424 Proceedings of the 



April 2bth. 



Mr. Sieviere gave a practical and illustrated account of the pro- 

 cesses used by the Sculptor. He described the operation of model- 

 ling in clay, and the use and nature of the tools employed ; then 

 proceeded to make a cast in plaster ; and afterwards, from other 

 casts, showed how, by means of the statuary's compass, the posi- 

 tions of the various points upon the finished cast were transferred 

 to a block of marble, and the manner in which, guided by these 

 points, the artist wrought the stone, and produced his finished work. 

 ITie various operations he described were performed by himself, or 

 by workmen ; and the use and principles of all the tools employed 

 were explained and shown. 



The library tables were covered with a handsome present 6y Dr. 

 Nicholl, of about 200 volumes of medical literature, which, with the 

 works on the same subject already in the Institution, will probably 

 become the nucleus of a perfect medical library of refereri(^^ ^_ . 



voqr May 2d. 



Mr. J. Knowles, F.R.S., of the Navy Office, began his account 

 of the rise, progress, and present state of naval architecture. See 

 May 16th. 



Numerous specimens of books, minerals, and. chenjKal prq)ara- 

 tions,.were laid upon the tables in the library, •vjm'ioh^q aJooH 

 '/jMiKJ- May 9th. ■ ' ' '' *' '^ .s^lov^t oj ^bj;.i 



' • Tfi^'lubject of the evening was the nature WMiislcS'^Mcfr it 

 was delivered by Mr. Faraday, but supplied by Mr. Wheatstone. 

 Musical sounds differ from noises in their quaUty of pitch, a qua- 

 lity usually expressed by the terms high and low, grave and acute. 

 So essential is pitch to a musical sound, that it alone renders the 

 sound subject to the laws of melody and harmony. However sounds 

 may differ in other qualities, and those of a bell, a harp, and a flute 

 may be taken as instances, yet agreeing in this, the most unpractised 

 ear can perceive their relation and musical nature. 



Gallileo first correctly indicated the^nature of the pitch of sounds, 

 and showed that it depended altogether upon the number of vibra- 

 tions or impulses made by a sounding body in a given time. Thus, 

 if two strings be taken, and one made to vibrate faster than the 

 otheri it will yield a sound of a higher pitch ; and if it vibrate 

 twice as fast, its note will be an octave higher than that of the other 

 string. 



All sounds are produced by impulses or vibrations, which are 

 usually communicated to the auditory nerves, through the medium 



