No. 53974. 



Optical Measuring Instruments. 



499 



53 934. 1 : 7. 



53935. 1:3. 



53,932 c. 2 Glow Lamp Holders and 1 Lens Mount on wood pillar, with glow lamps and mea- 

 suring rod, after Grimsehl, for determining the focal length of convex lenses and of 

 concave lenses in practical school work (E. Grimsehl, Ausgewahlte physikal. Schiiler- 



iibungen, Figs. 2326) 



Lenses for above: see No. 53,932 b. 



Optical Measuring Instruments. 



53.933. Jamin's Circle, Figure, for all kinds of measurements on reflection, refraction 

 and polarisation (Jamin, cours de physique) 



53.934. Total Reflectometer after Kohlrausch, Figure (W. u. E. phys. prakt. Fig. 159), 

 for determining the refractive indices of liquids and solids 



Spectrum Analysis and Synthesis. 



53,!35. Glass Prism, F i g u r c, polished, 100 mm high and equal-sided, length of side 25 mm 



Plate Glass Prisms, equilateral, with three polished surfaces; height length of side: 



List No. 53,936 53,937 53,938 53,939 53,940 53,941 

 Length of Side mm 30 35 40 45 50 60 



0.5.0 0.6.0 0.8.0 0.10.0 0.12.0 0.15.0 



Plate Glass Prisms, long pattern, equilateral, with three polished surfaces: 



List No. 53,942 53,943 53,944 53,945 53,946 53,947 53,948 

 Length of Side mm 25 30 35 40 45 50 60 



Height mm 50 60 70 80 90 100 120 



0. 8. 0. 10. 0. 12. 0. 16. 1. 0. 1. 4. 1. 10. 



Crown Glass Prisms, equilateral, with three polished surfaces; height == length of side: 



List No. 53,949 53,950 53,951 53,952 53,953 53,954 



Approx. Length of Side mm 30 35 40 45 50 60 



0. 10. 0. 12. 0. 15. 0. 18. 1. 0. 1. 5. 



Crown Glass Prisms, long pattern, equilateral, with three polished surfaces: 



List No. 53,955 53,956 53,957 53,958 53,959 53,960 53,961 



Approx. Length of Side mm 25 30 35 40 45 50 60 



Approx. Height mm 50 60 70 80 90 100 120 



0. 15. 1. 0. 1. 5. 1. 10. 1. 15. 2. 0. 2. 10. 



Prisms made of glasses whose refractive index is greater than 1.7, icrease 100% in price. 



Flint Glass Prisms, equilateral, with three polished surfaces; height == length of side: 

 List No. 53,962 53,963 53,964 53,965 53,966 53,967 

 Approx. Length of Side mm 30 35 40 45 50 60 



0. 10. 0. 12. 0. 15. 0. 18. 1. 0. 1. 5. 



Flint Glass Prisms, long pattern, equilateral, with three polished surfaces: 



List No. 53,968 53,969 53,970 53,971 53,972 53,973 53,974 



Approx. Length of Side mm 25 30 35 40 45 50 60 



Approx. Height mm 50 60 70 80 90 100 120 



0. 15. 1. 0. 1. 5. 1. 10. 1. 15. 2. 0. 2. 10. 



52.10.0 

 9. 0.0 



0. 2.0 



s. d. 



0. 12. 



(Jl. 6030, 1323. 



32* 



