130 



THE WORLD'S ADVANCE for JULY 



MURDOCK 



Wireless Receiver 



Special No. 55 

 Complete Double Sets 



2000 ohms $4.00 



3000 ohms $5.00 



Absolutely the most sensitive, 

 the most comfortable, the 

 most serviceable 'phones ever 

 offered at such low prices. 



GUARANTEED 



to equal or surpass in every 

 desirable quality, any 'phones 

 that you can buy for many 

 times the price. 



TRY THEM 



for fourteen days, and, if you 

 are not satisfied that they are 

 the best receivers you have 

 ever tried, send them back 

 and get your money. 



The latest 1915 catalog of 

 Murdoch's apparatus is 

 now ready. If it has not 

 reached you, send for it 

 today. 



Wm. J. Murdock Co. 



40 Carter St. 

 Chelsea, Mass. 



680 Howard St., San Francisco 



^POCKET WIRELESS S^AT? 



This outfit is a novelty in this line and is capable of receiving messages 

 |up to severalhundred miles. Nootherinstrumentsneeded.Itisso compact 

 vitisnotnoticeablein your pocket. Weight 10 

 7 oz. complete. No complicated parts. Nothing 

 togetoutoforder.Tunesuptol200meters.lt 

 innot be pui chased elsewhere as we are the 

 ilyfirmin America that makesthem. Bethe 

 st one in your section to own a real "Pocket 



Price - - $3.00 



Send stamp fer circulars T-l & 2 

 S. & K. ELECTRIC & MANUFACTURING CO. 



** ETv^^ntirkn^l U/ir-AlACC Annara+u c " 



BROOKLYN, N. V. 



Exceptional Wireless Apparatus." 

 SACKETT STREET, at COURT STREET, 



SEAMLESS CARDBOARD TUBING 



IN SIZES SUITABLE FOR 



TUNING COILS, LOOSE COUPLERS. 



TESLA COILS, Etc. 



SPECIAL SIZE 26" x 8" Dia. 



Send 2c stamp for price list 



BEETLE & MACLEAN 



21 BROMFIELD ST., BOSTON. MASS 



* 



BEEKAY 



New Type, Quick Adjusting Mineral 



' Price 



Postpaid 



BONDUAUX & KNIGHTS 



LOOSE-COUPLER 



BACKED BY A 

 GUARANTEE 



The cut shows our new Model 

 No. 8 Incorporating many points 

 of refinement never before intro- 

 duced In an instru- 

 ment at the price 

 quoted. 



Price $10.50 



3500 Meter wave re- 

 ception; "Radio" 

 improved slider op- 

 erates absolutely noiseless, green silk windings. 10 point 

 secondary switch. Extra loose coupling available. 

 Handsomely finished in Mahogany and Lac Brass Size 

 18" x 6%" x 7". A large supply on hand. 

 Order now on 10 days' trial and if not entirely satisfied 

 we will exchange for eaual value, or cheerfully refund the 

 purchase price. 



Our August Bulletin will describe No. 8 morefully. Insist 



on "Radio" Apparatus, don't accept a "just as good" 



The Radio Apparatus Co., Pottstown, Penna., U. S. A. 



WISDOM 



TO KNOW of the mechanical wonders of the world's 

 progressiveness, and to have it presented clearly and 

 interestingly ; to be shown hundreds of ways to bene- 

 fit yourself by the use of tried and true practical 

 short-cuts and easy ways of doing the irksome task, 



Read The World's Advance 



MIGNON 

 SYSTEM 



This is our R.C.I. 

 Receiving Set 



PRICE - - $10.00 



Patents Applied for, 

 Serial No. 808,264. 

 Write for Circular, 

 size 8 x 8 x i% in. All types of our ap- 

 paratus are greatly improved, well made 

 and efficient. Satisfaction guaranteed or 

 money refunded. 

 MIGNON WIRELESS CORP., ELMIRA, N. Y. 



For our Mutual Advantage mention The World's Advance when writing to Advertisers. 



