564 



Double Refraction. 



No. 54 702 



54 702 A. 4:5. 



54 702 B. 4:5. 



54 703 B. 2:3. 



54 703 A. 2:3. 



54 70S. 1 : 4. 



54 754. 1 : 5. 



54,539. Analyser after Delezenne, with two small parallel mirrors, in brass mount, Fisr. 54,539, s (1 

 p. 546 1. 8.0 



53,747. Kaleidoscope for polarised light, Fig. 53,747, p. 476, with black mirror, Nicol prism 



and gypsum objects 3. 0. 



54.702. Hamilton's (or Lloyd's) Apparatus, Figs. A and B, for subjective observation of conic 

 refraction 1. 10. 



54.703. Apparatus after Beer. Figs. A and B, for demonstrating double refraction, with two 



rotary rhombohedra and diaphragms 2. 0. 



* 54,641. Glass Press, with two glasses, for showing that glass becomes double refract in<r by 



the application of pressure (M. P. II, 2, Fig. 797 [II, 1, 790]), see Fig. 54,641, p. 55* 1. 2. o 



# 54,642. Fresnel's Press for showing that pressure renders glass double refracting (M. P. IT, 1, 



Fig. 753 [734]) ." 2.15.0 



*:.l,643. Press for bending Glass, with two glass strips (M. P. II, 2, Fig. 796 [II, 1, 789]) . 1. 2.0 



* 54,654. 8 rapidly annealed Glasses of different shapes, see Fig. 54,654, p. 560 2. Id. o 



Nos 1, 2, 3 and 4 cost singly 0. 5. each; No. 5, 0. 8. 0; and Nos. 6, 7 and 8, 0. 12. t-aHi. 



# .VI, 655. 2 crossed annealed Glasses, consisting of 2 single glasses mounted in cork, see Fiir. Vl,6.">."(, 



p. 560 0. lo.o 



These glasses show hyperbolae. 



.">l.704. 4 Coloured Plates, after Brezina, on interference phenomena in crystal plates, with 



text . . '. . . together 0. 16.0 



Plate 1 shows a uniaxial crystal, ruby; plate 2 circular-polarising quartz: plates 3 and 4 a biaxial 

 prismatic crystal ground perpendicular to optical centre line, in cross and hyperbola position (Cerussite 



Gypsum and Mica Preparations. 



54,70."). Gypsum Wedge, 45 mm long, 1 st to 2 nd order 0. l.">.o 



.M.706. - - 1 st to 3 nd order 0.12.0 



54,707. - - 1 st to 5 th order o. HI. 



.M. "OH. Convex and Concave Gypsum Plates, Figure, in mount; can he rotated over each 



by means of rack and pinion for varying (lie colour ring 2. 0. 



(1. 164!!. Hill. 1646. 



* (an be used with the Projection Apparatus 164S J>w lfi5J 



