Xo. 53629. 



Optics. 



465 



53 624 A. 



53 624 B. 



53 624 C. 



/.: /X, 



53626. 1:11. 



53 629. 1 : 2. 



Optics. 



Propagation and Intensity of Light. 



53.624. 1 Photometer Screen, Fig. A; 1 white screen with centimetre net, 1 screen with 

 square centre-piece cut away, Fig. B ; 1 screen with 5 diaphragms for inserting, Fig. C; 

 2 dull white screens, of metal, with eyes for hanging and with 3 stands (M. T., p. 167 

 and Fig. 121) . 



51,028. Projection Screen with Stand for raising and lowering (M. T., Fig. 122) 



53.625. Sal-ammoniac Vapour Apparatus (M. T., Fig. 123) 





53.626. Apparatus for Demonstrating the Rectilinear Propagation of Light, Figure (W. 

 D., Fig. 260 [246]) 



The apparatus consists of a paper screen on metal stand, a large pasteboard diaphragm screen, 

 and a stand (see above figure) with three small paraffin lamps, arranged triangularly. 



Measurement of the Velocity of Light after Fizeau and Foucault. Cf. Auxiliary Apparatus 

 to Rosenberg's Universal Optical Apparatus No. 53,866. 



53.627. Apparatus after Grimsehl for Determining the Ratio of the Velocity of Light in Air 

 and Water (Phys. Ztschr. 7, 1906, p. 472, Fig. 1) 



53.628. - - idem, for air and glass (Phys. Ztschr. 7, 1906, p. 473, Fig. 2) 



53.629. Light -Angle -Measurer after Weber, Figure, for determining the luminosity 

 of places (Ztschr. fiir Instrumentenkunde 4, 1884, p. 343), can be folded up .... 



This apparatus is used for measuring the angle from which the open sky is visible from the place 

 being investigated, and the angle of elevation at which the light falls upon the place. 



s. d. 



3. 0.0 

 0.16.0 

 0. 3.0 



0. 16. 



2. 5. 

 1.16.0 



4. 10. 



C'l. 5103, 5104, 

 1200, 1204. 



5102, 



30 



