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August 27. 1664. The engine to measure Refractions was produced Examind
and approued of and mr. Hooke the Inuentor thereof appointed to begin the next
Day to try expt. therein as also to giue a description of the Engine to be kept in the
Register Book. Dr Godderd brought in writing some obseruations vpon Expts for
merly made of seuerall liquors in a tube of about 36 foot in Length erected
perpendicular it was orderd they should be registred. The same was desired
to Describe his Instrument with springs & pullys Intended for a Hygroscope and
to take notice of the vselessnesse thereof as It hath been hitherto contriued and to
think of an other way fitter for successe. (mr Packer ^ /paper/ of Damps) Zulichems Letter
of his pendulum watch which may probaly serue for Longitude. his Reflection on the
velocity of Brasse wires. and of the Diuision of the monochord, also vpon those that are
made by mr. Hookes Instrument to measure the Descent of falling bodys &c -)
flatt bell metall plate wth. hole in the middle.) strung on a chord.) (tuning violl for
sounds.) Mr. Hooke made Report that a Leaden ball descended ^ /add/ in the first second
of time fall 15 1/2 foot being tryd by him seuerall times and that the Descent
holds in a duplicate proportion. Orderd that this Expt. should be carefully prosecuted
by him. wth. Balls of seuerall sises & different materialls and in particular wth
Bodys of a cylindricall. orderd that the seuerall expts of breaking wood be prosecu
ted by mr. Hooke. . . . and that they be made vpon the same kinds of wood of seue
rall ages grown at seuerall places and Cutt at different seasons of the year.
Expt. for next day. Refraction. velocity of bodys shot by guns & bows. firing & pulv. fulm
in a dark room to see if they will flame.
August 24. 1664 there was made an Expt. for finding the velocity of a Bullet by
meanes of the Instrument for measuring the time of falling bodys. which was soe con
triued that the bullet /pendulum/ was set on mouing by the bullets passing out of the mouth
of the Carabine and a boord was put vp for a mark at a determinate
distance and a string extended from that boord to the pendulum which was fixt
just by the gun. It was thought that by means of that string that was
stretched pretty stiff, and soe contriued that a small thrust against the boord would
stop the Pendulum the impuls of that bullet against the boord would be presently com-
municated back to the pendulum, by wch. meanes that vibrating body being stopd at the
very Instant, would haue shewn the time that the bullet was passing from the
mouth of the peice to the boord or mark. But it was found vpon seuerall
tryalls that the bullet peirced through the boord which was 3 inches thick
and did not break a small slender peice of white threed which was to haue stopt
the pendulum. Orderd that mr. Hooke consider a better way to try this Expt.
against next Day. Orderd that Dr. Charlton and mr. Hooke be curators for finding
the velocity of sounds wth small and great gunns, with and against the wind -
mr. Hooke Reported to the company how he had begun to make expts. vpon the top
of Paules steeple for measuring the time of the vibrations for such a pendulum
as Reacheth from the top ^ /down/ to the Bottom floor of the said church. which is about
200 foot, and that he had found that a weight of 4 pounds, being hung on
a string of the Bignesse of a crows quill, about 3/4 of the Pendulum remained
steady, the rest making one single vibration in 6 seconds. orderd that this Expt
be Repeated and the torricellian Expt. together wth that of weighing and of the
celerity of Descending bodys be like wise made in the same place [Dr. Popes Letter of
the terrible storm of Thunder lightning haile as bigg as great turky eggs. seconded by mr
Hammonds Letter.) There was Read a paper of mr Hooke concerning pertrifications de
signed by him as a part of his microscopicall book now vnder the presse The com
pany approued of the modesty used in his assertions, but aduised him to omit what
he had deliuerd concerning the Ends . . . in such petrifications -

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