In applying the compound Kaleidoscope to distant objects, the cell is removed and the lens substituted in its place. The instrument is then directed to the objects, and the tube =A B= drawn out till the inverted images of the objects are seen perfectly distinct, or in focus, and the pattern consequently perfectly symmetrical. When this is done, the pattern is varied, both by turning the instrument round its axis, and by moving it in any direction over the object to which it is pointed. When the object is about four inches from the lens, the tube requires to be pulled out as far as possible, and for greater distances it must be pushed in. The points suited to different distances can easily be determined by experiment, and marked on the inner tube, if it should be found convenient. In most of the instruments there is, near the middle of the tube =A B=, a mark which is nearly suited to all distances beyond _three feet_. The object-plates held in the hand, or the mirror-box placed upon a table, at a distance greater than five or six inches, may be also used when the lens =L= is in the tube. The furniture of a room, books and papers lying on a table, pictures on the wall, a blazing fire, the moving branches and foliage of trees and shrubs, bunches of flowers, horses and cattle in a park, carriages in motion, the currents of a river, waterfalls, moving insects, the sun shining through clouds or trees, and, in short, every object in nature may be introduced by the aid of the lens into the figures created by the instrument. The patterns which are thus presented to the eye are essentially different from those exhibited by the simple Kaleidoscope. Here the objects are independent of the observer, and all their movements are represented with the most singular effect in the symmetrical picture, which is as much superior to what is given by the simple instrument, as the sight of living or moving objects is superior to an imperfect portrait of them. When the flame of a blazing fire is the object, the Kaleidoscope creates from it the most magical fireworks, in which the currents of flame which compose the picture can be turned into every possible direction. In order to mark with accuracy the points on the tube =A B=, suited to different distances, the instrument should be directed to a straight line, inclined like _m n_, Fig. 3, to the line bisecting the angular aperture =A O B=, and brought nearer to the centre =O= of the field. The perfect junction of the reflected images of the line at the points _mʹ nʹ_, &c., so as to form a star, or a polygon with salient and re-entering angles, will indicate with great nicety, that the tube has been pulled out the proper length for the given distance. In this way, a scale for different distances, and scales for different lenses, may be marked on the tube.