7. A Narration of the Establishment of the _Lyncei_, an _Italian_ Academy,
and of their Design and Statutes: the Prince _Cesi_ being the Head of them,
who did also intend to establish such Philosophical Societies in all parts
of the World, and particularly in _Africa_ and _America_, to be by that
means well informed of what considerable productions of Nature were to be
found in those parts. The Author yet _Anonymus_.
8. To these I shall add, a Book newly Printed in _Oxford_ (and not yet
dispersed) being, _A Catalogue of Fixed Stars_ with their _Longitudes,
Latitudes, and Magnitudes_, according to the _Observations_ of _Uleg-Beig_
(a King, and famous Astronomer, who was _Great-Grand-childe_ to the famous
{146} _Tamerlane_, and one of his Successors in some of his Kingdoms) made
at _Samarcand_, his cheief seat, (for the year of the Hegira 841, for the
year of Christ 1427), who not finding the _Tables_ of _Ptolemy_ to agree
sufficiently with the Heavens, did with great diligence, and expense, make
observations anew; as _Tycho Brahe_ hath since done. It is a small part of
a larger _Astronomical Treatise_ of his, whereof there be divers _Persian_
Manuscript Copies in _Oxford_. Out of which this is Translated and
Published, both in _Persian_ and _Latine_, by Mr. _Thomas Hyde_, now
Library Keeper to the _Bodleyan_ Library in _Oxford_: (with Commentaries of
his annexed:) Like as another part of it hath formerly been by Mr. _John
Graves_. And it were a desirable work that the whole were Translated, that
we might be the better acquainted with what was the Eastern Astronomy at
that time.
* * * * *
_Published with License._
Oxford, Printed by _A: & L: Lichfield_, for _Ric: Davis_. 1666.
{147}
* * * * *
_Num._ 9.
PHILOSOPHICAL
_TRANSACTIONS._
* * * * *
_Munday_, _Feb._ 12. 1665/6.
* * * * *
The Contents.
_An _Apendix_ to the _Directions_ for Seamen, bound for far voyages. Of
the judgment of some of the _English_ Astronomers, touching the
difference between two learned men, about an Observation made of the
first of the two late _Comets_. Of a _Correspondency_, to be procured,
for the finding out of the _True_ distance of the _Sun_ and _Moon_ from
the Earth. Of an Observation not long since made in _England_ of
_Saturn_. An Account of some _Mercurial_ Observations, made with a
_Barometer_, and their Results. Some Observations of _Vipers_, made by
an _Italian_ Philosopher._
* * * * *
_An _Appendix_ to the _Directions_ for Seamen, bound for far Voyages._
Whereas it may be of good use, both _Naval_ and _Philosophical_, to know,
both how to sound depths of the sea _without a Line_, and to fetch up water
from any depth of the same; the following waies have been contrived by Mr.
_Hook_ to perform both; (which should have been added to the lately printed
_Directions for Seamen_, if then it could have been conveniently done.)
{148}
[Illustration]
_First_, for the sounding of depths without a Cord, consider _Figure_ 1,
and accordingly take a Globe of _Firr_, or _Maple_, or other light Wood, as
A: let it be well secured by Vernish, Pitch, or otherwise, from imbibing
water; then take a piece of Lead or Stone, D, considerably heavier then
will sink the Globe: let there be a long Wire-staple B, in the Ball A, and
a springing Wire C, with a bended end F, and into the said staple, press in
with your fingers the springing Wire on the bended end: and on it hang the
weight D, by its ring E, and so let Globe and all sink gently into the
water, in the posture represented in the first _Figure_, to the bottom,
where the weight D touching first, is thereby stopt; but the Ball, being by
the _Impetus_, it acquired in descending, carried downwards a little after
the weight is stopt, suffers the springing wire to fly back, and thereby
sets it self at liberty to reascend. And, by observing the time of the
Ball's stay under water (which may be done by a Watch, having minuts and
seconds, or by a good Minut-glass, or best of all, by a Pendulum vibrating
seconds) you will by this way, with the help of some _Tables_, come to know
any depth of the sea.
Note, that care must be had of proportioning the weight and shape of the
Lead, to the bulk, weight, and figure of the Globe, after such a manner, as
upon experience shall be found most convenient.
In some of the Tryals already made with this Instrument, the Globe being of
Maple-wood, well covered with Pitch to hinder soaking in, was 5-13/16
inches in diameter, and weighed 21/2 pounds: the Lead of 41/2 pounds weight,
was of a _Conical_ figure, 11. inches long, with the sharper end downwards,
1-9/16 inches at the top, and 1/16 at the bottom in diameter. And in those
Experiments, made in the _Thames_, in the depth of 19. foot water, there
passed between the Immersion and Emersion of the Globe, 6. seconds of an
hour; and in the depth of 10. foot water, there passed 31/2 seconds or
thereabout: From many of which kind of Experiments it will likely not be
hard to finde {149} out a method to calculate, what depth is to be
concluded from any other time of the like Globes stay under water.
