232 MAXIMUM DENSITY OF WATER. 



The refult of this experiment was very interefting, and It 

 feems to rae to throw much light on the fubjeftof thel'e invef- 

 tigations. 

 F-ffcft on the It was not till 50 feconds had elapfed that the thermometer 



lh^Tu""'much" ^^S^" ^^ ^^®^ ^^y ^S"^ °^ "^^"S» and ^^ ^^e end of one mi- 

 tfj. nute and feven feconds it had only rifen two degrees. 



In the foregoing experiments, when the metallic ball was 

 fo much colder, the thermometer began to rife in ten feconds, 

 and at the end of one minute and three feconds it had rifen 

 five degrees. 



This difference is very remarkable ; and if it does not prove 

 the exiftence, and great efficacy of currents, in conveying 

 heat in fluids, I muft confefs that I do. not fee how the exift- 

 ence of any invifible mechanical operation, the progrefs of 

 which does not immediately fall under the cognizance of our 

 fenfes, can ever be demonftrated 



As the experiment made with the ball heated in boiling 

 water appeared to me to be very interefting, I repeated it 

 twice, and its refults were. always nearly the fame. 



The mean refults of thefe three cj^periments were as fol- 

 lows: .. . 



Tabulated re- 

 fults of experi- 

 inents repeated ; 

 with the cone at 

 a confidcrable ^'""^ «'^P*^*^» 



beat* 



Comparative 

 view of the ex- 

 periments* 



Temperature of the 

 reckoned from water in the cork cup, 



the beginning of as ihewn by the thcr- 



the experiment. mometer. 



Min. Sec. 



32® 



At 50 the thermometer begun to rife. 32-|- 



At 1 2 had rifen to - - . - 33 



17 34f 



1 18 25 



22 36 



3 2 ------- 36| 



4 17 37 



6 12 38 



7 17 ------- 38f 



9 38f 



12 - - - - - - - 38| 



U - - 38| 



By comparing the mean refults of thefe experiments with 

 th^ mean refults of thofe in which the ball was at the tempe- 

 rature 



