w^ 



Experiments made tt a/certain 



of Its arms, its centre of gravity, and the three points of fufpenfion of the beam and fcales, 

 and having examined the weights, I proceeded to the remaining parts of this experiment. 



September ad, 1796. The balance-beam adjufted by the fcrew/>, till the vibrations were 

 fo flow as to require more than 50 feconds of time for each, x^ grain appeared to move the 

 index through three divifions* of the fcale s and i,=y inch, when the beam was not loaded ; 

 but when the beam was loaded with 16384 grains, or near 31b. troy, tt»u grain was equal 

 only to oi divifion f of the fame fcalc. 



§ 16. September 4th. The thermometer being at 63*, and the barometer at 29,36 



inches, 



Oz. Grains. Grains. 



The weight of the counterpoife to the! 



pan or fcale for weighing the cube in >• = 1 75,0a =555,02 

 air, was _ _ _ y 



To which the weight of the common-^ 

 pan, with the filk lines on the left arm I 



of the beam, and marked with *•, the > — — =413,40 



common right-hand pan having been I 

 removed _ _ _ J 



And the whole weight of the pan or ap-' 

 paratus for weighing the cube in air^ j- — - — — =968,42 

 becomes - _ _ 



§ 17. The counterpoife to the pan or 

 fcale for weighing the cylinder in airj 

 was found - - 



To which add the weight of the com- 

 mon pan on the left arm, as before 



And the whole weight of the pan or fcale 

 for weighing the cylinder in air be- 

 comes . - . 



f=» 72,34 



I- - 



=55a,34 

 =413,40 



=965,74 



Nate, in the preceding and fuch-Kke experiments, the common right-hand fcale being 

 removed, and the left-hand fcale being always ufed and always the fame weight, viz. 413,40 

 grains, when either the cube or cylinder, or any large body, is weighed, notice need only to 



• Twenty divifions are=i,o inch. 



t That is, the beam was fenfible with „/„oo part of the whole weight. Mr. Harris's beam, with which he 

 and Mr. Bird made their obfervations on the exchequer weights, turned with jj/j^j part of the whole weight, 

 and was confequently only one J part fo fenfible as this. See " The Report of the Committee of the Houfe 

 "of Commons in 1758, to inquire into the original ftandards of weighti and meafures in this kingdom, and 

 " to confider the laws relating the. to." See alfo a fccond Report in 1759 ; both of which contain a vaft 

 dealof ufeful information on this fubjeft, extending through fifty folio pages, and are to be found in the td 

 vol. of Reports, from 1737 to 1767. A bill was brought in, in confequence, but afterwards dropped ; and it 

 i« much to be lamented that this inquiry did not go to the full length of an aft of Parliament. Note farther, 

 the largeft of the beams, of which there are forae of different fizes now made ufe of in the duchy court of 

 Lancafter, for the aftual fiziog of the weights of the kingdom, is about three feet long, and is moveable with 

 •bout 30 grains when 561b. avoirdupois are in each fcale, viz. about ,,5„ part of the whole.— G. S. E.-^"" 

 S^n account of nine other balances may be feen in my Firft Principles ofCbemiJiry, chap. VI. — N- 



be 



