$94 © Onthe Invention of the Euphon, ' 
noulli, who,’next to the elder Euler, had made confiderable 
additrons to the fcience of acouftics; and) who unfortunately 
loft his lifeofoon after, while bathing ino the Nevay endea- 
voured}in coniequence of the above work, ‘to determine by 
caleulation’ the vibrations: of a fquare plate ; but theirefult 
didnot agree with experience, and Dr. Chladni does, not 
think! it:poflible to advance one ftep im this: theory by ana- 
dyfis alone, ‘ SILLY 
~ While Dr. Chladni was employed in thefe inveftioations; 
hisfituation was exceedinely unpleafant. He, however, did 
not fuller his courage to be deprefled, ‘but exerted his abi- 
Iyaes the more, in order that he might procure. for -himfelf 
better means of fubfifience.» Ashe had examined’ the nature 
of {o many fonorous bodies, be refolved to invent amewanu- 
fical infirument; and he began to confider whether it might 
nat be pofiible by rubbing glafs tubes in a ftraight line, with 
the wet fingers, to produce founds im the fame maineras is 
done inthe harmonica by rubbing them circularly. That 
elafs tubes, lke thofe in hiseuphon, would not merely by fuch 
rebhing emit any tones, he had long known by theory/and 
expericuce ;.and he therefore applicd himfeif;to the folution 
of the difficult quetiion, in what manner the inftrument ought 
to be contiructed to anfwer the intended purpofe. — After ve- 
nous fruitiels attempts for a year and a half, during which 
his gmagination was fo full of the idea,. that fometimes in 
his dreams he thought he faw the inflrument. and heard its 
tenes, that is, hke thofe of. the harmonica, but with more 
diliinctnels and leis confufion, he at length, in a flate ‘be- 
tween fleeping and wakine, obtained a folution of the pro- 
blem which had:given fomuch employment to his thoughts. 
@n the fecond of June 1789, beimg tired with walking, he 
fat down on a chair, ‘about nine iii-the evening, to enjoy a 
fhort flumber; but feareely had-he clofed his eves when the 
mage of an inftrument, fuch as be withed for, feemed. to 
prefent/itfelf before him, aid tertified him fo much that he 
awoke ds! if he had béen faruck by an deétrieflioeky He 
OR imme- 
