358 Messrs. W. H. Preece and A. Stroh. [Feb. 27, 



passing through a tube of lime as in (fig. 3). It is our intention to 

 try a combination of the electric arc and induction spark in these 

 crucibles. It is hardly necessary to note that the projection of the 

 reversals of the lines of metallic vapours may be effected by this 

 method better than by any method heretofore in use. 



February 27, 1879. 



THE PRESIDENT in the Chair. 



The Presents received were laid on the table, and thanks ordered for 

 them. 



Major- General Thuillier (elected 1869) was admitted into the 

 Society. 



The following Papers were read : — 



I. a Studies in Acoustics. I. On the Synthetic Examination of 

 Vowel Sounds." By William Henry Preece and Augus- 

 tus Stroh. Communicated by the President. Received 

 February 17, 187 9. 



[Plates 6, 7.] 



1. The authors of this paper have devoted much time during the 

 past twelve months to a study of sonorous vibrations and the reproduc- 

 tion of speech. The invention of the phonograph has proved a great 

 stimulus to this study. Many have worked in the same field, and 

 many of the facts elicited by the' authors have been anticipated by 

 those who have been able to give more continuous study to the subject. 

 Nevertheless, the mode of enquiry, the apparatus employed, and the 

 results obtained are thought to be of sufficient novelty to justify their 

 being brought before the Royal Society. 



2. The curves traced by the vibrating disk of the phonograph on 

 tinfoil, whether examined microscopically or reproduced by a species of 

 pantelograph, were soon found to be insufficiently delicate to give the 

 nicer shades of sound, and to fail to indicate the true curve of vibra- 

 tions in all cases. This is shown by the imperfect reproduction of 

 speech by the phonograph itself ; the merging of the labial and dental 

 sounds into one another, and the absence of all the sibilants and 

 generally of the "noises" of speech. The phonograph is in reality a 

 very imperfect speaker, and it requires the aid of much imagination 

 and considerable guessing to follow its reproductions. It produces 



