No. 64701. 



Technical Polarisation Apparatus. Double Refraction. 



563 



54681. 1:3. 



54 689 A. 1:5. 



54690. 1:7. 



54692. 1:8. 



54 689 B. 1:5. 



54693. 1:2. 



54 689 C. 1:5. 



54700B. 1 : 1. 



54 700 A. 1:1. 



54701. 1:5. 



54.689. 10 Pasteboard Models, after J. Miiller, Figs. A, B and C, for explaining the Ring Systems 

 in uniaxial and biaxial Crystals, after Fresnel (M. P. II, 1, Fig. 724, 725, 736 740 [658, 

 702, 703, 717, 718, 719. 720,. 729]), with two stands in boxes 



54.690. 2 Plaster Models for the isochromatic wave- surf aces, Figure, after Bertin . . . 



54.691. 2 Wood Prisms (can be taken to pieces) with Drawings on cardboard and Ellipsoids 

 after Pfaundler, for deriving the phenomena in uniaxial, negative crystals from the wave- 

 area by means of the Huyghenian construction (M. P. II, 1, Figs. 726 734 [704 707, 

 709, 711713, 715]) ' 



54.692. Model of the Vibration Planes of the Light in the Polarisation Apparatus, Figure, 

 after Prof. Triepel, Breslau, with description 



54.693. Glass Plate with Letters and Calc-spar Plate, Figure, for showing double refraction 

 (Gan.-Man., Fig. 420) ..." 



Double Refracting Prisms, of Calc-spar, achromatised by a glass prism (M. P. II, 1, Fig. 696 

 [674]). 



List No. 54,694 54,695 54,696 54,697 54,698 

 Aperture mm 10 15 20 25 30 



0.10.0 0.16.0 1.2.0 1.15.0 2.5.0 



Triple achromatised prisms arc double the price of above. 



54.699. Fresnel's Prism, consisting of three quartz prisms of reverse rotation, for showing 

 circular double refraction (M. P., 9 th Edn., II, 1, Fig. 835) 



54.700. Dichroscopic Magnifier after Haidinger, Figs. A and B 



54.701. Polarisation Polyoscope after Dove, Figure 



s. d. 



1.16.0 

 0.12.0 



1.10.0 

 1. 4.0 

 0.16.0 



