The system of endless changes is one of the most astonishing properties of the Kaleidoscope. With a number of loose objects—pieces of glass, for example,—it is possible to reproduce any figure we have admired, when it is once lost. Centuries may elapse before the same combination returns; if the objects, however, are placed in the cell so as to have very little motion, the same figure may be recalled, and if actually fixed, the same pattern will return in every evolution of the object-plate. A calculation of the number of forms is given upon the ordinary principles of combination; namely, that twenty-four pieces of glass may be combined 13,917,242,888,872,552,999,425,128,493,402,200 times—an operation the performance of which would take hundreds of thousands of millions of years, even upon the supposition that twenty combinations were effected every minute!