Fig. 48.
The most complicated combinations of three reflectors is represented in [Fig. 48]. In the first combination, all the angles were equal; in the second, two of the angles only were equal; but in the present combination, none of them are equal. The field of view, represented in the figure by D E H L M P, is a truncated rhomb, consisting of no fewer than thirty-one images of the aperture A O B. The figure is composed of two hexagons D E F B R C, R B K L M N, every division of the hexagon consisting of two reflected images, and of two rhombs C R N P, F B K H, each of which is composed of four reflected images.
In this combination, as in the last, the equally luminous sectors are not symmetrically arranged round the centre O of the figure. In the rhomb C R N P, for example, the four images are formed by three, four, and five reflexions; whereas in the corresponding rhomb F H K B, they are formed by two, three, and four reflexions. The effects produced by a Kaleidoscope constructed in this manner are very beautiful, particularly when the reflectors are metallic. In the four figures which represent the different combinations of the reflectors, the small figures indicate the number of reflexions by which each image is produced.
CHAPTER XIV.
ON KALEIDOSCOPES IN WHICH THE EFFECT IS
PRODUCED BY TOTAL REFLEXION FROM THE
INTERIOR SURFACES OF TRANSPARENT SOLIDS.
When light is incident upon the most perfectly polished metals, a very considerable quantity of it is absorbed, and even when the reflexion is made at the greatest obliquities, there is a very manifest difference in the intensity of the direct and the reflected pencil. In the total reflexion of light from the second surfaces of transparent bodies, the loss of light is very inconsiderable, and the reflexion is made with a degree of brilliancy far surpassing that of the most resplendent metals.
Fig. 49.
