the Ueffian Pyrites. 365 



IV. The ftem muft alfo be of equal thickneis 

 and ftrength throughout, otherwife it finks not 

 down ftraight, proportionally to the weights ap- 

 plied. 



V. The beft figure for the lowermoft body of 

 the balance is the conical, as fuch, may with lefs 

 refiftance force through the fluid. 



VI. The lines, or degrees on the ftem, muft be 

 made accurate and equal to each other, and one 

 tenth of an inch is a proper meafure, or ftandard 

 to divide by. 



VII. To the cone, or belly below, there is a 

 perforated fcale of a balance appended, for the flu- 

 id to pafs through, and thus the true degree of 

 gravity not to fuffer any alteration. Thefe fmall 

 perforations, however, have not hindered the 

 weighing of running mercury, without the leaft of 

 it draining through. 



VIII. The very balance wherewith the above 

 remarks were made, has a ftem of nine inches, each 

 divided into ten parts, making in all ninety divi- 

 fions i with one grain of fine filver, it finks fix 

 lines, cor.fequently bears in all (from one to a 

 ninetieth degree; only fifteen grains ; whereas my 

 amber ftem, eight inches long, and containing 

 eighty lines, fcarce finks one line with one grain 

 of filver i and thus the firft is fix times more kn- 

 fible than the fecond. A grain I call the fixty 

 fourth part of a drachm, namely, the piece which 

 is marked with fixteen ftandard penny weight. 



IX. A 