[Illustration]
In the same Tryals, made with this Instrument in the said River of
_Thames_, it has been found, that there is no difference in time, between
the submersions of the Ball at the greatest depth, when it rose two
Wherries length from the place where it was let fall (being carried by the
Current of the _Tide_) and when it rose within a yard or so of the same
place where it was let down.
The _other_ Instrument, for Fetching up water from the depth of the sea, is
(as appears by _Figure_ 2.) a square woodden _Bucket_ C, whose bottoms
_EE_, are so contrived, that as the weight A, sinks the Iron B, (to which
the Bucket C, is fastned by two handles DD, on the ends of which are the
moveable bottoms or Valves EE,) and thereby draws down the Bucket, the
resistance of the water keeps up the Bucket in the posture C; whereby the
water hath, all the while it is descending, a clear passage through;
whereas, as soon as the Bucket is pulled upwards by the Line F, the
resistance of the water to that motion beats the Bucket downward, and keeps
it in the posture G, whereby the Included water is preserved from getting
out, and the Ambient water kept from getting in.
By the advantage of which Vessel, it may be known, whether sea water be
Salter at and towards the bottom, then at or near the top: Likewise,
whether in some places of the sea, any sweet water is to be found at the
bottom; the _Affirmative_ whereof is to be met with in the _East Indian_
Voyages of the industrious _John Hugh Van Linsckoten_, who page 16 of that
Book, as 'tis _Englished_, records, that in the _Persian Gulph_, about the
Island _Barem_, or _Baharem_, they fetch up with certain Vessels (which he
describes not) water out of the sea, from under the salt-water, four or
five fathom deep, as sweet, as any Fountain water. {150}
* * * * *
_Of the Judgement of some of the _English_ Astronomers, touching the
difference between two learned men, about an Observation made of the First
of the two late _Comets_._
[Sidenote: _By _Telescopical_ Stars are understood such, as are not seen,
but by the help of a Telescope._]
Whereas notice has been taken in _Num._ 6. of these _Transactions_, that
there was some difference between those two deservedly celebrated
Philosophers, _Monsieur Hevelius_ and _Monsieur Auzout_, concerning an
Observation, made by the former of them, on the 8/18 of _February_ 1665. &
that thereupon some Eminent _English_ Astronomers, considering the
importance of the dispute, had undertaken the examination thereof; it will,
'tis conceived, not be unacceptable to such, as saw those Papers, to be
informed, what has been done and discerned by them in that matter. They
having therefore compared the Printed Writings of the two Dissenters, and
withall consulted the observations made with _Telescopes_ at home, by some
of the most intelligent Astronomers amongst them, who have attentively
observed the Position of that _Comet_ to the _Telescopical_ stars, that lay
in its way; Do thereupon Joyntly conclude, that, whatever that Appearance
was, which was seen near the _First Star_ of _Aries_, by _Monsieur
Hevelius_ (the truth of whose relation concerning the same, they do in no
wise question) the said _Comet_ did not come neer that _Star_ in the left
_Ear_ of _Aries_, where the said M. _Hevelius_ supposes it to have passed,
but took its course neer the _Bright Star_ in its _Left Horn_, according to
_Bayers_ Tables. And since that the Observations of judicious both _French,
Italian, & Dutch_ Astronomers (as many of them, as are come to the
knowledge of the _English_) do in the main fully agree with theirs, they do
not at all doubt, but that, there being such an unanimous {151} consent in
what has been just now declared, & the Controversie being about _Matter of
fact_, wherein Authority, Number, and Reputation must cast the Ballance,
Mons. _Hevelius_, who is as well known for his Ingenuity, as Learning, will
joyn and acquiesce in that sentiment.
* * * * *
_Of a correspondency, to be procured, for the Finding out the _True_
distance of the _Sun_ and _Moon_ from the Earth, by the _Paralax_, observed
under (or neer) the same _Meridian_._
Seeing that the knowledge of this distance may prove of important Use, for
the Perfecting of Astronomy, and for the better establishing the doctrine
of _Refractions_, it is in the thoughts of some very curious Persons in
_England_, for the finding out the same, to settle a Correspondency with
some others abroad, that are understanding in Astronomical matters, and
live in places farr distant in _Latitude_, and under (or near) the same
_Meridian_.
