Rubuta ci gaba ga wannan sakin layi - Wannan ya sa ya ƙirƙira bifilar da baƙin ƙarfe mai laushi. Waɗannan na'urori sun sami babban kyauta a St. Louis Exposition
a shekara ta 1904. Sun kasance mafi iko fiye da na gargajiya stroboscope, ƙirƙira a 1891 sa'an nan a amfani. Sun kasance hanya mafi kyau don yin rikodin abubuwan da ke faruwa na lantarki mai sauri fiye da shekaru 40 lokacin da aka maye gurbinsu da cathode ray oscilloscope. Sun buɗe hanya don ƙarin fahimtar halayyar canjin canji.