Lectures and collections made by Robert Hooke.
         Hooke, Robert, 1635-1703.
      
       
         
           1678
        
      
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             Lectures and collections made by Robert Hooke.
             Hooke, Robert, 1635-1703.
          
           [6], 112 p., [5] folded leaves of plates : ill.
           
             Printed by J. Martyn, Printer to the Royal Society,
             London :
             1678.
          
           
             Reproduction of original in the Bodleian Library.
          
        
      
    
     
       
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         eng
      
       
         
           Microscopy -- Early works to 1800.
           Microscopes -- Early works to 1800.
           Comets.
        
      
    
     
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           LECTURES
           AND
           COLLECTIONS
           Made
           by
           
             ROBERT
             HOOKE
          
           ,
           Secretary
           of
           the
           
             Royal
             Society
          
           .
        
         
           COMETA
           .
           CONTAINING
           
             
               Observations
               of
               the
               Comet
               in
               April
               ,
               1677.
               
            
             
               Fragments
               of
               several
               Lectures
               about
               those
               of
               1664.
               and
               1665.
               
            
             
               Sir
               Chr.
               Wren's
               Hypothesis
               and
               Geometrical
               Problem
               about
               those
               Comets
               ,
            
             
               A
               Discourse
               concerning
               the
               Comet
               of
               1677.
               
            
             
               Mr.
               
               Boyle's
               Observation
               made
               on
               two
               new
               Phosphori
               of
               Mr.
               Baldwin
               ,
               and
               Mr.
               Craft
               .
            
             
               Mr.
               
               Gallet's
               Letter
               to
               Mr.
               Cassini
               ,
               together
               with
               his
               Observation
               of
               ☿
               sub
               ☉
               .
            
             
               Mr.
               
                 Cassini
                 '
              
               Reflections
               upon
               those
               of
               Gassendus
               ,
               and
               Hevelius
               ,
               and
               upon
               this
               .
            
             
               Mr.
               
               Hally's
               Letter
               and
               Observation
               of
               the
               same
               made
               at
               St.
               Hellena
               .
            
             
               Mr.
               
               Cassini's
               Observation
               of
               the
               Diurnal
               motion
               of
               ♃
               ,
               and
               other
               changes
               happening
               in
               it
               .
            
          
        
         
           MICROSCOPIVM
           .
           CONTAINING
           
             
               Mr.
               
               Leeuwenhoeck's
               two
               Letters
               concerning
               some
               late
               Microscopical
               Discoveries
               .
            
             
               The
               Author's
               Discourse
               and
               Description
               of
               Microscopes
               ,
               improved
               for
               discerning
               the
               nature
               and
               texture
               of
               Bodies
               .
            
             
               P.
               Cherubine's
               Accusations
               answered
               .
            
             
               Mr.
               
               Young's
               Letter
               containing
               several
               Anatomical
               Observations
               .
            
          
        
         
           LONDON
           :
           Printed
           for
           
             J.
             Martyn
          
           ,
           Printer
           to
           the
           
             Royal
             Society
          
           ,
           at
           the
           Bell
           in
           St.
           
           Paul's
           Church-yard
           .
           1678.
           
        
      
       
         
         
           
        
         
         
         
           
        
         
         
         
           
        
         
         
           
        
         
         
         
           
        
         
         
         
         
         
         
      
       
         
         
         
           VIRO
           PERILLUSTRI
           D
           no
           JOSEPHO
           WILLIAMSON
           EQUITI
           AURATO
           ,
           Serenissimo
           CAROLO
           II
           
           o.
           Mag.
           Britan.
           Fran.
           &
           Hibern
           .
           REGI
           ,
           A
           Consiliis
           Secretioribus
           ,
           et
           a
           Secretis
           Status
           ,
           Nec
           non
           SOCIETATIS
           REGALIS
           LONDINENSIS
           ,
           Ad
           Scientiam
           Naturalem
           promovendam
           PRAESIDI
           DIGNISSIMO
           .
        
         
           NEC
           potui
           ,
           nec
           debui
           ,
           
             Nobilissime
             Vir
          
           ,
           cujusquam
           aliûs
           nomen
           his
           Chartis
           inscribere
           ,
           praeter
           Tuum
           .
           Sub
           Te
           natae
           ,
           Tibi
           vitam
           debent
           ;
           Tibi
           
           quoque
           debebunt
           quod
           lucem
           aspiciant
           .
           Egregius
           ille
           Tuus
           animus
           ad
           instaurandam
           Philosophiam
           artesque
           adeo
           omnes
           utiles
           ,
           mihi
           homini
           ,
           alioquin
           subtimido
           ,
           audaciam
           hujus
           dedicationis
           fecit
           .
           Ego
           quae
           nunc
           potui
           ,
           profero
           ,
           magis
           ad
           Gratulationem
           ostendendam
           ,
           quàm
           Eruditionem
           .
           Spero
           autem
           ,
           quemadmoduni
           sub
           Tuo
           PRAESIDIO
           majora
           indies
           Augmenta
           Scientiarum
           in
           hâc
           gente
           fiunt
           ,
           ita
           exorituros
           viros
           doctos
           ,
           qui
           Tibi
           justa
           praeconia
           laudum
           persolvant
           ;
           quod
           ego
           prae
           tenuitate
           ne
           conari
           quidem
           audeo
           ,
           quanquam
           cum
           primis
           sim
        
         
           
             Dignitatis
             &
             Honoris
             Tui
             Studiosissimus
             ,
             ROBERTUS
             HOOKE
             .
          
        
      
       
         
         
           SYNOPSIS
           .
        
         
           THE
           Comet
           seen
           April
           21.
           1677.
           between
           the
           Triangle
           and
           the
           Cloud
           of
           ♈
           ,
           its
           tail
           not
           directly
           opposite
           to
           the
           ☉
           ,
           its
           Magnitude
           ,
           Brightness
           ,
           Head
           ,
           Nucleus
           ,
           Blaze
           ,
           (
           1.
           )
           Why
           sometimes
           shorter
           ,
           sometimes
           longer
           ;
           without
           sensible
           motion
           of
           parts
           .
           Explanation
           of
           the
           first
           figure
           ,
           as
           seen
           by
           the
           eye
           .
           (
           2.
           )
           Of
           the
           second
           Figure
           ,
           as
           seen
           through
           a
           glass
           ,
           of
           a
           parabolick
           termination
           ,
           differing
           from
           the
           representations
           of
           Mr.
           Hevelius
           .
           (
           3.
           )
           The
           Medulla
           ,
           and
           blaze
           with
           the
           manner
           of
           shortning
           and
           lengthening
           ,
           explained
           by
           the
           third
           figure
           ;
           not
           seen
           the
           22d
           .
           but
           the
           23d
           .
           The
           bigness
           of
           the
           Nucleus
           and
           Head
           through
           a
           Telescope
           ,
           compared
           with
           the
           top
           of
           a
           Tower.
           (
           4.
           )
           The
           place
           it
           then
           appeared
           in
           .
           Why
           the
           motion
           was
           not
           more
           exactly
           observed
           .
           It
           s
           blaze
           still
           not
           opposite
           to
           the
           Sun.
           The
           24th
           .
           not
           seen
           ,
           nor
           25th
           .
           (
           5.
           )
           though
           the
           Sky
           clear
           by
           reason
           of
           the
           height
           of
           Vapors
           .
           How
           they
           do
           lengthen
           the
           Crepusculum
           .
           Why
           Physical
           Remarks
           only
           were
           made
           .
           (
           6.
           )
           Published
           in
           order
           to
           understand
           Objections
           ,
           and
           propound
           pertinent
           Queries
           .
           Some
           Observations
           ,
           Notes
           ,
           Queries
           ,
           &c.
           concerning
           the
           Comets
           in
           1664.
           and
           1665.
           here
           .
           Collected
           out
           of
           several
           scattered
           Papers
           and
           Lectures
           of
           them
           formerly
           read
           here
           imperfect
           .
           Queries
           of
           its
           substance
           ,
           magnitude
           ,
           density
           ,
           mutability
           ,
           dissolution
           ,
           fluidity
           ,
           gravity
           ,
           light
           ,
           figure
           ,
           motion
           bended
           or
           straight
           ,
           (
           7.
           )
           with
           equal
           or
           unequal
           velocity
           ,
           in
           the
           Atmosphere
           or
           Aether
           ,
           above
           or
           below
           the
           Moon
           .
           Whether
           it
           wasts
           ,
           or
           lasts
           to
           return
           .
           The
           Star
           of
           a
           compacted
           light
           (
           8.
           )
           varied
           possibly
           from
           position
           ,
           partly
           from
           real
           change
           ,
           Tail
           transparent
           ,
           Body
           supposed
           more
           dense
           ,
           side
           toward
           the
           Sun
           evenly
           defin'd
           ,
           Encompassed
           with
           a
           fluid
           yielding
           to
           motion
           ,
           but
           dissolving
           its
           parts
           .
           It
           s
           light
           from
           its
           self
           .
           (
           9.
           )
           It
           s
           Nucleus
           supposed
           dense
           possibly
           as
           the
           middle
           part
           of
           the
           Earth
           ,
           of
           which
           some
           conjectures
           .
           Dissolved
           by
           the
           Aether
           as
           in
           our
           Atmosphere
           .
           (
           10.
           )
           Argument
           for
           the
           looseness
           of
           the
           central
           parts
           of
           the
           Earth
           from
           the
           variation
           of
           magnetical
           direction
           .
           (
           11.
           )
           The
           Nucleus
           of
           Comets
           possibly
           the
           same
           .
           Internal
           motion
           may
           weaken
           gravitation
           .
           Parts
           separated
           may
           be
           agitated
           by
           the
           gravitation
           of
           the
           ☉
           .
           Tail
           made
           not
           so
           much
           by
           the
           particles
           receding
           as
           the
           Stars
           approaching
           the
           Sun.
           (
           12.
           )
           How
           the
           Comet
           may
           first
           lose
           its
           Orb
           in
           the
           Universe
           ,
           and
           passing
           through
           the
           
           spheres
           of
           Activity
           of
           several
           central
           bodies
           is
           deflected
           and
           attracted
           by
           them
           ,
           and
           the
           Blaze
           raised
           to
           a
           prodigious
           length
           .
           (
           13.
           )
           The
           bodies
           being
           attracted
           by
           some
           gravity
           ,
           Blaze
           expelled
           by
           levity
           ,
           explained
           by
           smoke
           ,
           and
           steams
           .
           Somewhat
           for
           positive
           levity
           .
           (
           14.
           )
           A
           digression
           concerning
           the
           method
           of
           speculating
           the
           great
           and
           first
           principles
           of
           the
           Universe
           .
           The
           Coma
           and
           Blaze
           like
           smoke
           or
           flames
           .
           (
           15.
           )
           Shining
           particles
           a
           shining
           point
           ,
           not
           a
           line
           of
           light
           .
           Considerations
           and
           Experiments
           about
           the
           ways
           light
           is
           augmented
           by
           ,
           as
           by
           swift
           motion
           ,
           adjacent
           dark
           medium
           ,
           Flame
           explained
           .
           Why
           the
           Particles
           coalesce
           into
           a
           stream
           .
           (
           16.
           )
           Enquiry
           about
           the
           magnitude
           and
           place
           of
           Comets
           .
           Many
           supposed
           them
           sublunary
           .
           Tycho
           and
           Kepler
           proved
           them
           coelestial
           .
           How
           far
           we
           may
           rely
           upon
           Observations
           for
           Parallax
           .
           Parallax
           and
           its
           effects
           described
           .
           (
           18.
           )
           Tycho
           supposed
           the
           Comet
           of
           1577.
           to
           move
           about
           the
           Sun.
           Kepler
           that
           of
           1607.
           to
           move
           in
           a
           straight
           line
           ;
           that
           of
           1664.
           had
           no
           sensible
           Parallax
           by
           what
           means
           it
           was
           found
           .
           (
           19.
           )
           Refraction
           in
           this
           way
           varies
           little
           .
           Theory
           of
           Comets
           defective
           as
           to
           Parallax
           hitherto
           .
           Parallax
           not
           to
           be
           enquired
           from
           the
           Observations
           of
           several
           men
           .
           Errors
           creep
           in
           from
           the
           Press
           and
           the
           Graver
           ,
           as
           in
           
             P.
             Gottignies
          
           Plates
           .
           (
           20.
           )
           Nothing
           to
           be
           concluded
           from
           Observations
           made
           by
           persons
           in
           differing
           places
           for
           want
           of
           accurate
           Instruments
           ,
           and
           Observations
           .
           (
           21.
           )
           Even
           the
           best
           as
           
             Hevelius
             ,
             Gottignies
             ,
             Petit
          
           ,
           or
           Auzout
           err
           .
           Some
           reason
           for
           this
           assertion
           .
           Most
           of
           the
           rest
           altogether
           insignificant
           .
           (
           22.
           )
           Want
           of
           Observers
           ,
           Instruments
           ,
           and
           Tables
           the
           cause
           .
           How
           these
           wants
           are
           to
           be
           supplied
           .
           What
           the
           world
           expects
           from
           Mr.
           Hevelius
           .
           (
           23.
           )
           And
           of
           how
           great
           use
           his
           Tables
           and
           Projections
           made
           by
           them
           will
           be
           .
           Parallax
           from
           diurnal
           motion
           failing
           .
           (
           24.
           )
           Other
           Parallaxes
           arising
           from
           other
           hypotheses
           of
           the
           proper
           motions
           either
           of
           the
           Earth
           ,
           or
           Comet
           ,
           or
           both
           together
           considered
           arise
           to
           a
           certainty
           .
           (
           25.
           )
           Others
           depending
           upon
           other
           suppositions
           define
           nothing
           of
           the
           magnitude
           or
           distance
           of
           Comets
           .
           The
           inconvenience
           of
           
           Tycho's
           ,
           and
           also
           of
           
           Kepler's
           Hypotheses
           explained
           .
           A
           third
           way
           I
           have
           taken
           .
           What
           consequences
           follow
           from
           it
           ,
           (
           26.
           )
           As
           that
           it
           moves
           in
           a
           Circle
           that
           comes
           within
           the
           Earth
           Orb
           in
           ♌
           ,
           and
           without
           ♃
           Orb
           in
           ♒
           ,
           a
           sextant
           in
           130
           days
           ,
           &c.
           
           This
           not
           relied
           on
           ,
           because
           there
           may
           be
           other
           hypotheses
           to
           solve
           the
           phaenomena
           ;
           as
           that
           the
           Earth
           is
           unmoved
           ,
           and
           the
           Comet
           moved
           in
           a
           Circle
           ,
           whose
           convex
           side
           is
           toward
           the
           Earth
           .
           (
           27.
           )
           This
           hypothesis
           explained
           by
           the
           sixth
           figure
           .
           (
           28.
           )
           The
           distance
           and
           bigness
           of
           the
           Circle
           of
           the
           Comet
           undeterminable
           this
           way
           without
           a
           diurnal
           parallax
           ,
           since
           the
           appearances
           may
           be
           solved
           by
           Circles
           of
           any
           bigness
           ,
           proved
           by
           the
           eighth
           figure
           ,
           (
           29.
           )
           Allowing
           inequality
           of
           motion
           ,
           or
           
           more
           compound
           curve
           lines
           ,
           nothing
           can
           be
           determined
           .
           The
           circular
           Orb
           it
           seemed
           the
           most
           probable
           solves
           
           Kepler's
           acceleration
           ,
           according
           to
           the
           increase
           of
           a
           line
           of
           Tangents
           .
           (
           30.
           )
           A
           gravitation
           towards
           the
           Sun
           makes
           out
           the
           motion
           of
           the
           Comet
           ,
           and
           Planets
           ,
           and
           of
           the
           Blaze
           .
           The
           Blaze
           explained
           by
           experiment
           of
           ♂
           dissolved
           in
           oyl
           of
           Virt.
           (
           31.
           )
           This
           experiment
           and
           hypothesis
           farther
           explained
           ,
           and
           applied
           to
           explain
           the
           Blaze
           which
           is
           from
           thence
           bent
           ,
           brighter
           on
           one
           side
           than
           the
           other
           ,
           not
           direct
           from
           the
           Sun.
           (
           32.
           )
           Cometical
           body
           and
           motion
           as
           old
           as
           the
           world
           ,
           yet
           wasting
           in
           the
           Aether
           ;
           explained
           by
           fire
           .
           Dissolution
           by
           menstruums
           .
           (
           33.
           )
           Thence
           the
           proprieties
           of
           Comets
           conjectured
           ,
           and
           the
           sum
           of
           the
           foregoing
           discourse
           repeated
           ,
           being
           the
           end
           of
           a
           Lecture
           .
           Recourse
           to
           Tycho
           Brahe's
           Observation
           (
           34.
           )
           for
           making
           out
           the
           Comets
           Orb.
           His
           supposing
           its
           motion
           unequal
           without
           reason
           a
           shift
           .
           Mr.
           Horrox
           his
           hypotheses
           in
           the
           ninth
           figure
           a
           product
           of
           chance
           .
           (
           35.
           )
           A
           discourse
           on
           it
           ,
           and
           some
           objections
           against
           
           Tycho's
           .
           (
           36.
           )
           
           Kepler's
           hypothesis
           examined
           by
           these
           Observations
           of
           
           Tycho's
           ,
           found
           the
           most
           likely
           ,
           but
           with
           some
           alteration
           .
           Line
           of
           Trajection
           bent
           a
           little
           .
           Motion
           accelerated
           towards
           the
           Sun
           ,
           retarded
           from
           it
           .
           (
           37.
           )
           The
           swifter
           and
           further
           off
           the
           Comet
           from
           the
           Sun
           ,
           the
           less
           the
           bend
           ,
           explained
           by
           the
           tenth
           figure
           .
           (
           38.
           )
           The
           way
           of
           enquiring
           parallax
           by
           Telescopes
           ,
           (
           39.
           )
           further
           explained
           .
           A
           second
           way
           by
           two
           Observers
           in
           distant
           places
           propounded
           .
           The
           third
           way
           of
           Sir
           
             Chr.
             Wren
          
           his
           Majesties
           Surveyor-General
           ,
           (
           40.
           )
           Set
           down
           and
           demonstrated
           by
           a
           Geometrical
           Problem
           .
           (
           41.
           )
           How
           exactly
           all
           those
           Observations
           he
           had
           were
           made
           out
           by
           it
           ,
           together
           with
           his
           own
           Schemes
           ;
           both
           which
           I
           had
           in
           the
           beginning
           of
           
             Feb.
             1664-5
          
           .
           (
           42.
           )
           Some
           other
           Papers
           about
           Comets
           added
           ,
           being
           reflections
           on
           Mr.
           Descartes
           and
           
           Kepler's
           hypotheses
           ,
           from
           particular
           tracings
           of
           the
           Comets
           of
           1664.
           and
           1665.
           
           A
           Scheme
           of
           the
           later
           Observations
           of
           that
           of
           1664.
           added
           ,
           and
           some
           reflections
           ,
           being
           all
           the
           papers
           could
           be
           found
           about
           those
           Comets
           .
           (
           43
           ,
           44.
           )
           Animadversions
           on
           this
           of
           April
           last
           .
           Why
           the
           former
           conjectures
           were
           adhered
           to
           concerning
           the
           light
           of
           Comets
           .
           (
           45.
           )
           Several
           sorts
           of
           shining
           bodies
           enumerated
           .
           (
           46
           )
           To
           which
           the
           light
           of
           the
           Comet
           seems
           to
           have
           most
           affinity
           ,
           and
           how
           produced
           .
           (
           47.
           )
           Further
           described
           and
           explained
           .
           (
           48.
           )
           The
           reason
           of
           its
           parabolick
           figure
           demonstrated
           from
           the
           proprieties
           of
           motion
           from
           or
           toward
           a
           gravitating
           body
           ,
           as
           the
           Sun.
           (
           49.
           )
           Concerning
           the
           wasting
           and
           lasting
           of
           the
           Cometical
           body
           .
           The
           bigness
           and
           nature
           of
           the
           Particles
           that
           compose
           the
           Blaze
           .
           (
           50.
           )
           Some
           difficulties
           in
           this
           supposition
           concerning
           the
           action
           of
           the
           Aether
           in
           levitation
           and
           ascent
           ,
           dissolution
           ,
           shining
           ,
           &c.
           cleared
           and
           explained
           by
           Experiments
           .
           (
           51
           ,
           52
           ,
           53.
           )
           But
           would
           have
           been
           further
           examined
           by
           
           Observation
           if
           there
           had
           been
           opportunity
           .
           (
           54.
           )
           That
           these
           assertions
           about
           the
           light
           of
           Comets
           may
           not
           seem
           too
           paradoxical
           ,
           some
           further
           Considerations
           and
           Observations
           about
           light
           are
           added
           ,
           and
           some
           new
           ways
           propounded
           .
           (
           55
           ,
           56.
           )
           Mr.
           
           Boyle's
           Memorial
           concerning
           a
           Phosphoros
           ,
           written
           for
           his
           own
           use
           ,
           inserted
           ;
           in
           which
           he
           first
           names
           the
           Author
           of
           it
           ,
           and
           describes
           his
           Apparatus
           .
           (
           57
           ,
           58.
           )
           Then
           the
           observables
           .
           1.
           
           Two
           spoonfuls
           of
           matter
           enlighten
           a
           large
           glass
           sphere
           .
           2.
           
           A
           little
           enlightens
           a
           large
           Cylinder
           .
           3.
           
           Liquor
           shaken
           had
           a
           smoke
           and
           flasht
           .
           4.
           
           A
           dry
           substance
           affirmed
           to
           have
           continued
           shining
           2
           years
           ,
           flashed
           .
           (
           59.
           )
           5.
           
           Some
           dust
           of
           this
           on
           a
           Carpet
           twinckled
           like
           Stars
           .
           Writing
           on
           paper
           with
           it
           shin'd
           ,
           and
           smelt
           of
           Sulphur
           and
           Onions
           .
           (
           60.
           )
           7.
           
           The
           hand
           on
           which
           it
           was
           rubbed
           ,
           shin'd
           ,
           but
           felt
           no
           heat
           .
           (
           61.
           )
           It
           fired
           Gun-powder
           first
           warm'd
           .
           (
           62.
           )
           And
           white
           paper
           held
           over
           coals
           .
           Other
           tryals
           propounded
           ,
           but
           refused
           .
           (
           63.
           )
           Some
           Experiments
           made
           on
           the
           Phosphoros
           
             Baldwini
             in
             vacuo
          
           ,
           and
           in
           the
           open
           air
           .
           (
           64.
           )
           Preserved
           in
           Vacuo
           ,
           but
           destroyed
           in
           Air.
           (
           65
           ,
           66.
           )
           Monsieur
           
           Gallet's
           Letter
           to
           Monsieur
           Cassini
           ,
           acquainting
           him
           with
           his
           Apparatus
           for
           observing
           ☿
           in
           ☉
           .
           (
           67
           ,
           68.
           )
           His
           Observation
           of
           sour
           spots
           in
           ☉
           .
           (
           69.
           )
           The
           particulars
           observed
           .
           (
           70.
           71
           ,
           72.
           )
           Monsieur
           
           Cassini's
           Reflections
           on
           these
           Observations
           .
           (
           73
           ,
           74.
           )
           Mr.
           
           Hally's
           Letter
           to
           Sir
           
             Jonas
             Moore
          
           ,
           containing
           an
           account
           of
           his
           Observations
           of
           ☿
           
             sub
             sole
          
           ,
           three
           Southern
           Stars
           .
           The
           two
           
             Nubeculae
             ,
             &c.
          
           (
           75
           ,
           76
           ,
           77.
           )
           Mr.
           
           Cassini's
           farther
           discoveries
           about
           the
           diurnal
           motion
           ,
           and
           several
           new
           appearances
           in
           ♃
           .
           (
           78
           ,
           79
           ,
           80.
           )
        
         
           A
           second
           Discourse
           called
           Microscopium
           ,
           or
           some
           new
           discoveries
           with
           Microscopes
           ,
           in
           a
           Letter
           of
           Mr.
           Leeuwenhoeck
           .
           (
           81.
           82.
           )
           A
           confirmation
           of
           some
           of
           them
           by
           Observations
           here
           .
           (
           83.
           )
           Mr.
           
           Leeuwenhoeck's
           second
           Letter
           ,
           containing
           Observations
           of
           the
           Globules
           of
           Blood
           ,
           Milk
           ,
           Flegm
           ,
           Gums
           first
           dissolved
           ,
           then
           precipitated
           out
           of
           the
           Spirit
           of
           Wine
           ;
           Eels
           a
           thousand
           times
           thinner
           than
           a
           hair
           .
           (
           84
           ,
           85
           ,
           86
           ,
           87
           ,
           88
           ,
           89.
           )
           The
           ways
           how
           these
           discoveries
           were
           made
           here
           .
           1.
           
           By
           holding
           the
           liquor
           in
           small
           pipes
           ,
           how
           fill'd
           ,
           how
           made
           .
           The
           Lamp
           ,
           Pipe
           ,
           Oyl
           ,
           Manner
           ,
           Materials
           for
           making
           them
           described
           .
           (
           89
           ,
           90.
           )
           Muscovy-glass
           used
           instead
           of
           these
           Pipes
           ,
           and
           how
           the
           Microscope
           was
           fitted
           for
           this
           purpose
           .
           (
           91.
           )
           What
           light
           convenient
           .
           Surfaces
           of
           bodies
           not
           perfectly
           fluid
           apt
           to
           delude
           an
           Observer
           .
           (
           92.
           )
           Plates
           removing
           that
           deluding
           cause
           ,
           and
           what
           farther
           use
           of
           them
           .
           (
           93.
           )
           How
           to
           find
           the
           figure
           and
           texture
           of
           Animal
           and
           Vegetable
           parts
           .
           Instance
           in
           a
           ligament
           of
           Beef
           .
           (
           94.
           )
           The
           figure
           of
           Muscles
           hinted
           ,
           and
           an
           instrument
           stretching
           them
           before
           the
           Glass
           described
           .
           (
           95.
           )
           A
           description
           of
           the
           Microscopes
           used
           ,
           1.
           
           Of
           the
           single
           Microscope
           ,
           and
           its
           advantages
           and
           difficulties
           ,
           (
           96.
           )
           another
           sort
           more
           easie
           described
           ,
           and
           the
           ways
           how
           to
           make
           and
           use
           it
           explained
           .
           (
           97.
           )
           Causes
           that
           vary
           the
           distance
           of
           objects
           from
           the
           Globule
           .
           The
           use
           of
           Selenites
           and
           Looking-glass-plates
           ,
           for
           holding
           the
           liquor
           .
           A
           Microscope
           of
           one
           single
           refraction
           .
           (
           98.
           )
           The
           only
           inconvenience
           of
           them
           hinted
           ,
           how
           prevented
           by
           double
           Microscopes
           .
           Where
           these
           are
           made
           .
           (
           99.
           )
           The
           double
           Microscope
           ,
           and
           its
           parts
           ,
           uses
           ,
           and
           advantages
           described
           .
           (
           100.
           )
           The
           benefit
           of
           a
           dark
           Room
           ,
           and
           appropriated
           lights
           .
           And
           a
           digression
           in
           answer
           to
           
             P.
             Cherubines
          
           Accusation
           .
           (
           101.
           )
           Some
           Observations
           made
           with
           this
           Microscope
           hinted
           .
           Animalcules
           in
           the
           steeping
           of
           other
           Grains
           besides
           Pepper
           .
           Their
           smallness
           estimated
           ,
           and
           compared
           to
           a
           Whale
           .
           Muscular
           fabrick
           hinted
           .
           Milk
           ,
           Blood
           ,
           Fat
           ,
           Sugar
           ,
           Allum
           ,
           &c.
           viewed
           .
           (
           102
           ,
           103.
           )
           Mr.
           
           Young's
           Letter
           of
           one
           who
           trying
           to
           cure
           a
           Colick
           by
           leaden
           Pills
           ,
           slipt
           one
           into
           his
           Lungs
           ;
           grievous
           symptoms
           ensue
           .
           (
           105.
           )
           Helps
           of
           skilful
           Physicians
           in
           vain
           attempted
           ,
           and
           particularly
           of
           Dr.
           Mayow
           ,
           of
           suspending
           with
           the
           head
           downward
           ;
           though
           in
           the
           interim
           he
           married
           and
           had
           Children
           ,
           yet
           it
           kill'd
           him
           .
           (
           106
           ,
           107.
           )
           His
           body
           diffected
           ,
           and
           remarkables
           taken
           notice
           of
           ,
           and
           their
           causes
           explained
           by
           Mr.
           Young
           ,
           (
           from
           107.
           to
           112.
           )
        
         
         
         
      
    
     
       
         
         
           COMETA
           ,
           OR
           ,
           Remarks
           about
           Comets
           .
        
         
           ON
           Saturday
           morning
           ,
           April
           21.
           1677.
           
           I
           first
           saw
           the
           Comet
           ,
           of
           which
           I
           had
           been
           advertised
           the
           day
           before
           .
           It
           appeared
           in
           the
           Sign
           Taurus
           ,
           between
           the
           base
           of
           the
           Triangle
           ,
           and
           the
           unformed
           Stars
           in
           the
           Cloud
           of
           Aries
           ,
           dignified
           by
           
             P.
             Pardies
          
           ,
           with
           the
           figure
           of
           the
           Flower-de-luce
           .
           The
           head
           of
           it
           was
           in
           a
           right
           line
           ,
           with
           the
           heart
           of
           Cassiopea
           ,
           and
           Alamak
           ,
           or
           the
           South
           foot
           of
           Andromeda
           .
           and
           as
           near
           as
           I
           could
           judge
           by
           my
           naked
           eye
           (
           having
           no
           Instrument
           or
           help
           by
           me
           )
           it
           was
           ⅙
           of
           the
           distance
           between
           the
           feet
           and
           the
           Girdle
           of
           Andromeda
           ,
           distant
           from
           the
           said
           Alamak
           towards
           the
           South
           .
        
         
           It
           s
           tail
           sometimes
           as
           the
           Air
           was
           clearer
           and
           darker
           ,
           extended
           about
           three
           quarters
           of
           its
           distance
           from
           the
           aforesaid
           Alamak
           ,
           and
           pointed
           directly
           at
           the
           Star
           in
           the
           nose
           of
           Cassiopea
           of
           the
           fourth
           Magnitude
           ,
           and
           consequently
           the
           head
           of
           the
           Comet
           pointed
           not
           directly
           at
           the
           Sun
           (
           the
           Sun
           then
           being
           about
           the
           eleventh
           degree
           of
           Taurus
           )
           but
           rather
           towards
           the
           fourteenth
           degree
           of
           the
           same
           Sign
           .
           It
           s
           appearance
           was
           very
           small
           and
           slender
           ,
           and
           as
           people
           commonly
           ghessed
           ,
           about
           two
           yards
           long
           ;
           and
           the
           head
           about
           the
           bigness
           of
           a
           Star
           of
           the
           first
           magnitude
           ,
           but
           of
           a
           much
           fainter
           and
           duller
           light
           .
           It
           s
           blaze
           about
           three
           o'
           the
           clock
           seemed
           to
           rise
           straight
           upward
           ,
           
           before
           that
           about
           half
           an
           hour
           after
           two
           it
           leaned
           a
           little
           Eastwards
           ,
           or
           towards
           the
           right
           hand
           ,
           and
           after
           three
           ,
           as
           it
           rose
           higher
           ,
           inclined
           towards
           the
           left
           side
           or
           Westwards
           .
           The
           head
           to
           the
           naked
           eye
           was
           brighter
           than
           the
           blaze
           ,
           and
           seemed
           to
           be
           somewhat
           bigger
           than
           that
           part
           of
           it
           which
           immediately
           joyn'd
           to
           the
           head
           ;
           but
           those
           parts
           of
           it
           which
           were
           farther
           distant
           ,
           were
           of
           a
           much
           greater
           breadth
           ;
           spreading
           wider
           and
           wider
           ,
           as
           they
           were
           more
           remote
           from
           the
           head
           ,
           and
           in
           the
           same
           proportion
           also
           growing
           fainter
           and
           fainter
           in
           their
           light
           ,
           especially
           towards
           the
           outsides
           :
           but
           the
           middle
           parts
           of
           medulla
           appear'd
           much
           longer
           ,
           and
           the
           brightness
           much
           greater
           ,
           which
           made
           the
           whole
           blaze
           to
           seem
           to
           taper
           ,
           or
           be
           pointed
           towards
           the
           top
           .
        
         
           The
           length
           of
           the
           Blaze
           appeared
           sometimes
           shorter
           ,
           and
           sometimes
           longer
           ,
           by
           several
           vicissitudes
           ;
           and
           as
           the
           day-break
           ,
           or
           dawning
           increased
           ,
           so
           the
           Blaze
           shortened
           ,
           and
           especially
           towards
           the
           sides
           near
           the
           top
           ,
           and
           shortly
           after
           before
           the
           Sun
           rose
           ,
           disappeared
           .
        
