on Spirituous Liquors * 
quadrupled, &c. according as one, two, three, or more weights 
were employed, the diameter of the item being leffened in the 
fubduplicate proportion of the increafed length of the divi- 
fions. Of late this principle feems to have been carried to ex- 
cefs;, the number of weights adapted to fome hydrometers 
being fo great as to prove very inconvenient in practice. A. 
mean between the two methods would certainly be bell, which 
might be fuited to our tables in the following manner. 
It is propofed to determine the fpecific gravity to three places- 
of decimals, water being taken as unity : the whole compafs 
of numbers, therefore, from rectified fpirit to water, at 60 
degrees of heat, would be the difference between ,825 and 
1,000, that is, 175 ; call it 220 to include the lighted: fpirit 
and heavieft water, at all the common temperatures. Of thefe 
divifions the ftem might give every twenty, and then ten 
weights would be diffident for the whole 220. By making v 
the ftem carry twenty divifions, an inconvenience much com- 
plained of, that of fluffing the weights, would in great rpiea- 
iure be avoided ; becaufe a per foil converfant in fuch- bufinefs 
would feldom err to that extent in judging of the ftrength of* 
his fpirit previous to trial ; and yet the ftem would' not need to- 
be fo large, or the divifions fb fmall, as to preclude the defired 
accuracy. In conformity to this arrangement it would be pro- 
per, that the weights adapted to the hydrometer fhould be 
marked -with the numbers of the fpecific gravity, zero on the top- 
of its ftem,. without a weight, being fuppofed to mean Soo 7 
and 20 at the bottom of the ftem to fignify 820, which number 
the firft weight would carry ; the fucceffive weights would be 
marked 840, 860, &c. ; and the divifion on the ftem cut by 
the fluid under trial would be a number to be always added to 
the number marked upon the weight,- the fum of the two 
fhewing. 
