I have not as yet made any attempts of that kind, though I know two or
three wayes, which, as far as I have yet considered, seem very probable,
and may invite me to make a tryal as soon as I have an opportunity, of
which I may hereafter perhaps acquaint the world. In the Interim, I shall
describe the Instrument I even now mention'd, by which the _refraction_ of
all kinds of Liquors may be most exactly measur'd, thereby to give the
curious an opportunity of making what further tryals of that kind they
shall think requisite to any of their intended tryals; and to let them see
that the laws of Refraction are not only notional.

The Instrument consisted of five Rulers, or long pieces placed
together, after the manner exprest in the second Figure of the first
_Scheme_, where AB denotes a straight piece of wood about six foot and
two inches long, about three inches over, and an inch and half thick,
on the back side of which was hung a small plummet by a line stretcht
from top to bottom, by which this piece was set exactly upright, and so
very firmly fixt; in the middle of this was made a hole or center, into
which one end of a hollow cylindrical brass Box CC, fashion'd as I
shall by and by describe, was plac'd, and could very easily and truly
be mov'd to and fro; the other end of this Box being put into, and
moving in, a hole made in a small arm DD; into this box was fastned the
long Ruler EF, about three foot and three or four inches long, and at
three foot from the above mention'd Centers PP was a hole E, cut
through, and cross'd with two small threads, and at the end of it was
fixt a small sight G, and on the back side of it was fixt a small Arm
H, with a Screw to fix it in any place on the Ruler LM; this Ruler LM
was mov'd on the Center B (which was exactly three foot distance from
the middle Center P) and a line drawn through the middle of it LM, was
divided by a Line of cords into some sixty degrees, and each degree was