         
           But
           notwithstanding
           this
           shortning
           and
           lengthening
           of
           the
           Blaze
           ,
           I
           could
           not
           perceive
           any
           kind
           of
           motion
           in
           the
           parts
           of
           it
           ,
           such
           as
           is
           observable
           in
           flame
           ,
           smoke
           ,
           or
           other
           steams
           rising
           from
           a
           burning
           or
           hot
           body
           :
           but
           the
           same
           parts
           of
           the
           Blaze
           seemed
           to
           appear
           and
           disappear
           in
           their
           proper
           places
           as
           if
           they
           had
           been
           fixed
           and
           a
           solid
           body
           .
        
         
           The
           first
           Figure
           I
           have
           here
           annexed
           will
           with
           some
           short
           explications
           ,
           represent
           the
           appearance
           of
           it
           to
           the
           eye
           ,
           more
           plainly
           than
           by
           a
           multitude
           of
           words
           ,
           without
           it
           't
           is
           possible
           to
           express
           .
        
         
           A
           ,
           represents
           the
           head
           of
           the
           Comet
           ,
           the
           middle
           of
           which
           appeared
           brighter
           than
           any
           other
           part
           ;
           about
           which
           was
           a
           hazy
           light
           somewhat
           like
           the
           shining
           of
           a
           Star
           through
           a
           thin
           cloud
           ;
           the
           lower
           part
           of
           which
           was
           pretty
           round
           and
           defined
           .
           B
           ,
           the
           neck
           of
           it
           ,
           which
           seemed
           to
           the
           naked
           eye
           of
           less
           Diameter
           ,
           and
           less
           bright
           than
           the
           head
           ,
           but
           through
           a
           six-foot
           glass
           ,
           as
           I
           
           shall
           mention
           by
           and
           by
           ,
           it
           appeared
           bigger
           ,
           though
           not
           so
           bright
           .
           The
           middle
           of
           this
           was
           very
           bright
           ,
           and
           seemed
           to
           issue
           from
           the
           Nucleus
           or
           Star
           in
           the
           middle
           of
           the
           head
           .
           C
           ,
           the
           brushy
           parts
           which
           were
           fainter
           and
           paler
           towards
           the
           sides
           ,
           especially
           nearer
           the
           top
           ,
           which
           made
           the
           whole
           seem
           to
           taper
           and
           resemble
           the
           Figure
           here
           exprest
           :
           Observing
           it
           with
           Telescopes
           (
           one
           of
           which
           was
           fifteen
           foot
           ,
           and
           the
           other
           six
           foot
           long
           )
           I
           found
           the
           shape
           of
           it
           much
           like
           this
           ,
           which
           I
           have
           represented
           in
           the
           second
           Figure
           .
        
         
           It
           had
           a
           pretty
           bright
           Star
           (
           if
           I
           may
           so
           call
           it
           )
           near
           the
           middle
           of
           the
           head
           ,
           seeming
           much
           about
           the
           brightness
           of
           ♄
           when
           near
           the
           Horizon
           ,
           and
           was
           about
           25
           seconds
           in
           Diameter
           ;
           as
           is
           represented
           by
           A
           ,
           not
           perfectly
           defined
           ,
           but
           hazy
           ;
           the
           cloudy
           part
           or
           beard
           of
           the
           body
           encompassing
           it
           on
           all
           sides
           :
           but
           that
           part
           of
           the
           Coma
           B
           ,
           which
           was
           next
           towards
           the
           Sun
           ,
           was
           the
           narrowest
           :
           nor
           was
           this
           Coma
           well
           defined
           ,
           but
           the
           outward
           parts
           of
           it
           were
           fainter
           and
           fainter
           .
           However
           they
           were
           regularly
           enough
           terminated
           to
           make
           the
           outwardmost
           bounds
           of
           it
           of
           a
           kind
           of
           Parabolical
           figure
           ;
           the
           most
           bent
           part
           of
           which
           was
           towards
           the
           Sun
           ,
           and
           most
           defined
           :
           And
           the
           bright
           Star
           of
           it
           was
           ,
           as
           I
           have
           expressed
           it
           about
           four
           of
           its
           Diameters
           distant
           from
           the
           said
           parabolical
           limb
           .
           The
           light
           parts
           of
           the
           ambient
           Cloud
           seemed
           to
           spread
           gradually
           towards
           that
           side
           of
           it
           ,
           which
           was
           opposite
           to
           the
           Sun
           ;
           but
           those
           which
           were
           next
           the
           middle
           were
           the
           brightest
           :
           and
           always
           as
           they
           were
           farther
           and
           farther
           from
           the
           Star
           in
           the
           head
           ,
           the
           fainter
           and
           paler
           they
           were
           .
        
         
           I
           could
           not
           observe
           any
           representations
           like
           those
           which
           are
           given
           us
           by
           Mr.
           Hevelius
           ,
           in
           his
           Cometography
           ,
           neither
           in
           the
           Head
           ,
           nor
           the
           Blaze
           ,
           no
           more
           than
           I
           could
           in
           those
           which
           appeared
           in
           the
           years
           1664.
           and
           1665.
           as
           may
           be
           easily
           taken
           notice
           of
           by
           comparing
           these
           which
           I
           have
           delineated
           with
           those
           .
        
         
           The
           middle
           part
           of
           the
           Blaze
           CC
           ,
           which
           ascended
           from
           the
           Star
           in
           the
           middle
           ,
           seemed
           the
           brightest
           ,
           and
           
           of
           this
           medulla
           or
           stem
           ,
           those
           parts
           were
           brightest
           which
           were
           nearest
           situated
           to
           the
           said
           Star.
           The
           sides
           of
           it
           grew
           fainter
           and
           fainter
           ,
           as
           they
           were
           farther
           from
           the
           head
           ;
           and
           though
           they
           had
           brightness
           enough
           to
           make
           them
           appear
           in
           a
           dark
           and
           clear
           sky
           ,
           yet
           the
           dawning
           quickly
           made
           them
           vanish
           ,
           and
           disappear
           ,
           as
           did
           any
           haziness
           of
           the
           Sky
           :
           and
           according
           as
           the
           light
           increased
           ,
           so
           was
           the
           Blaze
           diminished
           ,
           after
           the
           order
           of
           the
           tapering
           prickt
           lines
           exprest
           in
           the
           third
           Figure
           by
           aaa
           ,
           bbb
           ,
           ccc
           ,
           ddd
           ,
           &c.
           and
           even
           in
           a
           clear
           and
           dark
           Sky
           ,
           towards
           the
           farther
           end
           of
           the
           Blaze
           they
           often
           disappeared
           for
           some
           short
           space
           of
           time
           ,
           though
           the
           middle
           or
           stem
           continued
           ;
           and
           so
           it
           caused
           the
           remaining
           appearance
           to
           resemble
           the
           figure
           of
           a
           very
           slender
           birchen
           whisk
           or
           brush
           ,
           much
           like
           that
           represented
           in
           the
           first
           figure
           .
        
         
           The
           22.
           from
           half
           an
           hour
           after
           two
           ,
           till
           half
           an
           hour
           after
           three
           ,
           the
           North-east
           part
           of
           the
           Heavens
           to
           me
           was
           cloudy
           ,
           and
           the
           Sky
           between
           the
           Clouds
           was
           hazy
           ,
           and
           the
           dawning
           struck
           much
           higher
           than
           the
           day
           before
           ,
           so
           that
           I
           could
           not
           find
           it
           .
        
         
           The
           23.
           with
           several
           friends
           I
           observed
           it
           again
           ,
           the
           Sky
           being
           clear
           ,
           and
           confirmed
           my self
           in
           all
           my
           former
           observations
           ,
           taking
           again
           diligent
           notice
           of
           all
           circumstances
           remarkable
           ,
           both
           with
           my
           naked
           eye
           ,
           and
           with
           Perspective-glasses
           .
           And
           I
           had
           this
           morning
           a
           very
           notable
           observation
           in
           order
           to
           measure
           the
           bigness
           of
           the
           Star
           and
           its
           Coma
           which
           encompassed
           it
           ,
           by
           comparing
           it
           with
           somewhat
           fixt
           :
           for
           some
           few
           minutes
           before
           three
           of
           the
           Clock
           the
           head
           of
           it
           past
           just
           behind
           the
           type
           or
           top-post
           of
           a
           tower
           not
           far
           distant
           ,
           and
           was
           quite
           eclipsed
           by
           it
           ;
           and
           as
           soon
           as
           it
           appeared
           to
           have
           past
           it
           ,
           seeming
           yet
           contiguous
           ,
           I
           observed
           it
           with
           my
           six
           foot
           Telescope
           ,
           and
           found
           the
           Coma
           or
           whole
           head
           to
           appear
           full
           as
           big
           as
           the
           said
           type
           or
           timber
           post
           ,
           and
           the
           Nucleus
           or
           Star
           in
           the
           middle
           of
           it
           ,
           to
           be
           very
           near
           of
           the
           same
           bigness
           of
           the
           iron
           spindle
           ,
           upon
           which
           the
           weather-cock
           was
           fixt
           .
           Whence
           upon
           examining
           the
           
           bigness
           of
           the
           said
           parts
           ,
           since
           by
           an
           accurate
           Instrument
           I
           judge
           the
           head
           or
           Coma
           was
           about
           4
           ⅙
           minutes
           in
           Diameter
           ,
           and
           the
           Nucleus
           or
           Star
           about
           25
           seconds
           .
           I
           took
           notice
           this
           morning
           that
           it
           had
           much
           altered
           the
           position
           in
           the
           Heavens
           ,
           which
           it
           had
           upon
           Saturday
           morning
           ,
           and
           that
           the
           Blaze
           of
           it
           was
           very
           much
           deflected
           out
           of
           the
           line
           it
           appeared
           in
           the
           last
           time
           .
           And
           with
           a
           small
           crossstaff
           ,
           taking
           the
           distance
           of
           it
           from
           Alamak
           ,
           and
           from
           Genib
           ,
           in
           the
           left
           side
           of
           Perseus
           .
           I
           judged
           it
           to
           be
           in
           the
           mid-way
           between
           the
           Flower-de-luce
           aforesaid
           ,
           and
           Algol
           ,
           or
           the
           head
           of
           Medusa
           ,
           that
           is
           ,
           about
           14
           degrees
           of
           ♉
           ,
           and
           17
           degrees
           of
           Northern
           Latitude
           :
           so
           that
           I
           judged
           its
           motion
           almost
           East
           ,
           but
           a
           little
           deflecting
           South
           .
           I
           was
           not
           much
           solicitous
           of
           making
           observations
           of
           its
           true
           place
           ,
           as
           not
           designing
           my
           present
           enquiry
           to
           be
           for
           what
           kind
           of
           motion
           it
           had
           ,
           conceiving
           its
           motion
           to
           be
           towards
           the
           Sun
           ,
           and
           so
           of
           very
           little
           duration
           :
           and
           expecting
           to
           hear
           an
           account
           of
           that
           from
           other
           places
           ,
           and
           persons
           that
           were
           better
           furnished
           with
           Instruments
           and
           conveniences
           for
           observations
           of
           that
           kind
           than
           I
           was
           then
           .
        
         
           The
           Blaze
           extended
           it self
           in
           a
           right
           line
           towards
           the
           Star
           in
           the
           right
           thigh
           of
           Cassiopea
           ,
           being
           a
           Star
           of
           the
           third
           magnitude
           .
           It
           s
           length
           at
           first
           was
           about
           7
           or
           8
           degrees
           ,
           and
           did
           sometimes
           seem
           longer
           ,
           sometimes
           shorter
           ,
           as
           I
           noted
           before
           ,
           without
           seeming
           to
           have
           any
           other
           motion
           in
           it
           but
           the
           Diurnal
           motion
           ,
           the
           same
           with
           the
           fixt
           Stars
           on
           Earth
           .
           Whence
           I
           collected
           ,
           that
           the
           head
           of
           it
           pointed
           towards
           the
           seventeenth
           degree
           of
           Taurus
           in
           the
           Ecliptick
           ,
           though
           the
           Sun
           at
           that
           time
           was
           about
           the
           thirteenth
           degree
           of
           the
           same
           Sign
           .
        
         
           The
           24.
           with
           several
           others
           ,
           I
           attended
           the
           appearance
           of
           it
           ,
           but
           the
           Sky
           in
           that
           part
           of
           the
           Heavens
           was
           over-cast
           with
           Clouds
           .
        
         
           The
           25.
           
           I
           expected
           to
           have
           a
           farther
           Observation
           of
           it
           from
           half
           an
           hour
           after
           two
           ,
           till
           a
           quarter
           after
           four
           ;
           but
           notwithstanding
           the
           South-easterly
           wind
           ,
           and
           the
           clarifying
           quality
           of
           the
           air
           ,
           which
           before
           half
           an
           hour
           
           after
           three
           had
           partly
           carried
           off
           ,
           and
           partly
           dissolved
           the
           black
           thick
           Clouds
           (
           with
           which
           the
           North-east
           parts
           of
           this
           Horizon
           was
           over-cast
           about
           three
           of
           the
           Clock
           )
           and
           left
           that
           part
           of
           the
           Heavens
           where
           the
           Comet
           should
           have
           appeared
           clear
           ,
           and
           without
           Clouds
           .
           Yet
           the
           air
           being
           very
           high
           and
           heavy
           ,
           as
           the
           Barometer
           shewed
           ,
           the
           upper
           parts
           of
           it
           were
           so
           filled
           with
           the
           dawning
           light
           of
           the
           morning
           ,
           that
           neither
           the
           Blaze
           head
           or
           Star
           of
           the
           Comet
           appeared
           to
           me
           in
           the
           least
           :
           nor
           had
           I
           any
           sight
           of
           it
           since
           .
        
         
           The
           like
           appearance
           of
           the
           great
           height
           of
           vapors
           in
           the
           air
           ,
           when
           it
           is
           very
           heavy
           ,
           I
           have
           often
           taken
           notice
           of
           ,
           and
           have
           observed
           ,
           that
           the
           twy-light
           and
           dawning
           between
           the
           night
           ,
           and
           appearing
           of
           the
           Sun
           is
           very
           much
           altered
           thereby
           .
           And
           that
           a
           heavy
           air
           ,
           when
           the
           vapors
           are
           raised
           high
           ,
           will
           make
           the
           length
           of
           them
           much
           greater
           ,
           and
           consequently
           the
           night
           shorter
           .
           And
           a
           light
           air
           ,
           on
           the
           contrary
           ,
           shortning
           them
           ,
           doth
           lengthen
           the
           night
           .
        
         
           These
           were
           the
           most
           remarkable
           circumstances
           I
           took
           notice
           of
           in
           this
           Comet
           ,
           being
           altogether
           Physical
           ,
           and
           designed
           only
           for
           enquirng
           into
           the
           constitution
           of
           these
           wonderfull
           bodies
           :
           the
           accounts
           and
           opinions
           we
           have
           hitherto
           had
           of
           them
           of
           that
           kind
           ,
           being
           very
           unsatisfactory
           .
           Though
           other
           Observations
           ,
           to
           wit
           ,
           Mathematical
           ,
           of
           the
           way
           ,
           celerity
           ,
           and
           magnitude
           of
           Comets
           have
           been
           prosecuted
           with
           very
           much
           care
           ,
           and
           great
           skill
           ;
           such
           as
           those
           of
           the
           noble
           Tycho
           ,
           and
           the
           learned
           and
           diligent
           Hevelius
           ,
           insomuch
           that
           I
           could
           not
           expect
           to
           have
           better
           ;
           yet
           as
           to
           Physical
           remarks
           ,
           I
           wanted
           much
           information
           to
           be
           able
           to
           satisfie
           many
           difficulties
           that
           occurr'd
           to
           my
           thoughts
           ,
           upon
           enquiry
           into
           the
           particular
           natures
           of
           them
           .
           I
           did
           therefore
           ,
           as
           I
           designed
           ,
           employ
           all
           the
           time
           I
           could
           get
           of
           observing
           this
           Comet
           ,
           in
           taking
           notice
           of
           such
           circumstances
           as
           I
           judged
           would
           be
           pertinent
           to
           resolve
           any
           of
           those
           Queries
           I
           had
           formerly
           made
           ,
           in
           order
           to
           find
           out
           the
           nature
           of
           Comets
           in
           general
           .
           And
           though
           the
           little
           opportunity
           
           I
           now
           had
           ,
           and
           the
           disadvantageous
           appearance
           of
           this
           last
           were
           very
           short
           of
           giving
           me
           that
           satisfaction
           in
           many
           particulars
           which
           I
           wish'd
           for
           ,
           and
           expected
           at
           first
           ,
           yet
           since
           they
           may
           possibly
           serve
           for
           hints
           to
           others
           that
           may
           hereafter
           have
           better
           oportunity
           than
           I
           ,
           and
           that
           I
           might
           understand
           what
           material
           objections
           could
           be
           made
           by
           observers
           from
           preceding
           Comets
           ,
           and
           that
           they
           might
           for
           the
           future
           more
           diligently
           take
           notice
           of
           what
           from
           these
           queries
           and
           hints
           may
           be
           judged
           significant
           to
           this
           design
           ,
           such
           as
           they
           are
           I
           have
           here
           published
           as
           I
           had
           done
           formerly
           by
           my
           Lectures
           in
           
           Gresham-Colledge
           ,
           those
           which
           I
           had
           made
           of
           those
           in
           1664.
           and
           1665.
           
        
         
           Now
           before
           I
           come
           to
           make
           reflexions
           upon
           these
           remarks
           ,
           I
           thought
           it
           might
           not
           be
           improper
           to
           add
           some
           few
           of
           those
           things
           concerning
           those
           two
           former
           Comets
           observed
           by
           me
           in
           the
           said
           years
           .
           I
           say
           ,
           some
           few
           ,
           because
           it
           would
           be
           needless
           to
           set
           down
           all
           ,
           especially
           such
           of
           mine
           as
           do
           agree
           with
           others
           since
           published
           .
           I
           did
           therefore
           soon
           after
           I
           had
           seen
           the
           first
           Comet
           ,
           to
           wit
           ,
           December
           23.
           1664.
           propound
           to
           my self
           certain
           Queries
           necessary
           to
           be
           answered
           ,
           in
           order
           to
           find
           out
           a
           true
           theory
           of
           them
           ,
           and
           directed
           my
           Observations
           accordingly
           ;
           and
           they
           were
           these
           .
        
         
           Of
           what
           substance
           its
           body
           ,
           beard
           ,
           and
           blaze
           is
           ?
           and
           next
           ,
           of
           what
           magnitude
           each
           of
           those
           parts
           appear
           ,
           and
           of
           what
           real
           magnitude
           they
           are
           ?
        
         
           Other
           Queries
           were
           concerning
           its
           density
           and
           rarity
           ,
           its
           mutability
           or
           immutability
           ;
           that
           is
           ,
           whether
           it
           dissolved
           and
           wasted
           or
           not
           ?
           whether
           it
           were
           fluid
           or
           solid
           ?
           whether
           it
           participated
           of
           gravity
           or
           levity
           ?
        
         
           Whence
           it
           had
           its
           light
           ,
           colour
           ,
           &c.
           
        
         
           What
           was
           the
           figure
           of
           the
           Star
           ,
           Radiation
           ,
           Blaze
           ,
           &c.
           
        
         
           Whether
           the
           Blaze
           were
           always
           opposite
           to
           the
           Sun
           ,
           or
           deflected
           ?
           whether
           straight
           or
           bended
           ,
           &c.
           
        
         
           What
           kind
           of
           motion
           it
           was
           carried
           with
           ?
           whether
           in
           a
           straight
           or
           bended
           line
           ?
           and
           if
           bended
           ,
           whether
           in
           a
           circular
           or
           other
           curve
           ,
           as
           elliptical
           or
           other
           compounded
           
           line
           ,
           whether
           the
           convex
           or
           concave
           side
           of
           that
           curve
           were
           turned
           towards
           the
           earth
           ?
           Whether
           in
           any
           of
           those
           lines
           it
           moved
           equal
           or
           unequal
           spaces
           in
           equal
           times
           ?
        
         
           Through
           what
           parts
           of
           the
           universe
           it
           moved
           ,
           and
           how
           far
           distant
           it
           was
           at
           several
           times
           ?
           Whether
           in
           the
           lower
           Regions
           near
           the
           Earth
           in
           the
           Atmosphere
           ,
           or
           near
           it
           ,
           or
           in
           the
           Heavens
           ,
           or
           fluid
           Aether
           ,
           with
           which
           the
           space
           of
           the
           Heavens
           is
           filled
           ?
           Whether
           above
           or
           below
           the
           Moon
           ,
           &c.
           
        
         
           Whether
           it
           wasts
           ,
           and
           is
           dispersed
           and
           consumed
           ?
           or
           whether
           it
           lasts
           and
           endures
           for
           a
           longer
           time
           ?
           If
           it
           lasts
           ,
           Whether
           it
           ever
           appears
           again
           ,
           being
           moved
           in
           a
           circle
           ;
           or
           be
           carried
           clear
           away
           ,
           and
           never
           appear
           again
           ,
           being
           moved
           in
           a
           straight
           or
           paraboloeidical
           line
           ?
           Whether
           it
           be
           collected
           or
           generated
           when
           it
           first
           appears
           ?
           and
           dissipated
           or
           destroyed
           when
           it
           disappears
           ;
           or
           whether
           the
           several
           distances
           of
           it
           do
           not
           make
           that
           appearance
           ?
        
         
           Whether
           it
           may
           not
           have
           some
           such
           propriety
           ,
           as
           the
           Star
           in
           Cete
           ,
           whereby
           it
           may
           shine
           and
           appear
           for
           a
           certain
           period
           ,
           and
           again
           lose
           its
           light
           ,
           and
           disappear
           by
           several
           vicissitudes
           ?
           and
           whether
           that
           may
           not
           give
           some
           account
           of
           the
           appearance
           of
           so
           many
           Comets
           about
           Aries
           ?
        
         
           First
           ,
           As
           concerning
           the
           matter
           or
           substance
           of
           the
           Nucleus
           Star
           or
           body
           ,
           of
           the
           hazy
           shining
           part
           encompassing
           it
           ,
           and
           of
           the
           Tail
           or
           Blaze
           :
           I
           say
           ,
           that
           by
           comparing
           all
           the
           circumstances
           that
           I
           was
           able
           to
           take
           notice
           of
           from
           the
           beginning
           to
           the
           end
           ,
           I
           found
           that
           the
           Star
           in
           the
           head
           was
           of
           a
           very
           compacted
           and
           dense
           light
           ,
           and
           almost
           equalled
           that
           of
           Saturn
           ;
           though
           it
           were
           not
           like
           that
           confined
           by
           an
           equal
           limb
           :
           that
           there
           were
           some
           parts
           distinguishable
           in
           this
           body
           ,
           some
           having
           a
           brighter
           ,
           others
           a
           fainter
           light
           .
           That
           these
           parts
           did
           not
           continue
           the
           same
           ,
           but
           considerably
           varied
           ,
           which
           might
           in
           part
           be
           caused
           by
           the
           differing
           position
           of
           those
           parts
           which
           were
           seen
           before
           ,
           from
           the
           same
           seen
           afterwards
           ,
           
           in
           respect
           of
           the
           eye
           ,
           situate
           on
           the
           surface
           of
           the
           Earth
           ,
           moved
           one
           way
           ,
           and
           the
           Comet
           moved
           another
           ;
           though
           I
           do
           not
           conceive
           it
           wholly
           ascribable
           to
           that
           ,
           but
           partly
           also
           to
           a
           real
           alteration
           of
           the
           parts
           of
           the
           Comet
           .
           That
           I
           did
           very
           diligently
           watch
           to
           observe
           if
           it
           were
           possible
           ,
           when
           it
           pass'd
           over
           any
           fix'd
           Star
           to
           find
           whether
           it
           were
           transparent
           ;
           as
           I
           had
           several
           times
           observed
           the
           tail
           of
           it
           to
           be
           even
           in
           its
           brightest
           parts
           ,
           but
           I
           had
           not
           the
           opportunity
           ;
           but
           that
           I
           did
           several
           times
           observe
           the
           tail
           of
           it
           transparent
           ,
           not
           only
           with
           the
           naked
           eye
           ,
           but
           through
           a
           Telescope
           :
           if
           at
           least
           the
           fixed
           Stars
           be
           above
           it
           ,
           which
           I
           think
           few
           doubt
           ,
           that
           the
           light
           diminish'd
           by
           degrees
           towards
           the
           extremes
           of
           the
           hazy
           part
           encompassing
           it
           ;
           and
           yet
           the
           extremes
           of
           it
           as
           to
           that
           part
           of
           it
           which
           respected
           the
           Sun
           ,
           seemed
           pretty
           evenly
           and
           smoothly
           defined
           ,
           especially
           through
           a
           Telescope
           :
           From
           all
           which
           remarks
           ,
           and
           from
           the
           velocity
           of
           its
           motion
           ,
           I
           conjecture
           it
           to
           be
           made
           up
           of
           solid
           matter
           ,
           not
           fluid
           ;
           that
           the
           body
           of
           it
           especially
           ,
           is
           considerably
           dense
           ,
           but
           that
           the
           haziness
           or
           Coma
           about
           it
           is
           much
           more
           rarified
           ,
           and
           the
           tail
           thereof
           is
           most
           of
           all
           .
           That
           this
           body
           is
           encompassed
           with
           a
           body
           most
           fluid
           ,
           and
           easily
           permeable
           ,
           and
           which
           doth
           with
           very
           little
           resistance
           give
           way
           to
           the
           motion
           of
           it
           ,
           or
           any
           other
           body
           through
           it
           ,
           that
           it
           doth
           easily
           admit
           at
           least
           (
           if
           not
           actually
           take
           into
           it self
           )
           the
           parts
           of
           this
           body
           ,
           Coma
           ,
           and
           Blaze
           .
           I
           say
           ,
           admit
           at
           least
           ,
           (
           though
           there
           may
           be
           many
           reasons
           alledged
           that
           it
           doth
           actually
           prey
           upon
           ,
           and
           dissolve
           those
           parts
           into
           it self
           ,
           as
           I
           shall
           shew
           by
           and
           by
           )
           because
           that
           we
           find
           that
           the
           extreme
           parts
           do
           extend
           but
           to
           such
           a
           distance
           ,
           and
           beyond
           that
           there
           is
           no
           appearance
           of
           light
           ,
           and
           that
           the
           light
           is
           from
           it self
           ,
           and
           not
           produced
           by
           refraction
           or
           reflexion
           of
           the
           beams
           of
           the
           Sun
           ,
           I
           shall
           shew
           reasons
           by
           and
           by
           .
           And
           consequently
           ,
           where
           there
           is
           most
           light
           appears
           ,
           there
           are
           the
           greatest
           number
           ,
           and
           there
           is
           the
           greatest
           density
           of
           the
           Cometical
           parts
           .
           The
           middle
           of
           the
           body
           may
           be
           as
           
           dense
           as
           the
           body
           of
           the
           earth
           ;
           and
           I
           have
           not
           observed
           my self
           ,
           nor
           met
           with
           any
           body
           else
           that
           hath
           taken
           notice
           of
           any
           thing
           to
           the
           contrary
           :
           If
           I
           could
           have
           seen
           any
           Comet
           to
           have
           covered
           any
           Star
           in
           its
           way
           ,
           it
           would
           have
           afforded
           a
           very
           circumstantial
           information
           ,
           especially
           if
           for
           this
           purpose
           it
           had
           been
           taken
           notice
           of
           with
           a
           good
           Telescope
           .
           What
           the
           density
           of
           the
           innermost
           parts
           of
           this
           Earth
           we
           live
           on
           is
           ,
           none
           knows
           ;
           for
           though
           we
           find
           the
           parts
           on
           which
           we
           tread
           to
           be
           very
           compact
           ,
           and
           though
           by
           the
           industry
           of
           Miners
           it
           hath
           been
           proved
           so
           also
           to
           the
           depth
           of
           many
           hundred
           foot
           ,
           as
           
             Georgius
             Agrieola
          
           relates
           :
           and
           though
           it
           hath
           been
           found
           so
           even
           to
           a
           greater
           depth
           by
           the
           soundings
           of
           the
           bottom
           of
           the
           Sea
           ,
           yet
           none
           can
           bring
           an
           undeniable
           proof
           that
           the
           same
           is
           so
           solid
           to
           25
           miles
           deep
           ;
           much
           less
           that
           it
           is
           so
           to
           the
           center
           :
           if
           therefore
           the
           external
           shell
           of
           this
           Globe
           were
           broken
           ,
           and
           removed
           ,
           't
           is
           not
           impossible
           but
           that
           the
           middle
           parts
           thereof
           may
           be
           of
           the
           same
           nature
           with
           the
           middle
           parts
           of
           the
           Comets
           body
           ;
           and
           that
           those
           parts
           (
           were
           the
           superficial
           parts
           or
           shell
           removed
           )
           might
           ,
           like
           these
           of
           Comets
           expand
           themselves
           into
           the
           encompassing
           Aether
           .
           Nay
           we
           find
           ,
           that
           notwithstanding
           the
           compactedness
           of
           the
           superficial
           parts
           of
           this
           Earth
           ,
           yet
           the
           Aether
           is
           able
           to
           take
           up
           into
           it self
           vast
           quantities
           of
           them
           ,
           and
           to
           keep
           them
           suspended
           ,
           some
           of
           them
           ,
           even
           to
           the
           height
           of
           many
           miles
           ,
           if
           any
           argument
           may
           be
           drawn
           from
           the
           height
           or
           length
           of
           the
           dawning
           o●
           〈◊〉
           ;
           and
           this
           ,
           notwithstanding
           the
           attraction
           of
           the
           Earth
           in
           its
           perfect
           vigor
           ,
           or
           the
           gravitation
           of
           these
           parts
           thus
           taken
           up
           ,
           or
           their
           endeavour
           towards
           the
           center
           of
           the
           Earth
           .
           How
           much
           more
           freely
           then
           might
           we
           imagine
           the
           encompassing
           Aether
           to
           prey
           upon
           ,
           and
           take
           up
           into
           it self
           the
           internal
           parts
           ,
           if
           they
           were
           of
           a
           loose
           and
           pervious
           texture
           ,
           and
           almost
           in
           a
           state
           of
           fluidity
           ,
           like
           a
           heap
           of
           Sand
           ,
           or
           a
           vessel
           of
           Alabaster-dust
           in
           boyling
           ,
           and
           were
           not
           so
           firmly
           united
           by
           the
           bonds
           of
           gravity
           ,
           and
           the
           vinculum
           of
           petrifaction
           ,
           
           as
           we
           find
           the
           superficial
           parts
           of
           the
           earth
           now
           are
           .
           There
           is
           one
           argument
           to
           prove
           to
           us
           ,
           that
           there
           may
           be
           such
           a
           looseness
           of
           the
           internal
           parts
           of
           the
           earth
           ,
           and
           that
           is
           that
           the
           magnetical
           virtue
           varies
           ,
           which
           virtue
           without
           controversie
           diffused
           through
           the
           whole
           body
           of
           the
           Earth
           ,
           and
           which
           hath
           a
           relation
           to
           the
           whole
           Globe
           ,
           and
           to
           every
           magnetical
           part
           ther●of
           .
           For
           by
           observation
           't
           is
           found
           ,
           that
           the
           magnetical
           virtue
           ,
           acts
           upon
           a
           needle
           without
           it
           ,
           as
           the
           magnetical
           virtue
           of
           a
           round
           Loadstone
           doth
           on
           a
           Needle
           applied
           without
           that
           ,
           which
           ,
           as
           I
           may
           elsewhere
           shew
           ,
           hath
           a
           respect
           to
           the
           center
           of
           the
           stone
           differing
           from
           all
           the
           respects
           that
           Authors
           have
           hitherto
           ascribed
           to
           it
           ,
           even
           of
           
             Gilbert
             ,
             Kepler
             ,
             Kircher
             ,
             Descartes
             ,
          
           and
           our
           Country-man
           Mr.
           Bond
           ,
           who
           I
           think
           was
           the
           first
           man
           that
           endeavoured
           to
           reduce
           the
           variations
           observed
           by
           
             Wright
             ,
             Gellibrand
             ,
             Coster
          
           ,
           &c.
           into
           a
           Theory
           and
           calculation
           .
           Now
           this
           magnetical
           virtue
           ,
           (
           which
           may
           be
           called
           one
           emanation
           of
           the
           
             Anima
             mundi
          
           ,
           as
           gravity
           may
           be
           called
           another
           )
           being
           diffused
           through
           every
           part
           of
           it
           ,
           and
           seeming
           to
           be
           ,
           as
           it
           were
           
             Tota
             in
             toto
             &
             tota
             in
             qualibet
             parte
             ,
          
           and
           to
           be
           more
           spiritual
           ,
           and
           to
           act
           more
           according
           to
           Magical
           and
           Mystical
           Laws
           than
           Light
           ,
           Sound
           ,
           or
           the
           like
           ,
           it
           giving
           to
           every
           magnetical
           body
           ,
           and
           every
           piece
           of
           it
           ,
           though
           infinitely
           divided
           ,
           the
           same
           proprieties
           it
           hath
           it self
           ;
           This
           magnetical
           virtue
           ,
           I
           say
           ,
           having
           such
           a
           relation
           ,
           and
           being
           forced
           thus
           to
           vary
           ,
           't
           is
           very
           probable
           that
           the
           internal
           parts
           to
           which
           it
           hath
           a
           respect
           ,
           have
           a
           variation
           likewise
           ;
           and
           consequently
           ,
           that
           these
           internal
           parts
           which
           are
           supposed
           generally
           very
           dense
           ,
           compact
           ,
           and
           very
           closely
           and
           solidly
           united
           ,
           may
           be
           notwithstanding
           more
           loose
           ,
           and
           ununited
           ,
           and
           movable
           from
           certain
           causes
           .
        
