NATURAL PHILOSOPHY. 147 



which explanation, it is hoped that we shall hear no more scandals about 

 this much abused Saurian. 







CHROMEIDOSCOPE. 



Under this name a new form of kaleidoscope has recently been brought 

 out in England. The objects viewed, instead of being bits of colored glass, 

 etc., are patches of floss silk of various colors, arranged on a spindle, capa- 

 ble of being drawn in and out, and rotated, so as to make endless changes. 

 The effect is very pretty, and, as any figure can be reproduced and kept sta- 

 tionary, the instrument is likely to be of use to designers for manufactured 

 goods, as well as forming a pleasing optical toy. 



THE DEBUSSCOPE. 



This name has been given to a recent French invention, which consists of 

 two silvered plates, highly polished and of great reflective power, placed 

 together in a frame-work of cardboard or wood, at an angle of seventy 

 degrees. On being placed before a small picture, a design of any kind, no 

 matter how rough, or whether good or bad, the debusscope will reflect the 

 portion immediately under the eye, on all sides, forming the most beautiful 

 designs ; and, by being slowly moved over the picture, will form new designs 

 to any extent. The instrument gives the design in such a manner that it 

 can be made stationary at pleasure, until copied. It is, therefore, an inex- 

 haustible treasure to draughtsmen and others. Setting aside the utility of 

 the debusscope altogether, it can be made the means of gratification in the 

 drawing-room, and, doubtless, will soon assume its proper place along with 

 the microscope and stereoscope, as a source of amusement. 



LOSS OF LIGHT BY GLASS SHADES. 



A correspondent (W. King) of the London Journal of Gas-lighting gives 

 the following table, made up from a series of experiments, of the amount of 

 light lost by various shades : 



Description of shade. Loss of light 



Clear glass, .... . 10.67 per cent. 



Ground glass (entire surface ground), . 29.48 



Smooth opal, . . . 52.83 



Ground opal, 55.85 



Ground opal, ornamented with painted \ 



figures, the figures intervening between I 73.98 



the burner and the photometer screen, ) 



As the large amount of light lost by the use of a clear glass shade excited 

 some surprise, a sheet of common window glass was placed between the 

 burner and the photometer screen, when it was found that 9.34 per 

 cent of the light was intercepted, thus confirming the result obtained by 

 the employment of a shade of clear glass. The shades were selected from a 

 large number, and great pains taken to obtain an average specimen of each 

 kind. 



The result of a series of comparative experiments on the same subject 



