130 On Specific Gravity: 
the bulb. Let the band be fastened upon the rod, close te 
where it enters the tube, so as to mark the extent to whicls 
it rhay have entered. The rod must, im the next place, be 
drawa out frosts its tube, to its first position ; and the sector 
6 opened, as that the points may extend from 100 ¢ 
on one leg to 100 upon the other. Leaving the sector thus 
ared, place under the suspended ball, a vessel containing 
an adedoet quantity of the fluid, whose gravity is required. 
If the fluid be iighter than water, in order to cause the tm- 
mersion ‘of the bulb in it, the rod will not have to enter so far 
Stell iby the stop, the number on each leg of the sector, with 
which the points will coincide, gives the gravity of the fluid- 
Forcing as much water into the bucket as had been sufficient 
to sink the bulb in water, will not sink it in a heavier liquid; 
consequently, in the case of such liquids, it will be necessary 
to fill the ee a second time, and force as much more 
water from it, as may be sefficient to cause the immersion of 
ie. The sliding band being then fixed, and the points 
ted and applied to the sector, as before, the number to 
which they extend must be added to the weight of water 
=100, for the specific gravity of the fluid in question 
Small differences are better found by subtraction ; ie for 
instance, > the specific gravity of the fluid were 101 ; 
‘after the small addition of water made to the bucket, be- 
w 
yond the 100 parts required for the immersion of the bulb 
in water, (the band being unmoved,) the points would extend 
from 99 on one leg, to 99 on the other. The difference be- 
tween this number, and 100, is then to be added to the weight 
of water ; so that the specific gravity is found to be 101. 
angle made by the sectoral lines in using the same 
bulb, =< the same rod, will always be the same. Hence 2 
stay many be employed to give the sector the requisite open- 
“Indeed, were liquids alone in question, an immovable see~ : 
‘tofal _— would answer. Thus prepared, it were unneces- 
‘sary to have recourse to watiny Bs Secepiing in the first adjust- 
iment of me scale. The ber of parts required to merge 
‘the bulb in any fluid, will reach (at once or twice) the num- 
ber, or numbers, on the sector, which give the required gra- 
n this process, if greater accuracy be desirable, it is onl 
necessary to employ a smaller rod, or a larger bulb. Instead 