         
           To
           proceed
           therefore
           ,
           I
           say
           ,
           that
           it
           seems
           very
           probable
           to
           me
           ,
           that
           the
           body
           of
           Comets
           may
           be
           of
           the
           same
           nature
           and
           constitution
           with
           that
           of
           the
           internal
           parts
           of
           the
           Earth
           ,
           that
           these
           parts
           may
           ,
           by
           the
           help
           of
           the
           
           Aether
           ,
           be
           so
           agitated
           and
           blended
           together
           ,
           as
           to
           make
           them
           work
           upon
           ,
           and
           dissolve
           each
           other
           in
           the
           same
           manner
           ,
           as
           we
           have
           often
           had
           examples
           of
           some
           of
           the
           parts
           of
           the
           Earth
           ;
           a
           late
           instance
           of
           which
           was
           at
           Mongibel
           or
           Aetna
           in
           Sicily
           ,
           where
           the
           Fire
           continued
           for
           a
           long
           time
           ,
           and
           produced
           very
           considerable
           effects
           .
           That
           this
           internal
           agitation
           may
           confound
           the
           gravitating
           principle
           ,
           and
           so
           leave
           the
           parts
           in
           a
           greater
           freedom
           to
           be
           dissolved
           by
           the
           encompassing
           Aether
           ,
           which
           is
           the
           agent
           that
           sets
           the
           other
           two
           at
           work
           to
           destroy
           each
           other
           ,
           that
           it
           may
           at
           length
           prey
           upon
           both
           ,
           and
           dissolve
           them
           both
           into
           it self
           ;
           and
           consequently
           ,
           not
           only
           the
           parts
           thus
           dissolved
           are
           elevated
           to
           a
           greater
           distance
           from
           the
           center
           of
           the
           Star
           or
           Nucleus
           ,
           or
           the
           superficies
           of
           it
           ,
           whose
           gravitating
           or
           attractive
           principle
           is
           much
           destroyed
           ,
           the
           Coma
           being
           in
           this
           Comet
           four
           or
           five
           Diameters
           of
           the
           Star
           or
           Nucleus
           :
           but
           having
           given
           those
           parts
           leave
           thus
           far
           to
           ramble
           ,
           the
           gravitating
           principle
           of
           another
           body
           more
           potent
           acts
           upon
           it
           ,
           and
           makes
           those
           parts
           seem
           to
           recede
           from
           the
           center
           thereof
           ,
           though
           really
           they
           are
           but
           as
           it
           were
           ,
           left
           behind
           the
           body
           of
           the
           Star
           ,
           which
           is
           more
           powerfully
           attracted
           than
           the
           minuter
           steaming
           parts
           :
           for
           ,
           I
           suppose
           the
           gravitating
           power
           of
           the
           Sun
           in
           the
           center
           of
           this
           part
           of
           the
           Heaven
           in
           which
           we
           are
           ,
           hath
           an
           attractive
           power
           upon
           all
           the
           bodies
           of
           the
           Planets
           ,
           and
           of
           the
           Earth
           that
           move
           about
           it
           ,
           and
           that
           each
           of
           those
           again
           have
           a
           respect
           answerable
           ,
           whereby
           they
           may
           be
           said
           to
           attract
           the
           Sun
           in
           the
           same
           manner
           as
           the
           Load-stone
           hath
           to
           Iron
           ,
           and
           the
           Iron
           hath
           to
           the
           Loadstone
           .
           I
           conceive
           also
           that
           this
           attractive
           virtue
           may
           act
           likewise
           upon
           several
           other
           bodies
           that
           come
           within
           the
           center
           of
           its
           sphere
           of
           activity
           ,
           though
           't
           is
           not
           improbable
           also
           but
           that
           as
           on
           some
           bodies
           it
           may
           have
           no
           effect
           at
           all
           ,
           no
           more
           than
           the
           Load-stone
           which
           acts
           on
           Iron
           ,
           hath
           upon
           a
           bar
           of
           Tin
           ,
           Lead
           ,
           Glass
           ,
           Wood
           ,
           &c.
           so
           on
           other
           bodies
           ,
           it
           may
           have
           a
           clean
           contrary
           effect
           ,
           that
           is
           ,
           of
           protrusion
           ,
           thrusting
           off
           ,
           or
           driving
           away
           ,
           as
           
           we
           find
           one
           Pole
           of
           the
           Magnet
           doth
           the
           end
           of
           a
           Needle
           touched
           on
           the
           opposite
           part
           ;
           whence
           it
           is
           ,
           I
           conceive
           ,
           that
           the
           parts
           of
           the
           body
           of
           this
           Comet
           (
           being
           confounded
           or
           jumbled
           ,
           as
           't
           were
           together
           ,
           and
           so
           the
           gravitating
           principle
           destroyed
           )
           become
           of
           other
           natures
           than
           they
           were
           before
           ,
           and
           so
           the
           body
           may
           cease
           to
           maintain
           its
           place
           in
           the
           Universe
           ,
           where
           first
           it
           was
           placed
           .
           Whence
           instead
           of
           continuing
           to
           move
           round
           some
           central
           body
           ,
           whether
           Sun
           or
           Planet
           ,
           as
           it
           did
           whilst
           it
           maintained
           it self
           entire
           ,
           and
           so
           had
           its
           magnetical
           quality
           (
           as
           I
           may
           so
           call
           it
           )
           unconfounded
           ,
           it
           now
           leaves
           that
           circular
           way
           and
           by
           its
           motion
           (
           which
           always
           tends
           to
           a
           straight
           line
           ,
           and
           would
           be
           so
           were
           it
           not
           bended
           into
           a
           curve
           by
           the
           attractive
           virtue
           of
           the
           central
           body
           )
           it
           flies
           away
           from
           its
           former
           center
           by
           the
           Tangent
           line
           to
           the
           last
           place
           ,
           where
           it
           was
           before
           this
           confusion
           was
           caused
           in
           the
           body
           of
           it
           .
           In
           this
           line
           (
           't
           is
           probable
           )
           it
           passes
           from
           one
           part
           of
           the
           Heavens
           to
           another
           ,
           and
           so
           passes
           through
           the
           spheres
           of
           the
           activity
           of
           multitudes
           of
           central
           bodies
           ;
           in
           the
           passing
           through
           which
           spheres
           ,
           't
           is
           not
           improbable
           that
           those
           parts
           which
           by
           their
           dissolution
           are
           made
           of
           a
           nature
           differing
           from
           the
           body
           in
           the
           center
           ,
           are
           rather
           expelled
           from
           ,
           than
           attracted
           towards
           it
           ;
           and
           so
           being
           by
           this
           dissolution
           rarified
           ,
           and
           loosened
           from
           the
           middle
           ,
           and
           by
           their
           acting
           upon
           one
           another
           ,
           and
           dissolution
           of
           the
           Aether
           made
           of
           another
           nature
           ,
           after
           they
           have
           every
           way
           dispersed
           themselves
           to
           a
           considerable
           distance
           from
           their
           proper
           body
           ,
           are
           converted
           and
           driven
           in
           a
           way
           almost
           opposite
           to
           that
           expelling
           body
           ,
           and
           so
           continue
           to
           be
           driven
           away
           to
           such
           a
           vast
           distance
           ,
           as
           to
           make
           out
           that
           prodigious
           length
           of
           the
           tail
           or
           Blaze
           of
           some
           Comets
           (
           such
           as
           was
           that
           of
           1618.
           which
           ,
           as
           Kepler
           reports
           ,
           was
           extended
           to
           70
           degrees
           from
           the
           body
           or
           head
           of
           it
           )
           till
           at
           last
           they
           are
           dissolved
           also
           ,
           and
           commixed
           with
           the
           Aether
           within
           them
           .
           So
           that
           though
           I
           suppose
           the
           attractive
           power
           of
           the
           Sun
           ,
           or
           other
           central
           body
           may
           
           draw
           the
           body
           towards
           it
           ,
           and
           so
           bend
           the
           motion
           of
           the
           Comet
           from
           the
           streight
           line
           ,
           in
           which
           it
           tends
           ,
           into
           a
           kind
           of
           curve
           ,
           whose
           concave
           part
           is
           towards
           the
           Sun
           ,
           by
           reason
           that
           there
           are
           some
           central
           parts
           of
           it
           ,
           which
           are
           not
           yet
           destroyed
           ,
           and
           so
           retain
           somewhat
           of
           its
           gravitating
           principle
           :
           yet
           I
           conceive
           that
           all
           those
           parts
           of
           the
           Comet
           which
           are
           thus
           wrought
           upon
           by
           the
           other
           ,
           and
           changed
           into
           another
           state
           ,
           and
           are
           very
           much
           rarified
           ,
           and
           produce
           light
           ,
           are
           of
           a
           clean
           contrary
           nature
           ,
           and
           recede
           from
           the
           center
           of
           the
           Sun
           :
           much
           after
           the
           same
           manner
           as
           we
           find
           any
           combustible
           body
           with
           us
           ;
           as
           Coal
           ,
           &c.
           where
           we
           find
           that
           the
           body
           of
           the
           Coal
           ,
           before
           it
           be
           resolv'd
           into
           smoke
           ,
           is
           a
           very
           dense
           ,
           and
           very
           heavy
           body
           ,
           and
           tends
           to
           the
           center
           of
           the
           earth
           ;
           but
           the
           parts
           thereof
           agitated
           by
           the
           Air
           and
           Aether
           into
           steams
           and
           smoke
           ,
           and
           those
           yet
           farther
           dissolved
           into
           flame
           ,
           do
           tend
           upwards
           ,
           and
           from
           the
           center
           of
           the
           earth
           .
           Now
           though
           one
           cause
           of
           the
           recess
           of
           flame
           from
           the
           center
           of
           the
           Earth
           be
           the
           gravity
           of
           the
           ambient
           Air.
           Yet
           't
           is
           not
           impossible
           ,
           but
           that
           there
           may
           be
           somewhat
           also
           of
           positive
           levity
           conjoyned
           therewith
           .
           Most
           certain
           it
           is
           ,
           that
           there
           must
           be
           a
           tendency
           of
           receding
           ,
           as
           well
           as
           a
           tendency
           of
           approaching
           the
           center
           of
           the
           Earth
           ,
           and
           other
           attracting
           body
           .
           And
           there
           may
           be
           much
           said
           for
           the
           supposition
           ,
           that
           the
           recess
           of
           the
           purest
           Aether
           ,
           from
           the
           center
           ,
           is
           the
           cause
           of
           the
           motion
           of
           the
           grosser
           Aether
           ,
           and
           of
           all
           other
           bodies
           towards
           it
           ,
           though
           there
           are
           also
           very
           considerable
           arguments
           against
           it
           .
           But
           this
           discourse
           is
           not
           my
           present
           business
           ,
           though
           it
           may
           hereafter
           be
           the
           subject
           of
           a
           Lecture
           in
           this
           place
           ;
           for
           upon
           it
           do
           depend
           some
           of
           the
           greatest
           operations
           in
           the
           universe
           .
           And
           as
           in
           the
           History
           of
           the
           Creation
           ,
           we
           have
           an
           account
           of
           the
           production
           of
           light
           ,
           immediately
           after
           the
           making
           of
           matter
           ,
           which
           is
           a
           motion
           of
           recess
           from
           the
           center
           of
           the
           shining
           body
           .
           Next
           that
           ,
           a
           Firmament
           which
           divided
           between
           the
           waters
           or
           the
           fluids
           of
           the
           one
           ,
           and
           the
           fluids
           of
           another
           part
           of
           
           the
           world
           .
           And
           in
           the
           third
           place
           ,
           the
           collections
           of
           particular
           fluids
           to
           one
           center
           ,
           as
           the
           center
           of
           the
           Earth
           :
           and
           lastly
           ,
           out
           of
           that
           collection
           of
           fluids
           appeared
           the
           dry
           and
           solid
           land
           .
           So
           I
           conceive
           the
           most
           proper
           way
           of
           speculating
           on
           these
           great
           productions
           of
           the
           omnipotent
           Creator
           ,
           may
           be
           to
           begin
           with
           the
           consideration
           of
           light
           ,
           or
           the
           motion
           of
           recess
           from
           the
           center
           of
           a
           body
           .
           Next
           ,
           with
           the
           consideration
           of
           the
           cause
           of
           the
           separating
           of
           fluid
           from
           fluid
           ,
           as
           Aether
           from
           Aether
           ,
           as
           I
           may
           so
           call
           differing
           Aethers
           ;
           because
           we
           have
           not
           yet
           distinct
           names
           in
           use
           ,
           and
           the
           reason
           of
           their
           conglobation
           ,
           the
           Aether
           from
           the
           Air
           ,
           the
           Air
           from
           the
           Water
           ,
           the
           Water
           from
           Quicksilver
           ,
           Oyl
           ,
           or
           other
           fluid
           .
           Thirdly
           ,
           the
           cause
           of
           the
           conglobating
           property
           of
           each
           of
           these
           fluids
           when
           separated
           ,
           how
           they
           accept
           and
           embrace
           Homogenea
           ,
           and
           reject
           or
           expel
           Heterogenea
           .
           And
           fourthly
           ,
           how
           they
           condense
           and
           settle
           together
           ,
           and
           produce
           a
           solid
           body
           :
           whence
           proceeds
           the
           confirmation
           of
           attraction
           or
           gravitation
           ,
           &c.
           
           But
           to
           digress
           no
           further
           ,
           but
           conclude
           this
           part
           of
           enquiry
           in
           short
           ,
           I
           suppose
           the
           Nucleus
           or
           Star
           of
           the
           Comet
           may
           be
           much
           of
           the
           like
           nature
           with
           the
           central
           parts
           of
           the
           Earth
           ,
           Moon
           ,
           
             Mars
             ,
             Jupiter
             ,
             Saturn
          
           ,
           or
           other
           Planets
           ,
           but
           much
           impaired
           in
           its
           attractive
           or
           gravitating
           power
           .
        
         
           Next
           ,
           that
           the
           Coma
           or
           Hazy
           Cloud
           about
           it
           ,
           may
           be
           of
           the
           nature
           of
           the
           Atmosphere
           or
           Air
           about
           the
           Earth
           ,
           or
           the
           Smoke
           or
           steams
           about
           a
           heated
           or
           burning
           body
           ,
           before
           they
           are
           quite
           kindled
           ,
           converted
           into
           Flame
           ,
           or
           dissolved
           into
           the
           ambient
           Air.
           
        
         
           Thirdly
           ,
           that
           the
           Tail
           or
           Blaze
           is
           much
           of
           the
           nature
           of
           the
           parts
           of
           Flame
           ,
           though
           with
           those
           differences
           I
           conceive
           ,
           that
           the
           parts
           of
           these
           steams
           are
           not
           so
           close
           together
           ,
           as
           are
           those
           of
           Smoke
           :
           nor
           doth
           the
           motion
           of
           them
           ,
           though
           much
           swifter
           upwards
           than
           that
           of
           our
           Flame
           ,
           serve
           to
           make
           them
           appear
           a
           shining
           line
           ;
           but
           being
           at
           that
           distance
           ,
           they
           appear
           much
           slower
           to
           the
           eye
           ,
           and
           so
           discontinue
           the
           appearance
           ;
           whence
           every
           
           shining
           particle
           appears
           only
           a
           shining
           point
           ,
           though
           in
           the
           parts
           of
           flame
           (
           where
           notwithstanding
           the
           motion
           be
           much
           flower
           ,
           yet
           being
           nearer
           ,
           and
           so
           varying
           the
           position
           to
           the
           eye
           much
           quicker
           )
           each
           of
           the
           shining
           parts
           makes
           an
           appearance
           of
           a
           line
           of
           light
           ,
           and
           all
           of
           them
           passing
           pretty
           near
           together
           ,
           make
           the
           appearance
           of
           a
           continued
           fluid
           flame
           ;
           though
           that
           indeed
           be
           nothing
           but
           a
           great
           number
           of
           single
           parcels
           of
           the
           burning
           body
           ,
           raised
           up
           in
           the
           particles
           of
           Smoke
           .
           This
           will
           appear
           evident
           if
           we
           consider
           the
           appearances
           easily
           to
           be
           taken
           notice
           of
           in
           light
           :
           for
           't
           is
           obvious
           from
           multitudes
           of
           experiments
           ,
           that
           any
           shining
           body
           ,
           as
           a
           candle
           or
           brands
           end
           ,
           being
           moved
           very
           quick
           ,
           makes
           the
           same
           impression
           on
           the
           eye
           ,
           that
           a
           line
           of
           light
           doth
           standing
           still
           :
           And
           as
           obvious
           also
           that
           any
           very
           light
           body
           incompassed
           with
           a
           dark
           medium
           appears
           to
           the
           eye
           under
           an
           angle
           bigger
           than
           really
           it
           is
           ,
           and
           a
           dark
           body
           encompassed
           with
           a
           light
           medium
           much
           less
           .
           This
           any
           one
           may
           presently
           find
           ,
           if
           he
           make
           a
           small
           hole
           through
           a
           thin
           plate
           of
           metal
           ,
           and
           holding
           it
           first
           between
           the
           light
           and
           the
           eye
           ,
           and
           so
           seeing
           the
           light
           appear
           through
           it
           ,
           and
           then
           placing
           it
           so
           as
           there
           is
           nothing
           but
           darkness
           appears
           through
           the
           said
           hole
           ,
           for
           he
           will
           plainly
           perceive
           that
           the
           same
           hole
           will
           appear
           much
           bigger
           in
           the
           former
           position
           than
           in
           the
           latter
           .
           Upon
           this
           account
           indeed
           each
           of
           the
           shining
           parts
           of
           the
           Comet
           seems
           to
           fill
           and
           occupy
           a
           much
           greater
           space
           than
           really
           it
           doth
           :
           and
           so
           ,
           as
           't
           is
           observable
           in
           the
           milky
           way
           ,
           a
           great
           number
           of
           these
           small
           shining
           bodies
           though
           dispersed
           at
           a
           pretty
           distance
           one
           from
           another
           ,
           yet
           by
           reason
           of
           the
           imperceptibleness
           of
           each
           of
           them
           they
           all
           seem
           to
           coalesce
           into
           a
           stream
           or
           Blaze
           of
           light
           ,
           the
           brightness
           of
           which
           is
           yet
           farther
           augmented
           by
           a
           clear
           and
           unenlightened
           air
           ,
           and
           by
           such
           a
           part
           of
           the
           Heaven
           wherein
           there
           appears
           fewest
           of
           the
           Stars
           ,
           whether
           they
           be
           greater
           or
           lesser
           .
        
         
         
           To
           the
           Query
           ,
           
             Of
             what
             magnitude
             the
             Body
          
           ,
           Coma
           ,
           
             and
             Blaze
             of
             Comets
             may
             be
             ?
          
           No
           answer
           can
           be
           given
           until
           another
           question
           be
           first
           answered
           ;
           and
           that
           is
           ,
           
             What
             is
             the
             place
             of
             Comets
             ,
             and
             what
             is
             their
             distance
             from
             the
             Earth
             ?
          
           It
           was
           the
           opinion
           of
           most
           Modern
           Writers
           before
           
             Tycho
             Brahe
          
           and
           Kepler
           (
           I
           know
           divers
           of
           the
           Antients
           thought
           otherwise
           )
           that
           Comets
           were
           sublunary
           Meteors
           ,
           drawn
           up
           into
           the
           higher
           Regions
           of
           the
           Air
           ,
           and
           there
           set
           on
           fire
           ,
           and
           so
           continued
           burning
           till
           the
           Meteor
           were
           consumed
           ;
           and
           as
           the
           matter
           increased
           ,
           or
           wasted
           ,
           so
           did
           the
           appearance
           of
           the
           Comet
           .
           But
           this
           noble
           Dane
           ,
           and
           several
           others
           about
           that
           time
           found
           by
           accurate
           observations
           made
           ,
           that
           its
           Parallax
           was
           less
           than
           that
           of
           the
           Moon
           ;
           and
           consequently
           ,
           that
           it
           was
           farther
           distant
           from
           the
           earth
           :
           that
           it
           must
           be
           a
           body
           of
           another
           magnitude
           ,
           and
           nature
           ,
           than
           most
           before
           that
           time
           had
           imagined
           ;
           and
           therefore
           that
           it
           ought
           to
           be
           otherwise
           thought
           of
           than
           the
           generality
           of
           mankind
           believed
           concerning
           it
           .
           Many
           had
           been
           the
           attempts
           of
           former
           Writers
           concerning
           them
           ,
           to
           find
           out
           their
           parallax
           ;
           and
           whether
           from
           their
           unaccurate
           instruments
           ,
           or
           from
           their
           less
           skill
           and
           diligence
           in
           using
           them
           ,
           or
           from
           an
           imagination
           of
           the
           solidity
           ,
           and
           impenetrability
           of
           the
           Coelestial
           Orbs
           ,
           or
           from
           error
           in
           their
           calculations
           ,
           or
           from
           comparing
           Observations
           made
           at
           distant
           places
           ,
           one
           or
           both
           whereof
           were
           unaccurate
           ,
           or
           from
           a
           prepossession
           of
           Tradition
           or
           common
           Fame
           ,
           or
           from
           what
           other
           cause
           soever
           it
           were
           is
           uncertain
           ;
           but
           't
           was
           generally
           concluded
           by
           them
           ,
           that
           all
           Comets
           were
           sublunary
           Meteors
           :
           and
           there
           are
           not
           even
           at
           this
           day
           wanting
           some
           of
           the
           same
           opinion
           ,
           though
           for
           what
           reason
           I
           know
           not
           .
           'T
           will
           be
           hard
           to
           convince
           some
           of
           these
           ,
           that
           the
           opinion
           they
           have
           hitherto
           received
           for
           good
           ,
           is
           not
           so
           ,
           because
           they
           will
           hardly
           give
           themselves
           the
           trouble
           of
           examining
           strictly
           into
           the
           matter
           :
           And
           to
           understand
           the
           nature
           of
           Parallaxes
           ,
           and
           how
           significant
           they
           are
           in
           determining
           the
           distances
           of
           bodies
           from
           the
           surface
           of
           the
           
           Earth
           ,
           to
           certain
           degrees
           thereof
           ;
           beyond
           which
           ,
           by
           reason
           of
           the
           imperfections
           in
           Instruments
           ,
           and
           Observations
           ,
           and
           the
           exceeding
           niceness
           and
           curiosity
           necessary
           ,
           they
           signifie
           very
           little
           .
           It
           is
           not
           my
           present
           design
           to
           explain
           what
           Parallax
           is
           ,
           that
           I
           would
           suppose
           my
           Reader
           to
           understand
           ;
           otherwise
           there
           can
           be
           no
           reason
           shewn
           him
           to
           convince
           him
           that
           't
           is
           possible
           to
           prove
           that
           this
           or
           that
           Comet
           was
           not
           nearer
           than
           so
           many
           semidiameters
           of
           the
           Earth
           ,
           nor
           farther
           off
           than
           so
           many
           .
           There
           are
           then
           two
           ways
           ,
           by
           which
           we
           may
           come
           to
           some
           certainty
           of
           what
           distance
           a
           Comet
           is
           ;
           and
           those
           are
           ,
           first
           the
           Parallax
           of
           its
           Diurnal
           motion
           ,
           or
           its
           Parallax
           caused
           by
           the
           Diurnal
           motion
           of
           the
           Earth
           .
           And
           secondly
           ,
           the
           Parallax
           of
           its
           proper
           motion
           compared
           with
           the
           Periodick
           or
           Annual
           motion
           of
           the
           Earth
           .
           The
           first
           of
           these
           may
           be
           observed
           two
           ways
           ;
           either
           by
           two
           Observers
           at
           parts
           of
           the
           Earth
           very
           far
           distant
           from
           each
           other
           ,
           but
           as
           near
           as
           may
           be
           under
           the
           same
           Meridian
           :
           as
           suppose
           the
           one
           in
           London
           ,
           the
           other
           in
           St.
           Helens
           ;
           both
           conspiring
           in
           their
           observing
           of
           the
           place
           of
           the
           Comet
           amongst
           the
           fix'd
           Stars
           at
           the
           same
           time
           .
           Or
           secondly
           ,
           by
           one
           Observer
           in
           the
           same
           place
           ,
           by
           observing
           the
           place
           of
           it
           amongst
           the
           fix'd
           Stars
           ,
           in
           its
           rising
           or
           setting
           ,
           and
           in
           a
           greater
           ,
           or
           if
           it
           may
           be
           ,
           its
           greatest
           height
           :
           The
           noble
           Tycho
           by
           very
           accurate
           Observation
           of
           the
           Parallax
           ,
           proves
           the
           Comet
           of
           1577.
           to
           be
           above
           the
           Moon
           .
           Kepler
           by
           his
           own
           Observations
           proves
           that
           of
           1607.
           at
           its
           beginning
           to
           be
           four
           times
           farther
           distant
           ;
           and
           I
           doubt
           not
           but
           some
           may
           have
           been
           above
           forty
           times
           farther
           .
           But
           I
           do
           not
           yet
           find
           that
           any
           Observations
           have
           accurately
           determined
           that
           which
           is
           indeed
           the
           great
           help
           by
           which
           we
           are
           inabled
           to
           judge
           of
           the
           nature
           ,
           and
           all
           the
           other
           accidents
           and
           proprieties
           of
           Comets
           .
           The
           Aristotelian
           Philosophy
           for
           a
           long
           time
           prevailing
           ,
           made
           the
           world
           believe
           them
           to
           be
           nothing
           but
           Exhalations
           from
           the
           Earth
           ,
           drawn
           up
           into
           the
           higher
           Regions
           of
           the
           Air.
           But
           Tycho
           by
           his
           Observations
           of
           their
           Parallax
           ,
           raises
           
           them
           out
           of
           that
           confinement
           ,
           but
           yet
           he
           seems
           to
           place
           them
           in
           an
           Orb
           about
           the
           Sun.
           But
           Kepler
           frees
           them
           from
           that
           confinement
           ,
           and
           assigns
           them
           the
           Universe
           to
           expatiate
           in
           .
           But
           none
           of
           all
           these
           do
           accurately
           prove
           the
           true
           distance
           of
           them
           ,
           their
           Parallax
           being
           for
           the
           most
           part
           so
           very
           small
           ,
           that
           I
           fear
           Instruments
           with
           common
           lights
           will
           hardly
           reach
           them
           .
           But
           we
           must
           expect
           from
           future
           observations
           made
           with
           Telescopical
           Instruments
           to
           receive
           a
           certain
           Answer
           to
           this
           Query
           .
           Certain
           I
           am
           ,
           that
           the
           Comet
           which
           began
           to
           appear
           in
           November
           1664.
           and
           disappear'd
           in
           March
           following
           ,
           was
           far
           removed
           beyond
           the
           distance
           assigned
           by
           Kepler
           .
           For
           by
           my
           own
           Observations
           divers
           times
           repeated
           ,
           I
           could
           not
           find
           any
           sensible
           Parallax
           ,
           though
           I
           endeavoured
           by
           a
           new
           method
           to
           make
           my
           Observations
           more
           accurate
           .
           Now
           though
           I
           had
           not
           the
           convenience
           of
           making
           use
           of
           a
           Quadrant
           ,
           or
           any
           such
           Instrument
           ,
           to
           observe
           its
           place
           when
           near
           the
           Horizon
           ,
           yet
           the
           way
           I
           took
           ,
           would
           ,
           I
           think
           ,
           be
           as
           good
           ;
           which
           was
           this
           :
           With
           a
           very
           good
           six
           foot
           Perspective-glass
           or
           Telescope
           ,
           I
           observed
           the
           place
           of
           the
           Comet
           ,
           in
           respect
           of
           the
           adjacent
           small
           Stars
           ,
           as
           soon
           as
           it
           appeared
           ,
           and
           so
           traced
           its
           way
           till
           it
           disappeared
           in
           the
           vapors
           of
           the
           Horizon
           :
           the
           like
           I
           did
           several
           other
           days
           successively
           ,
           taking
           notice
           by
           what
           degrees
           ,
           in
           what
           times
           it
           made
           its
           progress
           ,
           to
           see
           whether
           by
           its
           Parallax
           ,
           when
           near
           the
           Horizon
           ,
           it
           would
           have
           been
           deprest
           below
           that
           line
           of
           its
           motion
           ,
           which
           it
           kept
           ,
           when
           at
           a
           greater
           height
           above
           it
           .
           But
           though
           I
           tried
           this
           several
           times
           ,
           yet
           I
           was
           not
           able
           to
           discern
           that
           the
           Parallax
           of
           it
           caused
           either
           any
           sensible
           bending
           of
           the
           line
           ,
           or
           any
           sensible
           inequality
           in
           its
           progress
           ,
           by
           which
           I
           should
           have
           sooner
           found
           it
           ,
           than
           by
           taking
           its
           altitudes
           with
           common
           Instruments
           :
           though
           I
           confess
           these
           Observations
           were
           made
           when
           the
           motion
           of
           the
           Comet
           was
           slow
           ,
           and
           consequently
           ,
           when
           in
           probability
           it
           was
           far
           distant
           from
           the
           earth
           .
           To
           me
           there
           seems
           no
           doubt
           but
           that
           it
           was
           a
           long
           way
           removed
           above
           the
           Moon
           
           when
           I
           made
           these
           Observations
           :
           for
           had
           it
           been
           of
           an
           equal
           distance
           with
           that
           they
           allow
           the
           Moon
           ,
           it
           must
           this
           way
           have
           manifested
           a
           very
           sensible
           Parallax
           of
           divers
           minutes
           :
           but
           whereas
           I
           could
           not
           certainly
           distinguish
           any
           sensible
           at
           all
           ,
           it
           must
           be
           many
           times
           higher
           than
           the
           Moon
           .
           Now
           that
           this
           way
           is
           abundantly
           to
           be
           preferred
           before
           an
           Observation
           made
           with
           a
           Quadrant
           for
           the
           taking
           of
           its
           altitude
           ,
           is
           pretty
           evident
           ;
           because
           ,
           by
           this
           means
           the
           greatest
           part
           of
           the
           irregularity
           ,
           caused
           by
           the
           refraction
           or
           inflection
           of
           the
           Air
           is
           removed
           ;
           for
           by
           this
           means
           ,
           though
           the
           Parallax
           be
           very
           large
           ,
           yet
           the
           refraction
           or
           inflection
           of
           the
           Air
           will
           not
           amount
           to
           many
           seconds
           ,
           both
           the
           objects
           being
           almost
           equally
           raised
           by
           refraction
           ,
           especially
           when
           5
           or
           10
           degrees
           high
           ;
           nearer
           than
           which
           the
           small
           Stars
           vanished
           out
           of
           sight
           by
           the
           thickness
           of
           our
           air
           .
           It
           follows
           therefore
           that
           a
           Semidiameter
           of
           the
           Earth
           must
           be
           a
           very
           inconsiderable
           measure
           in
           its
           distance
           .
        
