No. 83277. 



Hertzian Experiments. 



1041 



63 270 J. 1:8. 



63 270 H. 1:10. 



63275. 1 : 5. 



63 274 A. 1:4. 



63 274 B. 1:5. 



63.271. Hertzian Wave Transmitter (Vibrator), after Weinhold, separately, Fig. 63,270 B 

 (W. D., Fig. 613 [558]) 



63.272. Transmitter for Wireless Telegraphy after Weinhold, alone, Fig. 63,270 J (W. D., 

 Fig. 619 [564]) 



63.273. Branly Tube after Weinhold, separately (W. D., Fig. 611 [556]) 



63.274. Complete Exciter for short Waves after Prof. Jagadis Chunder Bose (Ztschr. f. d. 

 phys. u. chem. U. 10, p. 149), Figs. A and B 



The apparatus consists, as shown in Fig. 63,274 A, of a frame with manipulator, 1 Storage 

 Battery, 1 Induction Coil, 1 Interrupter the knob of which projects above the cover of the apparatus, 

 and one small Radiator in oil vessel with concave copper mirror. The entire device can be placed 

 in a protecting box formed of an iron and a copper sheet metal jacket, Fig. B, thus obviating the 

 influence of magnetic and electric waves on the apparatus. The waves emitted by the radiator can be 

 propagated through the tube inserted in the jacket. 



The apparatus is ready for use when closed since the interrupter can be operated externally by 

 the push mentioned. The secondary batteries can be cut out by means of the plug visible in 

 Figs. 63,274 A and B. 



Two double discs can be screwed out of the protecting jacket (Fig. B) in order to be able to 

 observe the two spark gaps. 



63.275. 1 Coherer for above, on stand, Figure 



61,280. 1 Pointer Galvanometer for above 



63,277. 1 Simple Optical Bench and a simple Goniometer for same, with cylindrical lens, 

 1 plane mirror, 1 cylindrical mirror, 1 prism, 2 half -cylinders, 2 copper wire gratings 

 for polarisation 



Cl. 4514 

 0136, 3016 

 3014. 3015 



S. d. 



0.12.0 



1.16.0 

 0. 6.0 



12. 0.0 



1. 4.0 

 2.10.0 



9. 0.0 



66 



