_Weights absolutely equall, moved with equall Velocity, are of
equall Force and Moment in their operations._
_DEFINITION V._
Moment, amongst Mechanicians, signifieth that Vertue, that Force,
or that Efficacy, with which the Mover moves, and the Moveable
resists.
_Which Vertue dependes not only on the simple Gravity, but on the
Velocity of the Motion, and on the diverse Inclinations of the
Spaces along which the Motion is made: For a descending Weight
makes a greater Impetus in a Space much declining, than in one less
declining; and in summe, what ever is the occasion of such Vertue,
it ever retaines the name of Moment; nor in my Judgement, is this
sence new in our Idiome, for, if I mistake not, I think we often
say; This is a weighty businesse, but the other is of small moment:
and we consider lighter matters and let pass those of Moment; a
Metaphor, I suppose, taken from the Mechanicks._
As for example, two weights equall in absolute Gravity, being put
into a Ballance of equall Arms, they stand in _Equilibrium_, neither
one going down, nor the other up: because the equality of the
Distances of both, from the Centre on which the Ballance is supported,
and about which it moves, causeth that those weights, the said
Ballance moving, shall in the same Time move equall Spaces, that is,
shall move with equall Velocity, so that there is no reason for which
this Weight should descend more than that, or that more than this; and
therefore they make an _Equilibrium_, and their Moments continue of
semblable and equall Vertue.