         
           This
           part
           therefore
           of
           the
           Theory
           of
           Comets
           hath
           been
           much
           defective
           hitherto
           .
           If
           we
           enquire
           the
           Parallax
           of
           them
           from
           the
           Observation
           of
           divers
           men
           made
           in
           differing
           places
           ▪
           we
           shall
           find
           them
           so
           differing
           one
           from
           another
           ,
           that
           there
           is
           great
           reason
           to
           suspect
           them
           all
           :
           Nay
           ,
           not
           only
           so
           ,
           but
           in
           this
           Comet
           of
           1664.
           by
           comparing
           two
           Tables
           or
           Charts
           of
           the
           Stars
           ,
           and
           Constellations
           of
           that
           part
           of
           the
           Heavens
           ,
           through
           which
           the
           Comet
           past
           ,
           on
           which
           was
           also
           markt
           out
           its
           way
           and
           place
           from
           day
           to
           day
           ,
           both
           of
           them
           Printed
           from
           Copper
           Plates
           ,
           I
           find
           that
           strange
           errors
           and
           mistakes
           may
           be
           created
           ,
           notwithstanding
           all
           the
           Authors
           care
           and
           accurateness
           possible
           ,
           from
           the
           carelesness
           or
           neglect
           of
           the
           Graver
           :
           This
           I
           noted
           in
           the
           two
           Tables
           of
           the
           learned
           and
           accurate
           Mathematician
           ,
           
             P.
             Aegidius
             Franciscus
             de
             Gotignies
          
           ,
           (
           whose
           skill
           and
           care
           from
           other
           works
           of
           his
           and
           other
           Observations
           of
           this
           Comet
           I
           am
           sufficiently
           assured
           of
           )
           and
           found
           that
           by
           the
           first
           table
           upon
           the
           21
           /
           31
           of
           December
           ,
           1664.
           it
           
           was
           in
           4½
           of
           ♊
           in
           Longitude
           ,
           and
           in
           33⅔
           of
           Southern
           Latitude
           ;
           but
           by
           the
           second
           it
           is
           placed
           at
           the
           same
           time
           in
           4
           o
           ♊
           for
           its
           Longitude
           ,
           and
           in
           34½
           of
           South
           Latitude
           .
           And
           this
           error
           is
           not
           only
           committed
           in
           the
           place
           of
           the
           Comet
           ,
           but
           also
           in
           the
           place
           of
           the
           fix'd
           Stars
           :
           for
           Riget
           in
           the
           first
           Table
           is
           placed
           in
           30¾
           South
           Latitude
           ,
           and
           in
           12¼
           ♊
           for
           Longitude
           ,
           but
           in
           the
           second
           in
           31½
           South
           Latitude
           ,
           and
           in
           11½
           ♊
           for
           Longitude
           :
           both
           which
           differ
           considerably
           from
           the
           place
           of
           it
           assigned
           by
           Riccioli
           and
           Grimaldi
           ;
           according
           to
           whose
           Observations
           it
           should
           be
           in
           31.
           
           11′
           South
           Latitude
           ,
           and
           12°
           .
           11′
           .
           40″
           .
           ♊
           in
           Longitude
           .
        
         
           Now
           if
           there
           be
           these
           differences
           to
           be
           remarked
           in
           the
           Observations
           of
           one
           ,
           we
           cannot
           but
           expect
           that
           much
           more
           disagreement
           should
           be
           found
           between
           those
           which
           have
           been
           made
           by
           differing
           persons
           in
           differing
           places
           ,
           and
           with
           differing
           ways
           ,
           and
           differing
           Instruments
           .
           And
           upon
           examination
           I
           have
           found
           it
           no
           better
           :
           for
           from
           comparing
           such
           Observations
           as
           I
           have
           received
           from
           several
           parts
           of
           the
           world
           ,
           even
           of
           those
           which
           have
           seemed
           more
           than
           ordinarily
           exact
           ,
           I
           find
           them
           for
           the
           most
           part
           so
           unaccurate
           ,
           that
           though
           they
           sufficiently
           manifest
           that
           the
           Comet
           of
           1664.
           which
           lasted
           above
           four
           months
           ,
           was
           visible
           in
           most
           parts
           of
           the
           world
           ,
           and
           seen
           to
           pass
           in
           all
           those
           places
           pretty
           near
           in
           the
           same
           way
           amongst
           the
           fixed
           Stars
           .
           Yet
           they
           are
           so
           far
           from
           manifesting
           the
           Parallax
           ,
           that
           some
           of
           them
           make
           the
           place
           of
           the
           Comet
           to
           be
           quite
           contrary
           to
           what
           Parallax
           would
           make
           it
           ;
           some
           of
           the
           Southern
           Observators
           placing
           it
           much
           more
           Southwardly
           than
           those
           of
           the
           North.
           Others
           indeed
           of
           them
           make
           the
           Parallax
           so
           great
           ,
           that
           one
           might
           ghess
           it
           to
           be
           not
           so
           far
           removed
           from
           the
           Earth
           .
           Something
           indeed
           in
           the
           general
           might
           be
           ghest
           of
           the
           way
           of
           that
           Comet
           amongst
           the
           fix'd
           Stars
           ,
           especially
           when
           it
           approaches
           them
           pretty
           near
           :
           but
           for
           exactness
           of
           Calculation
           for
           Parallax
           ,
           they
           were
           no
           way
           useful
           .
           And
           even
           
           in
           the
           former
           use
           too
           it
           seems
           very
           doubtful
           for
           comparing
           the
           Charts
           of
           the
           Comets
           way
           amongst
           the
           fix'd
           Stars
           published
           by
           that
           diligent
           and
           unwearied
           Observer
           Mr.
           Hevelius
           of
           Dantzick
           ,
           the
           above-mentioned
           
             P.
             Gottigies
          
           ,
           Professor
           at
           Rome
           ,
           and
           Monsieur
           Petit
           of
           Paris
           ,
           I
           find
           ,
           that
           the
           two
           former
           make
           the
           way
           of
           the
           Comet
           to
           lie
           below
           the
           Star
           in
           the
           Bill
           of
           Corvus
           ;
           whereas
           the
           later
           ,
           though
           in
           a
           Latitude
           interposed
           between
           the
           parallels
           of
           the
           former
           ,
           makes
           it
           to
           lie
           above
           ,
           or
           to
           the
           North
           of
           it
           :
           and
           with
           him
           agree
           some
           Observations
           which
           I
           have
           seen
           of
           Monsieur
           Hugenius
           .
           Other
           disserences
           I
           found
           between
           those
           Tables
           in
           the
           way
           of
           the
           Comet
           of
           64.
           near
           the
           middle
           of
           its
           arch
           ;
           wherein
           Monsieur
           Hevelius
           all
           the
           way
           places
           it
           more
           Southward
           than
           either
           Monsieur
           Petit
           ,
           or
           
             P.
             Gottignies
          
           :
           for
           whereas
           both
           
             P.
             Gottignies
          
           ,
           and
           Mounsieur
           Petit
           make
           it
           pass
           above
           the
           Star
           of
           the
           third
           magnitude
           in
           the
           right
           shoulder
           of
           Lepus
           ,
           Monsieur
           Hevelius
           makes
           it
           move
           below
           it
           ,
           which
           seem
           to
           be
           ascribable
           to
           Parallax
           .
           But
           I
           fear
           much
           cannot
           be
           concluded
           of
           certainty
           from
           them
           .
        
         
           I
           shall
           not
           trouble
           the
           Reader
           with
           a
           multitude
           of
           other
           Histories
           ,
           which
           I
           have
           received
           concerning
           that
           Comet
           of
           64.
           nor
           with
           the
           disagreements
           of
           them
           one
           with
           another
           ,
           and
           perhaps
           of
           most
           with
           the
           truth
           .
           They
           have
           given
           me
           sufficient
           trouble
           in
           the
           examination
           of
           them
           ,
           having
           little
           other
           benefit
           from
           them
           ,
           save
           only
           this
           ,
           that
           I
           was
           thereby
           informed
           what
           a
           man
           might
           think
           of
           a
           great
           number
           of
           Astronomical
           Observations
           that
           have
           been
           made
           :
           for
           ,
           saving
           the
           exact
           Observations
           of
           some
           few
           such
           ,
           as
           Mr.
           Hevelius
           ,
           Mr.
           
             Aurout
             ,
             P.
             Gottingnies
             ,
             &c.
          
           truly
           diligent
           and
           accurate
           men
           ,
           the
           greater
           the
           Collections
           of
           Observations
           are
           ,
           the
           more
           trouble
           and
           difficulty
           is
           created
           to
           the
           Examiner
           ;
           they
           not
           only
           confounding
           one
           another
           ,
           but
           perplexing
           those
           also
           which
           are
           real
           and
           perfect
           .
        
         
           Now
           the
           reasons
           or
           causes
           of
           these
           inconveniences
           seem
           to
           be
           these
           .
        
         
         
           First
           ,
           the
           want
           of
           accurate
           and
           knowing
           Observators
           .
        
         
           Secondly
           ,
           The
           scarcity
           of
           convenient
           Instruments
           .
        
         
           Thirdly
           ,
           The
           Imperfection
           of
           the
           Tables
           of
           the
           fix'd
           Stars
           .
        
         
           For
           the
           Observators
           ,
           't
           is
           not
           enough
           to
           know
           how
           to
           manage
           an
           instrument
           ,
           or
           to
           have
           a
           good
           eye
           ,
           or
           a
           dextrous
           and
           steady
           hand
           ;
           but
           with
           these
           there
           must
           be
           joyned
           a
           skilfulness
           in
           the
           theorical
           and
           speculative
           part
           ,
           and
           add
           to
           all
           a
           love
           and
           delight
           in
           the
           thing
           it self
           ;
           and
           even
           all
           these
           will
           signifie
           but
           little
           ,
           without
           convenient
           and
           accurate
           Instruments
           ,
           such
           as
           may
           be
           easily
           manageable
           and
           sufficiently
           exact
           .
        
         
           The
           first
           of
           these
           the
           love
           of
           the
           study
           being
           in
           it self
           the
           most
           excellent
           ,
           or
           the
           encouragement
           of
           Princes
           ,
           Noblemen
           ,
           and
           other
           Patrons
           of
           this
           Learning
           must
           procure
           :
           and
           where
           both
           of
           these
           concur
           ,
           thence
           most
           is
           to
           be
           expected
           ,
           and
           most
           fruit
           hath
           hitherto
           been
           proceeded
           ;
           though
           there
           are
           not
           wanting
           divers
           eminent
           instances
           where
           the
           first
           reason
           hath
           been
           the
           only
           inducement
           .
        
         
           As
           to
           the
           second
           ,
           I
           have
           already
           in
           some
           of
           my
           former
           Lectures
           described
           several
           convenient
           ones
           for
           these
           purposes
           ;
           and
           therefore
           I
           shall
           not
           here
           add
           any
           more
           concerning
           it
           .
        
         
           But
           as
           to
           the
           third
           ,
           I
           hope
           the
           indefatigable
           labour
           and
           skill
           of
           Monsieur
           Hevelius
           will
           shortly
           supply
           the
           present
           defect
           ,
           though
           it
           had
           been
           much
           to
           be
           wish'd
           ,
           that
           the
           Instruments
           he
           had
           made
           use
           of
           had
           been
           fitted
           with
           Telescopical
           sights
           .
           These
           Tables
           ,
           if
           well
           done
           ,
           will
           alone
           (
           as
           to
           the
           business
           of
           Comets
           at
           least
           )
           supply
           the
           place
           of
           all
           other
           Instruments
           almost
           ,
           save
           only
           a
           thread
           ,
           especially
           if
           they
           be
           so
           delineated
           in
           Tables
           after
           the
           Tangent
           projection
           ,
           as
           that
           the
           minutes
           of
           every
           degree
           may
           be
           very
           distinguishable
           ,
           which
           will
           not
           swell
           the
           Maps
           of
           the
           Heavens
           into
           an
           extraordinary
           large
           volume
           ,
           and
           may
           possibly
           be
           the
           cheapest
           Instrument
           for
           this
           purpose
           an
           Astronomer
           can
           be
           furnished
           
           withal
           ;
           for
           having
           such
           a
           volume
           of
           Tables
           ,
           it
           will
           be
           very
           easie
           with
           a
           thread
           and
           one's
           eye
           ,
           screen'd
           only
           with
           a
           spectacle
           made
           of
           a
           thin
           plate
           of
           Brass
           ,
           with
           a
           small
           hole
           through
           it
           ,
           instead
           of
           a
           glass
           ,
           to
           observe
           what
           place
           the
           Comet
           possesseth
           amongst
           the
           fixt
           Stars
           :
           for
           having
           by
           the
           help
           of
           the
           said
           thread
           observed
           what
           two
           Stars
           lie
           in
           the
           same
           line
           with
           the
           Comet
           on
           one
           side
           of
           it
           ,
           and
           what
           other
           two
           Stars
           lie
           in
           a
           line
           with
           it
           ,
           which
           is
           at
           right
           angles
           (
           as
           near
           as
           may
           be
           )
           with
           the
           former
           line
           ,
           by
           finding
           out
           those
           four
           Stars
           in
           the
           Tables
           ,
           ordered
           according
           to
           the
           Tangent
           projection
           ,
           and
           with
           a
           Ruler
           ,
           drawing
           lines
           over
           them
           respectively
           ,
           where
           those
           lines
           do
           intersect
           ,
           there
           will
           be
           the
           true
           place
           of
           the
           Comet
           ,
           from
           which
           it
           will
           not
           be
           difficult
           to
           find
           out
           the
           true
           Longitude
           and
           Latitude
           of
           it
           by
           a
           Sector
           with
           Tangents
           .
           Now
           as
           these
           Tables
           of
           all
           the
           fixt
           Stars
           visible
           to
           the
           naked
           eye
           ,
           would
           serve
           for
           finding
           its
           place
           whilst
           very
           big
           and
           swift
           of
           motion
           ;
           so
           the
           like
           Tables
           of
           the
           small
           Telescopical
           Stars
           that
           lie
           near
           its
           way
           ,
           when
           almost
           disappearing
           ,
           and
           moving
           very
           slow
           ,
           will
           by
           the
           help
           of
           a
           pair
           of
           measuring
           Compasses
           placed
           within
           the
           eye-glass
           of
           the
           Telescope
           ,
           and
           a
           straight
           line
           or
           hair
           drawn
           cross
           it
           ,
           serve
           to
           find
           the
           true
           motion
           and
           way
           of
           it
           ,
           when
           only
           visible
           with
           a
           Telescope
           :
           according
           to
           which
           method
           I
           made
           the
           annexed
           Schemes
           ,
           and
           Observations
           of
           the
           last
           appearances
           of
           the
           Comet
           .
        
         
           Now
           since
           neither
           from
           my
           own
           ,
           nor
           from
           any
           other
           Observations
           that
           I
           have
           hitherto
           met
           with
           ,
           there
           can
           be
           any
           certain
           conclusion
           drawn
           of
           the
           distance
           of
           these
           Comets
           ,
           save
           only
           this
           ,
           that
           their
           distance
           was
           very
           great
           ,
           and
           much
           higher
           than
           the
           body
           of
           the
           Moon
           ,
           because
           else
           there
           must
           have
           been
           a
           considerable
           Parallax
           caused
           by
           the
           Diurnal
           motion
           .
           The
           next
           enquiry
           will
           be
           ,
           what
           other
           ways
           there
           are
           of
           knowing
           its
           distance
           .
           Now
           though
           none
           could
           be
           more
           demonstrative
           than
           the
           Parallax
           found
           this
           way
           by
           the
           Diurnal
           motion
           ,
           yet
           there
           are
           some
           other
           which
           seem
           more
           easie
           
           arising
           from
           the
           consideration
           of
           the
           motions
           that
           may
           be
           thought
           to
           be
           concern'd
           in
           the
           producing
           the
           appearances
           .
           And
           though
           they
           be
           wholly
           hypothetical
           ,
           and
           so
           need
           some
           other
           arguments
           to
           prove
           the
           ground
           and
           principles
           on
           which
           they
           are
           founded
           ,
           yet
           since
           there
           are
           not
           very
           many
           considerable
           ones
           wanting
           to
           make
           them
           probable
           and
           rational
           ,
           I
           shall
           here
           add
           somewhat
           of
           my
           inquiries
           after
           the
           distance
           ,
           position
           ,
           motion
           ,
           magnitude
           ,
           &c.
           of
           these
           Comets
           by
           these
           means
           .
        
         
           Of
           these
           ways
           there
           are
           several
           depending
           upon
           several
           suppositions
           which
           produce
           very
           differing
           effects
           ,
           as
           to
           the
           magnitude
           ,
           distance
           ,
           motion
           ,
           and
           way
           of
           the
           same
           Comet
           .
        
         
           The
           suppositions
           are
           these
           :
        
         
           Either
           that
           the
           Earth
           moves
           in
           an
           annual
           orb
           about
           the
           Sun
           ,
           as
           the
           Sun
           is
           supposed
           by
           others
           to
           move
           about
           the
           Earth
           :
           Or
           that
           the
           Earth
           is
           perfectly
           fix'd
           ,
           and
           hath
           no
           such
           motion
           .
        
         
           Next
           ,
           that
           the
           Comet
           moves
           either
           in
           a
           straight
           line
           ▪
           or
           in
           a
           curve
           line
           ;
           and
           the
           curve
           is
           either
           a
           circle
           ,
           or
           some
           other
           regular
           or
           irregular
           curve
           .
        
         
           Further
           that
           the
           motion
           of
           the
           Comets
           in
           these
           lines
           is
           either
           by
           equal
           or
           unequal
           spaces
           in
           equal
           times
           .
        
         
           Now
           according
           as
           we
           take
           this
           ,
           or
           those
           of
           these
           differing
           suppositions
           ,
           and
           compound
           them
           together
           ,
           so
           will
           the
           product
           of
           them
           be
           strangely
           differing
           .
           Amongst
           the
           great
           variety
           of
           compositions
           of
           these
           principles
           or
           suppositions
           ,
           these
           seem
           the
           most
           simple
           ,
           and
           consequently
           being
           any
           otherwise
           proved
           ,
           will
           best
           determine
           the
           true
           distance
           and
           way
           of
           the
           Comet
           .
        
         
           First
           ,
           To
           suppose
           the
           Earth
           to
           stand
           still
           ,
           and
           the
           Comet
           to
           move
           equal
           spaces
           in
           equal
           times
           in
           a
           circle
           .
        
         
           Secondly
           ,
           To
           suppose
           the
           Earth
           to
           move
           in
           an
           annual
           Orb
           about
           the
           Sun
           ,
           and
           the
           Comet
           to
           move
           through
           the
           Aether
           or
           Expansum
           ,
           equal
           spaces
           in
           equal
           times
           in
           a
           straight
           line
           .
        
         
           Thirdly
           ,
           To
           suppose
           the
           Earth
           to
           move
           (
           as
           above
           )
           
           in
           its
           annual
           Orb
           ,
           and
           the
           Comet
           also
           to
           move
           equal
           spaces
           in
           equal
           lines
           in
           a
           circle
           .
        
         
           The
           other
           are
           indeterminate
           and
           infinite
           ,
           and
           nothing
           can
           be
           concluded
           from
           them
           as
           to
           the
           distance
           ,
           magnitude
           ,
           motion
           ,
           &c.
           of
           Comets
           ;
           for
           the
           line
           or
           way
           of
           the
           Comet
           may
           be
           placed
           at
           any
           distance
           ,
           if
           we
           will
           suppose
           it
           moved
           in
           an
           uncertain
           curve
           ,
           with
           unequal
           degrees
           of
           velocity
           :
           And
           indeed
           ,
           upon
           a
           supposal
           of
           an
           inequality
           of
           motion
           ,
           nothing
           of
           its
           way
           or
           distance
           can
           by
           any
           of
           these
           suppositions
           be
           found
           out
           .
           This
           fault
           had
           that
           of
           
             Tycho
             Brahe
          
           ,
           where
           he
           supposed
           an
           unequal
           motion
           of
           it
           in
           its
           Orb
           about
           the
           Orb
           of
           Venus
           ,
           which
           was
           founded
           upon
           the
           first
           Hypothesis
           ,
           but
           had
           introduced
           into
           it
           some
           inequality
           of
           motion
           ;
           besides
           his
           own
           supposition
           ,
           that
           it
           was
           moved
           about
           the
           Sun
           ,
           and
           the
           Sun
           about
           the
           Earth
           .
           See
           the
           fifth
           Figure
           .
           Keplers
           way
           ,
           which
           was
           after
           the
           second
           Hypothesis
           ,
           had
           the
           same
           fault
           ;
           for
           he
           supposed
           the
           annual
           motion
           of
           the
           Earth
           ,
           and
           the
           motion
           of
           the
           Comet
           in
           a
           straight
           line
           ,
           but
           introduces
           an
           acceleration
           of
           motion
           in
           the
           Tangent
           towards
           the
           latter
           end
           .
        
         
           The
           third
           way
           I
           have
           here
           taken
           ,
           and
           from
           the
           best
           observation
           I
           could
           meet
           with
           ,
           I
           have
           delineated
           its
           respects
           or
           angles
           to
           the
           Sun
           :
           and
           accordingly
           supposing
           it
           to
           move
           equal
           spaces
           in
           equal
           times
           ,
           in
           a
           curve
           which
           for
           so
           much
           of
           it
           as
           the
           Comet
           was
           observed
           to
           pass
           was
           very
           near
           a
           Circle
           ,
           I
           found
           this
           Circle
           would
           fall
           as
           it
           is
           express'd
           in
           the
           seventh
           Figure
           ,
           where
           't
           is
           obvious
           to
           take
           notice
           ,
           that
           when
           the
           Comet
           was
           nearest
           to
           the
           Earth
           ,
           namely
           ,
           about
           the
           19.
           or
           20.
           of
           December
           ,
           that
           it
           was
           not
           nearer
           than
           an
           eleventh
           part
           of
           the
           distance
           of
           the
           Sun
           ;
           that
           on
           the
           23
           ,
           it
           was
           twice
           as
           far
           ,
           that
           on
           the
           29.
           it
           was
           four
           times
           as
           far
           ;
           that
           on
           the
           15.
           of
           January
           it
           was
           as
           far
           as
           the
           Sun
           ,
           and
           on
           the
           14.
           of
           February
           it
           was
           above
           twice
           as
           far
           distant
           as
           the
           Sun.
           That
           this
           way
           or
           Orb
           of
           the
           Comet
           is
           here
           bended
           so
           as
           (
           if
           it
           were
           an
           entire
           Circle
           ;
           )
           one
           part
           of
           it
           would
           
           go
           without
           the
           Orb
           of
           Jupiter
           ,
           as
           the
           other
           which
           is
           here
           delincated
           comes
           within
           the
           Orb
           of
           the
           Earth
           ;
           that
           the
           plain
           of
           this
           Orb
           is
           inclined
           to
           the
           plain
           of
           the
           Ecliptick
           about
           18
           degrees
           ,
           that
           if
           from
           several
           parts
           this
           Orb
           perpendiculars
           be
           let
           fall
           upon
           the
           Plain
           of
           the
           Ecliptick
           ,
           those
           perpendiculars
           shall
           fall
           in
           an
           Ellipsis
           ,
           part
           whereof
           shall
           fall
           within
           the
           Orb
           of
           the
           Earth
           in
           ●
           ,
           and
           the
           opposite
           without
           the
           Orb
           of
           ♃
           in
           ♒
           .
           That
           the
           Comet
           moves
           a
           Sextant
           of
           this
           Orb
           in
           about
           130
           days
           ,
           and
           consequently
           if
           its
           motion
           should
           continue
           the
           same
           in
           such
           a
           Circle
           ,
           it
           would
           appear
           about
           
             February
             ,
             March
          
           ,
           or
           April
           ,
           1667.
           but
           being
           so
           far
           removed
           towards
           the
           South
           Pole
           ,
           will
           here
           hardly
           be
           seen
           :
           but
           by
           those
           that
           live
           towards
           the
           South
           ,
           it
           may
           appear
           to
           have
           some
           such
           motion
           by
           the
           South
           Pole
           ,
           as
           that
           of
           1618.
           had
           by
           the
           North.
           And
           't
           is
           not
           impossible
           ,
           but
           that
           the
           Comet
           of
           1618.
           might
           be
           the
           same
           with
           this
           ,
           if
           we
           suppose
           the
           Nodes
           of
           it
           to
           have
           a
           motion
           contrary
           to
           the
           order
           of
           Signs
           :
           and
           that
           the
           same
           Node
           which
           in
           this
           Comet
           ,
           according
           to
           this
           supposition
           was
           in
           ♊
           ,
           was
           then
           about
           ♍
           or
           ♐
           :
           but
           these
           as
           conjectures
           I
           shall
           not
           insist
           on
           ,
           because
           neither
           in
           this
           ,
           nor
           in
           that
           have
           we
           Observations
           sufficiently
           accurate
           to
           build
           any
           Theory
           upon
           .
           Now
           though
           upon
           these
           suppositions
           the
           motion
           and
           appearances
           of
           the
           Comet
           seem
           to
           be
           very
           regularly
           ,
           and
           very
           naturally
           made
           out
           ,
           yet
           't
           is
           not
           the
           only
           Hypothesis
           for
           that
           design
           :
           nor
           do
           I
           believe
           it
           so
           evident
           a
           demonstration
           for
           that
           end
           ,
           as
           some
           would
           suppose
           ;
           though
           for
           other
           reasons
           I
           am
           apt
           enough
           to
           think
           that
           opinion
           of
           the
           Earths
           motion
           very
           probable
           :
           but
           the
           motion
           of
           this
           Comet
           is
           so
           well
           made
           out
           ,
           by
           the
           contrary
           supposition
           ,
           that
           I
           think
           it
           may
           be
           alledged
           for
           a
           greater
           argument
           against
           the
           motion
           of
           the
           Earth
           ,
           than
           for
           it
           :
           for
           if
           we
           only
           grant
           one
           of
           the
           former
           postulata
           ,
           namely
           ,
           that
           the
           body
           of
           the
           Comet
           is
           moved
           equal
           spaces
           in
           equal
           times
           ,
           and
           a
           quite
           contrary
           postulatum
           to
           the
           former
           ;
           namely
           ,
           that
           the
           Earth
           remains
           fix'd
           as
           to
           an
           annual
           motion
           ,
           we
           may
           
           find
           all
           the
           observations
           of
           this
           Comet
           ,
           especially
           the
           most
           accurate
           of
           them
           ,
           to
           happen
           so
           ,
           that
           the
           Comet
           being
           supposed
           to
           be
           moved
           in
           a
           great
           Circle
           ,
           whose
           convex
           side
           is
           turned
           towards
           the
           Earth
           ,
           whose
           center
           is
           extended
           towards
           the
           fix'd
           ✴
           in
           ♋
           and
           whose
           Semidiameter
           is
           about
           sixscore
           times
           the
           nearest
           distance
           of
           the
           Comet
           from
           the
           Earth
           ,
           and
           the
           Comet
           be
           supposed
           to
           be
           moved
           very
           near
           equal
           spaces
           in
           equal
           times
           ,
           we
           shall
           find
           ,
           I
           say
           ,
           all
           the
           appearances
           most
           exactly
           solved
           ,
           and
           indeed
           much
           more
           exactly
           than
           by
           the
           other
           supposition
           I
           was
           able
           to
           find
           any
           ;
           for
           by
           this
           supposition
           both
           the
           magnitude
           ,
           longitude
           ,
           latitude
           ,
           retrogradation
           ,
           station
           ,
           and
           direction
           of
           the
           Comet
           is
           most
           exactly
           made
           out
           as
           any
           one
           might
           have
           found
           that
           should
           have
           by
           this
           means
           examined
           with
           me
           the
           observations
           I
           have
           hitherto
           either
           made
           or
           met
           with
           :
           and
           indeed
           all
           the
           Observations
           hitherto
           have
           so
           well
           answered
           this
           Hypothesis
           ,
           that
           I
           do
           almost
           promise
           my self
           to
           be
           able
           to
           see
           this
           Comet
           a
           month
           or
           six
           weeks
           hence
           ,
           after
           the
           Sun
           has
           past
           by
           it
           ;
           if
           by
           its
           exceeding
           elongation
           it
           be
           not
           quite
           grown
           out
           of
           sight
           ,
           as
           it
           is
           now
           indeed
           already
           so
           exceeding
           dim
           ,
           and
           faint
           ,
           that
           it
           cannot
           be
           seen
           without
           a
           very
           good
           glass
           ,
           which
           will
           endure
           an
           exceeding
           big
           aperture
           :
           nor
           could
           I
           these
           two
           last
           nights
           perceive
           it
           ,
           though
           the
           Air
           were
           clear
           ;
           but
           the
           reason
           I
           attribute
           to
           its
           nearness
           to
           a
           fixed
           ✴
           of
           ♈
           :
           This
           Hypothesis
           is
           explained
           in
           the
           seventh
           Figure
           .
           By
           this
           supposition
           the
           return
           of
           the
           Comet
           will
           be
           much
           longer
           ,
           and
           the
           time
           of
           seeing
           of
           it
           much
           more
           uncertain
           ;
           because
           the
           curvature
           is
           so
           little
           that
           the
           making
           the
           circle
           a
           twentieth
           ,
           or
           a
           sixteenth
           part
           bigger
           or
           less
           ,
           does
           not
           much
           alter
           the
           regularity
           ;
           whence
           't
           is
           exceeding
           difficult
           ,
           unless
           we
           had
           much
           more
           accurate
           Observations
           than
           I
           have
           hitherto
           met
           with
           ,
           to
           determine
           exactly
           the
           bigness
           of
           the
           circle
           ,
           and
           consequently
           the
           time
           of
           the
           return
           .
           And
           by
           this
           supposition
           the
           Comet
           may
           be
           supposed
           either
           nearer
           or
           farther
           from
           the
           Earth
           at
           any
           distance
           ,
           which
           is
           not
           
           contradicted
           by
           a
           Diurnal
           Parallax
           ;
           that
           is
           ,
           it
           may
           be
           supposed
           either
           above
           Saturn
           ,
           or
           below
           the
           Moon
           ,
           or
           in
           any
           place
           between
           ;
           by
           supposing
           only
           ,
           that
           the
           farther
           the
           nearest
           part
           of
           the
           Circle
           is
           distant
           from
           the
           Earth
           ,
           the
           greater
           must
           that
           Circle
           be
           ,
           and
           the
           swifter
           the
           motion
           of
           the
           Comet
           in
           it
           :
           to
           prove
           which
           affirmation
           ,
           let
           in
           the
           Eighth
           figure
           A
           be
           the
           Earth
           ,
           BCD
           the
           Orb
           of
           the
           Comet
           supposed
           very
           near
           the
           Earth
           ,
           and
           EFG
           the
           Orb
           of
           it
           supposed
           at
           a
           greater
           distance
           :
           let
           H
           be
           the
           center
           of
           BCD
           ,
           and
           I
           of
           EFG
           ,
           and
           let
           AC
           ,
           be
           to
           CH
           ,
           as
           AF
           ,
           to
           FI
           ,
           all
           the
           lines
           drawn
           from
           the
           point
           A
           ,
           so
           as
           to
           cut
           the
           Circles
           BCD
           and
           EFG
           ,
           shall
           divide
           those
           Circles
           EFG
           ,
           and
           BCD
           ,
           into
           similar
           segments
           :
           as
           let
           ABE
           be
           a
           line
           drawn
           cutting
           those
           Circles
           in
           B
           and
           E
           :
           I
           say
           ,
           the
           Arch
           BC
           shall
           be
           similar
           to
           EF.
           In
           which
           Hypothesis
           if
           we
           have
           together
           with
           the
           place
           of
           the
           Comet
           when
           stationary
           ,
           the
           place
           of
           it
           when
           in
           its
           greatest
           celerity
           ,
           perige
           ,
           or
           the
           places
           of
           it
           when
           of
           the
           same
           celerity
           on
           each
           side
           of
           its
           perige
           ,
           we
           have
           from
           thence
           the
           proportion
           of
           the
           Radius
           of
           its
           Orb
           to
           the
           perigean
           distance
           ,
           and
           consequently
           all
           the
           other
           distances
           ,
           the
           line
           in
           which
           it
           appears
           when
           stationary
           ,
           being
           the
           Tangent
           to
           the
           Circle
           in
           which
           it
           moves
           ,
           as
           ABE
           ,
           to
           which
           a
           Perpendicular
           raised
           at
           BBE
           ,
           and
           produced
           till
           it
           cut
           the
           line
           AC
           ,
           (
           produced
           )
           at
           HHI
           ,
           it
           gives
           the
           Center
           of
           its
           Orb
           HHI
           ,
           and
           the
           proportions
           of
           the
           lines
           AB
           ,
           AC
           ,
           BH
           =
           HC
           ,
           or
           of
           AE
           ,
           AF
           ,
           EI
           =
           FI
           ,
           the
           Angle
           BAC
           ,
           being
           given
           by
           observation
           .
           So
           that
           by
           this
           Hypothesis
           the
           Phaenomena
           of
           the
           motion
           and
           bigness
           of
           the
           Comet
           will
           be
           solved
           ,
           though
           supposed
           of
           any
           distance
           .
           Nor
           are
           these
           the
           only
           Hypotheses
           by
           which
           the
           hitherto
           observ'd
           Phaenomena
           may
           be
           solv'd
           :
           for
           if
           we
           will
           admit
           an
           unequal
           motion
           ,
           such
           as
           is
           now
           granted
           to
           all
           the
           Planets
           :
           and
           if
           further
           we
           will
           admit
           it
           to
           be
           moved
           in
           an
           Elleipsis
           ,
           or
           other
           such
           like
           curve
           ,
           there
           may
           be
           divers
           other
           Hypotheses
           that
           will
           solve
           the
           Phaenomena
           ;
           so
           that
           the
           Comet
           may
           be
           supposed
           to
           
           have
           no
           motion
           at
           all
           as
           to
           Longitude
           ,
           but
           only
           as
           to
           Latitude
           :
           that
           is
           ,
           it
           may
           be
           supposed
           to
           be
           moved
           in
           an
           Elleipsis
           ,
           described
           in
           a
           plain
           which
           shall
           be
           at
           right
           Angles
           with
           the
           plain
           of
           the
           Ecliptick
           ,
           and
           the
           ways
           of
           the
           Earth
           in
           it
           :
           it
           may
           be
           supposed
           also
           to
           have
           been
           mov'd
           direct
           ,
           according
           to
           the
           order
           of
           the
           signs
           ,
           that
           is
           ,
           to
           have
           been
           first
           about
           Gemini
           ,
           in
           respect
           of
           the
           Sun
           ,
           and
           to
           be
           now
           in
           some
           part
           of
           Leo
           :
           And
           it
           is
           not
           impossible
           to
           solve
           the
           phaenomena
           of
           its
           periodick
           or
           proper
           motion
           ,
           though
           it
           be
           supposed
           not
           so
           high
           as
           the
           Moon
           ,
           and
           that
           the
           motion
           of
           the
           Earth
           passing
           by
           it
           did
           really
           alter
           its
           motions
           ,
           had
           there
           not
           been
           made
           some
           Observations
           about
           the
           Parallax
           of
           it
           ,
           which
           prove
           it
           higher
           :
           so
           that
           according
           to
           this
           or
           that
           Hypothesis
           which
           we
           take
           ,
           the
           time
           of
           its
           return
           ,
           if
           permanent
           ,
           will
           be
           longer
           or
           sooner
           .
        