To perform which, the following Method is proposed to be observed; _viz._
That at certain times agreed on by two Observatours, making use of
_Telescopes_, large, good and well fitted for this purpose, by a measuring
rod, placed within the Eye glass at a convenient distance, that it may be
distinctly seen, and serve for measuring small distances by minuts and
seconds (which is easie enough in large _Telescopes_) that, I say, each of
such observers, thus furnish't shall observe the visible way of the _Moon_
among the _Fixt Stars_, (by taking her exact distance from any _Fixt
Starr_, that lyes in or very near her way, together with the exact time of
her so appearing) and the then apparent Diameter of her Disk; continuing
these Observations every time for two or three hours; that so, {152} if
possible, two exact observations of her _Apparent_ place among the _Fixt
Stars_ being made, at two places thus distant in _Latitude_, and as near as
may be under the same _Meridian_, by these Observators concurring at the
same time, her true and exact distance may be hence collected, not onely
for that time, but at all other times, by any single Observator's viewing
her with a _Telescope_, and measuring exactly her _Apparent_ Diameter. It
were likewise desirable, that as often as there happens any considerable
_Eclipse_ of the _Sun_, that this also might be observed by them, noting
therein the exact measure of the greatest Obscuration compared with the
then _Apparent_ Diameter of his Disk. For by this means, after the distance
of the _Moon_ hath been exactly found, the distance of the _Sun_ will
easily be deduced.
As for the time, fittest for making Observations of the _Moon_, that will
be, when she is about a Quarter or somewhat less illuminated, because then
her light is not so bright, but that with a good _Telescope_ she may be
observ'd to pass close by, and sometimes over several _Fixt Stars_; which
is about four or five days before or after her Change: Or else at any other
time, when the _Moon_ passes near or over some of the bigger sort of _Fixt
Stars_, such as of the first or second _Magnitude_; which may be easily
calculated and foreseen: Or best of all, when there is any _Totall Eclipse_
of the _Moon_; for then the smallest _Telescopical Stars_ may be seen close
adjoyning to the very body of the _Moon_. Of all which particulars the two
Correspondents are to agree, as soon as he, that is to joyn abroad, shall
be found out; whereupon they are mutually to communicate to each other,
what they shall have thus observed in each place.
* * * * *
_Of an Observation, not long since made in _England_, of _Saturn_._
[Illustration]
This Observation was made by Mr. _William Ball_, {153} accompanied by his
brother, Dr. _Ball_, _October_ 13. 1665. at six of the Clock, at _Mainhead_
near _Exeter_ in _Devonshire_, with a very good _Telescope_ near 38 foot
long, and a double Eye-glass, as the observer himself takes notice, adding,
that he never saw that _Planet_ more distinct. The observation is
represented by _Figure_ 3. concerning which, the Author saith in his letter
to a friend, as follows; This appear'd to me the present figure of
_Saturn_, somewhat otherwise, than I expected, thinking it would have been
decreasing, but I found it full as ever, and a little hollow above and
below. Whereupon the Person, to whom notice was sent hereof, examining this
shape, hath by Letters desired the worthy Author of the _Systeme of this
Planet_, that he would now attentively consider the present _Figure_ of his
_Anses_ or _Ring_, to see whether the appearance be to him, as in this
_Figure_, and consequently whether he there meets with nothing, that may
make him think, that it is not _one_ body of a Circular Figure, that
embraces his _Diske_, but _two_.
And to the end that other Curious men, in other places might be engaged, to
joyn their Observations with him, to see, whether they can find the like
appearance to that, represented here, especially such Notches or
Hollownesses, as at A and B, it was thought fit to insert here the newly
related Account.
* * * * *
_A Relation of some _Mercurial_ Observations, and their Results._
Modern _Philosophers_, to avoyd Circumlocutions, call that Instrument,
wherein a Cylinder of Quicksilver, of between 28. and 31. Inches in
Altitude, is kept suspended after the manner of the _Torricellian_
Experiment, a _Barometer_ or _Baroscope_, first made publick by that Noble
Searcher of Nature, Mr. _Boyle_, and imployed by Him and others, to detect
all the minut variations in the Pressure and weight of the Air. For the
more {154} curious and nice distinguishing of which small changes, Mr.
_Hook_ in the _Preface_ to his _Micrography_, has described such an
Instrument with a _Wheel_, contrived by himself, and, by these two last
years trials of it, constantly found most exact for that purpose: which
being so accurate, and not difficult to be made, it were desirable, that
those who have a Genius and opportunities of making Observations of this
kind, would furnish themselves with such of these Instruments, as were
exactly made and adjusted according to the Method, delivered in the newly
mentioned place.
To say something of the Observations, made by this Instrument, and withal
to excite studious _Naturalists_ to a sedulous prosecution of the same, the
_Reader_ may _first_ take notice, that the lately named Mr. _Boyle_ hath
(as himself not long since did intimate to the Author of these _Tracts_)
already made divers Observations of this kind in the year 1659. and 1660.
before any others were publick, or by him so much as heard of; though he
has hitherto forborn to divulge them, because of some other Papers (in
whose Company they were to appear) which being hindred by other studies and
employments, he hath not as yet finished.
