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and with that Speed, as tis done in Animalls. yet the Curator was orderd to consider more fully of it, and to acquaint the Societ[y]
with the result of his further considerations. He suggested that if it can be done Leisurely this way, he thought, the motion-
might be rendred quick by Springs.
Feb. 10. the Curator Absen. Wintrops Letter and present produced qr. what is meant by writing my name three times in these minutes
Feb: 17. Mr. Hooke produced a peice of staining improued. the same promisd for next Day an Anatomicall Expt. concerning the Lungs. --
Feb: 24. The Curator reported that the Anatomicall Expt. concerning the vse of the Lungs which he had promised to make in priuate
had not succeeded, but that he intended to try it again before the next meeting. He shewd an experiment to illustrat
how those pretty figures of trees that are naturally made vpon Diuers stones may be formed by art which he did by rub-
bing two polisht marbles together, between which there was putt some water; soe that after they had been a
Little while rubbed together, and were therevpon soe drawn as that some air might intermix and Dilute the Water
there appeard plain figures of the . . . . . . forme of trees. whence it was guessed that the like figures formed by
nature vpon sundry . . . stones, may be made by some water ousing through stones & working vpon them
air being intermediat and Dilating the liquor. [about making salt water fresh.
March. 3. Mr. Ieffryes gaue some account of the two stellar Eclipses Lately obserued by him & mr Hook he was desired to
bring it in writing the next Day. [the Spanish plow. Willisell to Deliuer his collection to Mr Hooke]. Orderd that Dr Pope Mr Iefferys
& mr Hooke doe inform Thomas Willisell of such Naturall things as may be had in England and are yet wanting in the Societys
repository, and that the said Willisell take order & Directions from them what to inquire after and bring home for the future. -
(Dr. Du moulin translated Dr Sprats history of the R. Soc into French. (mr C. Howard Red glasse.
Mar. 10. redstreak grafts. Vz. Expt. about the swelling of Arterys by pulse. Ent clark Goddard croon of contrary opinion.) the opera
tor was inioyned to put Mr Hooke who was absent in mind of the anatomicall expt. concerning the motion of the blood in ani-
malls without the concurrence of the Lungs.
Mar. 17. there was made an Expt with 2 long pendulums having two Leaden balls of aequall weight fastned to them and mouing the
one in water and the other in air, to see the difference of the resistance of the two mediums to them, it was found that the pen-
dulum mouing in the air made 13 vibrations, whilst that in Water made but 12. It was suggested that it were worth while
to try this expt. in a large exhausted Receiuer with a large cane to it to see how long the pendulum will moue before it stops
and afterward to try it also in compresst air. Orderd that this Expt. be made next Day.
Mar. 24. the curator being calld vpon for the expt. of mouing a pendulum in an exhausted Receiuer, said that Mr. Boyle since the Last
meeting had told him that there was noe sensible Difference between the Celerity of a pendulums motion in the air & that in Vacuo.
Howeuer it was orderd that this Expt. should be made before the Company at their next Meeting. The same made a Report of the
obseruations made by himself and Mr. Iefferys to two Late stellar eclipses predicted by Mr Flamstead and hapned feb. 25
and March 3. 1669/ 70 concerning which he said that in the former they could not see the subingresse but saw the Egresse
The time of which agreed very neer with that assigned by Mr Flamstead. And that in the Latter they obserued the time
of the Subingresse 17h. 2'. which differs considerably from the Calculated time of Mr Flamstead. And they added that they
expected the egresse till 18h. 45' but the day then cleering vp and the Smoke & vapours ascending they lost the sight
they had of the moon. These observations were said to haue been made wth a 6 foot telescope. -- On this occasion it was
mentiond that the same mr Flamstead had affirmed that though the Almanack makers had pretermitted the eclipse of the of Apr. 9. next
as invisible here, yet heeded by his Calculations from the Caroline tables found that a part of the said eclipse, if the air were serene would
be conspicious in these parts which he publisht together with the whole calculus in the transactions numb: 55. [more mineralls
controversy between Wallis & chaldrey] -- March. 31. 1670. noe sessions -
Apr. 7. 1670. Mr. Flamstead to be desird by Mr. Oldenburg to proceed in making the Calculatio & tht M Hooke will vndertake to make
the Obseruations. --- Mr. Hooke was desired to find out a place to make his obseruations of the sun & stars by a new
way he then proposed Vz. Vz.
