November 8, 1901.] 



SCIENCE. 



725 



apparatus. From that day to the present 

 Koenig's instruments, and especially his 

 tuning forks, have been generally recog- 

 nized as standard, 



Koenig was not satisfied to fill orders 

 and maintain his reputation as a constructer 

 of instruments. He early perceived the 

 value of the graphic method for the study 

 of harmonic motion, and to this he devoted 

 much time and labor during the first few 

 years after establishing himself independ- 

 ently. Wertheim and Duhamel had al- 

 ready used the tuning fork with style at- 

 tachment for the registration of simple 

 vibrations, as suggested a half century 

 previously by Dr. Thomas Young in Eng- 

 land. Koenig extended it to the study and 

 registration of compound harmonic motion 

 for both parallel and rectangular vibrations. 

 The mathematical analysis of wave motion 

 had been abundantly brought out in tech- 

 nical treatises, and Lissajous had but 

 recently excited admiration by his optical 

 method of presenting rectangular vibra- 

 tions. Koenig devised the method of re- 

 cording these directly from the sounding 

 tuning fork. At an international exhibi- 

 tion held in London in 1862 he exhibited 

 an album containing a large variety of such 

 phonograms, recorded with apparatus of 

 his own device, and accompanied with the 

 tracings of the corresponding theoretical 

 curves. This was the starting point for the 

 use of the graphic method of self- registra- 

 tion which has since been so extensively 

 employed in laboratories of physics, physi- 

 ology and psychology. 



It was at the same exhibition that Koenig 

 made known a wholly new method of 

 causing the efiects of sonorous vibration to 

 become visible by utilizing the delicate sen- 

 sitiveness of flame to variations of atmos- 

 pheric pressure. The suggestion had come 

 from America, where Le Conte had pub- 

 lished, in 1858, his observations on the effect 

 of sound waves upon naked gas flames. 



Koenig devised the manometric capsule, 

 and resorted to Wheatstone's application 

 of the revolving mirror for spreading the 

 flame images. The last improvements on 

 this method have been made by the appli- 

 cation of instantaneous photography to per- 

 petuate the images, some of the best of this 

 work having been done within the last few 

 years by Hallock in New York and Merritt 

 in Ithaca. The manometric flame is not 

 equal to the tuning fork curve as a means 

 of studying the composition of vibration, 

 but the novelty and attractiveness of the 

 method quickly made its author famous. 

 He received a number of medals, and in 

 1868 the honorary degree of doctor of phi- 

 losophy was conferred upon him by the 

 university of his native city, Koenigsberg, 

 in acknowledgment of his meritorious orig- 

 inal work in science. 



Prior to 1882 Koenig had published about 

 sixteen scientific papers, some in the 

 Comptes Bendus, but most of them in the 

 Annalen of Poggendorff" and Wiedemann. 

 These were gathered into a volume entitled, 

 'Quelques experiences d'acoustique. ' Since 

 that time he has published a number of con- 

 tributions to Wiedemann's Annalen, the last 

 of which appeared in the summer of 1899. 

 Failing health had already put a check 

 upon his activity, but his passion for ex- 

 perimental research continued long after 

 the time when most men lose their enthu- 

 siasm for abstract investigation. All his 

 research work was the outcome of the love 

 of science without the promise of pecuniary 

 reward. It was done, moreover, with full 

 knowledge that as a branch of pure science 

 acoustics had been forced to the background 

 by such subjects as heat, and more espe- 

 cially electricity, in which the field has be- 

 come widened almost without limit during 

 the last two or three decades. 



In the absence of systematic university 

 training in early manhood Koenig as an 

 investigator in physics was compelled al- 



