178 On the floating of Cork Balls. 



of heat, very ill adapted to the purpofe; and 

 that to arrive at any degree of certainty, it will 

 perhaps be neceffary to weigh the body in vacuo, 

 or at leaft in a vefTel fo confined, as that any 

 current of air through it fhall be prevented ; 

 and that the beam of the fcales fliall be formed 

 of materials lefs liable to expanfion by heat, 

 than metals in general are. 



Remarks on the floating of Cork. Balls in Wa- 

 ter } iy Mr. Banks, Lecturer in Natural Pbilofo- 

 phy. Communicated by the Rev. Thomas Barnes, 

 D. D. Fellow of the American Philojophical So- 

 ciety ^ holden at Philadelphia. 



READ DECEMBER 6, I786. 



PERHAPS no fimple appearance feems fo 

 generally mifunderftood as that of Cork 

 Balls, &c. on Water i and as one falfe princi- 

 ple, adopted, is often produftive of more, a few 

 obfervations on fo fimple a phenomenon, per- 

 haps, may not be thought below the notice of 

 the learned, although perfedly acquainted with 

 the true caufe. That clean bubbles of glafs or 

 pieces of cork, left to fwim in water, contained 

 in clean vefiels of glafs or china, and at the 



diftancc 



