189

And further that in the thinnest medium though the acceleration were
pretty neer what was supposed by the afforesaid authors yet that it
was in none mathematically true - but that there would be in all
all mediums a certaine Degree of velocity wch. the same Descending
body would neuer exceed. though other descending bodys might &
some other would neuer arriue to, After wch. Degree was attained
the progresse of the body would always be made by aequall spaces
in aequall times though neuer soe farr continued prouided the
Grauitating powers remained the same.

notice also was taken that Galileo had supposed that the motion
of a common pendulum was Isocrone, and but that It was after
wards Experimented by mersennus that this assertion would not hold
Though the other problem of Galileo of the Isocrone Descent
of a body vpon the Inclined plaines wthin the circumference of
a circle were mathematically & mechanically true

That mr. Hugens was the first that found out that the motion
of the weight of a pendulum in a cycloeid would make /all/ its
excursions Isocrone, but that he was not the first that applyed
the pendulum to a clock for the Regulating thereof.

Sr. Iohn Lowther queryd who it was that first found out that
the motion of the Descent of Heauy bodys was not the same wth
wt Galileo had ascerted ?

Dr. Croon supposd it was monr. monconys. And that he had it
from a Iesuite in france. But mr. Hooke supposd it to be long
before him and that he did not Remember the mention of it in his
trauells. but that the Iesuite Ricciolus had mentioned it Long
before in his Almagest. -

Dr Croon added that De chales in his Cursus had sayd much
concerning it both from his own & others experiments - -

After this Discourse was ended mr. Hooke shewd an Experiment
of the compression of the water in a glasse pipe in order to the
exhibiting the experiment of examining the Depth of the Sea. And
It was very visible that the effect did answer to wt. was asserted
concerning it to wit that the compression was proportionate to
the Depth of the glasse below the surface. /

Ref: CELL/RS/HF_191  © Centre for Editing Lives and Letters