A
LETTER
OF
Monſieur de Robberval
TO
Monſieur de Fermates,
Counſellour of THOULOUSE,
Containing certain Propoſitions in the
MECHANICKS.
LETTER
OF
Monſieur de Robberval
TO
Monſieur de Fermates,
Counſellour of THOULOUSE,
Containing certain Propoſitions in the
MECHANICKS.
MONSIEUR,
I have, according to my promiſe, ſent you the
Demonſtration of the Fundamental Propoſi
tion of our Mechanicks, in which I follow the
common method of explaining, in the firſt
place, the Definitions and Principles of which
we make uſe.
Demonſtration of the Fundamental Propoſi
tion of our Mechanicks, in which I follow the
common method of explaining, in the firſt
place, the Definitions and Principles of which
we make uſe.
We in general call that Quality a Force or
Power, by means of which any thing whatever
doth tend or aſpire into another place than that in which it is, be it
downwards, upwards, or ſide waies, whether this Quality naturally
belongeth to the Body, or be communicated to it from without.
From which definition it followeth, that all Weights are a ſpecies
of Force, in regard that it is a Quality, by means whereof Bodies
do tend downwards. We often alſo aſſign the name of Force to
that very thing to which the Force belongeth, as a ponderous Bo
dy is called a Weight, but with this pre-caution, that this is in re
ference to the true Force, the which augmenting or diminiſhing
ſhall be called a greater or leſſer Force, albeit that the thing to
which it belongeth do remain alwaies the ſame.
Power, by means of which any thing whatever
doth tend or aſpire into another place than that in which it is, be it
downwards, upwards, or ſide waies, whether this Quality naturally
belongeth to the Body, or be communicated to it from without.
From which definition it followeth, that all Weights are a ſpecies
of Force, in regard that it is a Quality, by means whereof Bodies
do tend downwards. We often alſo aſſign the name of Force to
that very thing to which the Force belongeth, as a ponderous Bo
dy is called a Weight, but with this pre-caution, that this is in re
ference to the true Force, the which augmenting or diminiſhing
ſhall be called a greater or leſſer Force, albeit that the thing to
which it belongeth do remain alwaies the ſame.
If a Force be ſuſpended or faſtned to a Flexible Line that is
without Gravity, and that is made faſt by one end unto ſome Ful
ciment or ſtay, in ſuch ſort as that it ſuſtain the Force, drawing
without Gravity, and that is made faſt by one end unto ſome Ful
ciment or ſtay, in ſuch ſort as that it ſuſtain the Force, drawing