178 HERMANN VON HELMHOLTZ 



excellent. Then a rather dull sitting with speeches, more 

 Bavarian beer, and a rest at mid-day. Then dinner with His 

 Majesty, preceded by a very long and elaborate reception. 

 The King is very friendly, and talks sensibly, but seems to 

 have inherited his father's bad constitution. He congratulated 

 himself on making personal acquaintance with me ; I thanked 

 him for graciously permitting me to do so. He hoped that 

 I would make some acoustic discoveries that would benefit 

 the architecture of public halls; but I could hold out small 

 prospect of that. The banquet in the Barbarossa Hall was 

 most brilliant: the food very delicate and not substantial, as 

 I like it. Subsequently Oedipus Colonus at the Theatre, with 

 Mendelssohn's music, but it is less inspired than his Antigone. 



1 To-day the saloons of the Castle are thrown open to us ; 

 in the evening a great May Festival at the Rathhaus, when 

 the beer is tapped solemnly. ... I must conclude, for R. Wagner 

 has just come to fetch me/ 



During this Academic Festival, Helmholtz gave a lecture on 

 April 2, ' On the Quality of Vowel Sounds ' ; the important parts 

 of it were subsequently published in Poggendorff, after the 

 Vowel Theory had been completed by verbal and written 

 discussion with Bonders. 



On June 13, 1859, he writes to Ludwig that the necessary 

 preliminary study of the motion of air in tubes had led him 

 to a definite theory of timbre (Klangfarbe). His detailed 

 explanation shows how chords of different timbre and equal 

 pitch of fundamental tone are distinguished by the ear because 

 of the different frequencies and strengths of the harmonic over- 

 tones, i. e. timbre results from the combination of the prime 

 tone with different intensities of over-tones. He defines as 

 the musical quality of tone that part of it which is independent 

 of the irregular murmur that cannot properly be reckoned 

 with the musical constituents of the tone, e. g. the scraping 

 of the violin bow, the whistling of the stream of air blown 

 over a flute, the varying intermittency of the expired breath 

 in the pronunciation of consonants ; and then proceeds to the 

 question of whether the distinction of musical timbre depends 

 only on the perception of over-tones of different intensity, or 

 whether the ear can distinguish differences of phase also. 

 Quite different wave-forms obtain for a wave composed of a 



