No. 54 605. 



Polarisation Apparatus. 



553 



54 602. 1 : 4. 



54 604. 1 : 6. 



* 54,600. Simple Polarisation Apparatus, Figure (Tyndall, Das Licht [Light], p. 125), with two 



large tourmaline plates 5x15 mm, fastened on the glass, one of which is rotary . . 



* 51,074. Polarisation Apparatus for Objective Demonstration, Figure (W. D., Fig. 323 [305]) 



* 54,601. 1 Set of Preparations for preceding apparatus: 2 gypsum figures, 2 rapidly annealed 



glasses, 2 gypsum plates, calc-spar, rock crystal, aragonite, potassium-cyanide, strontium 

 copper acetate and tourmaline 



54.602. Large Projection-Polarisation Apparatus after Duboscq and von Lang, Figure (M. P., 

 9 th Edn., II, 1, Figs. 746 and 747), for use with the heliostat or projection lantern and 

 for demonstrating all phenomena of double refraction and polarisation 



The apparatus consists of a rotary stand adjustable vertically containing one fixed and three 

 sliding attachments; one condenser; 3 lenses; 4 calc-spar prisms as polariser; 1 Nicol as analyser and 

 1 bi-concave lens on stand for rendering the luminous rays of the projection lantern parallel. To the 

 apparatus appertain: 1 Delezenne polariser; 1 black mirror; 1 gap; 1 set glass plates; 1 quartz plate 

 cut parallel to the axis; 1 ditto cut perpendicular to the axis; 2 quarter-wave mica plates; 1 direct 

 vision prism; 1 wedge compensator with quartz plate after Soleil and 1 double quartz plate; 2 gypsum 

 plates: 1 piece aragonite; 1 piece tourmaline; 1 piece calc-spar; 1 gypsum figure. 



54.603. Polarisation Apparatus after Norrenberg, simple, of brass, with coarsely divided 

 circle, with rotary stage and with black mirror as analyser 



54,603 a. -- idem, with Glass Plate Column as analyser 



54.604. --idem, F i g u r e, with Nicol prism as analyser 



54.605. - - id e m, with black mirror and glass plate column, without Nicol 



54.606. - - i d e in, with black mirror, glass plate column and Nicol prism (Gan.-Atk., 

 Figs. 654, 655; Gan.-Man., Figs. 439, 440) 



s. d. 

 3. 0.0 



7. 0.0 



3. 5.0 



34. 0.0 



2. 0.0 



2. 5.0 

 2.10.0 

 2.10.0 



3. 5.0 



Can be used with Projection Apparatus. 



ci. 318, 1614. 



