488 



Refraction. Total Reflection. 



No. 53 859 



53 859 A. 1:6. 



53 860. 1 : 6. 



53,859. Optical Disc after Hartl, Figs. A and B (Nos. 1 17), for demonstrating the laws of s. d. 

 elementary optics (Ztschr. f. d. phys. u. chem. U. 9, 1896, p. 113; M. T. Fig. 134), for 

 experiments with single rays and parallel rays 3. 18. 



The apparatus is used in an undarkened room with direct sunlight; the entire arrangement is 

 very comprehensive. The following can be demonstrated: the Law of Reflection for PlaneJ Mirrors; the 

 effects and laws relative to the concave and convex mirror; Refraction by a plane parallel plate; 

 prismatic refraction and chromatic aberration; the action of condensing and dispersion lenses; expla- 

 nation of the rainbow. 



The following pertain to the apparatus: 2 Slotted Sheets with three and seven gaps; Coloured 

 Glass Plates and small Brass Plates; 1 Glass Plane Mirror; 1 Concave and 1 Convex Mirror, of .<Jass : 

 1 each semi-circular, circular, and trapezoidal Crystal Plate; 1 Bi-convex and Bi-concave Cylindrical 

 Lens of crystal glass, also a rectangular prism with members of equal length. 



Fig. 53,589 B shows the path of the rays in the following experiments: (1) Reflection on plane 

 surfaces; (2) Parallel Rays parallely reflected; (3) Reflection on the Concave Mirror; (4) incident parallel 

 Rays are reflected to the focus; after removing the slot diaphragm, demonstration of Catacautery; 

 (5) corresponding Phenomena on the Convex Mirror; (6) Refraction and Reflection of Light between 

 Air and Glass, determination of the refractive indices; (7) the same, between Glass and Air; (8) total 

 Reflection in Glass; (9) Refraction in a plane Plate; (10) Refraction on the 45 prism; chromatic- all 

 erration; (11) minimum deflection with symmetrical Ray; (12) Refraction at condensing lens, focus; 

 (13) collecting parallel Rays at the focus; (14) Diacautery; (15) aberration of parallel Rays; (16) com- 

 bination of Lenses; (17) explanation of the Rainbow; (18) Reflection of a central pencil of rays on a 

 plane surface; (19) idem, on the concave Mirror; (20) central pencil of rays, rendered parallel. 



53,860. Addition to the Optical Disc, Figure, for experiments with central pencils of rays 

 (Ztsclir. f. d. phys. u. chem. V. 10, 1897, p. 236), see also Figure r>3,sr>!) B, Nos. 1820 



Eight cones of rays, proceeding divergently from a point, are produced with this apparatus. 

 The following can be demonstrated: the Rule of the Image for the Plane Mirror; the Reflection of the 

 Luminous Rays issuing from a point, on Concave and Convex Mirrors; existence of the real Image; 

 Refraction by a Condensing Lens or Aberrating Lens of the Rays issuing from one point; Action of 

 Spectacles; Action of Diaphragms. 



TJe additional apparatus consists of a separate ground crystal phite on iron stand, one bi-conrex 

 crystal glass lens and one diaphragm. 



53,861. Reflector for reflecting the Solar Rays 



1. 6. 



(I. \-2. 



Liquid Prisms for determining Kei'rurtive 

 Indices: see page 501 and ">02. 



CI. 6100, 3677. 



