80

for the instrument of Representing the suns motion to a Second. the Operator was inioyned to procure at Woolwich
a glasse body as long and wide as can be made for making Expts. of the Descent of Bodys in Water. [mariott about
observing the winds] It was orderd that a weather clock should be bespoke by the Curator, such a one as Dr. Wren had for -
merly contriued, for obseruing not only the winds and their quarters and degrees of Strength, but also the quantitys of Raine
and other particulars relating to the temperature of the air. [.qr. Gillams paper On the file abt. Hudson's Bay. -
May. 26. the Curator produced an opticall Expt. whereby the Representation of Obiects in a Dark room furnisht with a Lens
is made applicable to painting soe as to Exhibit and Draw in colours the face of a man or any other obiect as bigg as
the life. It was ordered that against the next Day something should be designed and if it could be painted by the -
meanes of this Instrument. It was suggested that whereas the pictures represented in the Darkned box are inverted
they may be reuerted by the Reflection of a flat piece of metall, though others were of opinion that that would alter
the colours of the Obiects represented. The Curator being Calld vpon for the New windgun. as also for the Weather clock
sayd they were both bespoken & should be brought in soe soon as they were ready. - Sr Ro: Moray was Remembred to -
make an obseruation of the variation of the needle together with Mr. Hooke. [miscellenea curiosa & travaginj Books] qr.
about Sr. Nic. Millets obseru. of Variatio]
Iune.2. 1670. The expt. of applying the Representations of outward objects in a dark room to painting was Repeated
and it being Doubted, whether if any fals line were drawn this way, the Painter could correct it. It was orderd some pic
ture should be drawn against the next Day. [about travaginj book] The Curator was put in minde of the Weather clock. Of
bringing in the written account of the Expt. of Representing serene & cloudy weather in a glasse of making an Obseruatio
of the present variation of the needle. Of procuring a Manuscript concerning Many years of obseruations of the same. Of Ob:
seruing Iune. 10. the Distance of the starr in the Head of the Dragon from the Zenith. --
Iune. 9. the Dark box for painting all sorts of Obiects was produced again with Some Improuements which were chifely 2. i.e.
1. the changing it into a conuenient posture for Drawing, and the Representing the figures Direct. But the Later being
Done only by a looking glasse which taketh off much of the brightnesse of the picture, the Curator thought that a Met
=talline plate well polisht would Doe much better. It was orderd the Curator should try to make a picture this way against
next Day. Orderd also that Sr R Moray & the Curator doe meet at whitehall to morrow night for Obseruing the present variatio
of the needle, and that the curator prepare things necessary for that Obseruation. Orderd likewise that the curator make
ready for measuring a degree vpon the Earth in the next Uacation. The place to Doe it in was appointed to be Bedford
Riuer about 20 miles in Length, formerly Surueyed with Exactnesse by Mr. More. [about Grafting mentio of Sr. Sam
Morelands speaking instrument.] -
Iune 16. nothing entred. - 23. Sr. Rob: Moray & Mr Hooke made a Report that Iune 13. 1670 they had made an obseruation to finde whether
there were now a difference of the present meridian from that which was formerly made on the Diall in white hall Garden. they made their Ob-
servation by the north starr, in this manner. at 10h wanting 4 minutes they began to obserue the said Starr to be iust East at 1h & 1/4
they hung on poles perpendicular threeds which couered one another and the starr and the south east side of the said Dyall. The bredth
of the sayd Dyalls vper edge to the opposite was 4 foot 41/2 inches and the plain between the two perpendiculars threeds was Distent
from the north edge east edge of the Diall 3 inches wanting a twentieth part, which giues the angule of the Poles Distance
eastward from the meridian of the Dyall. here the Bredth of the Dyall giues the Radius, and the Distance of the plane between
the two perpendiculars giues the tangent. Then the Difference between the Distance of the starrs from the pole and
the Distance of the plane between the perpendiculars from the side of the Diall giues the Distance of the Diall from the Me
ridian if any there be. [Vz. Oldenburg Enterd not the 3 last meetings. vizt. Iune. 16. 23. & 30. but only this Last nonsense - - -
Iuly. 7. the Curator produced again his Darkned box improued, soe that now it is proper for the hand to Draw a picture conueniently by a Me -
talline speculum and a movable Bottom, whereby the picture appears both erect & Direct. some Expts. were made to find out the
comparatiue weights of some metalline bodys to water. [they are all fals & shams Vz - Iuly 14. showed off.
