6;o 



NA TURE 



[October 24, 1901 



RUDOLPH KOENIG. 



'T^HERE has passed away in the person of Dr. 

 -•- Rudolph Koenig one whose name will be remem- 

 bered in the science of physics, and who filled a unique 

 place. To the outer w'orld he was known simply as a 

 maker of tuning-forks. To the inner circle of science 

 he was known as the author of original researches in a 

 line peculiarly his own. To the few who had the privilege 

 of an intimate acquaintance he was known as a simple- 

 hearted, whole-souled devotee of his chosen science of 

 acoustics : one who lived for and loved his work. 



Born at Konigsberg in 1S33 of a family connected 

 with the University, he was himself trained in the Philo- 

 sophical Faculty of that famous centre. He graduated 

 as Doctor of Philosophy, and well might have looked 

 forward to a successful career as professor of physics in 

 one of the Universities of his native land. What cross- 

 currents of destiny drove him far afield are not clearly 

 known to the present writer. But the year i860 saw 

 him established in Paris as a constructor of acoustical 

 instruments, carrying out the traditions of fine 

 workmanship established by Cavaille-Coll. He had 

 an atelier in the Place du Lycee Louis le Grand, 

 and here he worked out a number of new 

 acoustical instruments. The phonograph, or phonauto- 

 graph as it was later called, of M. .Scott de Martinville 

 for recording the vibrations of tones and words was 

 brought to Koenig to be put into shape. Accounts of 

 this inetrument »ill be found in Cosmos, vol. ,\iv., in the 

 Athenaeum of 1S59, and in the Report of the British 

 Association for the same year. It N\as Koenig's part to 

 devise a better mouthpiece and a more sensitive 

 membrane. He also devised the recording drum, driven 

 on an a.\is cut with a screw thread. I once asked him 

 whether, when he was working with M. Scott on this 

 instrument, it had not occurred to either of them that the 

 record of the vibrations might not be used over again to 

 reproduce the sound, as discovered nearly twenty years 

 afterwards by Edison. His reply was : " No, the idea never 

 occurred to either of us ; we never thought of anything 

 except recording." He constructed series of standard 

 tuning-forks furnished with recording styluses ; he im- 

 proved the mechanical construction of the Seebeck siren ; 

 he studied the vibrations of plates and of columns of air. 

 In 1862 he brought over to London to the second of the 

 series of International Exhibitions a fine set of his new 

 apparatus, including an acoustical album or collection of 

 graphic tracings recording the composition of vibrations ; 

 and for the exhibit he was awarded a gold medal. .-Ybout 

 the same time began the publication of his experimental 

 researches in acoustics which lasted nearly forty years. 

 The earliest of these to be noted was the invention of the 

 manometric flame. Organ pipes fitted with manometric 

 capsules for investigating the vibrations of the air column 

 by means of gas-flames were shown in the London 

 Exhibition of 1862, and they were described by him in 

 vol. cxxii. of Poggendorff's Annalen, pp. 242 and 246, 

 of the same year. He constructed resonators for 

 Helmholtz (see .A.ppendix I. of the first edition of the 

 "Tonempfindungen," 1863) ; he repeated the experiments 

 of Philipp Reis with the primitive telephone of that 

 neglected inventor ; he devised a new stethoscope 

 furnished with one or more flexible rubber tubes to admit 

 of simultaneous auscultation by several observers. In 

 the Coinptes rendus of March 1864 he had a memoir 

 upon the vibration of plates, in which he discussed the 

 sound-figures in sand discovered by Chladni and the 

 explanation of their formation then recently suggested 

 by Wheatstone. In 1870 he had another article in the 

 Comptes rendus, on the fixed notes which are charac- 

 teristic of the different vowels. In 1872 came a second 

 memoir on manometric flames in the Annaten. 



During these ten years Koenig had been attempting 



NO. 1669, VOL. 64] 



to build up the business of manufacturer of acoustical 

 instruments. His standard tuning-forks were sought 

 after by physical investigators. The impulse given to 

 acoustical subjects by the publication of the famous book 

 of Helmholtz was undoubtedly great ; and the researches 

 of Chladni, Wertheim, Melde, Terquem, Wheatstone and 

 Mach were claiming great attention. Koenig adopted 

 the suggestion, urged by Chladni in 1830, of fixing as 

 the normal scientific pitchforhis standards that in which 

 middle C of the keyboard is assigned to 256 complete 

 vibrations per second. In the "Catalogue of .Acoustical 

 Apparatus" which Koenig published in 1865 — itself an 

 evidence of his scientific and industrial activities — he 

 notified his adherence to this standard for the diapason 

 iiorinal. He had now moved into the Rue Hautefeuille 

 on the south side of the Seine, where he lived and 

 worked until about 1878, when the house was demolished 

 in the construction of the Boulevard St. Germain through 

 the Quartier Latin. Unhappily the outbreak of the 

 Franco-Prussian War rendered it difficult for a German 

 to live in Paris. Of a retiring and sensitive disposition, 

 he found himself somewhat isolated in his work. The 

 scientific world was rather cold toward the man who 

 made a living out of selling tuning-forks. Other instru- 

 ment makers began to copy his instruments, and were 

 able, not having the same scientific ideals, to undersell 

 his manufactures by producing less carefully-made articles. 

 Koenig never swerved one hair's breadth to meet this 

 competition. He knew the quality of the work that left 

 his little factory. Not one tuning-fork, during these 

 more than thirty years, left the place without having been 

 personally adjusted and verified by him. No single in- 

 strument of second quality ever bore his mark. The 

 monogram " R. K." stamped upon his work became an 

 absolute guarantee of first-rate workmanship. Others 

 might cheapen their manufacture by neglect of quality : 

 he would maintain the quality of his coute que coute. 

 If by some stroke of luck he sold instruments that 

 brought in a few hundred francs abo\e the regular income 

 of his business he would hail it as the means of construct- 

 ing some new piece of experimental apparatus that might 

 never find a sale, but would help his investigations. 

 And so with a slender business and a few faithful work- 

 men at his back he maintained a proud independence, 

 sufficient to enable him to continue research. 



In 1876 he went over to .America and took with him 

 to the Centennial Exposition at Philadelphia a splendid 

 series of his beautiful instruments in the hope of 

 doing advantageous business. The Jury's report of the 

 awards in Group xxv. speaks in glowing terms of 

 this effort. " In the present Exhibition," it runs, 

 " Dr. Koenig has presented a collection of instruments 

 of demonstration and investigation constructed on a 

 scale of magnitude heretofore unattempted, and exhibit- 

 ing with surprising power the effects of interfering un- 

 dulations. He also presents a tonometric apparatus, 

 consisting of about 670 diapasons or tunmg forks, giving 

 as many different shades of pitch, extending over four 

 complete octaves, and making equal intervals of eight 

 simple vibrations each for the first octave, and of twelve 

 each for the succeeding octaves ; the whole forming an 

 absolutely perfect means of testing, by count of beats, 

 the number of vibrations producing any given musical 

 sound, and of accurately tuning any musical instrument. 

 In addition to these more conspicuous portions of his 

 display. Dr. Koenig exhibits the various forms of 

 apparatus of demonstration for which he is so well 

 known, all of which are marked by the accuracy of 

 indications and excellence of workmanship which have 

 given him his deserved reputation as a constructor." 

 . . . "Of the exhibit of Dr. Koenig, as a whole, it may 

 be said that there is no other in the present International 

 Exhibition which surpasses it in scientific interest." The 

 interest excited by this exhibit was so great that an 



