[ 437 ] 
and their Velocities being i and 2 refpeclively, it is 
plain, that the moving Forces are proportional to the 
Mafles and Velocities jointly. Which was to be de- 
monftrated. 
For the greater Facility of examining this Demon- 
Aration, we have fuited it to a fingle Cafe only, and 
that the moft fimplc that can be fuppoled : But every 
body will fee, how eaiy it is to form a general one 
upon the fame Principles. 
As we do not think, that any Flaw can be found 
in either of the Demonftrations above laid down ; 
and the Axioms, upon which they are founded, have 
never yet been difputed, as far as we know; we pre- 
fume, that the Leibnitian Opinion about the Meafure 
of moving Forces, is inconteftably overthrown by 
the firft Proportion, and the oppofite Sentiment is 
as evidently eftablifhed by the lecond. 
Bur, if any Reader fhall be of a different Opinion, 
we muft beg Leave to propofe to his Confideration 
the following Experiment, which we hope may juftly 
deferve the Name of an Experimenting Crucis jand, 
as fuch, may put a final Period to this Controvcrfy. 
It is not new indeed, having been propofed be- 
fore by myfelf and others; bur, as the Manner, in 
which it wasTormerly offered, has given Occafion 
to fome Objections, which, tho' not affe&ing the 
Subltance of the Argument drawn from it, may yet 
have amufed and embaraffed the lefs attentive Read- 
ers, I (hall now propofe it in fuch a Manner, as 
may obviate all thofe Difficulties, and, I think, will 
render it ablblutely decifive. To me, I am f'ure, it 
will be fo, iince I fhall immediately embrace the 
K k k Leibnitian 
