Show Puzzle I Dead Spots I I Radio Experimenters 4 W WASHINGTON AS March 19 Gov Cov Gov Government scientists are trying to de determine tie tie- I termine the cause of dead spots between a number of cities clUes in the United States which form forman an al almost almost almost al- al most impenetrable barrier barier to the direct exchange of r radio messages mess The most pronounced of these ap appears appears appears ap- ap I pears to be between Washington and ald Baltimore Dr J. J H. H Bellinger Dellinger r chief of the radio division of the bureau of ot st standards says the most plausible theory now advanced 1 Is the existence existence existence exist exist- ence of it a radio activity activity- in the these e dead spots which s so so affects certain certain tain layers of or the atmosphere as to render transmission ot of radio waves Impossible Theories advanced in other quarters tera are that the dead spot may be caused by the electric railway line Une between tho cities |