         
           And
           these
           Hypotheses
           may
           be
           so
           various
           ,
           that
           till
           regulated
           by
           very
           exact
           Observation
           of
           the
           Parallax
           ,
           't
           is
           not
           to
           be
           hoped
           that
           the
           appearance
           of
           a
           Comet
           can
           be
           certainly
           predicted
           :
           So
           that
           I
           fear
           the
           prophetick
           saying
           of
           
             Seneca
             ,
             Erit
             qui
             demonstret
             aliquando
             in
             quibus
             Cometae
             partibus
             errent
             ,
             cur
             tam
             seducti
             à
             caeteris
             eant
             ,
             quanti
             qualesque
             sint
             ,
          
           will
           hardly
           be
           verified
           at
           this
           time
           by
           the
           help
           of
           this
           present
           Comet
           .
           Though
           in
           truth
           I
           cannot
           find
           by
           the
           examination
           of
           several
           of
           them
           ,
           but
           that
           they
           all
           seem
           to
           promise
           very
           fairly
           a
           return
           of
           it
           :
           for
           all
           the
           Calculations
           I
           have
           hitherto
           made
           of
           its
           motion
           ,
           seem
           to
           cast
           it
           into
           a
           circular
           ,
           and
           not
           a
           into
           straight
           line
           ,
           as
           Kepler
           supposed
           ;
           and
           indeed
           upon
           examining
           even
           Keplers
           own
           Calculations
           of
           those
           Comets
           which
           he
           observed
           ,
           and
           has
           endeavoured
           to
           make
           to
           move
           in
           a
           straight
           line
           ,
           I
           cannot
           find
           that
           any
           of
           them
           will
           be
           found
           to
           move
           equally
           in
           such
           a
           line
           :
           but
           to
           solve
           the
           appearances
           ,
           he
           is
           fain
           to
           make
           them
           move
           in
           such
           supposed
           straight
           lines
           ,
           by
           a
           line
           of
           Tangents
           ,
           that
           is
           ,
           to
           make
           the
           motion
           of
           Comets
           accelerated
           the
           further
           they
           are
           moved
           ;
           all
           which
           Phaenomena
           may
           be
           very
           easily
           solved
           by
           supposing
           them
           to
           have
           moved
           equal
           spaces
           
           in
           a
           curve
           or
           circle
           .
           The
           physical
           reason
           indeed
           seems
           pretty
           difficult
           ,
           by
           what
           means
           it
           should
           be
           confin'd
           or
           bound
           so
           as
           to
           move
           in
           a
           Circle
           :
           but
           this
           is
           no
           more
           than
           is
           usually
           supposed
           in
           all
           the
           Planets
           ,
           and
           without
           supposing
           a
           kind
           of
           gravitation
           throughout
           the
           whole
           Vortice
           or
           Coelum
           of
           the
           Sun
           ,
           by
           which
           the
           Planets
           are
           attracted
           ,
           or
           have
           a
           tendency
           towards
           the
           Sun
           ,
           as
           terrestrial
           bodies
           have
           towards
           the
           center
           of
           the
           Earth
           .
           I
           cannot
           imagin
           how
           their
           various
           motions
           can
           with
           any
           satisfaction
           be
           imagined
           ,
           but
           that
           being
           granted
           (
           for
           which
           had
           I
           now
           time
           ,
           I
           could
           alledg
           many
           reasons
           ,
           and
           may
           do
           it
           hereafter
           on
           another
           occasion
           )
           not
           only
           the
           reason
           of
           all
           the
           irregular
           motion
           of
           the
           Planets
           may
           be
           easily
           found
           ,
           but
           the
           reason
           also
           of
           the
           strange
           and
           various
           motions
           of
           the
           Comets
           .
           The
           reason
           why
           its
           Beard
           is
           for
           the
           most
           part
           opposite
           to
           the
           Sun
           ,
           which
           was
           another
           Query
           ,
           of
           which
           I
           have
           already
           said
           somewhat
           of
           my
           suppositions
           ,
           and
           shall
           now
           add
           ,
           that
           the
           brighter
           spot
           or
           kernel
           in
           the
           middle
           did
           seem
           to
           be
           some
           kind
           of
           body
           ,
           which
           though
           it
           be
           not
           actually
           burnt
           ,
           may
           yet
           by
           the
           encompassing
           fluid
           Aether
           be
           dissolved
           and
           wasted
           ,
           and
           those
           dissolved
           parts
           may
           ascend
           upwards
           ,
           or
           from
           the
           center
           of
           the
           Sun
           ,
           (
           which
           seems
           indeed
           to
           be
           the
           center
           of
           gravitation
           throughout
           the
           whole
           systeme
           of
           it
           .
           )
           To
           illustrate
           which
           explication
           ,
           I
           could
           produce
           several
           experiments
           which
           would
           make
           a
           perfect
           representation
           of
           the
           phaenomena
           of
           the
           body
           ,
           and
           beard
           of
           the
           Comet
           :
           I
           shall
           only
           instance
           in
           one
           .
           Take
           a
           very
           clear
           long
           Cylindrical
           Glass
           ,
           which
           may
           hold
           about
           a
           quart
           of
           water
           ;
           fill
           it
           three
           quarters
           full
           with
           water
           ,
           and
           put
           into
           it
           a
           quarter
           of
           a
           pound
           of
           Oyl
           of
           Vitriol
           ,
           and
           in
           the
           midst
           of
           this
           suspend
           by
           a
           small
           silver
           wire
           ,
           a
           small
           wax-ball
           ,
           rould
           in
           filings
           of
           iron
           or
           steel
           ,
           and
           you
           may
           plainly
           observe
           a
           perfect
           representation
           of
           the
           Head
           ,
           Halo
           ,
           and
           Beard
           of
           the
           Comet
           ;
           for
           the
           menstruum
           falling
           on
           ,
           or
           dissolving
           the
           iron
           ,
           there
           is
           a
           continual
           eruption
           of
           small
           bubbles
           ,
           and
           dissolv'd
           particles
           from
           all
           the
           
           sides
           of
           this
           body
           ;
           and
           after
           the
           eruption
           they
           all
           ascend
           upwards
           from
           the
           center
           of
           the
           earth
           ;
           for
           being
           of
           a
           much
           lighter
           consistence
           than
           the
           anbient
           liquor
           ,
           they
           are
           by
           the
           greater
           gravity
           of
           that
           ,
           continually
           protruded
           upwards
           .
           The
           same
           appearance
           may
           be
           made
           with
           any
           kind
           of
           menstruum
           ,
           and
           a
           convenient
           dissoluble
           body
           suspended
           in
           it
           ;
           so
           that
           if
           we
           suppose
           the
           Aether
           to
           be
           somewhat
           analogous
           to
           a
           menstruum
           ,
           and
           that
           there
           is
           a
           gravitation
           towards
           the
           center
           of
           the
           Sun
           ,
           if
           the
           Nucleus
           or
           head
           of
           the
           Comet
           be
           supposed
           such
           a
           dissoluble
           substance
           ,
           the
           phaenomena
           of
           the
           shape
           of
           the
           Comet
           may
           ,
           I
           think
           ,
           be
           rationally
           explained
           .
           Now
           that
           the
           Aether
           may
           have
           such
           a
           kind
           of
           propriety
           ,
           seems
           to
           me
           to
           be
           argued
           from
           this
           ,
           that
           the
           Air
           about
           the
           Earth
           seems
           to
           owe
           its
           original
           to
           it
           ,
           it
           being
           only
           a
           dissolution
           of
           terrestrial
           bodies
           into
           the
           Aether
           ,
           the
           Aether
           being
           the
           principal
           fluid
           body
           ,
           and
           greatest
           part
           of
           this
           dissolution
           ;
           and
           the
           substance
           of
           the
           Air
           ,
           some
           very
           few
           and
           small
           saline
           and
           earthy
           particles
           :
           of
           which
           elsewhere
           .
           By
           this
           Hypothesis
           the
           phaenomena
           of
           the
           Comet
           may
           be
           solved
           ;
           for
           hence
           't
           is
           easie
           to
           deduce
           the
           reason
           why
           the
           Beard
           grows
           broader
           and
           broader
           ,
           and
           sainter
           and
           fainter
           towards
           the
           top
           :
           why
           there
           is
           a
           Halo
           about
           the
           body
           ;
           for
           this
           will
           appear
           clearly
           in
           the
           experiment
           :
           why
           the
           Beard
           becomes
           a
           little
           deflected
           from
           the
           body
           of
           the
           Sun
           ;
           for
           if
           the
           dissolving
           Ball
           be
           by
           the
           wire
           mov'd
           either
           this
           way
           or
           that
           way
           ,
           the
           arising
           stream
           or
           bubbles
           will
           bend
           the
           contrary
           :
           and
           to
           countenance
           this
           supposition
           ,
           both
           in
           those
           Comets
           observed
           by
           
             Tycho
             ,
             Kepler
          
           ,
           and
           also
           in
           this
           last
           the
           beard
           was
           contrary
           to
           the
           motion
           ;
           so
           that
           the
           head
           or
           body
           going
           faster
           ,
           seemed
           to
           leave
           the
           beard
           or
           tail
           somewhat
           behind
           :
           by
           this
           supposition
           also
           't
           will
           be
           easie
           to
           explicate
           why
           the
           beard
           is
           sometime
           bended
           ,
           and
           not
           straight
           ,
           and
           why
           it
           is
           sometimes
           brighter
           upon
           one
           side
           than
           upon
           another
           ?
           why
           the
           bottom
           of
           it
           is
           more
           round
           ,
           and
           the
           other
           sides
           more
           undefin'd
           ;
           and
           divers
           of
           the
           like
           phaenomena
           .
           Against
           
           this
           supposition
           it
           seems
           difficult
           to
           conceive
           whence
           so
           vast
           a
           body
           should
           be
           generated
           ;
           next
           ,
           how
           it
           should
           be
           able
           to
           supply
           such
           a
           constant
           stream
           of
           ascending
           parts
           ,
           and
           yet
           last
           so
           long
           as
           this
           has
           done
           ,
           almost
           a
           quarter
           of
           a
           year
           .
           Thirdly
           ,
           Whence
           such
           a
           newly
           generated
           body
           should
           receive
           so
           great
           a
           degree
           of
           motion
           .
           In
           answer
           to
           which
           ,
           I
           say
           ,
           't
           is
           not
           impossible
           but
           that
           the
           body
           of
           it
           may
           be
           as
           old
           as
           the
           world
           ,
           and
           that
           it
           may
           have
           then
           received
           its
           first
           determination
           ,
           or
           laws
           of
           motion
           ,
           and
           may
           have
           ever
           since
           preserved
           them
           ,
           that
           it
           may
           have
           been
           all
           this
           time
           also
           in
           dissolution
           ,
           and
           yet
           not
           be
           quite
           wasted
           ;
           and
           that
           it
           may
           continue
           yet
           for
           many
           ages
           before
           it
           be
           quite
           dissolved
           into
           the
           Aether
           .
           And
           to
           make
           this
           probable
           ,
           divers
           experiments
           and
           reasons
           might
           be
           alledged
           ,
           as
           that
           of
           the
           slowness
           of
           the
           wasting
           of
           many
           bodies
           ,
           by
           the
           dissolution
           made
           on
           them
           by
           the
           fire
           :
           the
           slowness
           also
           of
           the
           dissolution
           of
           multitudes
           of
           bodies
           in
           menstruums
           .
           And
           I
           have
           already
           shewn
           how
           small
           a
           quantity
           of
           dissolved
           particles
           will
           be
           able
           to
           make
           as
           great
           a
           shew
           of
           light
           :
           besides
           that
           ,
           the
           motion
           of
           the
           ascending
           stream
           or
           beard
           being
           but
           slow
           ,
           there
           needs
           no
           very
           quick
           supply
           of
           other
           parts
           .
           We
           see
           also
           into
           what
           a
           vast
           quantity
           of
           smoke
           a
           small
           parcel
           of
           a
           combustible
           body
           may
           be
           turn'd
           .
           From
           all
           which
           particulars
           ,
           't
           is
           not
           unlikely
           but
           that
           the
           Comet
           may
           be
           a
           body
           moved
           with
           a
           regular
           circular
           or
           elliptical
           motion
           as
           the
           Planets
           are
           ,
           that
           it
           may
           be
           a
           body
           of
           such
           a
           constitution
           ,
           as
           that
           the
           fluid
           Aether
           through
           which
           it
           passes
           ,
           may
           dissolve
           it
           much
           after
           the
           manner
           as
           a
           menstruum
           ;
           (
           such
           as
           Aquafortis
           ,
           Spirit
           of
           Niter
           ,
           &c.
           )
           does
           a
           dissoluble
           body
           ;
           that
           by
           this
           means
           there
           may
           be
           a
           slow
           ,
           but
           continual
           eruption
           of
           somewhat
           opacous
           parts
           ,
           which
           may
           by
           their
           dissolution
           afford
           a
           sufficient
           quantity
           of
           light
           to
           make
           as
           great
           an
           appearance
           as
           any
           of
           the
           Comets
           ,
           that
           this
           stream
           or
           beard
           may
           by
           the
           resistance
           of
           the
           Aether
           be
           a
           little
           deflected
           backwards
           in
           the
           same
           manner
           as
           an
           ascending
           stream
           of
           smoke
           will
           be
           by
           the
           resistance
           of
           
           the
           Air
           ,
           if
           the
           burning
           body
           be
           mov'd
           this
           or
           that
           way
           through
           it
           ,
           that
           the
           body
           of
           the
           Comet
           may
           be
           both
           as
           ancient
           and
           as
           lasting
           as
           the
           world
           ;
           and
           that
           this
           which
           has
           lately
           appeared
           may
           have
           appeared
           heretofore
           ,
           and
           may
           likewise
           hereafter
           appear
           again
           ;
           that
           't
           is
           probable
           the
           nearest
           distance
           of
           it
           was
           much
           greater
           than
           that
           of
           the
           Moon
           ,
           that
           the
           length
           of
           its
           Beard
           was
           longer
           than
           its
           distance
           from
           the
           Earth
           ,
           and
           consequently
           several
           times
           longer
           than
           the
           distance
           between
           the
           Earth
           and
           the
           Moon
           ;
           that
           its
           visible
           way
           among
           the
           Stars
           was
           very
           differing
           from
           a
           great
           circle
           ,
           especially
           towards
           the
           latter
           end
           ,
           when
           it
           became
           retrograde
           ;
           that
           its
           way
           through
           the
           Aether
           could
           not
           be
           supposed
           equal
           in
           a
           straight
           line
           ,
           though
           it
           might
           be
           supposed
           equal
           in
           a
           curve
           or
           circle
           ,
           that
           the
           exact
           way
           of
           it
           could
           not
           be
           certainly
           determined
           by
           the
           best
           Observations
           I
           have
           yet
           met
           with
           :
           and
           that
           therefore
           the
           best
           help
           we
           have
           to
           ghess
           of
           its
           way
           and
           distance
           ,
           is
           by
           its
           manner
           of
           moving
           ,
           as
           to
           appearance
           among
           the
           fixed
           Stars
           ,
           which
           I
           have
           already
           shewn
           to
           be
           explicable
           by
           various
           Hypotheses
           :
           for
           both
           the
           Earth
           and
           Comet
           may
           be
           supposed
           to
           be
           moved
           ,
           either
           both
           one
           way
           ,
           or
           contrary
           ways
           ,
           or
           cross
           ways
           ,
           the
           Earth
           may
           be
           supposed
           to
           stand
           still
           ,
           and
           the
           Comet
           only
           to
           be
           moved
           ,
           and
           the
           like
           .
        
         
           These
           Requisites
           therefore
           being
           hitherto
           wanting
           in
           the
           Observations
           I
           have
           met
           with
           of
           this
           Comet
           ,
           all
           that
           can
           be
           said
           of
           it
           will
           at
           best
           be
           but
           conjectural
           and
           hypothetical
           ;
           since
           nothing
           can
           be
           reasonably
           built
           upon
           those
           Observations
           where
           the
           truth
           of
           them
           is
           dubious
           ;
           wanting
           therefore
           sound
           materials
           to
           work
           upon
           in
           this
           Comet
           ,
           I
           had
           recourse
           to
           the
           Observations
           of
           the
           noble
           Dane
           
             Tycho
             Brahe
          
           ,
           being
           sufficiently
           satisfied
           both
           of
           the
           ability
           ,
           industry
           ,
           and
           veracity
           of
           that
           excellent
           Author
           ,
           who
           left
           nothing
           unattempted
           for
           the
           perfecting
           of
           such
           Observations
           as
           seem'd
           to
           him
           requisite
           for
           the
           compleating
           a
           History
           of
           that
           Comet
           which
           appeared
           in
           1577.
           
           And
           from
           those
           Observations
           of
           his
           
           I
           endeavoured
           to
           trace
           the
           way
           of
           it
           according
           to
           several
           hypotheses
           ;
           and
           found
           ,
           that
           supposing
           the
           Earth
           not
           to
           be
           moved
           with
           an
           annual
           motion
           ,
           but
           only
           a
           diurnal
           about
           its
           own
           Axis
           ,
           the
           way
           of
           Comets
           will
           fall
           in
           a
           line
           very
           near
           approaching
           the
           nature
           of
           a
           circle
           ,
           though
           neither
           into
           an
           exact
           circle
           ,
           nor
           an
           exact
           ellipse
           ;
           and
           therefore
           seems
           irregular
           ,
           and
           not
           at
           all
           probable
           .
           Again
           ,
           supposing
           it
           moved
           about
           the
           Sun
           ,
           as
           Tycho
           has
           done
           ,
           we
           find
           from
           his
           Calculation
           of
           it
           ,
           he
           was
           fain
           to
           allow
           it
           a
           quicker
           and
           slower
           motion
           in
           its
           Orbit
           ,
           to
           solve
           the
           Phaenomena
           ,
           which
           seems
           to
           me
           but
           a
           shift
           ,
           that
           will
           serve
           to
           help
           out
           any
           lame
           Hypothesis
           whatsoever
           :
           And
           that
           granted
           ,
           and
           the
           Parallax
           of
           the
           Comet
           unknown
           ,
           I
           will
           undertake
           very
           easily
           to
           make
           out
           almost
           any
           Hypothesis
           ,
           which
           is
           the
           fault
           also
           of
           Mr.
           Horox
           his
           Hypothesis
           ,
           wherein
           he
           supposes
           the
           Earth
           to
           be
           moved
           about
           the
           Sun
           ,
           and
           the
           Comet
           like
           a
           Rocket
           to
           be
           shot
           out
           of
           the
           Sun
           ,
           and
           by
           degrees
           to
           return
           to
           it
           again
           ;
           in
           which
           Hypothesis
           indeed
           there
           seems
           to
           be
           much
           more
           reason
           for
           an
           inequality
           of
           motion
           ,
           though
           not
           in
           the
           manner
           as
           he
           has
           placed
           it
           ;
           't
           was
           very
           rational
           that
           the
           motion
           of
           it
           at
           first
           ,
           if
           cast
           out
           of
           the
           Sun
           ,
           should
           be
           very
           swift
           ;
           but
           then
           it
           ought
           likewise
           to
           have
           accelerated
           its
           motion
           in
           the
           same
           manner
           in
           its
           return
           back
           to
           it
           again
           ,
           which
           it
           does
           not
           in
           his
           Hypothesis
           ;
           for
           a
           stone
           or
           any
           other
           heavy
           body
           being
           shot
           up
           into
           the
           Air
           ,
           does
           make
           its
           return
           back
           again
           to
           the
           Earth
           ,
           almost
           by
           the
           same
           degrees
           of
           velocity
           ,
           by
           which
           it
           ascended
           from
           it
           :
           almost
           ,
           I
           say
           ,
           because
           the
           resistance
           of
           the
           Air
           does
           so
           far
           impede
           the
           motion
           of
           the
           body
           through
           it
           ,
           that
           it
           never
           suffers
           it
           to
           acquire
           the
           same
           degree
           of
           velocity
           with
           which
           it
           was
           first
           shot
           upward
           .
           This
           is
           sufficiently
           evident
           from
           a
           Pendulum
           ,
           which
           if
           it
           be
           thrown
           upwards
           ,
           and
           be
           suffered
           to
           return
           back
           ,
           it
           will
           never
           rise
           again
           on
           the
           opposite
           side
           to
           an
           equal
           height
           ,
           with
           that
           it
           descended
           from
           ,
           on
           that
           side
           towards
           which
           it
           was
           thrown
           :
           but
           besides
           ,
           in
           his
           Hypothesis
           he
           seems
           to
           take
           no
           notice
           at
           
           all
           of
           the
           Latitude
           of
           the
           Comet
           ,
           which
           seemed
           to
           carry
           it
           much
           farther
           off
           from
           the
           Sun
           ,
           when
           he
           supposes
           it
           to
           be
           returning
           nearer
           .
           And
           indeed
           upon
           the
           whole
           his
           Hypothesis
           seems
           rather
           a
           product
           of
           chance
           than
           of
           any
           contrivance
           .
           For
           he
           in
           endeavouring
           to
           set
           off
           the
           Longitude
           of
           the
           Comet
           according
           to
           
           Tycho's
           Tables
           ,
           and
           to
           trace
           its
           way
           by
           supposing
           the
           Earths
           annual
           motion
           ,
           making
           use
           always
           of
           the
           same
           Radius
           to
           set
           off
           the
           aspect
           ,
           or
           apparent
           angle
           of
           it
           with
           the
           Sun
           ,
           his
           line
           of
           Chords
           he
           made
           use
           of
           did
           always
           direct
           the
           point
           of
           his
           Compasses
           to
           the
           place
           where
           he
           situates
           the
           Comet
           ,
           as
           may
           be
           easily
           found
           by
           examining
           the
           ninth
           figure
           ;
           where
           you
           may
           find
           that
           he
           places
           the
           Comet
           always
           equally
           distant
           from
           the
           Earth
           ,
           and
           that
           distance
           is
           always
           equal
           to
           the
           distance
           of
           the
           Sun
           ,
           which
           has
           so
           many
           inconveniencies
           and
           improbabilities
           ,
           that
           I
           shall
           not
           insist
           farther
           on
           it
           ;
           especially
           since
           I
           do
           not
           find
           that
           he
           bestowed
           any
           farther
           pains
           in
           explicating
           or
           cultivating
           this
           his
           Hypothesis
           ,
           than
           only
           the
           bare
           delineation
           of
           this
           ninth
           figure
           .
           But
           to
           return
           to
           
           Tycho's
           Hypothesis
           ,
           if
           that
           be
           true
           ,
           why
           did
           not
           the
           Comet
           again
           appear
           after
           a
           certain
           space
           of
           time
           ?
           and
           why
           could
           not
           he
           have
           foretold
           when
           it
           should
           again
           appear
           ,
           as
           well
           as
           he
           could
           predict
           the
           appearance
           of
           Venus
           ,
           about
           whose
           Orb
           he
           supposes
           it
           to
           circulate
           ?
           I
           shall
           pass
           by
           several
           other
           very
           material
           objections
           that
           might
           be
           made
           against
           that
           his
           supposition
           ,
           because
           many
           of
           them
           might
           be
           made
           also
           against
           his
           Hypothesis
           of
           the
           Heavens
           in
           general
           ,
           which
           I
           shall
           the
           rather
           omit
           ,
           because
           I
           do
           not
           find
           he
           has
           many
           followers
           in
           that
           supposition
           ;
           the
           generality
           of
           Astronomers
           embracing
           rather
           the
           Copernican
           System
           ,
           especially
           as
           it
           is
           refined
           and
           rectified
           by
           the
           ingenious
           Kepler
           .
        
         
           Lastly
           ,
           I
           endeavoured
           to
           trace
           the
           way
           of
           the
           Comet
           from
           
           Tycho's
           Tables
           ,
           according
           to
           Keplers
           Hypothesis
           ;
           which
           was
           ,
           that
           the
           appearances
           of
           the
           motion
           of
           the
           Comet
           were
           ascribable
           to
           two
           causes
           ;
           
           namely
           ,
           the
           motion
           of
           the
           Earth
           about
           the
           Sun
           in
           its
           annual
           Orbit
           ,
           and
           the
           motion
           of
           the
           Comet
           in
           a
           straight
           line
           ,
           not
           accelerated
           according
           to
           the
           proportion
           of
           the
           increase
           of
           Tangents
           ;
           but
           upon
           supposition
           that
           it
           mov'd
           equal
           spaces
           in
           equal
           times
           :
           (
           for
           I
           cannot
           imagine
           what
           reason
           he
           had
           to
           suppose
           its
           motion
           to
           be
           accelerated
           ,
           and
           much
           less
           why
           he
           should
           assert
           it
           to
           be
           according
           to
           the
           proportion
           of
           Tangents
           ,
           which
           in
           a
           little
           time
           must
           necessarily
           come
           to
           move
           infinitely
           swift
           :
           than
           which
           nothing
           is
           more
           hard
           to
           be
           granted
           .
           )
           And
           I
           found
           it
           after
           many
           trials
           and
           essays
           to
           fall
           in
           a
           straight
           line
           ,
           inclining
           to
           the
           plain
           of
           the
           Ecliptick
           by
           anangle
           of
           47.
           40.
           and
           cutting
           it
           in
           9
           degrees
           of
           Scorpio
           ,
           if
           computed
           out
           of
           the
           Sun
           ,
           and
           moved
           faster
           by
           half
           than
           the
           Earth
           in
           its
           Orb
           ;
           and
           this
           to
           so
           great
           an
           exactness
           to
           answer
           all
           the
           Observations
           of
           Tycho
           ,
           that
           from
           a
           very
           large
           Scheme
           which
           I
           drew
           of
           it
           on
           a
           plain
           ,
           I
           could
           never
           find
           many
           minutes
           difference
           ;
           so
           that
           I
           concluded
           that
           to
           be
           the
           most
           likely
           Hypothesis
           for
           that
           Comet
           ,
           it
           seeming
           to
           solve
           all
           the
           several
           Phaenomena
           of
           the
           motion
           and
           magnitude
           of
           the
           Comet
           ,
           with
           the
           least
           imaginable
           difficulty
           ,
           and
           to
           be
           most
           agreeable
           with
           my
           physical
           notions
           of
           Comets
           :
           For
           ,
           first
           it
           only
           supposes
           a
           solid
           body
           moved
           in
           a
           fluid
           ,
           with
           an
           almost
           direct
           motion
           .
           I
           say
           ,
           almost
           direct
           ,
           because
           for
           some
           physical
           reasons
           ,
           as
           I
           have
           said
           before
           ,
           I
           imagine
           it
           not
           exactly
           straight
           ,
           but
           inflected
           a
           little
           towards
           the
           curvity
           of
           a
           circle
           ,
           which
           I
           shall
           presently
           endeavour
           to
           explain
           farther
           in
           this
           Comet
           .
           Next
           ,
           it
           supposes
           that
           body
           to
           move
           in
           that
           line
           almost
           equal
           spaces
           in
           equal
           times
           ;
           I
           say
           ,
           almost
           equal
           ,
           because
           some
           of
           those
           equal
           spaces
           may
           be
           increased
           by
           an
           accelerating
           cause
           or
           principle
           ,
           such
           as
           that
           of
           a
           gravitation
           towards
           the
           body
           of
           the
           Sun
           ,
           placed
           in
           the
           center
           of
           its
           Vortice
           or
           System
           ,
           when
           the
           motion
           of
           the
           Comet
           carries
           it
           towards
           the
           Sun
           ,
           and
           may
           be
           diminish'd
           from
           other
           impeding
           causes
           ,
           such
           as
           the
           impediment
           of
           the
           fluid
           medium
           through
           which
           it
           passes
           ,
           and
           the
           attraction
           of
           the
           
           Sun
           operating
           on
           it
           when
           its
           motion
           carries
           it
           farther
           and
           farther
           off
           from
           it
           :
           besides
           ,
           't
           is
           not
           unlikely
           ,
           but
           that
           the
           attraction
           of
           the
           Earth
           ,
           or
           some
           of
           the
           other
           Planets
           may
           have
           some
           kind
           of
           influence
           on
           it
           ,
           especially
           ,
           when
           its
           line
           of
           Direction
           does
           somewhat
           nearer
           approach
           those
           attractive
           points
           .
           But
           the
           deflection
           from
           a
           straight
           line
           is
           always
           so
           much
           the
           less
           by
           how
           much
           the
           swifter
           the
           body
           is
           moved
           ,
           and
           by
           how
           much
           the
           farther
           off
           its
           line
           of
           trajection
           is
           perpendicularly
           distant
           from
           those
           attracting
           bodies
           .
           According
           to
           this
           supposition
           of
           mine
           ,
           I
           have
           endeavoured
           to
           make
           out
           all
           the
           appearances
           of
           this
           last
           Comet
           ,
           taken
           notice
           of
           in
           the
           best
           observations
           I
           have
           yet
           met
           with
           ,
           amongst
           which
           I
           find
           no
           one
           of
           the
           Parallax
           satisfactory
           ,
           as
           in
           the
           tenth
           figure
           ,
           let
           S
           represent
           the
           Sun
           ,
           ORB
           ,
           the
           Orb
           of
           the
           Earth
           ,
           ACDEF
           ,
           a
           bended
           or
           curve
           line
           in
           which
           the
           Comet
           is
           supposed
           to
           move
           :
           the
           Comet
           then
           coming
           into
           the
           Sphere
           of
           the
           attractive
           power
           of
           the
           Sun
           ,
           by
           the
           straight
           line
           PAG
           ,
           at
           A
           ,
           the
           power
           of
           the
           Sun
           worketh
           on
           it
           ,
           and
           by
           degrees
           attracting
           it
           towards
           its
           own
           Center
           by
           that
           time
           the
           Comet
           hath
           moved
           to
           C
           ,
           the
           attractive
           power
           hath
           deflected
           its
           direct
           course
           from
           PAG
           ,
           to
           CH
           ,
           and
           so
           the
           Comet
           would
           continue
           to
           move
           in
           that
           straight
           line
           CH
           ,
           but
           it
           is
           still
           deflected
           so
           ,
           that
           at
           D
           ,
           it
           moves
           towards
           I
           ,
           but
           the
           gravitation
           of
           the
           Sun
           attracting
           it
           ,
           deflects
           it
           from
           that
           line
           towards
           E
           ,
           and
           so
           from
           E
           to
           F
           ,
           when
           it
           begins
           again
           to
           Jet
           out
           of
           the
           attractive
           beams
           of
           the
           Sun
           ,
           and
           so
           it
           will
           continue
           to
           proceed
           ,
           as
           if
           it
           had
           come
           to
           that
           point
           by
           the
           line
           MFL
           ,
           the
           reason
           of
           which
           is
           the
           great
           velocity
           of
           these
           bodies
           ,
           which
           are
           generally
           much
           swifter
           in
           their
           motions
           than
           the
           Earth
           or
           other
           Planets
           are
           supposed
           to
           be
           ,
           in
           theirs
           .
           We
           must
           seek
           out
           some
           other
           way
           therefore
           of
           finding
           of
           the
           distance
           of
           Comets
           than
           the
           commonly
           used
           :
           I
           shall
           therefore
           somewhat
           further
           explain
           the
           contrivance
           I
           newly
           invented
           for
           this
           purpose
           ,
           by
           which
           not
           only
           the
           Parallax
           of
           the
           Comet
           but
           of
           the
           Planets
           
           also
           may
           be
           found
           with
           great
           facility
           and
           exactness
           .
        
