348 Description of the Kaleidophone, 



The first rod is cylindrical, about ].-lOth of an inch in diameter, 

 and is surmounted by a spherical bead * which concentrates and 

 reflects the light which falls upon it. The second is a similar rod, 

 upon the upper extremity of which is placed a plate moving 

 on a joint, so that its plane may be rendered either horizontal, 

 oblique, or perpendicular ; this plate is adapted to the reception 

 of the objects, which consist of beads differently coloured and 

 arranged on pieces of black card in symmetrical forms. The 

 third is a four-sided prismatic rod, and a similar plate is at- 

 tached to its extremity for the reception of the same objects. 

 Another rod is fixed at the centre of the board ; this is bent to 

 a right angle, and is furnished with a bead similarly to the first- 

 mentioned rod. A small nut and screw is fixed to the board 

 near the lower end of the first rod, in order by pressing upon it 

 to render occasionally its rigidity unequal. A hammer, softened 

 by a leather covering, is employed to strike the rods; and a 

 \dolin-bow is necessary to produce some varieties of effect. 



I shall now proceed to describe the different appearances 

 which the rods present when in action, and to give directions 

 for the production of the different effects, following the order in 

 which the rods have been previously mentioned. 



curately observed. According to the different ways by which the wire is 

 put in motion, the form of this path is no less diversified and amusing 

 than the multifarious forms of the quiescent lines of vibrating <plates 

 discovered by Professor Chladni ; and it is, indeed, in one respect even 

 more interesting, as it appears to be more within the reach of mathe- 

 matical calculation to determine it." 



The extremely limited extent of the excursions of a vibrating chord 

 prevents its motions from being distinctly observed by the naked eye, but 

 as the rods employed in the present experiments can extend their excur- 

 sions to nearly two inches, and as the means employed greatly increase 

 the intensity of the light, the phenomena are exhibited in a far more 

 evident manner. 



♦ The only beads well adapted for this purpose are made of extremely 

 thin glass silvered on the interior surface, and about one-sixth of an 

 inch in diameter ; they are to be obtained at the shops under the name of 

 steel beads. The protuberances at the apertures must be removed or 

 blackened, otherwise the reflections from them will render the images 

 confused. To produce the coloured tracks, these beads must be coated 

 with transparent colours, such as are ordinarily used for painting on 

 glass ; the light will then be reflected through the coloured surface ; but 

 in beads made of coloured glass, the reflection being made from the ex- 

 ternal surface, shows only white light. The bead is cemented into a 

 small brass cup screwed to the top of the wire. 



