riment (for it being a very good one, I had carefully preserv'd it:)
And after having tryed it over and over again; and being not well satisfied
of some particulars, I, at last, having put all things in very good order,
and being as attentive, and observant, as possibly I could, of every
circumstance requisite to be taken notice of, did register my several
Observations in this following Table. In the making of which, I did not
exactly follow the method that I had used at first; but, having lately
heard of Mr. _Townly_'s _Hypothesis_, I shap'd my course in such sort, as
would be most convenient for the examination of that _Hypothesis_; the
event of which you have in the latter part of the last Table.

The other Experiment was, to find what degrees of force were requisite to
compress, or condense, the Air into such or such a bulk.

The manner of proceeding therein was this: I took a Tube about five foot
long, one of whose ends was sealed up, and bended in the form of a
_Syphon_, much like that represented in the fourth Figure of the 37.
_Scheme_, one side whereof AD, that was open at A, was about fifty inches
long, the other side BC, shut at B, was not much above seven inches long,
then placing it exactly perpendicular, I pour'd in a little Quicksilver,
and found that the Air BC was 6-7/8 inches, or very near to seven; then
pouring in Quicksilver at the longer Tube, I continued filling of it till
the Air in the shorter part of it was contracted into half the former
dimensions, and found the height exactly nine and twenty inches; and by
making several other tryals, in several other degrees of condensation of
the Air, I found them exactly answer the former _Hypothesis_.

But having (by reason it was a good while since I first made) forgotten
many particulars, and being much unsatisfied in others, I made the
Experiment over again, and, from the several tryals, collected the former
part of the following Table: Where in the row next the left hand 24.
signifies the dimensions of the Air, sustaining only the pressure of the
_Atmosphere_, which at that time was equal to a _Cylinder_ of _Mercury_ of
nine and twenty inches: The next Figure above it (20) was the dimensions of
the Air induring the first compression, made by a _Cylinder_ of _Mercury_
5-3/16 high, to which the pressure of the _Atmosphere_ nine and twenty
inches being added, the elastick strength of the Air so comprest will be
found 34-3/16, &c.

_A Table of the Elast