CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 



155 



No. 3050. 



No. 3050A, 



3050. COLORIMETER, Hess-Ives Tint Photometer, for comparing different shades and hues of light 



colored materials or liquids with each other and with fixed standards. The instrument is used 

 like a telescope, presenting to the eye a circular field with vertical hairline central division, one 

 side of which is filled with light passing through a slit directly from a standard white magnesia 

 block, while the other is filled with light passing through a slit from the sample whose color is 

 to be evaluated. The slits are adjustable in width, and are provided with graduated scales 

 from which a direct comparison of the degree of whiteness of two samples may be read. The 

 light coming from the slits is thoroughly mixed and spread across the half fields by means of a 

 patented revolving optical mixing wheel inserted between the slits and the field lens. 



Comparisons of colors may be made just as readily by making successive measurements through 

 three color screens, pure red, green and blue-violet. The instrument eliminates entirely the per- 

 sonal equation and offers a fixed standard of color measurements which may readily be 

 reproduced. 



This instrument is especially adapted for use with oils, paper, flour, sugar, soaps, pigments, etc. 

 Complete as described with motor for operating optical mixing wheel, on adjustable supports $175.00 



3050A. CABINET for Xo. 3050, constructed of hardwood, nicely finished and provided with drawers and 

 cabinets for the storage of accessories. This cabinet provides a convenient and portable dark 

 room for color measurements 60.00 



3051. DAYLIGHT LAMPS for use with Xo. 3050, providing a definite and constant illumination. 



No A B 



For volts 110 220 



Each . 20.00 20.00 