Iuly 27. [Wallis has 2d part de motu. Mengolj about Refractions. Hevelius his obs. of needle at Dantzick Declination Westward 7o. 20'
on Iune 22 last. but in 1642. its declination westward was but 3o.5'.] mr Hook was put in mind to pursue the Obseruation of the meri
dian at whitehall together with Sr. R moray. [Dr Wittys Letter. - The Expts of weighing copper & siluer were referred to the next
meeting as also the examination of Mr. Hookes Instrument for taking angules. --
Iuly. 28. There was examined an Instrument diuised by Mr. Hooke for measuring the Distances of celestiall bodys, by ta-
king angules conceiued to be of greatest vse at night which is soe contriued that two obiects meeting at the point of a pin
are seen at once, one Direct vpon one arm of the instrument furnisht with a telescope, the other by reflection on the other
arme sliding vpon a Ruler diuided into aequall parts. It was orderd that such an instrument as this should be made to
be sent to Sea. [Dr Crone was desird to procure Sr Nic Millets observs. of the needle for many years. and he & mr Hooke to per
use it & make a report] this was never seen by R Hooke]. Sr. R Moray & Mr Hooke were desired to Obserue the present variation
" of the needle at whitehall garden during the Discontenuance of the societys meetings. -- The curator reported to
" the Society that he had already found soe much as to suspect some Parallax of the Earths Orb and conceiud it would
" be more sensible half an year hence. He sayd that by a perpendicular tube he did Obserue the Starrs which passe
" our zenith at Different times of the year, and by noting whether the same starr, be at those Different times of Ob
" seruation, at the same distance from the zenith or noe. Concerning which the Observer affirmd that a certain
" Starr was now Lesse Distant from the Zenith then it had been a month agoe. He was orderd carefully to prose
" cute this observation soe important to Determine the Controuersy of the motion of the earth.
The Society thinking fit to discontinue their publique meetings there was recommended to the Curator during this Re
-cesse the care of these 3 things.1. to continue to obserue whether there be a parallax in the earths orb. 2. to Obserue the
present variation of the needle. 3. to measure the precise quantity of a Degree vpon the Earth --
Octob. 27. many letters books &c.] a Letter of Mr Hugenius at the Hague oct. 31. 1670 (St. N.) conteining his Obseratio of Saturn agree
ing with those of M Hevelius and Mr Hooke, the Later of whom produced his also made in september Last. &c. The Curator
promised to produce the next Day a new watch work which should be quivalent to a pendulum. the same was put
minde to finish at Last the mensuration of the quantity of a degree vpon the earth, he promised that he would by the first
frost and cleer weather observe the Latitudes of the places in Reference to that businesse.
Nou: 3. 10 tracts from montanarj. Dr. Morhosius present and gaue an account of breaking a Romer by singing.
Nou. 10. 5. more tracts from Montanarj.] the Curator produced an essay of a new watchwork which he sayd might be made
into a pocket watch and should goe equally in all positions & motions at Sea. He was desired to perfect it if he could against
the next meeting. --- mr. Hooke made mention of a Little book lately Englished out of french and printed here
about locall motion pretending to haue demonstrated the Rules of motion and proued that of the seuen Rules
giuen by Descartes of that subiect there is but one true. He intimated that he intended to make some Experim
to explore the truth of this authours assertions & to shew them to the Society. - -
Nou. 17. the Curator produced another watch work performing the effect of a pendulum, but acknowledged it not to be as valuable as
what he shewd the Last Day. which therefore he was desired to prosecute & perfect --- the Curator being asked whether he had tryed the
Expt. of Breaking a glasse with an human Voyce, sayd he had tryed it, but found noe other successe than that the glasse had sounded, upon the
sound of a Mans voyce. He was desired to try it again, and to take care of finding the tone of 8 requisite for the effect, and that being
found to continue it for a while forceably & without Interruption. -
Nou. 24. Comitte abt. account Wallis & Flamsteds Letters. Curator Absent. Nou. 30. Electio Day. 0 -
Dec. 8. 1670 The Curator Brought in this Problem of architecture. The Basis of the Distance It should be the Distance of the Bases of
two pillars and the altitutude of an arch being Giuen to find out the right figure of that arch for the firm susteining vpon
the whole or any part of it any weight Giuen as also to find out the Butments of that arch. The proposer being asked
whether he had the Demonstration of this usefull Probleme, said he had it, & would shew it to the President.
He was Desired to shew /represent/ at the next meeting, the mechanicall way of making such an arch by peices of Angules
Standing in such angules as to make the figure of an arch required. which he promised to Doe. --- The Secret

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