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Dr. wilkins mentiond that mr Hook had a way of Discouering a second minute
of time by a sundiall or the starrs to be performed by a certaine Instrument, which
Discouery he looked vpon as greatly conducing for the finding of the vniuersall measure
It was orderd the Instrument should be made for that purpose.
August the 31. 1664. The expt. of measuring the refraction of common water was made wth
the new Instrument prepared for that purpose, and the angle of inclination being 40 deg:
filled vp to the wire 14 degrees. But when the same was soe filled that it Iust couered
the wire it was 20o. orderd that this Expt. wth Common water be prosecuted, to see how it
agreeth to what has been of the same kind Experimented by others, and that it be
done at the seuerall Degrees of Inclination from the perpendicular & wth. seuerall
depths of water. afterwards to try with other liquors. Sr. Rob: moray gaue an account
of the Expt. tryed againe on Pauls steeple wth a pendulum of 200 foot Long wth an appendent
weight of 14ll. vizt that it made two Vibrations in 15". (Zulichems Letter: describing
his Instrument for falling bodys ^ /which was found/ not much Differing from that of mr Hooke invented before)
also a new Obsn: of Saturn made by Campini at Rome vizt that the circle had couerd a
part of the sphere aboue and couered thereby below with a Little shadow vpon the circle
below and vpon the sphere aboue also of campanys pretending to make telescope by a turne wth
out a tool. about woonds. powder tryed.

There was also made an Experiment of the velocity of bodys descending in Common
water & it was found that small shot did in a narrow cane of 81 inches long fall
to the bottom in Somewt more than 2".
Sep: 7. 1664 The Expts. of the Descent of bodys in Water were prosceuted wth Balls of wax of Se

uerall bignesses, and it Did appear in a Glasse Cane of 81 inches Long that the Lesser Balls descended
wth ^ /an/ equall velocity But the Bigger with vnequall. (to be prosecuted in Dr Godderds vessell)
The expt. of firing Prince Ruperts powder in the steel case, was tryed againe the holes formerly
made in the Case being stopped vp. & it was found that the powder kept a hissing for a pretty
while before it went off, and then made a report wthout any breech of the peice, but only opend
all the holes that were stopped vp. orderd that these holes be screwed vp for another expt. & that
the touch hole be made somewt greater. (Pulvis fulm: flames before it goes off.)
Orderd that Dr. Charlton & mr. Hooke doe meet on Saturday next in the afternoon to try the
velocity of a Bullet shot out of a Gun.
mr Hook gaue an account to the Company that the mercury in the Torricellian Expt. made at
Paules was at the top of the steeple fallen about half an inch, beneath the station thereof
at the Bottom of the Church. Orderd to be prosecuted on tuesday morning next at 9 of the clock
The same Related to haue found those starrs in Orions Belt. wch. monr De Zulichem
maketh but three to be 5. It was orderd that he hauing a 36 foot glasse, a fit tube
should be made for it vpon the account of the Society to make celestiall obseruations
with. The same was put in mind to prepare his Instrument for measuring seconds
of time by the Sun or starrs (about in octob: 25. 1664.)
septemb: 14: 1664. An account giuen by the Pret. of some expts. made on the top of Pauls steeple 1st. was to measure the
vibrations of a Pendulum of 200 foot long which was found to vibrate 13 times in 100". the excursion
being about 12 foot and when the excursion was but 1 foot or thereabout there wanted in those 13 vibra
tions about 1" or 2" in 100". 2ly. to discouer the Difference of the weight of Bodys on the top of the
steeple & below where an Iron and chord enough to reach from the top to the bottom being coun
terpoysed wth. 15ll. pounds troy and brought to an equilibrium and the Iron being let down by
the chord, the weight aboue did preponderate the weight below by a drachm. 3. was a repetiti
=on of the Torricellian Expt where the mercury was found as formerly to subside on the top of
the steeple about 1/2 an inch beneath its standerd below. the Experiment for finding the ve
locity of falling bodys could not be made, because the Instrument for measuring broke, it was there
fore orderd to try it another time as also to repeat the Expt. of weighing bodys aboue and below
by trying it with a single weight on a wire (Pr: Rupert to be furnisht, & desired to try in his Expedi
tion to Guinea the sounding Balls and the Bucket for fetching water from the bottom

Ref: CELL/RS/HF_035  © Centre for Editing Lives and Letters