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THE WORLD'S ADVANCE 



Any One of Several Detectors May be Cut In by 

 Means of This Simple Detector Switch. 



DETECTOR SWITCH HAS NOVEL 

 FEATURES 



A detector switch that will be found 

 very useful for making comparative tests 

 with various types of detectors is shown 

 in the accompanying drawing. 



The construction is quite simple. A 

 block of wood measuring eight inches 

 by six should be cut. Brass rods of the 

 same approximate length as the block 

 should be procured and fitted with slid- 

 ers. The rods are to be mounted on the 

 base about one inch apart. Contact 

 springs are soldered to the under sur- 

 face of the sliders, and the sliders con- 

 nected firmly by a stout fibre bridge. 



Round-headed brass upholstering 

 tacks should be driven in the baseboard 

 and wires led from them to binding posts. 

 It will be seen by consulting the drawing 

 that the tacks are "staggered," that is, 

 the tacks in the two rows are not oppo- 

 site. When one contact spring touches 

 the head of one tack, the other spring 

 will be resting upon the tack head a 

 fraction of an inch in advance of it in 

 the other row. 



Detectors of various sorts can be con- 

 nected to the binding posts, as shown. 

 The two rods should be inserted in the 

 receiving circuit in the same way that a 

 single detector is inserted ordinarily. 

 H. S. PAINE. 



PLYMOUTH RADIO ASSOCIATION 

 IS FORMED 



At a recent meeting of the radio ama- 

 teurs held in Brockton, Mass., the Plym- 

 outh County Radio Association was 

 formed and the following officers elected 

 for the first term: President, Arthur 

 Barnes; Vice-President, Fred Elliott; 

 Secretary and Treasurer, Thos. C. Bar- 

 ham. 



The purpose of the association is to 

 promote good fellowship among the ama- 

 teurs of Plymouth County as well as 

 to aid them when obstacles are encoun- 

 'tered. The association will be glad to 

 hear from other similar institutions. Cor- 

 respondence should be addressed to 

 Thos. C. Barham, 833 Brockton Avenue, 

 Abington, Mass. 



MASSACHUSETTS RADIO CLUB 

 ORGANIZED 



The organization of a new radio club 

 The Massachusetts Radio Society took 

 place in May. The following officers, 

 who are distributed over the state, were 

 elected: Herbert L. Fowle of Reading, 

 President ; Leland Cummings, Stoneham, 

 Vice-President; Dustin Downs, Stone- 

 ham, Secretary, and Herman Arnold, 

 Stoneham, Treasurer. The new club an- 

 nounces that all wireless enthusiasts of 

 Massachusetts who wish to join should 

 communicate with the president or sec- 

 retary for application blanks. 



WEATHER FORECASTS SENT BY 

 WIRELESS 



It is announced that inland distribu- 

 tion of weather forecasts by wireless will 

 soon be inaugurated for the Middle 

 West. The plan contemplates the send- 

 ing of forecasts for Illinois from the 

 wireless station at Illiopolis between 

 12.45 P. M. and I P. M. each day. The 

 station sending the weather bulletins will 

 have a range of at least 125 miles and it 

 is proposed to send the messages at a 

 slow speed so that they may be read by 

 the amateur wireless operators. 



If you enjoy THE WORLD'S ADVANCE, 

 tell others ; if not, tell us your reasons. 