         
           Having
           a
           large
           Telescope
           prepared
           (
           as
           I
           formerly
           directed
           )
           with
           Eye-glasses
           capable
           of
           taking
           in
           an
           Angle
           of
           about
           two
           degrees
           at
           once
           ,
           and
           furnished
           with
           a
           dividing
           Scale
           ,
           observe
           when
           the
           motion
           of
           the
           Comet
           or
           Planets
           is
           not
           too
           fast
           ,
           the
           position
           and
           distances
           of
           the
           small
           fixed
           Stars
           which
           are
           next
           adjoyning
           to
           the
           moved
           body
           whose
           Parallax
           you
           would
           find
           ;
           of
           these
           small
           fixed
           Stars
           you
           shall
           seldom
           miss
           a
           sufficient
           number
           ,
           which
           will
           be
           taken
           into
           the
           glass
           at
           once
           ,
           if
           at
           least
           the
           object-glass
           be
           allowed
           a
           very
           large
           aperture
           ;
           and
           having
           found
           such
           Stars
           as
           will
           be
           convenient
           for
           your
           purpose
           ,
           be
           very
           diligent
           in
           taking
           ,
           by
           the
           help
           of
           the
           dividing
           Scale
           ,
           the
           exact
           distance
           of
           them
           one
           from
           an
           other
           ,
           and
           when
           the
           body
           is
           highest
           above
           the
           Horizon
           ,
           viz.
           in
           or
           near
           the
           Meridian
           ,
           by
           the
           same
           means
           take
           the
           exact
           distance
           of
           it
           from
           two
           or
           three
           of
           the
           nearest
           and
           most
           conspicuous
           fixt
           Stars
           about
           it
           ,
           and
           by
           the
           help
           of
           a
           plumb-line
           ,
           hung
           likewise
           within
           the
           cell
           ,
           near
           the
           dividing
           Ruler
           ,
           find
           exactly
           the
           positions
           of
           all
           those
           bodies
           you
           take
           notice
           of
           to
           the
           Perpendicular
           or
           Horizon
           ,
           which
           may
           be
           easily
           enough
           done
           ,
           if
           together
           with
           a
           Plumb-line
           or
           Perpendicular
           plac'd
           within
           the
           glass
           you
           have
           also
           a
           small
           Diagonal
           thred
           fastned
           to
           a
           ring
           ,
           whose
           circumference
           is
           divided
           into
           360
           degrees
           ,
           and
           moveable
           so
           as
           by
           the
           finger
           easily
           to
           be
           turn'd
           any
           way
           ,
           by
           which
           means
           this
           Diagonal
           thred
           may
           be
           made
           to
           cross
           over
           any
           two
           of
           the
           bodies
           you
           observe
           ,
           and
           by
           observing
           what
           division
           of
           this
           divided
           limb
           the
           Perpendicular
           cuts
           ,
           it
           will
           be
           easie
           to
           determine
           the
           exact
           position
           of
           those
           Stars
           to
           the
           Horizon
           ;
           this
           same
           may
           be
           done
           by
           the
           dividing
           Scale
           also
           ,
           if
           that
           be
           fixt
           in
           a
           divided
           Circle
           which
           is
           movable
           ,
           in
           the
           same
           manner
           as
           the
           thred
           is
           supposed
           to
           be
           .
           This
           Observation
           ,
           with
           all
           other
           circumstances
           of
           it
           is
           likewise
           to
           be
           repeated
           at
           the
           setting
           or
           rising
           of
           the
           Planet
           or
           Comet
           ,
           and
           again
           
           the
           next
           night
           when
           it
           comes
           to
           the
           Meridian
           ,
           and
           in
           each
           of
           those
           observations
           the
           exact
           time
           is
           to
           be
           noted
           by
           a
           time-keeper
           ,
           and
           the
           altitude
           by
           some
           of
           those
           I
           have
           before
           described
           ,
           for
           by
           comparing
           these
           three
           observations
           together
           it
           will
           be
           very
           easie
           to
           find
           what
           irregularity
           in
           its
           motion
           is
           ascribable
           to
           its
           Parallax
           .
           And
           this
           will
           be
           so
           much
           the
           easier
           because
           the
           examination
           and
           reduction
           of
           it
           may
           be
           done
           (
           with
           as
           great
           exactness
           as
           the
           observation
           can
           be
           made
           ,
           )
           by
           the
           help
           only
           of
           Ruler
           and
           Compasses
           ,
           for
           all
           the
           distances
           will
           be
           set
           off
           by
           equal
           divisions
           of
           straight
           lines
           ,
           the
           line
           also
           of
           the
           periodick
           motion
           ,
           whether
           of
           the
           Comet
           or
           Planet
           ,
           especially
           if
           the
           observations
           be
           made
           when
           the
           body
           is
           near
           an
           opposition
           with
           the
           Sun
           ,
           which
           is
           much
           the
           best
           time
           ,
           will
           be
           with
           sufficient
           exactness
           taken
           for
           a
           straight
           line
           ,
           and
           the
           motion
           in
           that
           line
           may
           be
           supposed
           by
           equal
           spaces
           in
           equal
           times
           ;
           for
           the
           difference
           between
           the
           Tangents
           of
           the
           centesms
           of
           a
           degree
           to
           two
           degrees
           is
           not
           increased
           much
           more
           then
           2
           /
           1745
           that
           is
           not
           a
           quarter
           of
           a
           centesm
           of
           the
           hundredth
           part
           of
           a
           degree
           ,
           which
           is
           much
           more
           exact
           than
           I
           fear
           our
           observations
           will
           ever
           be
           .
        
         
           Another
           way
           of
           finding
           the
           Parallax
           may
           be
           by
           the
           help
           of
           exact
           observations
           made
           by
           several
           persons
           at
           the
           same
           time
           ,
           in
           places
           much
           differing
           in
           Latitude
           ,
           though
           as
           near
           as
           may
           be
           under
           the
           same
           Meridian
           (
           because
           of
           saving
           the
           trouble
           of
           Calculation
           ,
           and
           for
           being
           assured
           that
           the
           observations
           were
           both
           made
           exactly
           at
           the
           same
           time
           )
           each
           person
           by
           the
           help
           of
           very
           long
           Telescopes
           observing
           the
           exact
           distance
           of
           the
           body
           from
           the
           small
           fixt
           Stars
           next
           adjoyning
           .
        
         
           A
           third
           way
           of
           finding
           the
           Parallax
           of
           Comets
           is
           wholly
           new
           ,
           and
           though
           hypothetical
           (
           as
           supposing
           the
           annual
           motion
           of
           the
           Earth
           ,
           and
           the
           motion
           of
           the
           Comet
           in
           a
           right
           line
           through
           equal
           spaces
           in
           equal
           times
           )
           yet
           't
           is
           founded
           upon
           a
           Problem
           in
           Geometry
           (
           invented
           by
           the
           incomparable
           Mathematician
           ,
           Doctor
           
             C.
             Wren
          
           )
           which
           is
           truly
           noble
           and
           wholly
           new
           ,
           and
           
           though
           it
           had
           been
           of
           no
           use
           in
           Astronomy
           ,
           deserves
           none
           of
           the
           meanest
           places
           in
           Geometry
           ,
           by
           the
           help
           of
           which
           (
           which
           is
           much
           more
           than
           either
           of
           the
           other
           ways
           is
           capable
           of
           )
           one
           may
           easily
           find
           the
           true
           parallax
           of
           the
           Comet
           ,
           from
           any
           four
           exact
           observations
           of
           it
           ,
           made
           at
           differing
           times
           in
           the
           same
           place
           :
           Nor
           does
           it
           require
           so
           nice
           and
           accurate
           Instruments
           and
           Observators
           as
           are
           altogether
           necessary
           in
           the
           other
           ways
           .
           The
           Problem
           as
           I
           received
           it
           ,
           is
           this
           .
        
         
           
             
               
                 
                   Problema
                   .
                
                 
                   Datis
                   quatuor
                   lineis
                   utcunque
                   ductis
                   (
                   quarum
                   nec
                   tres
                   sunt
                   parallelae
                   neque
                   ab
                   eodem
                   puncto
                   ductae
                   )
                   quintam
                   ducere
                   quae
                   à
                   quatuor
                   primo
                   datis
                   in
                   tres
                   partes
                   secetur
                   ratione
                   &
                   positione
                   datas
                   .
                
                 
                   Sint
                   in
                   Figuris
                   13
                   ,
                   14
                   ,
                   15
                   ,
                   16
                   ,
                   17
                   ,
                   &
                   18
                   ,
                   quatuor
                   rectae
                   ADC
                   ,
                   BEC
                   ,
                   AE
                   ,
                   BD
                   ,
                   productae
                   versus
                   K
                   ,
                   γ
                   φ
                   ,
                   M
                   ,
                   oportet
                   quintam
                   ducere
                   ut
                   KM
                   ,
                   quae
                   secetur
                   à
                   primo
                   datis
                   in
                   segmenta
                   KN
                   ,
                   NO
                   ,
                   OM
                   ,
                   secundum
                   datas
                   rationes
                   R
                   ,
                   S
                   ,
                   T.
                   Fiat
                   ut
                   Rad
                   S
                   ,
                   T
                   ,
                   simul
                   sumptas
                   ita
                   CD
                   ,
                   ad
                   CF.
                   Rursus
                   ut
                   Tad
                   S
                   ,
                   R
                   ,
                   simul
                   sumptas
                   ,
                   ita
                   EC
                   ,
                   ad
                   CG
                   ,
                   ductis
                   autem
                   AGH
                   ,
                   BFH
                   ,
                   à
                   mutua
                   intersectione
                   H
                   ,
                   ducantur
                   H
                   γ
                   K
                   ,
                   H
                   φ
                   M
                   ,
                   parallelae
                   nimirum
                   lineis
                   AC
                   ,
                   BC
                   ,
                   quae
                   mediae
                   interjacent
                   inter
                   extremas
                   ,
                   BD
                   ,
                   AE
                   .
                   Denique
                   inter
                   puncta
                   extremarum
                   KM
                   ,
                   ducatur
                   Recta
                   secans
                   medias
                   in
                   NO
                   .
                   Dico
                   segmenta
                   KN
                   ,
                   NO
                   ,
                   OM
                   ,
                   esse
                   in
                   Data
                   ratione
                   RST
                   .
                
                 
                   Quoniam
                   FD
                   ,
                   parallela
                   est
                   ipsi
                   HK
                   ,
                   ergo
                   ut
                   CD
                   ,
                   ad
                   CF
                   ,
                   ita
                   K
                   γ
                   ,
                   ad
                   γ
                   H
                   ,
                   &
                   quoniam
                   γ
                   N
                   ,
                   parallela
                   est
                   ipsi
                   HM
                   ,
                   ergo
                   ,
                   ut
                   K
                   γ
                   ad
                   γ
                   H
                   ,
                   ita
                   KN
                   ,
                   ad
                   NM
                   ,
                   ergo
                   ut
                   KN
                   ,
                   ad
                   NM
                   ,
                   ita
                   CD
                   ,
                   ad
                   CF
                   ;
                   sed
                   CD
                   ,
                   ad
                   CF
                   ,
                   est
                   ut
                   Rad
                   S
                   ,
                   T
                   ,
                   simul
                   sumptas
                   ,
                   ergo
                   KN
                   ,
                   est
                   ad
                   NM
                   ,
                   ut
                   R
                   ,
                   ad
                   ST
                   ,
                   simul
                   sumptas
                   .
                   Similiter
                   quoniam
                   EG
                   ,
                   parallela
                   est
                   ipsi
                   MH
                   ,
                   &
                   φ
                   O
                   ,
                   ipsi
                   HK
                   ,
                   demonstratur
                   MO
                   ,
                   esse
                   ad
                   OK
                   ,
                   ut
                   T
                   ad
                   S
                   ,
                   R
                   ,
                   simul
                   sumptas
                   ▪
                   Quare
                   tres
                   KN
                   ,
                   NO
                   ,
                   OM
                   ,
                   erunt
                   ad
                   invicem
                   ut
                   R
                   ,
                   S
                   ,
                   T
                   ,
                   ergo
                   ducitur
                   linea
                   K
                   M
                   ,
                   cujus
                   tria
                   segmenta
                   à
                   quatuor
                   lineis
                   datis
                   intercepta
                   sunt
                   in
                   data
                   Ratione
                   R
                   ,
                   S
                   ,
                   T
                   ,
                   &
                   servata
                   quidem
                   
                   positione
                   sive
                   rationum
                   ordine
                   R
                   ,
                   S
                   ,
                   T
                   ,
                   quod
                   erat
                   faciendum
                   .
                
              
            
          
        
         
           From
           the
           invention
           of
           which
           Problem
           't
           will
           be
           very
           easie
           by
           any
           four
           observations
           Graphically
           to
           describe
           ,
           or
           Geometrically
           to
           calculate
           the
           true
           distance
           of
           the
           line
           of
           the
           trajection
           of
           the
           Comet
           ,
           and
           consequently
           to
           answer
           all
           those
           questions
           that
           can
           be
           demanded
           concerning
           the
           bigness
           of
           the
           body
           and
           head
           ,
           and
           concerning
           the
           bigness
           and
           length
           of
           the
           blaze
           ,
           and
           concerning
           the
           distance
           of
           it
           from
           the
           Earth
           in
           every
           part
           of
           its
           way
           when
           it
           was
           nearest
           the
           Earth
           ,
           when
           nearest
           the
           Sun
           ,
           where
           it
           cuts
           the
           Plain
           of
           the
           Ecliptick
           ,
           seen
           from
           the
           Sun
           ,
           and
           where
           seen
           from
           the
           Earth
           ,
           with
           what
           Angle
           it
           was
           inclined
           to
           the
           said
           Plain
           ,
           how
           swift
           the
           motion
           was
           ,
           that
           is
           ,
           what
           length
           it
           passed
           ,
           in
           what
           time
           ,
           when
           it
           must
           appear
           Stationary
           ,
           when
           Retrograde
           ,
           when
           disappear
           ,
           and
           the
           like
           .
        
         
           According
           to
           this
           method
           I
           received
           at
           the
           same
           time
           ,
           (
           whilst
           it
           yet
           appeared
           very
           visible
           to
           the
           Eye
           ,
           and
           was
           not
           Retrograde
           ,
           )
           the
           way
           of
           the
           first
           Comet
           delineated
           by
           the
           said
           person
           ,
           which
           did
           very
           near
           solve
           all
           the
           appearances
           preceding
           and
           subsequent
           ,
           which
           I
           have
           therefore
           here
           annexed
           in
           the
           Table
           expressed
           in
           the
           19.
           20.
           and
           21.
           figures
           ,
           where
           in
           the
           19.
           is
           delineated
           the
           Place
           of
           the
           Sun
           in
           the
           Center
           of
           the
           Circle
           ♈
           ,
           N
           ,
           D
           ,
           I
           ,
           ♎
           ,
           which
           represents
           the
           annual
           Orb
           of
           the
           Earth
           about
           the
           Sun
           ,
           the
           points
           between
           N
           and
           D
           represent
           the
           places
           of
           the
           Earth
           in
           that
           Orbit
           in
           the
           days
           of
           November
           ,
           and
           the
           lines
           drawn
           from
           them
           to
           the
           points
           in
           the
           straight
           line
           ,
           represent
           the
           lines
           in
           which
           the
           Comet
           appeared
           in
           respect
           to
           the
           Sun
           ;
           in
           like
           manner
           the
           points
           between
           D
           and
           I
           ,
           the
           places
           of
           the
           Earth
           in
           December
           ,
           and
           the
           lines
           drawn
           from
           them
           to
           the
           straight
           line
           ,
           as
           before
           the
           visible
           places
           of
           the
           Comet
           at
           those
           times
           ,
           &c.
           
           The
           20.
           figure
           represents
           singly
           the
           several
           Longitudes
           of
           the
           Comet
           at
           several
           times
           seen
           from
           the
           Earth
           .
           And
           the
           21.
           represents
           the
           several
           Latitudes
           ,
           at
           the
           several
           times
           ,
           together
           with
           the
           
           true
           distances
           of
           the
           Comet
           at
           those
           times
           ,
           both
           which
           are
           made
           out
           of
           the
           19.
           figure
           ,
           where
           E
           at
           the
           end
           of
           the
           line
           represents
           the
           Center
           of
           the
           Earth
           ,
           from
           which
           to
           the
           figures
           in
           the
           prickt
           curve-line
           ,
           are
           the
           true
           distances
           of
           the
           Comet
           ,
           the
           Perpendiculars
           from
           those
           figures
           to
           the
           line
           EC
           are
           the
           signs
           of
           the
           Latitude
           of
           the
           Comet
           from
           the
           plane
           of
           the
           Ecliptick
           EC
           ,
           the
           aforesaid
           distances
           being
           made
           the
           Radii
           .
        
         
           Now
           though
           according
           to
           my
           former
           Delineation
           the
           Comet
           seemed
           to
           take
           a
           circuit
           ,
           as
           if
           it
           would
           within
           three
           years
           return
           to
           its
           former
           position
           ,
           yet
           I
           am
           not
           wholly
           convinced
           that
           it
           moves
           in
           a
           circle
           or
           Ellipse
           ,
           but
           I
           rather
           incline
           to
           the
           incomparable
           Keplers
           opinion
           ,
           that
           its
           natural
           motion
           tends
           towards
           a
           straight
           line
           ,
           though
           in
           some
           other
           suppositions
           I
           differ
           from
           him
           .
        
         
           As
           first
           that
           the
           Comet
           perseveres
           exactly
           in
           a
           straight
           line
           .
           Secondly
           ,
           that
           after
           it
           has
           past
           its
           Perige
           it
           accelerates
           its
           motion
           in
           proportion
           to
           Tangents
           of
           equal
           Angles
           .
           Thirdly
           ,
           that
           it
           either
           is
           extinguisht
           dissipated
           ,
           broken
           in
           pieces
           ,
           or
           burnt
           out
           into
           ashes
           .
           Fourthly
           ,
           that
           it
           receives
           all
           its
           light
           from
           the
           Sun.
           Fifthly
           ,
           that
           if
           the
           blaze
           were
           not
           made
           by
           the
           beams
           of
           the
           Sun
           passing
           through
           the
           head
           of
           the
           Comet
           ,
           and
           so
           carrying
           the
           parts
           along
           with
           them
           ,
           the
           blaze
           would
           not
           be
           opposite
           to
           the
           Sun.
           Sixthly
           ,
           that
           the
           cause
           of
           the
           bending
           of
           the
           blaze
           is
           the
           refraction
           of
           the
           Suns
           raies
           in
           the
           body
           ,
           and
           their
           being
           bent
           by
           the
           Aether
           as
           with
           a
           wind
           (
           which
           is
           the
           opinion
           that
           the
           Ingenious
           Descartes
           follows
           also
           .
           )
           To
           these
           I
           cannot
           consent
           ,
           and
           I
           have
           many
           objections
           to
           several
           other
           of
           his
           opinions
           concerning
           this
           matter
           ,
           which
           would
           be
           too
           tedious
           to
           insert
           ;
           only
           I
           shall
           add
           ,
           that
           having
           traced
           several
           of
           the
           Comets
           according
           to
           the
           best
           observations
           I
           could
           get
           ,
           I
           found
           it
           very
           difficult
           to
           make
           their
           motion
           fall
           in
           a
           straight
           line
           ,
           unless
           it
           be
           granted
           that
           their
           motions
           are
           really
           accelerated
           and
           retarded
           in
           that
           line
           ,
           which
           seems
           not
           so
           probable
           ,
           at
           
           least
           not
           in
           those
           parts
           of
           their
           transit
           where
           he
           places
           them
           .
           And
           particularly
           by
           tracing
           the
           way
           of
           this
           Comet
           of
           1664.
           it
           is
           very
           evident
           that
           either
           the
           observations
           are
           false
           ,
           or
           its
           appearances
           cannot
           be
           solved
           by
           that
           supposition
           ,
           without
           supposing
           the
           way
           of
           it
           a
           little
           incurvated
           by
           the
           attractive
           power
           of
           the
           Sun
           ,
           through
           whose
           system
           it
           was
           passing
           ,
           though
           it
           were
           not
           wholly
           stayed
           and
           circumflected
           into
           a
           Circle
           ,
           as
           I
           have
           already
           mentioned
           .
        
         
           That
           it
           is
           not
           extinguisht
           or
           quite
           burnt
           out
           ,
           when
           it
           ceases
           to
           appear
           ,
           I
           argue
           from
           this
           ,
           that
           I
           was
           able
           to
           see
           it
           with
           a
           Telescope
           above
           a
           month
           after
           it
           disappeared
           to
           the
           naked
           Eye
           ,
           as
           may
           be
           seen
           by
           the
           observations
           I
           have
           annext
           in
           Fig.
           4.
           and
           had
           not
           the
           cloudy
           weather
           and
           the
           light
           of
           the
           Moon
           ,
           and
           nearness
           of
           the
           Crepusculum
           hindred
           ,
           I
           suppose
           I
           might
           have
           seen
           it
           much
           longer
           ,
           as
           I
           am
           apt
           to
           believe
           the
           great
           one
           in
           1618.
           might
           have
           been
           seen
           several
           months
           longer
           ,
           if
           it
           had
           been
           diligently
           followed
           with
           Telescopes
           ,
           it
           disappearing
           in
           such
           a
           part
           of
           the
           Heavens
           as
           might
           have
           been
           seen
           every
           clear
           night
           between
           the
           Crepusculum
           and
           Dawning
           .
        
         
           Nor
           can
           I
           suppose
           it
           to
           receive
           all
           its
           light
           from
           the
           Sun
           ,
           since
           if
           so
           it
           would
           follow
           ,
           that
           the
           Nucleus
           in
           the
           head
           ,
           would
           have
           a
           dark
           shadow
           opposite
           to
           the
           Sun
           ,
           the
           contrary
           of
           which
           has
           always
           been
           observed
           .
           Nor
           can
           I
           well
           understand
           that
           the
           Sun
           beams
           are
           like
           a
           stream
           of
           water
           ,
           carrying
           the
           parts
           of
           the
           Comet
           along
           with
           them
           so
           as
           to
           make
           its
           blaze
           ,
           since
           no
           such
           effect
           is
           found
           of
           them
           here
           with
           us
           upon
           the
           Earth
           :
           Nor
           how
           they
           should
           come
           to
           be
           bended
           like
           smoke
           ,
           since
           we
           observe
           no
           such
           property
           of
           light
           in
           a
           uniform
           medium
           ,
           such
           as
           in
           probability
           the
           Aether
           is
           .
        
         
           These
           were
           my
           thoughts
           about
           those
           Comets
           which
           appeared
           in
           1664.
           and
           1665.
           which
           I
           have
           found
           in
           several
           loose
           papers
           of
           Lectures
           ,
           read
           in
           the
           beginning
           of
           1665.
           
           And
           I
           have
           not
           had
           the
           opportunity
           of
           making
           many
           observations
           since
           ,
           concerning
           Comets
           ,
           save
           these
           two
           last
           ,
           in
           which
           I
           had
           
           not
           the
           convenience
           of
           observing
           any
           thing
           certain
           concerning
           its
           motion
           or
           Parallax
           .
           And
           therefore
           I
           applyed
           my self
           to
           mark
           as
           near
           as
           I
           could
           the
           true
           figure
           of
           it
           ,
           through
           a
           six
           foot
           Telescope
           ,
           and
           to
           take
           notice
           of
           as
           many
           circumstances
           as
           the
           short
           time
           I
           had
           would
           permit
           ,
           which
           though
           they
           were
           very
           short
           and
           transitory
           observations
           ,
           and
           I
           wanted
           time
           to
           repeat
           them
           so
           often
           as
           I
           could
           have
           desired
           ,
           yet
           even
           from
           them
           I
           was
           sufficiently
           satisfied
           ,
           that
           I
           had
           reason
           to
           adhere
           to
           my
           former
           conjecture
           ,
           that
           the
           light
           of
           the
           Comet
           did
           not
           depend
           wholly
           from
           the
           reflection
           of
           the
           Sun
           beams
           ,
           from
           the
           parts
           thereof
           ,
           but
           rather
           from
           its
           own
           light
           ,
           for
           upon
           well
           considering
           of
           the
           form
           of
           this
           Comet
           ,
           I
           manifestly
           saw
           that
           the
           middle
           of
           the
           blaze
           was
           brighter
           than
           the
           side
           parts
           thereof
           ,
           and
           especially
           that
           part
           which
           was
           immediatly
           opposite
           to
           the
           Sun
           ,
           was
           the
           brightest
           of
           all
           ,
           which
           would
           have
           been
           otherwise
           if
           the
           light
           had
           depended
           wholly
           from
           the
           deflection
           of
           the
           rays
           of
           the
           Sun
           ,
           for
           one
           might
           rationally
           conclude
           that
           the
           Nucleus
           or
           Star
           in
           the
           middle
           ,
           which
           reflected
           so
           great
           a
           quantity
           of
           light
           should
           have
           caused
           a
           darkness
           in
           the
           parts
           behind
           it
           ,
           as
           we
           see
           all
           strong
           reflecting
           bodies
           do
           ,
           and
           consequently
           that
           the
           middle
           part
           of
           the
           stream
           or
           blaze
           ,
           especially
           that
           which
           was
           next
           the
           body
           should
           not
           have
           been
           so
           bright
           as
           those
           other
           parts
           to
           which
           the
           light
           of
           the
           Sun
           had
           a
           more
           free
           access
           ,
           unless
           it
           may
           be
           said
           that
           even
           the
           Star
           it self
           ,
           though
           it
           seem
           so
           bright
           ,
           is
           notwithstanding
           not
           so
           Dense
           ,
           but
           that
           it
           admits
           rays
           enough
           to
           pass
           through
           it
           unreflected
           ,
           to
           inlighten
           the
           parts
           behind
           it
           .
           But
           this
           seems
           not
           so
           likely
           ,
           since
           be
           the
           body
           of
           the
           Star
           supposed
           a
           thousand
           times
           thinner
           than
           a
           Cloud
           (
           which
           yet
           t
           is
           hard
           to
           suppose
           ,
           since
           it
           gives
           so
           considerable
           a
           reflection
           ,
           )
           yet
           it
           being
           in
           all
           probability
           ten
           thousand
           times
           bigger
           in
           bulk
           ,
           the
           rays
           in
           passing
           through
           so
           great
           a
           bulk
           ,
           must
           needs
           meet
           with
           more
           obstruction
           than
           in
           the
           thinnest
           Cloud
           ,
           and
           yet
           we
           find
           that
           there
           is
           no
           Cloud
           so
           thin
           ,
           but
           casts
           
           shadow
           opposite
           to
           the
           Sun
           ,
           and
           therefore
           in
           probability
           this
           would
           do
           the
           like
           ,
           but
           I
           diligently
           observed
           that
           there
           was
           no
           such
           appearance
           here
           ,
           but
           the
           contrary
           ,
           that
           is
           ,
           that
           where
           the
           shadow
           should
           have
           been
           ,
           there
           was
           the
           lightest
           part
           of
           all
           the
           blaze
           ,
           and
           consequently
           in
           probability
           it
           did
           depend
           upon
           some
           other
           cause
           than
           a
           reflection
           of
           light
           .
        
         
           It
           is
           a
           hard
           matter
           to
           assign
           the
           particular
           cause
           of
           its
           light
           ,
           but
           it
           seems
           from
           these
           circumstances
           to
           be
           very
           probable
           that
           it
           was
           (
           in
           part
           at
           least
           )
           from
           its
           own
           nature
           ,
           whether
           that
           might
           be
           somewhat
           of
           that
           of
           the
           Sun
           and
           Stars
           ,
           or
           of
           that
           of
           our
           fire
           ,
           or
           of
           that
           of
           decaying
           fish
           ,
           rotten
           wood
           ,
           glow-worms
           ,
           &c.
           or
           of
           that
           of
           the
           Ignis
           Fatuus
           ,
           at
           Land
           or
           Sea
           ,
           or
           like
           that
           of
           Sea-water
           ,
           or
           a
           Diamond
           ,
           or
           like
           that
           of
           the
           falling
           meteors
           ,
           or
           Star-shoots
           ,
           it
           will
           be
           very
           hard
           to
           determine
           ,
           unless
           one
           had
           a
           much
           greater
           stock
           of
           observations
           to
           build
           upon
           .
           But
           it
           may
           possibly
           be
           somewhat
           of
           the
           nature
           of
           them
           all
           ,
           though
           it
           agree
           not
           in
           all
           particulars
           with
           any
           one
           of
           them
           .
           All
           these
           ways
           that
           I
           have
           named
           seeming
           to
           agree
           in
           one
           particular
           ,
           and
           that
           is
           an
           internal
           motion
           of
           the
           parts
           which
           shine
           ,
           whether
           that
           motion
           be
           caused
           by
           some
           external
           menstruum
           dissolving
           it
           as
           in
           fire
           ,
           and
           Ignes
           fatui
           ,
           or
           an
           external
           motion
           ,
           stroke
           ,
           or
           impulse
           as
           in
           a
           Diamond
           ,
           Sea-water
           ,
           and
           possibly
           some
           Ignes
           fatui
           ,
           or
           from
           the
           parts
           of
           the
           bodies
           working
           and
           dissolving
           one
           another
           ,
           as
           in
           decaying
           fish
           ,
           rotten
           wood
           ,
           glow-worms
           ,
           or
           whether
           it
           be
           susceptible
           of
           a
           much
           more
           subtil
           impulse
           ,
           even
           from
           light
           it self
           ,
           as
           the
           Bononian
           stone
           ,
           and
           Bladwines
           Phsophorus
           ,
           which
           seems
           to
           be
           so
           harmonious
           (
           as
           I
           may
           so
           speak
           )
           to
           the
           motion
           of
           light
           ,
           that
           a
           new
           motion
           is
           thereby
           raised
           in
           it
           ,
           and
           continues
           for
           some
           time
           to
           move
           of
           it self
           after
           the
           impulse
           or
           influence
           ceases
           ,
           not
           much
           unlike
           the
           unison
           string
           ,
           or
           other
           sounding
           body
           ,
           which
           in
           Musick
           receives
           a
           tremulation
           and
           sound
           from
           the
           motion
           and
           sound
           of
           the
           unison
           body
           ,
           or
           string
           that
           is
           struck
           .
        
         
         
           To
           me
           It
           seems
           most
           probable
           that
           the
           body
           and
           parts
           of
           the
           Comet
           are
           in
           a
           state
           of
           dissolution
           ,
           whether
           that
           dissolution
           be
           caused
           by
           the
           parts
           of
           the
           Aether
           through
           which
           it
           passes
           ,
           after
           the
           manner
           as
           a
           Torch
           is
           dissolved
           by
           the
           air
           ,
           or
           whether
           by
           the
           internal
           working
           of
           the
           constituent
           parts
           one
           upon
           the
           other
           ,
           as
           in
           Gun-powder
           ,
           shining
           Fish
           and
           rotten
           Wood
           ,
           I
           cannot
           determine
           ;
           but
           I
           rather
           guess
           it
           to
           be
           in
           some
           things
           analogous
           to
           the
           one
           ,
           and
           somewhat
           to
           the
           other
           ,
           though
           not
           exactly
           the
           same
           with
           either
           .
           And
           this
           I
           conceive
           from
           the
           figure
           and
           make
           of
           the
           shining
           parts
           ,
           for
           if
           it
           had
           been
           of
           the
           same
           nature
           with
           a
           Torch
           ,
           the
           blaze
           would
           have
           resembled
           that
           of
           the
           flame
           of
           a
           Torch
           or
           Candle
           ,
           that
           is
           ,
           the
           sides
           would
           have
           been
           brighter
           ,
           and
           the
           middle
           darker
           ,
           as
           I
           have
           shewn
           in
           my
           Lampas
           ;
           whereas
           it
           was
           very
           manifest
           that
           the
           middle
           of
           the
           blaze
           was
           brightest
           ,
           and
           of
           that
           blaze
           that
           which
           was
           next
           the
           Star
           or
           Nucleus
           was
           brighter
           than
           that
           which
           was
           further
           off
           :
           whereas
           in
           flame
           the
           contrary
           is
           very
           observable
           ,
           as
           I
           have
           in
           the
           said
           Treatise
           shewn
           .
        
