No. 63310. 



Wireless Telegraphy. 



1047 



f 



63 309 A. 1:7. 



63 308. 1 : 15. 



63 309 B. 1:7. 



63.308. Apparatus for comparative Explanation of Wireless and Ordinary Telegraphy, Figure 



For explaining ordinary telegraphy the apparatus is assembled as in the illustration. Instead 

 of the push the .simple connecting wire given in with the apparatus can be inserted at the point of inter- 

 ruption so that the bell works continuously. After the push is inserted the modus operandi of the 

 house telegraph should be explained. Between push and bell any length of conductor can be supposed; 

 such a conductor is absolutely necessary in this arrangement for connecting the transmitting and 

 receiving station. 



If instead of the push the coherer supplied is inserted, the entire apparatus represents the 

 receiver only in a wireless telegraphy system. The coherer establishes a local circuit if the spark 

 from an induction coil, an influence machine, or the like, is allowed to spring over in the same room. 

 A conductor is not necessary between transmitter and receiver. 



63.309. Wireless Telegraphy Demonstration Apparatus after Marconi; comprising a Trans- 

 mitting Station, Fig. A, with Eighi radiator of 100 and 40 mm size of sphere, in a lock-up 

 polished carrying case fitted with handle; and a Receiving Station, Fig. B, with one 

 coherer, 1 polarised relay, 1 electric tapper, 2 resonators, 2 switches and 4 dry cells, in 

 polished lock-up carrying case having four levelling screws and handle 



The apparatus is specially suitable for better-class schools and colleges. 



63.310. - - idem, smaller, with Rigid radiator 80 and 30 mm size of spheres, cf. Fig. 63,309 A 



s. d. 

 2. 4. 



and B 



13. 0. 



10. 0. 



Cl. 4125, 3045, 

 3046. 



