THE WORLD'S ADVANCE 



389 



magnets also take their current from the 

 common battery; these electro-magnets 

 serving the purpose of throwing in vari- 

 ous friction drives as the buttons are 

 pressed. The main motor is mounted 

 on a felt base and has a special gear 

 case filled with oil, insuring practically 

 silent operation. 



Weighing but thirty pounds in all, the 

 automatic receiving set, aside from its 

 use by amateurs, Government and com- 

 mercial operators, promises to become 

 widely used on aircraft, according to 

 Mr. Goodchild. That it is ideal for this 

 purpose would seem true from the fact 

 that an aviator could press the different 

 buttons while driving his machine, 

 whereas the average receiving set would 

 require too much attention. Further- 

 more, by the use of a fixed and perma- 

 nent detector that requires no adjustment 

 whatsoever and is not affected by vibra- 

 tion, which is incorporated in the set, the 

 outfit is absolutely dependable. 



But the greatest field of employment 

 of the automatic receiving set will prob- 

 ably be on shipboard in times of disas- 

 ter, either to the ship on which it is in- 

 stalled or when the ship is speeding to 

 the succor of another vessel in distress. 

 By means of a multi-conductor cable and 

 a small push button board the receiving 



Especially Intended for Amateur Use, this Inductive 

 Tuner is Designed along the Same General Lines as 

 the Automatic Receiving Set. It is, However, Man- 

 ually Operated 



set in the wireless room can be operated 

 from the bridge or, for that matter, 

 any other part of the ship. The opera- 

 tor, receiving messages and standing be- 

 side the captain and other officers, can 

 keep them constantly informed regarding 

 the messages he is receiving. 



The appearance of the automatic re- 

 ceiving set marks a new step in wireless. 

 It is but a forerunner of the efforts 

 that are bound to follow towards sim- 

 plifying radio apparatus and bringing its 

 operation within the scope of the laity. 



AN INSTRUMENT FOR MEASUR- 

 ING DECREMENT OF 

 TRANSMITTERS 



Professor Kolster, of the Bureau of 

 Standards, has recently designed an in- 



A Portable, Direct-Reading Decremeter De- 

 signed by Professor Kolster of the Bureau 

 of Standards. 



strument by which the decrement of a 

 transmitter may be measured. The in- 

 strument is now largely employed by 

 radio inspectors in determining whether 

 or not transmitting sets are tuned suf- 

 ficiently sharp to emit the waves in keep- 

 ing with the wireless laws. 



