a Stamhird of FFe'ight and Meajurc, .IJJ 



In another great circle, 90' from the preceding, comprifing the diameters already taken, 



EF and CD, at the interfeclion of the two former circles, were taken : 



Div, of micr. 



"41" 

 44 

 44 



The- diameter 



« /3 



41 

 L40j 



therm. 



diameter 



Div. of micr 



■40 

 41 



42 

 40 



L42J 



therm. 



The diameters 



^n] taken as before ^'^4>^ 

 CD 5 ^43,9 



«/3 - . - 42,5. 



5/ S - - 41,0 



Mean - - t= 43)0, which is that of another great circle or meridian, at right angles 

 to the former ; from- whence it will be feen, that not one of the three circles differs from 

 another more than about ^^i-^ inch. 



The preceding 9 mean dimenlions of the diameter, collected, are 



AB=45, -^ 

 C D =43,9 

 GH=42,6 



Tj y — Q \J^^ mean of which Is =: 43,7 

 'Zf'''*^ ^ in the temperature - 6a'',6 



3'4 =4i>i 



«/3 =42,5 

 y d =4i,o_ 



■Now the import of the foregoing experiments Is this, that when the mean diameter of the 



Iphere is holden between the points of contacl of the gauge, near and ^, the index of the 



micrometer ftiews - - -- - „ =43 '7 divis. 



but, when the bar r is placed there, it fliews ■• » ^ s= 64,5 



the difference is 



and by fo much is the bar fliorter than the diameter of the fphere. 



Thefe divifions^ 20,8, are equal to (§. 26.) 

 and the length of the bar has already (§. 25.) been found 

 therefore the true diameter of the fphere becomes - - 



= 20,8 



inches. 

 ,0,00202 

 = 6,00543 

 = 6,00745 



"nrs5-B 



inch. 



which quantity I think muft be true to within 



(§. 28.) The cube of this diameter, 6,00745 inches X ,5236, as Is well known, will give 

 the contents of the fphere In ciibic inches, viz. = 113,5194 inches, which muft be very near 

 the truth : for, if not, let it be fuppofed that the Inaccuracy In the meafurement, or the irre- 

 gularities in the figure of this fphere, fliould be fuch as to amount to ^^-^a inch, and thefq fo 

 many, without balancing each other, as to produce a fpheroidical form, one of whofe diame- 

 ters 