Apr. 14. the expt. of mouing 2 pendulu of aequall Length and bignesse with two Leaden Balls of aequall weight the one
in the open air the other in an Exhausted Receiuer, was made and it was found that that in the Receiuer moued a conside-
rable time longer then that in the open air, which later was set at somewhat a bigger arch to giue it the ad
vantage ouer the other. It was orderd that this expt. should be made again the next Day, in such a manner that a gage to put into
the Receiuer to see what air it holds. as also to put both the pendulums into Receiuers one exhausted the other not, thereby
to keep the Later as well as the former from the agitation of the air. Further to try it with Balls of light Materialls, as-
cork. seald bubbles &c. to make the disproportion appear the more. ----- There was also made an Experiment
to represent the thickning & cleering of the air, by a Glasse filld with a cleer solutio of copper, which hauing another
liquor powred into it became thick, by hauing some of its particles precipitated, and then another liquor being
infused into it cleered up from the Bottom, and Represented cloudes hanging in the midst of the Liquor, and by little
& little exhaling into the air [Auzouts obs: of magnet Variatio at Rome 2o Westward.] this being consonent to what is
pretended hereby Mr Bond. whose hypothesis of the motio of the magnet Leads him to affirm that this year the Variation
at London will be 2o. 18'. It was orderd that Mr. Hooke should direct an easy & sure way to Describe an Exact Meri-
dian, And that then obseruations should be made to see how far they did verify mr. Bonds hypothesis: Mr. Hooke
suggested a Way for Striking exact meridians by the north starr, and by obseruing the time of the Night -
Apr. 21. there was made an Expt. with 2 pendulums having two leaden balls of aequall weight appended to them, the one hanging in
the open air the other in a tun of water in which it was immersed about a foot deep. and it was found that the pendulum in the air
made 12 uibrations whilst that in the water made but 11. It was ordered that an history should be brought in of the Expts. made
of this kind for the Register booke. Mr Hooke brought in his Instrument to obserue the motion of the Sun to Seconds
This was orderd to be produced again the next Day. and to shew it vpon the Leads of Arundell house if the Sun Shine
[mr Hyerns hypothesis of tides by a librating motion north & south Recomended to the consideration of Dr. Wallis.] Mr Hooke intimated that
he had another Hypothesis concerning the tydes differing both from that of Dr. Wallis & Mr. Hyern, which when he had Ripened he
would present to the Society. The same was desired to giue in writing a Description of an Expt. that he had made the Last Day
Representing the Serenity & Cloudinesse of the air by the successiue infusion of two different Liquors into a solution of copper.
which he promised to Doe. the Obseruation of the present Declination of the needle was again recomended to Mr Hooke.
The curator was put in mind of prosecuting the Experiments of the motion of Pendulums in the air and in the exhausted Reci
-uer. And of the motion of the blood in animalls out of the veines into the arterys, without the concurrance of the lungs.
Apr. 28. It was orderd tht the Operator should forthwith bespeak a glasse tube as Large as it can be made & 8 foot long at Least,
therein to make Expts. concerning the Descent of Bodys in Water. Orderd also that the instrument contriued by the curator for
Obseruing the Motion of the Sun, be produced again the next Day. The Curator produced his contriuance of the glasse tube
posited perpendicularly for obseruing the starrs in the zenith to try the finding The Parallax of the Eaths Orb, in order to
Determine the question of the Earths motion. He was Solicited to carry on these obseruations with Care & Diligence. -
May. 5. The Curator brought in his Instrument for obseruing the motion of the Sun to Seconds. The Experiment being -
made with it but imperfectly, it was ordered that against the next Day it should be fitted with a ball & socket to keep
it steady. [Dr Wrens way for winding vp weights by the Rope winding about 2 cylinders.] this being esteemed applicable to
clocks the Curator was orderd to make a tryall of it. May. 12 noe sitting.
May. 19. Dr. wrens newly invented instrument for Drawing vp great weights from deep places, was described in writing.
The curator produced an engin that may Serue for a wine gun and be more easily charged than an ordinary one, & yet shoot as certainly as tht. the Value
being yet wanting, it was ordered it should be made ready for the next Day. It was also ordered that the Variation of the needle should be obserued by
Sr. Rob: Moray & Mr Hooke at Whitehall Iune 1. next. The curator was put in minde to get a ball & socket made against next day for the Instru

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