         
           From
           the
           shape
           of
           the
           figure
           ,
           the
           manner
           of
           its
           dissolution
           seems
           to
           be
           thus
           .
           The
           Star
           or
           Nucleus
           in
           the
           middle
           ,
           seems
           to
           be
           the
           fomes
           or
           source
           from
           whence
           all
           the
           light
           proceeds
           :
           this
           we
           suppose
           to
           be
           a
           dense
           body
           encompast
           with
           a
           very
           fluid
           body
           (
           such
           as
           the
           Aether
           seems
           to
           be
           )
           but
           of
           such
           a
           loose
           and
           spongy
           nature
           ,
           as
           that
           the
           Aether
           doth
           cause
           those
           parts
           which
           are
           contiguous
           to
           it
           ,
           to
           be
           dissolved
           and
           expanded
           into
           it self
           .
           This
           dissolution
           and
           expansion
           I
           conceive
           doth
           generate
           or
           cause
           the
           light
           that
           seems
           to
           proceed
           from
           it
           ,
           that
           dissolution
           causing
           such
           a
           motion
           of
           the
           Aether
           ,
           as
           is
           necessary
           to
           produce
           the
           appearance
           of
           light
           ;
           now
           so
           long
           as
           any
           part
           thereof
           remains
           in
           dissolution
           ,
           so
           long
           doth
           it
           continue
           to
           shine
           ,
           as
           is
           also
           observable
           in
           the
           flame
           of
           any
           body
           burning
           in
           the
           air
           ,
           but
           when
           the
           part
           separated
           from
           the
           body
           is
           quite
           dissolved
           into
           the
           Aether
           ,
           the
           effect
           of
           shining
           ceases
           ,
           as
           it
           doth
           
           also
           in
           the
           parts
           of
           flame
           .
           Now
           I
           have
           observed
           that
           the
           blaze
           is
           so
           very
           much
           rarified
           ,
           that
           first
           the
           Aether
           I
           conceive
           comes
           very
           freely
           to
           every
           particle
           of
           the
           body
           after
           it
           is
           separated
           from
           it
           ,
           but
           especially
           to
           the
           outermost
           ,
           and
           continues
           to
           be
           incompassed
           with
           it
           so
           long
           as
           till
           it
           be
           quite
           dissolved
           into
           it
           ,
           which
           I
           conceive
           to
           be
           at
           a
           little
           farther
           distance
           from
           the
           head
           than
           the
           greatest
           length
           of
           the
           blaze
           seems
           to
           be
           to
           our
           sight
           .
           And
           further
           I
           conceive
           that
           the
           outward
           parts
           being
           thus
           incompassed
           more
           perfectly
           with
           the
           free
           and
           undisturbed
           Aether
           ,
           are
           sooner
           dissolved
           into
           it
           than
           those
           of
           the
           middle
           ,
           and
           consequently
           the
           sides
           seem
           first
           to
           disappear
           ,
           and
           the
           middle
           parts
           continue
           their
           shining
           to
           a
           much
           greater
           distance
           from
           the
           Star
           in
           the
           head
           ,
           though
           somewhat
           also
           of
           that
           appearance
           may
           be
           ascribed
           to
           the
           dispersing
           and
           rarity
           of
           the
           parts
           near
           the
           sides
           .
        
         
           The
           Nucleus
           or
           Ball
           in
           the
           middle
           of
           the
           head
           ,
           which
           I
           have
           called
           the
           Star
           ,
           I
           conceive
           to
           be
           dissolved
           equally
           on
           all
           sides
           ,
           and
           the
           parts
           which
           are
           dissolved
           or
           separated
           from
           it
           ,
           I
           conceive
           to
           fly
           every
           way
           from
           the
           center
           of
           it
           ,
           with
           pretty
           near
           equal
           celerity
           or
           power
           ,
           like
           so
           many
           blazing
           Granadoes
           or
           Fire-balls
           ,
           these
           continue
           their
           motion
           so
           far
           toward
           the
           way
           they
           are
           shot
           ,
           till
           the
           Levitation
           from
           the
           body
           of
           the
           Sun
           deflect
           them
           upwards
           ,
           or
           in
           opposition
           to
           the
           Sun
           into
           a
           Parabolick
           curve
           ,
           in
           which
           Parabolick
           curve
           ,
           every
           single
           particle
           continues
           its
           motion
           till
           it
           be
           wholly
           burnt
           out
           ,
           or
           dissolved
           into
           the
           Aether
           .
           These
           are
           continually
           succeeded
           by
           new
           separations
           from
           the
           aforesaid
           body
           in
           the
           same
           manner
           as
           t
           is
           observable
           in
           a
           burning
           ,
           steaming
           ,
           or
           smoaking
           body
           in
           our
           air
           ,
           or
           a
           dissolving
           body
           incompassed
           with
           its
           proper
           menstruum
           ,
           as
           I
           before
           mentioned
           ,
           and
           will
           so
           continue
           until
           the
           whole
           be
           at
           length
           dissolved
           into
           the
           Aether
           ,
           through
           which
           it
           passes
           .
        
         
           It
           hath
           been
           demonstrated
           by
           Torricellius
           ,
           of
           bullets
           or
           other
           bodies
           cast
           or
           shot
           upwards
           ,
           that
           the
           same
           
           or
           equal
           bullets
           discharged
           or
           shot
           out
           from
           the
           same
           point
           ,
           with
           the
           same
           degree
           of
           strength
           ,
           but
           with
           differing
           degrees
           of
           inclination
           to
           the
           Horizon
           ,
           each
           of
           them
           shall
           be
           moved
           in
           a
           parabolical
           line
           ,
           and
           every
           one
           of
           those
           parabolical
           lines
           shall
           touch
           a
           parabolical
           line
           ,
           whose
           axis
           is
           the
           perpendicular
           ,
           and
           whose
           apex
           is
           distant
           from
           the
           said
           point
           ,
           the
           full
           altitude
           of
           the
           perpendicular
           shot
           :
           So
           that
           supposing
           in
           the
           twenty
           second
           figure
           ,
           A
           to
           be
           the
           point
           from
           whence
           all
           the
           shots
           are
           made
           with
           equal
           velocity
           ,
           AC
           the
           greatest
           height
           of
           the
           perpendicular
           shot
           ,
           and
           AD
           the
           greatest
           Horizontal
           random
           at
           45
           degrees
           of
           inclination
           ,
           and
           suppose
           EDCDE
           a
           parabola
           passing
           through
           those
           points
           DCD
           ,
           all
           the
           shots
           made
           with
           equal
           bullets
           ,
           with
           equal
           velocity
           from
           A
           ,
           but
           with
           all
           variety
           of
           inclination
           between
           the
           perpendicular
           upwards
           ,
           and
           the
           perpendicular
           downwards
           that
           touch
           the
           said
           parabolical
           line
           ,
           and
           consequently
           if
           there
           be
           an
           indefinite
           number
           of
           such
           balls
           continually
           flowing
           out
           of
           the
           point
           A
           ,
           with
           equal
           degrees
           of
           celerity
           every
           way
           dispersing
           themselves
           equally
           
             in
             orbem
          
           ,
           the
           whole
           aggregate
           of
           such
           an
           emanation
           will
           make
           a
           solid
           parabolical
           conoeid
           EDCDE
           .
           Now
           about
           the
           point
           A
           ,
           if
           we
           suppose
           a
           Sphere
           as
           BBBB
           ,
           and
           from
           this
           Sphere
           an
           indefinite
           number
           of
           such
           equal
           Balls
           be
           thrown
           off
           perpendicularly
           to
           the
           superficies
           of
           it
           ,
           from
           every
           point
           thereof
           ,
           with
           equal
           celerity
           at
           their
           leaving
           it
           ,
           those
           emanations
           will
           form
           also
           a
           conoeid
           ,
           which
           will
           be
           very
           near
           the
           same
           with
           the
           former
           :
           And
           if
           this
           Ball
           in
           the
           middle
           be
           supposed
           a
           burning
           and
           shining
           body
           ,
           and
           that
           all
           these
           emanations
           have
           every
           one
           of
           them
           equal
           light
           in
           proportion
           to
           the
           Globe
           BBBBA
           ,
           the
           effect
           produced
           hereby
           will
           perfectly
           resemble
           the
           appearance
           and
           figure
           of
           Comets
           ,
           if
           at
           least
           the
           Parabolical
           conoeid
           be
           inverted
           ;
           which
           will
           somewhat
           explain
           the
           manner
           how
           I
           conceive
           the
           figure
           of
           the
           Cometical
           body
           is
           naturally
           ,
           and
           most
           proportionably
           formed
           ;
           for
           if
           the
           effect
           of
           
           
           
           
           
           such
           an
           emanation
           of
           shining
           bodies
           be
           examined
           ,
           it
           will
           very
           plainly
           exhibit
           the
           exact
           and
           true
           apparent
           figure
           of
           Comets
           ,
           as
           they
           may
           be
           seen
           through
           a
           good
           Telescope
           ,
           which
           is
           to
           me
           a
           very
           great
           argument
           ,
           that
           't
           is
           the
           genuine
           cause
           of
           its
           shape
           and
           figure
           :
           Now
           though
           the
           Comets
           appearance
           be
           this
           way
           caused
           ,
           and
           so
           a
           man
           might
           conceive
           the
           Globous
           body
           would
           in
           a
           little
           time
           (
           by
           so
           copious
           an
           emanation
           )
           be
           consumed
           ,
           yet
           I
           do
           not
           believe
           that
           it
           doth
           in
           a
           short
           time
           wast
           and
           disperse
           the
           whole
           Ball
           ,
           nor
           can
           I
           conceive
           that
           the
           disappearing
           of
           those
           blazing
           bodies
           toward
           the
           latter
           end
           ,
           does
           depend
           upon
           their
           dissolution
           (
           though
           possibly
           that
           may
           somewhat
           diminish
           them
           )
           but
           that
           rather
           is
           to
           be
           ascribed
           to
           their
           distance
           and
           position
           in
           respect
           of
           us
           :
           Though
           this
           I
           remember
           I
           observed
           very
           manifestly
           in
           that
           of
           1664.
           that
           the
           body
           toward
           the
           latter
           end
           of
           its
           appearing
           was
           very
           much
           less
           in
           proportion
           to
           the
           radiations
           about
           it
           ,
           than
           it
           seemed
           to
           be
           at
           the
           beginning
           ,
           but
           whether
           that
           might
           not
           be
           partly
           ascribed
           to
           the
           great
           distance
           it
           then
           was
           from
           us
           ,
           and
           the
           turning
           of
           the
           head
           pretty
           near
           towards
           us
           ,
           and
           thence
           the
           spreading
           of
           the
           Tail
           (
           appearing
           beyond
           it
           ,
           )
           might
           add
           to
           the
           breadth
           of
           the
           radiation
           about
           the
           Nucleus
           ,
           I
           will
           not
           positively
           determine
           .
           Now
           though
           for
           explication
           sake
           ,
           I
           have
           compared
           the
           parts
           separated
           from
           the
           body
           of
           the
           Comet
           to
           blazing
           Granadoes
           or
           Fire-balls
           ,
           yet
           I
           would
           not
           be
           understood
           to
           suppose
           these
           parts
           so
           separated
           to
           be
           of
           any
           very
           large
           bulk
           ,
           for
           I
           see
           no
           necessity
           to
           suppose
           them
           bigger
           than
           the
           Atoms
           of
           smoke
           ,
           or
           the
           particles
           of
           any
           other
           steaming
           body
           ,
           or
           than
           the
           parts
           of
           the
           Air
           ,
           which
           make
           the
           body
           of
           it
           appear
           thick
           and
           hazy
           ;
           nor
           do
           I
           believe
           that
           all
           the
           light
           of
           the
           Star
           ,
           head
           ,
           and
           blaze
           ,
           does
           depend
           only
           upon
           the
           shining
           of
           the
           dissolving
           body
           and
           particles
           thereof
           :
           but
           I
           do
           suppose
           that
           it
           doth
           proceed
           both
           from
           the
           reflection
           of
           the
           Sun-beams
           from
           those
           parts
           ,
           and
           also
           from
           an
           innate
           and
           momentaneous
           light
           produced
           by
           
           the
           action
           of
           dissolution
           wrought
           on
           the
           parts
           by
           the
           incompassing
           Aether
           .
        
         
           It
           may
           possibly
           seem
           very
           difficult
           to
           suppose
           that
           the
           dissolution
           of
           the
           parts
           of
           the
           Nucleus
           ,
           by
           the
           incompassing
           Aether
           ,
           should
           cause
           or
           impress
           so
           violent
           a
           motion
           into
           the
           separated
           parts
           ,
           as
           to
           make
           them
           depart
           from
           it
           to
           the
           space
           of
           four
           or
           five
           Diameters
           ,
           before
           it
           be
           over-powered
           by
           the
           power
           of
           Levitation
           from
           the
           body
           of
           the
           Sun
           ,
           and
           so
           deflected
           into
           a
           parabolical
           line
           upwards
           .
           It
           may
           likewise
           seem
           strange
           to
           suppose
           that
           the
           Aether
           should
           have
           such
           power
           in
           it
           ,
           as
           first
           to
           dissolve
           a
           body
           into
           it self
           ,
           and
           secondly
           to
           cause
           a
           shining
           ,
           and
           thirdly
           to
           cause
           a
           Levitation
           of
           the
           dissolved
           parts
           upwards
           ;
           whereas
           I
           supposed
           before
           (
           and
           I
           think
           't
           is
           very
           manifest
           )
           that
           they
           cause
           a
           gravitation
           downwards
           ,
           towards
           the
           Center
           of
           the
           Sun
           :
           But
           to
           these
           for
           explication
           ,
           I
           answer
           that
           we
           need
           not
           go
           far
           for
           instances
           to
           make
           these
           things
           probable
           ,
           the
           Atmosphere
           about
           the
           Earth
           ,
           as
           I
           have
           formerly
           mentioned
           in
           my
           Micrographia
           ,
           I
           take
           to
           be
           nothing
           else
           but
           the
           dissolution
           of
           the
           parts
           of
           the
           Earth
           into
           the
           incompassing
           Aether
           ;
           for
           the
           proof
           of
           which
           ,
           I
           could
           bring
           many
           arguments
           ,
           were
           it
           here
           a
           proper
           place
           ,
           by
           which
           I
           could
           most
           evidently
           demonstrate
           the
           thing
           to
           be
           as
           I
           have
           asserted
           .
           It
           is
           here
           evident
           that
           this
           Aether
           doth
           take
           up
           the
           particles
           of
           bodies
           to
           a
           very
           great
           distance
           from
           the
           surface
           from
           which
           they
           were
           separated
           ,
           and
           it
           doth
           not
           only
           raise
           them
           but
           susteins
           them
           at
           those
           heights
           ,
           nor
           is
           this
           peculiar
           only
           to
           the
           Aether
           when
           a
           menstruum
           ,
           but
           to
           all
           dissolving
           menstruums
           in
           general
           .
        
         
           As
           to
           give
           one
           instance
           ,
           in
           stead
           of
           many
           ,
           we
           find
           that
           Gold
           (
           the
           heaviest
           of
           all
           Terrestrial
           bodies
           we
           yet
           know
           ,
           )
           being
           dissolved
           by
           
             Aqua
             Regis
          
           ,
           is
           taken
           up
           into
           it
           ,
           and
           kept
           suspended
           therein
           ,
           though
           the
           parts
           of
           the
           Gold
           be
           fifteen
           times
           heavier
           than
           the
           parts
           of
           the
           
             Aqua
             Regis
          
           .
           So
           Pit-coal
           though
           very
           heavy
           ,
           is
           yet
           taken
           up
           into
           the
           Air
           ,
           and
           kept
           suspended
           therein
           ,
           
           though
           it
           will
           be
           found
           to
           be
           some
           thousands
           of
           times
           more
           ponderous
           than
           the
           menstruum
           of
           the
           Air
           that
           keeps
           it
           suspended
           .
        
         
           Many
           reasons
           I
           could
           produce
           to
           shew
           the
           great
           power
           of
           the
           Aether
           ,
           and
           the
           universality
           of
           its
           activity
           almost
           in
           all
           sensible
           motions
           ,
           but
           reserving
           them
           for
           another
           Discourse
           hereafter
           ,
           I
           shall
           at
           present
           ,
           only
           mention
           those
           suppositions
           which
           seem
           to
           have
           the
           greatest
           difficulty
           ,
           in
           this
           Theory
           ,
           viz.
           how
           the
           dissolution
           of
           the
           parts
           of
           the
           Star
           by
           the
           incompassing
           Aether
           should
           cause
           light
           ,
           and
           secondly
           how
           it
           should
           cause
           an
           actual
           Levitation
           of
           the
           dissolving
           particles
           upwards
           .
           For
           the
           explication
           of
           these
           two
           difficulties
           ,
           I
           must
           at
           present
           crave
           favour
           to
           explain
           them
           by
           examples
           taken
           from
           operations
           of
           Nature
           in
           the
           Atmosphere
           wherein
           we
           live
           ,
           very
           similar
           and
           analogous
           to
           them
           .
           First
           ,
           for
           the
           production
           of
           light
           ,
           we
           find
           that
           the
           Air
           incompassing
           the
           steams
           of
           bodies
           prepared
           by
           heat
           or
           otherwise
           ,
           and
           made
           fit
           for
           dissolution
           ,
           doth
           so
           operate
           upon
           them
           ,
           as
           to
           make
           them
           fly
           and
           part
           asunder
           with
           a
           very
           impetuous
           motion
           ,
           insomuch
           that
           the
           small
           particles
           or
           Atoms
           of
           the
           dissolved
           bodies
           ,
           do
           not
           only
           leave
           one
           another
           ,
           but
           depart
           and
           dart
           out
           with
           so
           great
           an
           impetuosity
           ,
           as
           to
           drive
           off
           all
           the
           incompassing
           Air
           from
           their
           Center
           from
           whence
           they
           flew
           ,
           and
           this
           I
           take
           to
           be
           the
           cause
           not
           only
           of
           their
           Light
           ,
           but
           also
           of
           their
           Levity
           upwards
           ,
           this
           may
           be
           seen
           very
           plainly
           by
           the
           small
           parts
           of
           crackling
           Char-coal
           ,
           which
           upon
           the
           blowing
           them
           with
           Bellows
           ,
           and
           so
           crowding
           a
           great
           quantity
           of
           the
           fresh
           menstruum
           on
           them
           ,
           fly
           and
           dart
           asunder
           with
           great
           celerity
           and
           noise
           ,
           but
           is
           abundantly
           more
           evident
           in
           the
           kindling
           of
           Gun-powder
           ,
           where
           the
           impetuosity
           is
           so
           very
           great
           as
           to
           drive
           away
           not
           only
           all
           the
           incompassing
           Air
           but
           all
           other
           bodies
           ,
           though
           never
           so
           solid
           ,
           that
           hinder
           its
           expansion
           ,
           in
           the
           performing
           of
           which
           operation
           the
           Aether
           hath
           a
           great
           share
           ,
           as
           I
           may
           hereafter
           shew
           ,
           't
           is
           very
           probable
           that
           the
           
           Aether
           in
           the
           same
           manner
           dissolving
           the
           particles
           of
           the
           Star
           ,
           causeth
           the
           Atoms
           thereof
           to
           fly
           asunder
           with
           so
           great
           an
           impetuosity
           as
           to
           leave
           a
           vacuity
           even
           of
           the
           parts
           of
           the
           Aether
           ,
           which
           flying
           asunder
           doth
           not
           only
           cause
           light
           by
           impressing
           on
           the
           Aether
           a
           stroke
           or
           pulse
           which
           propagates
           every
           way
           
             in
             Orbem
          
           ,
           but
           maketh
           such
           an
           agitation
           of
           the
           the
           Aether
           ,
           as
           causes
           a
           rarefaction
           in
           the
           parts
           thereof
           ,
           whilst
           the
           parts
           that
           are
           once
           actually
           separated
           ,
           by
           continual
           rebounding
           one
           against
           another
           before
           they
           come
           to
           be
           at
           rest
           and
           quietly
           to
           touch
           each
           other
           ,
           prolong
           that
           first
           separation
           or
           vacuity
           between
           them
           .
        
         
           This
           Explication
           ,
           though
           it
           be
           somewhat
           difficult
           ,
           yet
           I
           hope
           it
           is
           intelligible
           ,
           and
           may
           be
           ,
           with
           probability
           enough
           ,
           supposed
           to
           be
           the
           true
           cause
           of
           the
           appearance
           ,
           whilst
           there
           is
           nothing
           therein
           supposed
           which
           is
           not
           manifestly
           the
           method
           of
           Nature
           in
           other
           operations
           ;
           and
           though
           the
           supposition
           even
           of
           the
           Aether
           ,
           may
           seem
           to
           be
           a
           Chimera
           and
           groundless
           ;
           yet
           had
           I
           now
           time
           ,
           I
           could
           by
           many
           very
           sensible
           and
           undeniable
           experiments
           ,
           prove
           the
           existence
           and
           reality
           thereof
           ,
           and
           that
           it
           doth
           actually
           produce
           not
           only
           as
           sensible
           effects
           as
           these
           I
           have
           named
           ,
           but
           very
           much
           the
           same
           ,
           and
           many
           others
           much
           more
           cosiderable
           ,
           which
           by
           Philosophers
           have
           hitherto
           been
           ascribed
           to
           quite
           different
           causes
           .
        
         
           Had
           I
           been
           able
           to
           have
           made
           some
           other
           observations
           (
           which
           I
           designed
           ,
           if
           I
           had
           had
           the
           opportunity
           of
           seeing
           it
           ,
           some
           of
           the
           succeeding
           Nights
           ,
           )
           I
           should
           have
           hoped
           to
           have
           explained
           several
           other
           difficulties
           concerning
           the
           nature
           of
           the
           body
           and
           blaze
           of
           Comets
           ,
           but
           being
           therein
           prevented
           ,
           I
           must
           leave
           them
           till
           I
           can
           make
           some
           further
           observations
           on
           some
           Comets
           that
           may
           hereafter
           appear
           .
        
         
           In
           the
           mean
           time
           that
           what
           I
           have
           discoursed
           concerning
           the
           light
           of
           Comets
           ,
           may
           not
           seem
           so
           altogether
           paradoxical
           and
           unintelligible
           as
           some
           may
           imagine
           ,
           
           I
           have
           here
           added
           an
           account
           of
           some
           trials
           and
           observations
           made
           on
           shining
           substances
           of
           natures
           exceedingly
           differing
           from
           those
           that
           are
           commonly
           to
           be
           met
           withal
           .
           And
           this
           I
           the
           rather
           do
           ,
           not
           only
           because
           it
           affords
           an
           instance
           of
           shining
           where
           there
           is
           no
           Air
           ,
           but
           that
           hereby
           I
           may
           enlarge
           the
           limits
           of
           their
           imagination
           ,
           who
           shall
           consider
           of
           this
           subject
           .
           For
           nothing
           is
           more
           apt
           to
           misguide
           our
           reasoning
           than
           a
           narrow
           and
           limited
           knowledg
           of
           causes
           ,
           we
           are
           not
           to
           conclude
           the
           body
           of
           a
           Comet
           a
           sulphureous
           vapour
           exhaled
           from
           the
           Earth
           and
           kindled
           above
           ,
           because
           here
           are
           such
           vapours
           observed
           and
           such
           effects
           produced
           ,
           nor
           a
           collection
           of
           Sun
           beams
           made
           by
           a
           Lentiformed
           vapour
           ,
           after
           the
           manner
           of
           a
           Burning-glass
           (
           as
           some
           eminent
           Writers
           have
           lately
           done
           ,
           )
           because
           some
           such
           appearances
           may
           be
           Artificially
           produced
           in
           a
           smoaky
           or
           thickned
           Air
           ;
           since
           if
           we
           diligently
           inquire
           ,
           we
           may
           find
           that
           light
           which
           is
           the
           most
           sensible
           quality
           of
           Comets
           that
           affects
           our
           senses
           ,
           may
           be
           ,
           and
           really
           is
           produced
           by
           very
           many
           ,
           and
           those
           very
           differing
           ways
           .
           In
           Nitre
           and
           Sulphur
           kindling
           each
           other
           by
           heat
           ,
           we
           have
           one
           way
           ;
           in
           a
           body
           burning
           in
           the
           Air
           a
           second
           ,
           in
           a
           heated
           Iron
           or
           Glass
           a
           third
           ,
           in
           a
           piece
           of
           Iron
           hammered
           till
           red
           hot
           a
           fourth
           ,
           in
           rotten
           Wood
           and
           decayed
           Fish
           a
           fifth
           ,
           in
           Glow-worms
           ,
           Scolopondras
           ,
           and
           other
           living
           Worms
           ,
           and
           in
           the
           sweat
           and
           excrements
           of
           other
           living
           creatures
           a
           sixth
           ,
           in
           a
           Diamond
           rubbed
           a
           seventh
           ,
           in
           Dews
           Ignes
           fatui
           ,
           &c.
           an
           eighth
           ,
           in
           Sea-water
           a
           ninth
           ,
           in
           the
           Bononian
           stone
           ,
           and
           in
           the
           Phosphorus
           Baldwini
           (
           which
           I
           take
           to
           be
           much
           of
           the
           same
           nature
           )
           a
           tenth
           ,
           in
           the
           Phosphorus
           of
           Mr.
           Kraft
           an
           eleventh
           ,
           and
           possibly
           wholly
           differing
           from
           all
           these
           ,
           may
           be
           the
           light
           of
           the
           Sun
           ,
           a
           twelfth
           ,
           and
           that
           of
           the
           Star
           may
           differ
           from
           that
           of
           Sun
           ,
           and
           the
           Comet
           may
           be
           differing
           from
           all
           the
           rest
           .
           Whether
           they
           be
           so
           or
           not
           ,
           the
           being
           acquainted
           with
           the
           several
           proprieties
           of
           them
           will
           the
           better
           enable
           one
           to
           judg
           of
           what
           is
           pertinent
           
           to
           be
           observed
           in
           Comets
           ,
           in
           order
           to
           find
           out
           which
           is
           concerned
           .
        
         
           The
           Phaenomena
           of
           most
           of
           these
           shining
           bodies
           are
           very
           common
           and
           obvious
           ,
           and
           therefore
           needless
           to
           be
           added
           ;
           but
           that
           of
           the
           Bononian
           stone
           prepared
           ,
           and
           that
           of
           the
           
             Phosphorus
             Baldwini
          
           (
           lately
           discovered
           by
           Mr.
           Baldwine
           )
           are
           rare
           and
           hard
           to
           be
           got
           ,
           and
           the
           effects
           of
           them
           are
           wholly
           differing
           from
           all
           the
           ways
           I
           have
           yet
           met
           with
           ,
           and
           will
           therefore
           prove
           
             Experimenta
             Crucis
          
           ,
           highly
           instructive
           in
           the
           Theory
           of
           Light
           ,
           of
           which
           more
           hereafter
           .
           As
           for
           the
           
             Phosphoros
             Fulgurans
          
           of
           Mr.
           Kraft
           (
           more
           scarce
           and
           rare
           than
           the
           other
           )
           't
           is
           wholly
           differing
           from
           any
           of
           the
           rest
           ,
           and
           very
           strange
           and
           surprising
           ,
           at
           least
           it
           appeared
           so
           to
           me
           ,
           who
           had
           the
           good
           fortune
           to
           be
           present
           at
           a
           good
           part
           of
           the
           experiments
           made
           by
           the
           Author
           in
           the
           presence
           and
           at
           the
           Chamber
           of
           the
           Honourable
           
             Robert
             Boyle
          
           ,
           
             Esq
          
           that
           great
           Judg
           and
           Promoter
           of
           all
           curious
           inquiries
           into
           Nature
           and
           Art
           ,
           who
           at
           my
           earnest
           intreaty
           ,
           was
           not
           only
           pleased
           to
           commit
           to
           writing
           what
           he
           observed
           ,
           but
           (
           for
           the
           information
           of
           Curious
           and
           Inquisitive
           Naturalists
           ,
           )
           to
           give
           me
           liberty
           here
           to
           publish
           it
           .
        
         
           
           
           
             A
             short
             Memorial
             of
             some
             Observations
             made
             upon
             an
             Artificial
             Substance
             ,
             that
             shines
             without
             any
             precedent
             Illustration
             .
          
           
             
               September
               ,
               1677.
               
            
          
           
             ON
             Saturday
             the
             fifteenth
             of
             this
             month
             I
             was
             after
             supper
             visited
             by
             Mr.
             Kraft
             ,
             a
             famous
             German
             Chymist
             ,
             who
             was
             pleased
             to
             come
             and
             shew
             me
             a
             strange
             rarity
             he
             hath
             newly
             brought
             into
             England
             ,
             to
             the
             sight
             whereof
             he
             allowed
             me
             to
             invite
             several
             members
             of
             the
             Royal
             Society
             ,
             he
             being
             desirous
             ,
             because
             the
             matter
             he
             imploys
             is
             very
             costly
             and
             of
             difficult
             preparation
             ,
             to
             be
             a
             good
             Husband
             of
             it
             ,
             and
             by
             shewing
             it
             to
             several
             curious
             persons
             at
             once
             ,
             to
             exempt
             himself
             from
             the
             need
             of
             showing
             it
             often
             .
             The
             Company
             being
             met
             ,
             the
             Artist
             took
             out
             of
             a
             pretty
             large
             box
             he
             had
             brought
             with
             him
             ,
             divers
             Glass
             Vessels
             and
             laid
             them
             in
             order
             on
             the
             Table
             .
             The
             largest
             of
             them
             was
             a
             Sphere
             of
             Glass
             ,
             which
             I
             guessed
             to
             be
             four
             or
             five
             Inches
             in
             Diameter
             ,
             being
             hollow
             and
             intire
             ,
             save
             that
             in
             one
             place
             there
             was
             a
             little
             hole
             ,
             at
             that
             time
             stopt
             with
             sealing
             wax
             ,
             whereat
             to
             pour
             in
             the
             Liquor
             ,
             which
             seemed
             to
             me
             to
             be
             about
             two
             Spoonfuls
             or
             somewhat
             more
             ,
             and
             to
             look
             like
             muddy
             water
             made
             a
             little
             reddish
             with
             brick-dust
             or
             some
             other
             powder
             of
             that
             colour
             ,
             he
             also
             took
             out
             of
             his
             Box
             three
             or
             four
             little
             pipes
             of
             Glass
             sealed
             ,
             or
             otherwise
             
             stopt
             at
             both
             ends
             ,
             being
             each
             of
             them
             somewhat
             bigger
             than
             a
             Swans
             quill
             ,
             and
             about
             five
             or
             six
             Inches
             long
             ,
             and
             having
             at
             one
             end
             a
             small
             fragment
             or
             two
             of
             that
             matter
             that
             was
             to
             shine
             in
             the
             dark
             .
          
           
             He
             likewise
             laid
             upon
             the
             Table
             three
             or
             four
             Vials
             of
             several
             sizes
             ,
             but
             none
             of
             them
             judged
             capable
             to
             hold
             above
             very
             few
             Ounces
             of
             water
             :
             in
             each
             of
             which
             Vials
             there
             was
             some
             Liquor
             or
             other
             ,
             that
             was
             neither
             transparent
             nor
             well
             coloured
             ,
             which
             Liquors
             I
             confess
             upon
             his
             making
             no
             particular
             mention
             of
             what
             they
             were
             to
             do
             ,
             I
             was
             not
             curious
             to
             compare
             together
             ,
             either
             as
             to
             quantity
             or
             as
             to
             colour
             .
             Besides
             all
             these
             substances
             which
             were
             fluid
             ,
             he
             had
             in
             a
             small
             Crystalline
             button
             Bottle
             ,
             a
             little
             lump
             of
             matter
             ,
             of
             which
             he
             seemed
             to
             make
             much
             more
             account
             than
             of
             all
             the
             Liquors
             ,
             and
             which
             he
             took
             out
             for
             a
             few
             moments
             to
             let
             us
             look
             upon
             it
             ,
             whereby
             I
             saw
             that
             it
             was
             a
             consistent
             body
             ,
             that
             appeared
             of
             a
             whitish
             colour
             ,
             and
             seemed
             not
             to
             exceed
             a
             couple
             of
             ordinary
             Pease
             ,
             or
             the
             kernel
             of
             a
             Hasel
             Nut
             in
             bigness
             ,
             some
             other
             things
             't
             is
             possible
             Mr.
             Kraft
             took
             out
             of
             his
             Box
             ,
             but
             neither
             I
             or
             (
             for
             ought
             I
             know
             )
             others
             of
             the
             Company
             took
             notice
             of
             them
             ,
             partly
             because
             of
             his
             hast
             ,
             and
             partly
             because
             the
             confused
             curiosity
             of
             many
             spectators
             in
             a
             narrow
             compass
             ,
             kept
             me
             from
             being
             able
             to
             observe
             things
             as
             particularly
             and
             deliberately
             as
             I
             would
             gladly
             have
             done
             ,
             and
             as
             the
             occasion
             deserved
             .
             Which
             Advertisement
             may
             I
             fear
             be
             but
             too
             applicable
             to
             a
             great
             part
             of
             the
             following
             Narrative
             .
          