_Next_, that, besides several others, who, since have had the curiosity of
making such observations, the Worthy and Inquisitive Dr. _John Beal_, is
doing his part with much assiduity (of which he hath by several Letters
acquainted his Friends in _London_) both by observing himself, and by
procuring many Correspondents in several places in _England_ for the same
purpose; judging it of great importance, that Observations of this kind be
made in parts somewhat distant from one another, that so from many of
those, accurately made and then compared, it may be discovered, whether the
Aire gravitates more in the parts of the Earth lying more _East_ or _West_,
_North_ or _South_? whether on such as lie neerer to the _Sea_, or further
up into the _Mainland_? in hotter or colder weather? whether in {155} high
Winds or Calms? whether in wet weather or dry? whether most when a North,
or when a South, when an East or a West wind blows? and whether it keeps
the same seasons of Changes? and whether the seasons and changes of the Air
and Weather can be thereby discover'd, and the now hidden causes of many
other _Phaenomena_ detected?
The said _Doctor_ is so much pleased with the discovery already made by the
help of this Instrument, that he thinks it to be one of the most wonderful
that ever was in the World, if we speak of strangeness, and just wonder,
and of Philosophical importance, separate from the interest of lucre. For
(_saith he in one of his Letters_) who could ever expect, that we men
should find an Art, to weigh all the Air that hangs over our heads, in all
the changes of it, and, as it were, to weigh, and to distinguish by weight,
the Winds and the Clouds? Or, who did believe, that by palpable evidence we
should be able to prove, the _serenest_ Air to be most heavy, and the
_thickest_ Air, and when darkest Clouds hang neerest to us, ready to
dissolve, or dropping, _then_ to be lightest. And though (_so he goes on_)
we cannot yet reach to all the Uses and Applications of it, yet we should
be entertain'd for a while, by the truly Honourable Mr. _Boyle_, as the
leading person herein, upon the delight and wonder. The _Magnet_ was known
many hundreds of years before it was applied to find out _New Worlds_. To
me (_saith he_) tis a wonderful delight, that I have alwaies in my Study
before my eye such a _Curious Ballance_.
Having thus in _General_ expressed his thoughts about this Invention, and
the singular pleasure, he takes in the Observations made therewith, he
descends to particulars, and in several Letters communicates them to his
Correspondent, as follows:
[Sidenote: _The Exclusion of _all_ Air is here necessary, because Air being
subject to the operation of Heat and Cold, if any of it remain in the
_Barometer_, it will cause it to vary from shewing the true Pressure of the
Air._]
1. My _Wheel-barometer_ I could never fill so exactly with _Mercury_ as to
exclude _all_ Air; and therefore I trust more {156} to a _Mercurial_ Cane,
and take all my Notes from it. This Cane is but 35. Inches long, of a very
slender Cavity, and thick Glass. This may easily be conveyed to any place,
for Trials. The Vessel for the stagnating _Mercury_, into which the said
Cane is immersed, is about two _Inches_ wide. The _Mercury_ so well fill'd,
that for some daies it would not subside, but hung to the top of the
Glass-cane. I keep it in a Closet pretty close, 9. foot high, 8. foot
broad, 15. foot long; neer a Window. This I note, because possibly the
closeness of the room may hinder, that it gives not the full of all
Changes, as it might in a more passable Air.
2. In all my Observations from _May_ 28. 1664 to this present (_December_
9. 1665.) the Quicksilver never ascended but very little above 301/4 Inches.
3. It ascended very seldom so high (_videl._ to 301/4 Inches) chiefly
_Decemb._ 13. 1664. the weather being fickle-fair, Evening.
4. I find by my _Calender_ of _June_ 22. 1664. at 5. in the Morning, in a
time of long setled fair weather, that the _Mercury_ had ascended about
half an Inch higher then 30: but I fear some mistake, because I then took
no impression of _wonder_ at it; yet for 3. or 4. daies, at that time it
continued high, in well-setled, fair and warm weather; most part above 30.
Inches. So that I may note, the _Mercury_ to rise as high in the hottest
_Summer_, as in the coldest _Winter-weather_.
[Sidenote: _Perhaps this is from some included Air._]
5. Yet surely I have noted it ascend a little higher for the Coldness of
the Weather; and very frequently, both in {157} Winter and Summer to be
higher in the cold Mornings and Evenings, then in the warmer Mid-day.
6. Generally in setled and fair weather both of Winter and Summer, the
_Mercury_ is higher, than a little _before_ or _after_, or _in_ Rainy
weather.