. Smith, were general officers of great distinction, it was from first to last maintained and guided by Ropes, who presented to it his military library and his collection of prints and medals. He died at Boston on the 28th of October 1899. His principal work is an unfinished Story of the Civil War, to which he devoted most of his later years; this covers the years 1861–62. The Army under Pope is a detailed narration of the Virginia campaign of August-September 1862, which played a great part in reversing contemporary judgment on the events of those operations, notably as regards the unjustly-condemned General Fitz John Porter. Outside America, Ropes is known chiefly as the author of The Campaign of Waterloo, which is one of the standard works on the subject.

The greater part of his studies of the Civil War appears in the Military Historical Society’s publications. Papers on the Waterloo cam aign appeared in the Atlantic Monthly of June 1881, and in Scribner’s Magazine of March and April 1888. Amongst his miscellaneous works is a paper on “The Likenesses of Julius Caesar” in Scribner’s Magazine (February 1887).

See Memoir of John Codman Ropes (Boston, privately printed. 1901).

ROPE-WALKING, the art of walking, dancing and performing tricks of equilibrium on a rope or wire stretched between two supports. It has been popular with most Asiatic and European peoples from the beginning of history. Before the middle of the 19th century a rope was invariably used, and was stretched as tightly as possible, on which account the art was called Tight-rope Walking. About the year 1875 the slack wire, stretched loosely from support to support, was introduced, and is now more commonly used. The performer is often aided in keeping his balance by a Chinese umbrella or a long pole.

ROPS, FÉLICIEN (1833–1898), Belgian painter, designer and engraver, was born at Namur, in Belgium, on the 7th of July 1853; he spent his childhood in that town, and afterwards in Brussels, where he composed in 1856, for his friends at the university, the Almanach Crocodilien, his first piece of work. He also brought out two Salons Illustrés, and collaborated on the Crocodile, a magazine produced by the students. The humour shown in his contributions attracted the attention of publishers, who offered him work. He designed, among other things, frontispieces for Poulet-Malassis, and afterwards for Gay and Doucé. In 1859 he began to contribute to a satirical journal in Brussels called Uylenspiegel, a sort of Charivari. The issue, limited unfortunately to two years, included his finest lithographs. About 1862 he went to Paris and worked at Jacquemart’s. He subsequently returned to Brussels, where he founded the short-lived International Society of Etchers. In 1865 he brought out his famous “Buveuse d’Absinthe,” which placed him in the foremost rank of Belgian engravers; and in 1871 the “Dame au Pantin.” After 1874 Rops resided in Paris. His talent, which commanded attention by its novel methods of expression, and had been stimulated by travels in Hungary, Holland and Norway, whence he brought back characteristic sketches, now took a soaring flight. To say nothing of the six hundred original engravings enumerated in Ramiro’s Catalogue of Rops’ Engraved Work (Paris, Conquet, 1887), and one hundred and eighty from lithographs (Ramiro’s Catalogue of Rops’ Lithographs, Paris, Conquet, 1891), besides a large number of oil-paintings in the manner of Courbet, and of pencil or pen-and-ink drawings, he executed several very remarkable water-colour pictures, among which are “Le Scandale,” 1876; “Une Attrapade,” 1877 (now in the Brussels Museum); a “Tentation de St Antoine,” 1878; and “Pornocrates,” 1878. Most of these have been engraved and printed in colours by Bertrand. From 1880 to 1890 he devoted himself principally to illustrating books: Les Rimes de joie, by Théo Hannon; Le Vice suprême and Curieuse, by J. Péladan; and Les Diaboliques, by Barbey d’Aurévilly; L’Amante du Christ, by R. Darzens; and Zadig, by Voltaire; and the poems of Stéphane Mallarmé have frontispieces due to his fertile and powerful imagination. Before this he had illustrated the Légendes Flamandes, by Ch. Decoster; Jeune France, by Th. Gautier;