1042 



Voltaic Electricity. Section 10: Electrical Oscillations. 



No. 63278 



63 280. 1 : 18. 



63278. 1:18. 



63281. 1:18. 



63283. 1:10. 



63285. 1:3. 



Large Pattern Apparatus for Hertzian Wave Experiments. 



63.278. 2 Parabolic concave Mirrors after Garbasso, Figure, 0.7 m high, 1.2 m aperture, 

 0.12 m focal distance, composed of two wood formers and a mimber of well-rounded 

 nickelled sheet iron strips 27 cm long and 5 cm width 4. 10. 



63.279. - - idem, same size, after Zehnder, of three wood formers and a number of per- 

 pendicular wires, constructed as a wire mirror (Wieden. Ann. d. phys. Vol. 52, 1894, p. 55) 4. 10. 



63.280. Octagonal Wire Grating in Wood Frame, 0.7x0.7 m, Figure, can be used verti- 

 cally and horizontally, stretched with copper wires 1. 4.0 



63.281. Large Pitch Prism, Figure, with refracting angle of 30, 1.2 m side length and 

 0.7 m high, composed of three single prisms. Bach prism consists of a wood box into 



which hard pitch is run in G. IL*. o 



63.282. 2 Screens of Sheet Zinc on Wood Frames, 1 m long, 0.7 m high, for reflection experi- 

 ments Each 0.14.0 1. s. o 



63.283. Primary Conductor after /Hinder, Figure, on special wood stand with levelling 



screws (Wied. Ann. d. I'liysik, Vol. 52, 1894, p. 52) 2. 0. 



The halves of the primary conductor are cylinders made of brass tubing, brass spheres being 

 soldered on one end and simple arched surfaces on the other. The conductor wires are secured 1>\ 

 conical plugs. The primary conductor halve* are enclosed in a pasteboard box having a glass front wall. 



t'l. 3020,3021,3023, 

 3022. 3024, 3025. 



