No. 63269. 



Seibt's Apparatus. Hertz's Experiments. 



1039 



63 268 A. 



63268, 63269. 



63 268 B. 



63 268 C. 



53,508. Resonance Tube on base, with open ends, but can be closed at one end, s. A. 

 Figure 1. 8. 



5.3,500. Tuning Fork Cj = 256 compound vibrations, with grip 1. 0. 



53.510. - - idem, c. 2 = 512 compound vibrations 0. 18. 



53.511. - - i d e m, g 2 = 768 compound vibrations 0.18.0 



Apparatus for the Experiments on Electric Power Rays, 



after Prof. Heinrich Hertz. 



(of. Hertz, Untersuchungen iiber die Ausbreitung elektrischer Kraft, Leipzig, 1895, Johann 



Ambrosius Barth.) 



63.267. Apparatus after Grimsehl for repeating Hertz's Fundamental Experiments, Figs. A C 

 (Grimsehl, Figs. 10571059) 3. 0. 



In these apparatus, as in the original Hertzian Experiments, the secondary spark in the so-call- 

 ed resonator is used as indicator. The induction coil should have a spark about 10 cm long. 



63.268. 2 Parabolic Mirrors, one with Hertzian transmitter (oscillator), the other with a 

 coherer (resonator), Figure s, together with a tuned electric bell for signalling, 2 

 Dry Cells, 1 Wire Grating, 2 Sheet Iron Screens and 1 small Metal Plate for setting the 

 distance of the oscillator balls (Richarz, Neuere Fortschritte auf dem Gebiete der Elek- 

 trizitat, 2 nd Edn., pp. 66 75), without the induction coil or accumulators illus- 

 trated 4. 0.0 



In this set, in which a coherer (Branly Tube) is used as indicator, the following experiments can 

 be made: rectilinear expansion of waves (Fig. A), screening effect, reflection (Fig. B), polarisation 

 (Fig. C). The following paraffin prism No. 63,269 is used for refraction. The induction coil should 

 have a spark-length of not more than 2 3 cm. Description and precise directions for use are ap- 

 pended. 



63.269. Paraffin Prism, F i g u r e, with board and wood wedges 1. 16. 



CI. 5879, 



5877, 5905, 587R. 



