90 



EECEEATIVE SCIENCE. 



colours unmixed, though in close proximity. 

 As soon as the machinery is again set in 

 motion, look at that fly-wheel. The zigzags 

 have vanished; there is not a line of blue or 

 white about it, but it is painted of a uniform 

 gray colour ! Ko ; it is as you left it, in zig- 

 zags of two colours, but by its rapid action 

 the eye fails to detect them, and sees the 

 two as one, and the only point of interest 

 about it that we need now mention is, that 

 the change has taken place in the organs of 

 vision, not in the painting of the wheel. 



Chevreid has analyzed the laws of colour 

 with a view to point out how harmonics and 



motion as an agency powerfully operative in 

 effecting such modifications. 



The Kaleidoscopic Colour-top, is intended 

 for the express purpose of effecting changes 

 in colour by motion, and promises to become 

 most instructive to the artist and the philo- 

 sopher, as well as a source of high gratifica- 

 tion as a toy for the family circle. 



What is the colour-top P Strictly it is 

 but a coloured card made to revolve horizon- 

 tally on a vertical axis ; or rather, the card 

 is an addendum to the simple apparatus whose 

 business it is to spin when desired, and the 

 card plays the part of the fly-wheel we just 



contrasts are best produced, and iu effecting 

 his object he has taken occasion to explain 

 how colours reciprocally act on each other, 

 so as to heighten, diminish, or otherwise 

 alter the proper effects of each when 

 variously brought into juxtaposition. In 

 this case, too, the changes take place in the 

 sense of vision, not in the colours them- 

 selves. But Chevreul's experiments with 

 strips of coloured paper, instructive as they 

 are, do not induct us very far into the mysfce- 

 cious region of blended colours and harmo- 

 nized tints, and we mxist have recourse to 



now instanced as an example of distinct 

 colours blended into one, different from either 

 of its components, by rapid rotation. 



This is a mere elementary hint of what the 

 colour- top is capable of in regard to blending 

 of hues and colours. In the hands of the 

 man of science it is an instrument of won- 

 derful power, and, like a magician's shuttle, 

 weaves as it were the rainbow itself into pat- 

 terns of endless variety, in which form as 

 well as colour plays its part in the produc- 

 tion of extraordinary appearances. 



In a description published in the pages 



