and other atouftic Difcoveries. of Dr. Chladni. 393 
merely by ftriking it.. The obfervation, that not only ftrings 
but alfo other elaftic bodies may be made to produce founds 
by drawing a violin bow over them, Dr. Chladni does not 
give as a difcovery of his own; as the fo called iron violin 
has been long known, and as he had read of an inftrument, 
conftructed in Italy *, where glafs or metal bells were made 
to, found. by means of two or more yiolin bows drawn over 
them. But the idea of employing this inftrument to exa- 
mine yibrating tones was firft entertained by himfelf. Hav- 
ing accurately remarked the tones produced by the aboves 
mentioned metal plate, he found that they gave a progreffion 
which correfponded with the fquares of a, 3, 4, &c. Not 
long before he had read, in the Tranfactions of the Royal 
Society of Gottingen, the obferyations of Mr. Lichtenberg 
on the phenomena produced by ftrewing pounded refin over 
a glafs plate or cake of refin, and he repeated many of his 
experiments.. This led him to the idea that, perhaps, the 
various vibratory moyements of {uch a plate would be difco- 
vered by a diverfity of phenomena, if he {trewed over it fand 
or any thing of the like kind. | By this experiment there 
was produced a fiar-formed figure; and the author, having 
continued his. refearches, publifhed the refult of them in a 
work entitled, Difcoveries refpecting the Theory of Sound, 
printed at Leipfic in 1787+. It contains a multitude, of 
new obferyations on the vibrations. of different bodies,, the 
proportions of the tones of which had, been incorreétly 
given by others; on the vibrations which are produced by 
vibration and rotation. conjointly; on the longitudinal vi- 
brations of a ftring, firft announced by the author ; and up- 
on. various other. circumftances relating to acouftics. The 
author addrefled this work to the Academy. of Sciences at 
Peterfburgh, with a view, perhaps, that it might, give.occa- 
fion to analytical inveftigations on the fame Fabia J. Ber- 
4 
tc “ all probability the harmonica of the Abbé Mazzuchi. 
4+ Entdeckungen iiber die Theorie des Klanges, Leipfic, 4787, 4te..., 
noulli, 
