Democratic Sentinel, Volume 19, Number 35, Rensselaer, Jasper County, 6 September 1895 — AN INTERESTING TOY. [ARTICLE+ILLUSTRATION]

AN INTERESTING TOY.

The Artificial Spectrum Top Perplexes Scientists. Scientists of England have been giving a great deal of serious consideration lately to the study of a mere toy \vjiich they are still unable to explain satisfactorily. It is a top called the “artificial spectrum top,” in which mere tracings of black and white are made to assume colors when in motion. The top as now constructed consists

of a revolving disc, half black and half white. On the white half are short, concentric arcs of black. When the top reVolves close tinder a bright lamp these arcs appear, not as gray lines, as might be expected, but as lines of color. To most eyes the effect is as follows: (1) When the revolution is such that the black line is preceded by the black half of the disc and followed by the remainder of the white, it appears red; (2) when the direction of rotation is reversed it appears blue; (3) when the lines are on the central portion of the white (so as to have equal white immediately on each side) the color is green; (4) intermediate positions give approximately the intermediate colors of the spectrum. A few people see the colors differently, and one or two people, by no means color blind, can see no color at all. Curiously enough, a few people who are somewhat color blind can see the colors on the top very well.

THE MYSTERIOUS TOP.