Annual report of the Board of Regents of the Smithsonian Institution . O CD EADIOTELEGRAPHY FLEMING, 173 The space occupied by such closed antennae has hitherto preventedtheir employment on ships. There is still, therefore, an opening forthe invention of apparatus capable of being used on board shipwhich will enable one ship to locate, within narrow limits, thedirection of another ship sending signals to it, and therefore ofascertaining immediately the direction from which some call for helpis proceeding. Closely connected with this part of the subject is the question sofrequently discussed as
Annual report of the Board of Regents of the Smithsonian Institution . O CD EADIOTELEGRAPHY FLEMING, 173 The space occupied by such closed antennae has hitherto preventedtheir employment on ships. There is still, therefore, an opening forthe invention of apparatus capable of being used on board shipwhich will enable one ship to locate, within narrow limits, thedirection of another ship sending signals to it, and therefore ofascertaining immediately the direction from which some call for helpis proceeding. Closely connected with this part of the subject is the question sofrequently discussed as to the isolation or secrecy of radiotelegraphiccommunication. Up to the present moment the only really practicalmethod of isolating any particular receiver so as to make it sensitiveonly to signals coming from a certain direction, is to avail ourselvesto the utmost of the principle of resonance and to tune the sendingand receiving circuits to exact cor-respondence. The question thenarises, Wliat is it which determinesthe effectiveness of this tuning?If waves of one
Size: 1734px × 1440px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorsmithsonianinstitutio, bookcentury1800, bookdecade1840
