Page:The American Cyclopædia (1879) Volume IX.djvu/755

 KALEIDOSCOPE KALIDASA 735 orable conditions which he had accorded at Mentz, and was made field marshal. In the same year he concluded a truce with Berthier at Tilsit, preliminary to the treaty of peace which he and Goltz negotiated in July with Talleyrand. In 1810 he became governor of Berlin, which office he resumed in 1814, after having been governor of Breslau. His son, Count FRIEDRICH, published in 1825 Drama- tische Dichtungen ; and a nephew of the latter, Count STANISLAUS (born Dec. 25, 1820), be- came a landscape painter and director of the school of art at Weimar. KALEIDOSCOPE (Gr: mzJWr, beautiful, rWoc, a form, and axoireiv, to see), an optical instru- ment for multiplying the reflected images of small colored objects, producing by the sym- metry of their arrangement patterns of great beauty. An instrument on this principle was originally described by Battista della Porta and Kircher ; and in a work by R. Bradley, pub- lished in 1717, entitled "New Improvement of Planting and Gardening," it was recommended for aiding in the production of designs for garden plots and fortifications. Its true prin- ciples were first developed, however, by Sir David Brewster, who devised the proper method of its construction, and in 1817 took out a patent for it. When two oblong mirrors of the same dimensions are placed so as to hinge together along an edge of each, their reflecting surfaces facing each other, and are then opened, so as to make an angle which is an aliquot part of 180, an object placed between the planes of the mirrors, or in contact with one of the extremities of the pair, is reflected from one mirror to the other, and produces as many images as the angle of the opening is contained in 360. These images are arranged in sym- metrical order around a circular area, the ra- dius of which is the width of the mirror, and the centre the point of meeting in the two planes. The perfect symmetry of their ar- rangement depends on the angle of the open- ing being an aliquot part of two right angles, and that usually employed is either 18 or 20. Another requisite is, that the line of junction of the two mirrors should be fine and smooth, as any irregularities would produce imperfec- tions. As usually constructed, the mirrors are strips of glass blackened on one side. They are kept together by a piece of cloth glued over the edges in contact, and the proper an- gle is preserved by securing them in a tube of suitable shape. The open side of the triangu- lar prism formed by the two mirrors is closed by a strip of black velvet of suitable width glued to the backs of the two mirrors. The cylindrical tube is of the diameter of the larger end of the prism, and the angle formed by the meeting of the two planes at the other extrem- ity is nearly coincident with the centre of the circular end of the tube. Through the cover of this a small aperture is made exactly in the angle, to which the eye is to be applied in using the instrument. At the other extremity a 400 VOL. ix. 47 plain disk of thin transparent glass is fitted close to the ends of the mirrors, and outside of this is another disk, the two kept apart by a ring set in between them. In the intervening space the objects to be reflected are placed. These may be small fragments of colored transparent glass intermixed with a variety of other small bright objects. But care must be taken not to fill the case too full for the objects to move freely among themselves while the tube is made to turn in the hand upon its axis. By looking into the circular aperture made for the eye, the most gorgeous figures are perceived sym- metrically arranged, and all forming one com- plete pattern. Kaleidoscopes are also made with three, four, five, or more mirrors, and are then termed polycentral. To produce symme- try and regularity of form in the images of these kaleidoscopes, the angles which the mir- rors make with each other must necessarily be aliquot parts of 180; and as their number is increased, the range of the instrument in the variation of these angles is diminished. Thus three mirrors only should be arranged to make the three angles of 60 each, or two of 45 each and one of 90, or one of 30, one of 60, and one of 90. By the first arrangement, the images appear in groups of three repeated throughout the pattern. This instrument is called the triascope. By the second arrange- ment, the instrument, called the tetraserope, produces a pattern divided into square com- partments. By the third arrangement, the pat- tern, of hexagonal form, presents a remarkable symmetry, and the instrument is termed a hex- ascope. The last two forms are especially useful to the draughtsman. h U.t.ltnis. Demetrius, a Greek soldier, born in Candia about 1803, died in Athens, April 24, 1867. He was educated in Russia, distin- guished himself in the war of Grecian inde- pendence, was one of the promoters of the revolutionary movement of 1843, into which he entered as a partisan of Russia, and subse- quently became general and adjutant of King Otho, but resigned in 1845. In London he became acquainted with Louis Napoleon, which led to his being appointed Greek ambassador at Paris in 1861, after having in the interval acted for some time as minister of war. KALGAN, or Cliangklakan, a town of China, in the province of Chihli, 110 m. N. W. of Pe- king, renowned as a commercial station be- tween Russia and China, and as one of the great market towns of the empire. It extends several miles along the W. bank of a tributary of the Yangho, the stream breaking through a narrow gorge and forming a natural outlet for the highway of N. Asia. Remains of a gate of the great wall are visible on either side of the gorge, and the scenery is fine. KALEVALA, the national epic of Finland. See FINLAND, vol. vii., p. 203. KALIDASA, an Indian poet, who, according to tradition, lived at the court of King Vikrama- ditya, in the 1st century B. 0. He was one