           
             The
             forementioned
             Glasses
             being
             laid
             in
             order
             upon
             the
             Table
             ,
             the
             windows
             were
             closed
             with
             woodenshuts
             ,
             and
             the
             Candles
             were
             removed
             into
             another
             Room
             by
             that
             we
             were
             in
             ;
             being
             left
             in
             the
             dark
             we
             were
             entertained
             with
             the
             ensuing
             Phaenomena
             .
          
           
           
             I.
             Though
             I
             noted
             above
             that
             the
             hollow
             Sphere
             of
             Glass
             had
             in
             it
             but
             about
             two
             Spoonfuls
             (
             or
             three
             at
             most
             )
             of
             matter
             ,
             yet
             the
             whole
             Sphere
             was
             illuminated
             by
             it
             ,
             so
             that
             it
             seemed
             to
             be
             not
             unlike
             a
             Cannon
             bullet
             taken
             red
             hot
             out
             of
             the
             fire
             ,
             except
             that
             the
             light
             of
             our
             Sphere
             lookt
             somewhat
             more
             pale
             and
             faint
             .
             But
             when
             I
             took
             the
             liberty
             to
             hold
             this
             Glass
             in
             my
             hand
             and
             shake
             it
             a
             little
             ,
             the
             contained
             Liquor
             appeared
             to
             shine
             more
             vividly
             ,
             and
             sometimes
             as
             it
             were
             to
             flash
             .
          
           
             II.
             I
             took
             one
             of
             the
             little
             pipes
             of
             Glass
             formerly
             mentioned
             ,
             into
             my
             hand
             ,
             and
             observed
             that
             though
             the
             shining
             matter
             had
             been
             lodged
             but
             at
             one
             end
             ,
             yet
             the
             whole
             Glass
             was
             enlightened
             ,
             so
             that
             it
             appeared
             a
             luminous
             Cylinder
             ,
             whose
             light
             yet
             I
             did
             not
             judg
             to
             be
             always
             uniform
             ,
             nor
             did
             it
             last
             like
             that
             which
             was
             included
             in
             the
             Vials
             .
          
           
             III.
             In
             the
             largest
             of
             the
             Vials
             next
             the
             Spherical
             already
             mentioned
             ,
             the
             Liquor
             that
             lay
             in
             the
             bottom
             being
             shaken
             ,
             I
             observed
             a
             kind
             of
             smoke
             to
             asscend
             and
             almost
             to
             fill
             the
             cavity
             of
             the
             Vial
             ,
             and
             near
             the
             same
             time
             there
             manifestly
             appeared
             as
             it
             were
             a
             flash
             of
             lightning
             that
             was
             considerably
             diffused
             ,
             and
             pleasingly
             surprized
             me
             .
          
           
             IV.
             After
             this
             I
             took
             up
             that
             small
             Crystaline
             Vial
             that
             I
             lately
             called
             (
             by
             a
             name
             familiar
             in
             our
             Glass-shops
             )
             a
             Button-Bottle
             ,
             wherein
             was
             contained
             the
             dry
             substance
             which
             the
             Artist
             chiefly
             valued
             ,
             as
             that
             which
             had
             continued
             luminous
             about
             these
             two
             years
             ,
             and
             having
             held
             that
             Vial
             long
             in
             my
             hand
             ,
             in
             the
             same
             position
             in
             reference
             to
             my
             eye
             ,
             and
             lookt
             attentively
             at
             it
             ,
             I
             had
             the
             opportunity
             to
             observe
             (
             what
             I
             think
             none
             of
             the
             Company
             did
             )
             that
             not
             only
             this
             stuff
             did
             in
             proportion
             to
             its
             bulk
             ,
             shine
             more
             vividly
             than
             the
             fluid
             substances
             ,
             but
             thaat
             which
             was
             the
             Phaenomenon
             I
             chiefly
             attended
             )
             though
             I
             could
             perceive
             no
             smoke
             or
             fumes
             ascend
             from
             the
             luminous
             matter
             ,
             yet
             I
             
             could
             plainly
             perceive
             by
             a
             new
             and
             brisker
             light
             that
             appeared
             from
             time
             to
             time
             in
             a
             certain
             place
             near
             the
             top
             of
             the
             Glass
             ,
             that
             there
             must
             be
             some
             kind
             of
             flashy
             motion
             in
             the
             matter
             that
             lay
             at
             the
             bottom
             ,
             which
             was
             the
             cause
             of
             these
             little
             coruscations
             ,
             if
             I
             may
             so
             call
             them
             .
          
           
             V.
             The
             Artist
             having
             taken
             a
             very
             little
             of
             his
             consistent
             matter
             ,
             and
             broken
             it
             into
             parts
             so
             minute
             ,
             that
             I
             judged
             the
             fragments
             to
             be
             between
             twenty
             and
             thirty
             ,
             he
             scattered
             them
             without
             any
             order
             about
             the
             Carpet
             ,
             where
             it
             was
             very
             delightful
             to
             see
             how
             vividly
             they
             shined
             ;
             and
             that
             which
             made
             the
             spectacle
             more
             taking
             ,
             especially
             to
             me
             ,
             was
             this
             ,
             that
             not
             only
             in
             the
             darkness
             that
             invironed
             them
             ,
             they
             seemed
             like
             fixt
             Stars
             of
             the
             sixth
             or
             least
             magnitude
             ,
             but
             twinkled
             also
             like
             them
             ,
             discovering
             such
             a
             scintillation
             as
             that
             whereby
             we
             distinguish
             the
             fixt
             Stars
             from
             most
             of
             the
             Planets
             .
             And
             these
             twinkling
             sparks
             without
             doing
             any
             harm
             (
             that
             we
             took
             notice
             of
             )
             to
             the
             Turky
             Carpet
             they
             lay
             on
             ,
             continued
             to
             shine
             for
             a
             good
             while
             ,
             some
             of
             them
             remaining
             yet
             vivid
             enough
             till
             the
             Candles
             being
             brought
             in
             again
             made
             them
             disappear
             .
          
           
             VI.
             Mr.
             Kraft
             also
             calling
             for
             a
             sheet
             of
             Paper
             and
             taking
             some
             of
             his
             stuff
             upon
             the
             tip
             of
             his
             finger
             ,
             writ
             in
             large
             Characters
             two
             or
             three
             words
             ,
             whereof
             one
             being
             DOMINI
             ,
             was
             made
             up
             of
             Capital
             Letters
             ,
             which
             being
             large
             enough
             to
             reach
             from
             one
             side
             of
             the
             page
             to
             the
             other
             ,
             and
             being
             (
             at
             least
             as
             I
             guessed
             )
             invigorated
             by
             the
             free
             contact
             of
             the
             external
             Air
             ,
             shone
             so
             briskly
             and
             lookt
             so
             oddly
             ,
             that
             the
             sight
             was
             extreamly
             pleasing
             ,
             having
             in
             it
             a
             mixture
             of
             strangeness
             ,
             beauty
             and
             frightfulness
             ,
             wherein
             yet
             the
             last
             of
             those
             qualities
             was
             far
             from
             being
             predominant
             .
             And
             this
             Phaenomenon
             did
             in
             more
             senses
             than
             one
             afford
             us
             the
             most
             of
             light
             ,
             since
             not
             only
             the
             Characters
             shone
             very
             vividly
             upon
             the
             white
             Paper
             ,
             but
             approaching
             it
             to
             my
             Eyes
             and
             Nostrils
             ,
             I
             could
             
             discern
             that
             there
             ascended
             from
             them
             a
             fume
             ,
             and
             could
             smell
             that
             fume
             to
             be
             strong
             enough
             ,
             and
             (
             as
             it
             seemed
             to
             me
             )
             to
             participate
             of
             the
             odour
             of
             Sulphur
             and
             of
             that
             of
             Onions
             .
             And
             before
             I
             past
             from
             the
             mention
             of
             these
             resplendent
             Characters
             ,
             I
             must
             not
             forget
             that
             either
             by
             their
             light
             ,
             or
             that
             of
             the
             Globe
             ,
             or
             both
             by
             the
             one
             and
             the
             other
             a
             man
             might
             discern
             those
             of
             his
             fingers
             that
             were
             nearest
             the
             shining
             stuff
             ,
             and
             that
             this
             being
             held
             to
             the
             face
             though
             without
             touching
             it
             ,
             some
             of
             the
             conspicuousest
             parts
             ,
             especially
             the
             Nose
             ,
             were
             discoverable
             .
          
           
             VII
             .
             After
             we
             had
             seen
             with
             pleasure
             ,
             and
             not
             without
             some
             wonder
             ,
             the
             fore-going
             particulars
             ,
             the
             Artist
             desired
             me
             to
             give
             him
             my
             hand
             ,
             which
             when
             I
             had
             done
             ,
             he
             rub'd
             partly
             upon
             the
             back
             of
             it
             ,
             and
             partly
             on
             my
             cuff
             ,
             some
             of
             his
             luminous
             matter
             ,
             which
             as
             if
             it
             had
             been
             assisted
             by
             the
             warmth
             of
             my
             hand
             shone
             very
             vividly
             ,
             and
             though
             I
             took
             not
             notice
             of
             any
             thing
             upon
             my
             skin
             ,
             that
             was
             either
             unctuous
             or
             rough
             ,
             yet
             I
             often
             times
             tried
             in
             vain
             by
             rubbing
             it
             with
             my
             other
             hand
             to
             take
             it
             off
             ,
             or
             manifestly
             diminish
             its
             splendor
             ,
             and
             when
             I
             divers
             times
             blow'd
             upon
             some
             of
             the
             smaller
             parts
             of
             it
             ,
             though
             they
             seemed
             at
             the
             instant
             that
             my
             breath
             beat
             upon
             it
             ,
             to
             be
             blown
             out
             ,
             yet
             the
             tenacious
             parts
             were
             not
             really
             extinguisht
             ,
             but
             presently
             after
             recovered
             their
             former
             splendor
             .
             And
             all
             this
             while
             this
             light
             that
             was
             so
             permanent
             ,
             was
             yet
             so
             mild
             and
             innocent
             that
             in
             that
             part
             of
             my
             hand
             where
             it
             was
             largely
             enough
             spread
             ,
             I
             felt
             no
             sensible
             heat
             produced
             by
             it
             .
          
           
             By
             that
             time
             these
             things
             were
             done
             't
             was
             grown
             late
             ,
             which
             made
             Mr.
             Kraft
             ,
             who
             had
             a
             great
             way
             to
             go
             home
             ,
             take
             leave
             of
             the
             Company
             after
             he
             had
             received
             our
             deserved
             thanks
             for
             the
             new
             and
             instructive
             Phaenomena
             ,
             wherewith
             he
             had
             so
             delightfully
             entertained
             us
             .
          
           
           
             Because
             Mr.
             Kraft
             had
             twice
             attempted
             to
             fire
             heated
             Gun-powder
             with
             his
             Phosphorus
             ,
             but
             without
             success
             ;
             probably
             because
             the
             powder
             was
             not
             very
             good
             (
             as
             by
             some
             circumstances
             I
             conjected
             )
             and
             because
             it
             was
             not
             sufficiently
             heated
             before
             the
             matter
             that
             should
             set
             it
             on
             fire
             was
             put
             upon
             it
             ,
             he
             promised
             me
             he
             would
             come
             another
             time
             to
             repair
             that
             unsuccesfulness
             :
             And
             accordingly
             ,
             On
             the
             two
             and
             twentieth
             of
             September
             in
             the
             Afternoon
             I
             recived
             a
             visit
             from
             Mr.
             Kraft
             ,
             who
             told
             me
             he
             came
             to
             make
             good
             his
             promise
             of
             letting
             me
             see
             that
             his
             shining
             matter
             was
             able
             to
             kindle
             heated
             Gun-powder
             ,
             and
             because
             no
             strangers
             were
             present
             ,
             I
             had
             the
             fairer
             opportunity
             to
             view
             it
             ,
             which
             I
             was
             able
             to
             do
             better
             by
             day
             light
             ,
             than
             I
             had
             done
             by
             its
             own
             light
             ,
             for
             when
             he
             had
             taken
             it
             with
             a
             new
             Pen
             out
             of
             the
             liquor
             with
             which
             he
             kept
             it
             covered
             to
             preserve
             it
             ,
             I
             perceived
             it
             to
             be
             somewhat
             less
             than
             the
             nail
             of
             one
             of
             my
             fingers
             ,
             and
             not
             much
             thicker
             than
             a
             shilling
             ,
             and
             I
             observed
             that
             when
             it
             had
             lain
             a
             little
             while
             upon
             a
             piece
             of
             clean
             Paper
             and
             discharged
             it self
             from
             its
             superfluous
             moisture
             ,
             it
             began
             to
             emit
             whitish
             fumes
             which
             seemed
             to
             be
             very
             ponderous
             ,
             since
             for
             the
             most
             part
             they
             did
             not
             ascend
             but
             surrounding
             the
             matter
             whence
             they
             issued
             ,
             by
             their
             stagnation
             made
             as
             it
             were
             a
             little
             Pond
             or
             small
             Atmosphere
             about
             it
             ;
             so
             that
             lest
             it
             should
             wast
             too
             fast
             ,
             he
             was
             obliged
             as
             soon
             as
             he
             had
             cut
             off
             a
             little
             corner
             less
             than
             half
             a
             pins
             head
             ,
             to
             put
             the
             stuff
             nimbly
             back
             into
             the
             Vial
             out
             of
             which
             he
             he
             had
             taken
             it
             ;
             where
             I
             observed
             it
             for
             a
             very
             short
             time
             to
             send
             up
             exhalations
             into
             the
             liquor
             that
             covered
             it
             ,
             and
             quickly
             after
             ,
             as
             it
             were
             ,
             quencht
             it
             .
             This
             done
             the
             Artist
             divided
             the
             little
             corner
             he
             had
             cut
             off
             into
             two
             parts
             ,
             one
             of
             which
             he
             spread
             as
             far
             as
             it
             would
             reach
             upon
             a
             piece
             of
             white
             Paper
             ,
             which
             he
             presently
             after
             held
             at
             a
             distance
             over
             a
             chafing-dish
             of
             burning
             Coals
             ,
             by
             whose
             heat
             being
             excited
             it
             presently
             flasht
             and
             burnt
             away
             ,
             and
             I
             having
             perceived
             that
             there
             was
             another
             part
             of
             the
             
             Paper
             which
             though
             not
             heeded
             by
             him
             ,
             had
             been
             lightly
             besmeared
             by
             the
             same
             matter
             ,
             I
             held
             it
             over
             the
             Coals
             ,
             but
             at
             a
             considerable
             distance
             from
             them
             ,
             and
             yet
             this
             little
             matter
             nimbly
             took
             fire
             and
             burnt
             a
             hole
             in
             the
             Paper
             .
             And
             to
             satisfie
             my self
             that
             the
             heat
             did
             but
             excite
             the
             luminous
             matter
             ,
             and
             that
             t
             was
             this
             its
             self
             that
             lighted
             the
             Paper
             ,
             I
             held
             the
             rest
             of
             the
             same
             piece
             of
             Paper
             far
             nearer
             the
             fire
             and
             kept
             it
             there
             a
             pretty
             while
             without
             finding
             it
             at
             all
             scorched
             or
             discoloured
             .
             Lastly
             ,
             the
             other
             part
             of
             the
             divided
             fragment
             of
             the
             hitherto
             mentioned
             matter
             ,
             Mr.
             Kraft
             put
             upon
             the
             tip
             of
             a
             quil
             ,
             and
             having
             at
             a
             distance
             from
             the
             fire
             ,
             very
             well
             dryed
             and
             warmed
             some
             Gun-powder
             upon
             another
             piece
             of
             Paper
             ,
             he
             laid
             that
             Paper
             upon
             the
             ground
             ,
             and
             then
             holding
             his
             quill
             upon
             it
             ,
             as
             if
             it
             had
             been
             a
             match
             ,
             within
             half
             a
             minute
             (
             by
             my
             guess
             )
             that
             powder
             took
             fire
             and
             blew
             up
             .
          
           
             'T
             will
             not
             perhaps
             be
             impertinent
             to
             add
             that
             on
             occasion
             of
             the
             operation
             I
             observed
             the
             Air
             to
             have
             on
             the
             shining
             substance
             when
             freely
             exposed
             to
             it
             .
             I
             took
             a
             rise
             to
             tell
             Mr.
             Kraft
             that
             I
             presumed
             it
             might
             be
             worth
             while
             to
             try
             whether
             his
             Phosphorus
             did
             shine
             by
             virtue
             of
             a
             kind
             of
             real
             or
             (
             if
             I
             may
             so
             call
             it
             )
             living
             flame
             ,
             which
             like
             almost
             all
             other
             flames
             required
             the
             presence
             and
             concourse
             of
             the
             Air
             to
             maintain
             it
             ,
             or
             whether
             it
             were
             of
             such
             a
             kind
             of
             nature
             as
             the
             Phosphorus
             of
             the
             learned
             Baldwinus
             ,
             which
             I
             suspected
             to
             shine
             not
             like
             a
             flame
             or
             a
             truly
             kindled
             substance
             ;
             but
             like
             a
             red
             hot
             Iron
             ,
             or
             an
             ignited
             piece
             of
             Glass
             ,
             wherein
             the
             shining
             parts
             are
             not
             repaired
             by
             fewel
             ,
             as
             in
             other
             burning
             bodies
             ,
             but
             are
             put
             by
             the
             action
             of
             the
             fire
             into
             so
             vehement
             an
             agitation
             as
             whilst
             it
             lasts
             suffices
             to
             make
             the
             body
             appear
             luminous
             .
             This
             conjecture
             Mr.
             Kraft
             seemed
             much
             to
             approve
             of
             when
             I
             told
             him
             that
             the
             way
             I
             proposed
             to
             examine
             his
             noctiluca
             by
             ,
             was
             to
             put
             a
             little
             of
             it
             into
             our
             Pneumatick
             Engine
             ,
             and
             Pump
             out
             the
             Air
             ,
             whose
             
             absence
             ,
             if
             it
             were
             of
             the
             nature
             of
             other
             flames
             ,
             would
             probably
             extinguish
             ,
             or
             very
             much
             impair
             its
             light
             ,
             but
             yet
             since
             he
             offered
             not
             to
             have
             the
             trial
             made
             ;
             probably
             because
             he
             had
             but
             very
             little
             of
             his
             shining
             substance
             left
             ,
             I
             thought
             it
             not
             civil
             to
             press
             him
             .
             But
             to
             countenance
             what
             I
             said
             of
             the
             nature
             of
             
               Baldwinus
               Phosphorus
            
             ,
             I
             shall
             recite
             an
             Experiment
             that
             I
             purposely
             made
             ,
             to
             examin
             whether
             the
             presence
             of
             the
             Air
             were
             necessary
             to
             the
             shining
             of
             this
             Phosphorus
             ,
             as
             I
             had
             long
             since
             found
             it
             to
             that
             of
             some
             pieces
             of
             shining
             wood
             .
          
           
             We
             exposed
             for
             a
             competent
             time
             to
             the
             beams
             of
             a
             vigorous
             light
             ,
             a
             portion
             of
             matter
             of
             about
             the
             breadth
             of
             the
             palm
             of
             ones
             hand
             ,
             which
             we
             had
             prepared
             to
             be
             made
             luminous
             by
             them
             .
             And
             then
             causing
             the
             Candles
             to
             be
             removed
             (
             for
             we
             chose
             to
             make
             tryal
             by
             night
             )
             we
             nimbly
             conveyed
             the
             matter
             into
             a
             receiver
             that
             was
             kept
             in
             readiness
             for
             it
             ,
             presuming
             (
             as
             the
             event
             shewed
             we
             might
             )
             that
             by
             using
             diligence
             the
             light
             would
             last
             as
             long
             as
             the
             experiment
             would
             need
             to
             do
             ;
             making
             hast
             therefore
             to
             Pump
             out
             the
             Air
             ,
             we
             heedfully
             watched
             whether
             the
             withdrawing
             of
             it
             would
             ,
             contrary
             to
             my
             conjecture
             ,
             notably
             diminish
             the
             light
             of
             the
             shining
             matter
             .
             And
             after
             we
             had
             thus
             withdrawn
             the
             Air
             gradually
             ,
             we
             tryed
             whether
             by
             letting
             it
             return
             hastily
             ,
             it
             would
             produce
             a
             more
             sensible
             change
             in
             the
             matter
             (
             which
             had
             been
             purposely
             put
             in
             without
             any
             thing
             to
             cover
             it
             ,
             that
             it
             might
             be
             the
             more
             exposed
             to
             the
             Airs
             Action
             .
             )
             But
             neither
             upon
             the
             gradual
             recess
             of
             the
             Air
             ,
             nor
             yet
             upon
             its
             rushing
             in
             when
             it
             was
             permitted
             to
             return
             ,
             could
             we
             certainly
             observe
             any
             manifest
             alteration
             in
             the
             luminousness
             of
             the
             Phosphorus
             ,
             other
             than
             that
             slow
             decrement
             that
             might
             well
             be
             imputed
             to
             the
             time
             during
             which
             the
             experiment
             was
             making
             .
             It
             being
             well
             known
             that
             this
             luminous
             substance
             requires
             no
             long
             time
             to
             make
             it
             decay
             ,
             and
             by
             degrees
             to
             lose
             all
             its
             light
             ;
             so
             that
             though
             once
             there
             seemed
             to
             one
             
             or
             two
             of
             the
             by-standers
             ,
             upon
             the
             return
             of
             the
             Air
             ,
             to
             be
             some
             recovery
             of
             part
             of
             the
             lost
             splendor
             ,
             yet
             after
             repeated
             experiments
             it
             was
             concluded
             that
             the
             presence
             of
             the
             Air
             was
             not
             at
             all
             necessary
             to
             the
             shining
             of
             our
             matter
             ,
             and
             it
             was
             judged
             most
             probable
             that
             the
             absence
             or
             presence
             of
             the
             Air
             ,
             had
             
               no
               manifest
            
             operation
             on
             it
             .
             I
             might
             add
             to
             this
             that
             perhaps
             the
             presence
             of
             the
             Air
             is
             rather
             hurtful
             than
             advantagious
             to
             this
             sort
             of
             lights
             ,
             since
             for
             having
             had
             a
             large
             Phosphorus
             that
             was
             much
             esteemed
             ,
             and
             ,
             whilst
             I
             kept
             it
             ,
             exactly
             protected
             from
             the
             Air
             did
             very
             well
             ;
             a
             part
             of
             the
             Glass
             that
             covered
             it
             ,
             having
             by
             mischance
             been
             somewhat
             crackt
             ,
             though
             none
             of
             the
             splinters
             appeared
             displaced
             ,
             yet
             it
             seems
             some
             of
             the
             Corpuscles
             of
             the
             Air
             made
             a
             shift
             to
             insinuate
             themselves
             at
             these
             chinks
             (
             as
             narrow
             as
             they
             were
             )
             and
             in
             not
             many
             days
             made
             the
             matter
             cease
             to
             be
             capable
             of
             being
             made
             luminous
             as
             before
             .
             I
             cannot
             stay
             to
             inquire
             whether
             this
             unfitness
             or
             indisposition
             may
             be
             imputed
             to
             the
             bare
             moisture
             of
             the
             Air
             ,
             or
             to
             some
             other
             substance
             or
             quality
             that
             alone
             or
             in
             conjunction
             with
             the
             moisture
             ,
             may
             spoil
             that
             peculiar
             texture
             ,
             or
             constitution
             that
             fits
             the
             matter
             of
             the
             Phosphorus
             assisted
             by
             the
             impressions
             of
             external
             light
             to
             become
             luminous
             .
             This
             ,
             I
             say
             ,
             I
             cannot
             stay
             to
             examine
             ,
             though
             ,
             That
             this
             Phosphorus
             is
             of
             a
             nice
             and
             tender
             constitution
             ,
             and
             easily
             alterable
             ,
             I
             was
             induced
             to
             think
             ,
             by
             finding
             that
             the
             want
             of
             circumstances
             ,
             seemingly
             slight
             enough
             ,
             would
             keep
             it
             from
             being
             made
             ;
             and
             I
             guess
             that
             a
             convention
             of
             circumstances
             did
             more
             contribute
             to
             the
             production
             than
             any
             peculiar
             and
             incommunicable
             nature
             of
             the
             matter
             :
             Because
             having
             had
             the
             curiosity
             to
             make
             some
             trial
             upon
             so
             obvious
             a
             material
             as
             quick
             Lime
             ,
             though
             the
             success
             did
             not
             answer
             my
             designs
             ,
             yet
             ,
             neither
             was
             it
             so
             bad
             ,
             but
             that
             some
             luminous
             quality
             was
             produced
             in
             the
             Lime
             by
             the
             action
             of
             the
             fire
             ,
             and
             a
             saline
             Liquor
             ;
             and
             I
             scarce
             question
             but
             other
             materials
             will
             be
             found
             
             capable
             of
             being
             made
             luminous
             by
             the
             same
             or
             the
             like
             operation
             ,
             that
             is
             imploy'd
             by
             Baldwinus
             ,
             when
             that
             learned
             man
             shall
             think
             fit
             to
             communicate
             his
             way
             to
             the
             Publick
             .
             But
             to
             return
             to
             what
             I
             was
             saying
             ,
             that
             the
             contact
             of
             the
             Air
             might
             be
             rather
             hurtful
             than
             advantagious
             to
             the
             Phosphorus
             ,
             I
             shall
             only
             add
             here
             as
             matter
             of
             fact
             ,
             (
             for
             my
             conjectures
             about
             Light
             belong
             to
             my
             yet
             unpublisht
             Notes
             ,
             
               of
               the
               Origine
               of
               Qualities
            
             )
             that
             whereas
             the
             contact
             of
             the
             Air
             ,
             though
             it
             were
             not
             free
             ,
             did
             in
             a
             few
             days
             destroy
             the
             luminousness
             of
             a
             good
             Phosphorus
             ,
             yet
             having
             included
             another
             in
             a
             Receiver
             ,
             whence
             we
             afterwards
             pumpt
             out
             the
             Air
             ,
             this
             matter
             though
             inferior
             to
             the
             other
             in
             vividness
             was
             so
             little
             spoiled
             by
             lying
             open
             in
             our
             Vacuum
             ,
             that
             at
             the
             end
             of
             not
             only
             some
             weeks
             ,
             but
             some
             months
             ,
             I
             found
             that
             the
             beams
             of
             a
             Candle
             passing
             to
             it
             through
             the
             Receiver
             ,
             would
             notwithstanding
             the
             Vacuum
             it
             yet
             continues
             in
             ,
             suffice
             to
             re-excite
             in
             it
             a
             manifest
             light
             .
          
           
             Thus
             far
             was
             the
             communication
             of
             this
             excellent
             person
             ,
             who
             it
             's
             hoped
             may
             be
             further
             prevailed
             with
             to
             communicate
             those
             other
             accurate
             observations
             ,
             and
             curious
             researches
             he
             hath
             made
             concerning
             the
             light
             of
             the
             Bononian
             Stone
             ,
             and
             the
             
               Phosphoros
               Baldwini
            
             ,
             which
             are
             indeed
             truly
             admirable
             ,
             and
             very
             much
             differing
             from
             the
             usual
             processes
             of
             Nature
             for
             the
             exhibiting
             of
             light
             .
          
           
             Before
             I
             take
             leave
             of
             my
             Astronomical
             Readers
             ,
             I
             shall
             here
             acquaint
             them
             with
             some
             Collections
             I
             have
             made
             of
             other
             Astronomical
             matters
             and
             discoveries
             ,
             which
             I
             hope
             will
             not
             be
             less
             pleasing
             to
             them
             than
             they
             were
             at
             first
             to
             me
             .
             The
             Discoveries
             are
             new
             ,
             and
             not
             less
             significant
             .
             The
             first
             is
             ,
          
        
         
           
           
             A
             Letter
             from
             Johannes
             Carolus
             Gallet
             ,
             L.L.D.
             and
             Provost
             of
             the
             Church
             of
             St.
             Symphorean
             at
             Avignon
             ,
             directed
             thus
             .
          
           
             CLarissimo
             Eruditissimoque
             viro
             D.
             Johanni
             Dominico
             Cassino
             ,
             Matheseos
             Professori
             Celeberrimo
             ,
             Astronomo
             praestantissimo
             &
             Academiae
             Regiae
             scientiarum
             alumno
             meritissimo
             .
          
           
             Conteining
             an
             account
             of
             his
             observation
             of
             Mercury
             passing
             under
             the
             Sun.
             
          
           
             Mr.
             Gallet
             then
             acquaints
             Mr.
             Cassini
             with
             his
             observation
             of
             ☿
             sub
             ☉
             and
             the
             whole
             method
             and
             process
             of
             his
             observation
             .
             First
             ,
             he
             fitted
             two
             excellent
             Telescopes
             ,
             the
             Glasses
             of
             which
             were
             given
             him
             by
             Mr.
             
               Jac.
               Borrellius
            
             ,
             one
             of
             the
             Academy
             Royal
             of
             Paris
             .
             The
             one
             of
             twenty
             three
             foot
             ,
             he
             fitted
             with
             a
             Glass
             covered
             with
             smooke
             ,
             placed
             in
             the
             outward
             focus
             of
             the
             Eye-Glass
             :
             The
             other
             of
             three
             foot
             he
             fixt
             to
             the
             Arm
             of
             his
             Quadrant
             of
             the
             same
             Radius
             ,
             this
             was
             so
             exquisite
             that
             compared
             with
             one
             of
             Divini
             ,
             which
             was
             chosen
             by
             the
             care
             of
             
               Honorato
               Fabri
            
             ,
             and
             procured
             by
             Monsieur
             
               de
               Beauchamps
            
             ,
             it
             was
             found
             to
             represent
             the
             objects
             clearer
             :
             By
             this
             the
             figure
             of
             the
             Sun
             was
             cast
             on
             an
             opposite
             Table
             ,
             on
             which
             he
             had
             drawn
             a
             Circle
             of
             the
             bigness
             proper
             to
             the
             Distance
             and
             Magnifying
             of
             the
             Glasses
             to
             contain
             the
             whole
             Face
             of
             the
             Sun
             ,
             and
             by
             Parallel
             Circles
             had
             subdivided
             the
             same
             into
             digits
             and
             Sexagesimals
             ,
             he
             had
             also
             placed
             three
             threds
             in
             the
             interior
             focus
             of
             the
             Glasses
             ,
             that
             the
             middlemost
             went
             through
             the
             Center
             ,
             and
             the
             two
             outward
             touched
             the
             Limb
             of
             the
             Sun
             by
             their
             shadow
             on
             the
             Table
             ,
             he
             had
             also
             a
             Pendulum
             Clock
             that
             vibrated
             thrice
             in
             a
             second
             .
             Thus
             accoutred
             he
             watched
             the
             fifth
             
             and
             sixth
             day
             ,
             from
             Sun
             rising
             to
             Sun
             setting
             ,
             and
             the
             seventh
             after
             the
             Cloudy
             Sky
             had
             seemed
             to
             delude
             his
             curiosity
             till
             Eleven
             a
             Clock
             almost
             ,
             it
             then
             began
             to
             open
             and
             discovered
             to
             him
             Mercury
             got
             within
             the
             Eastern
             Limb
             of
             the
             Sun
             ,
             about
             1
             /
             10
             of
             its
             Semidiameter
             ;
             at
             length
             the
             Clouds
             being
             dispersed
             ,
             the
             Sun
             being
             27°
             45.
             high
             ,
             or
             at
             10
             h.
             54′
             ☿
             it self
             marked
             out
             its
             own
             place
             in
             the
             disk
             of
             the
             ☉
             by
             its
             own
             shadow
             cast
             on
             the
             Table
             by
             the
             shorter
             tube
             .
             Then
             he
             disposed
             the
             shadow
             of
             the
             aforesaid
             thred
             so
             Paralel
             to
             the
             Equator
             ,
             that
             this
             figure
             of
             the
             Sun
             should
             move
             between
             the
             outward
             ones
             ,
             and
             that
             the
             middle
             should
             mark
             out
             the
             Paralel
             described
             by
             the
             Center
             of
             the
             Sun
             in
             motion
             ,
             at
             the
             same
             time
             he
             took
             the
             declination
             of
             ☿
             from
             this
             middle
             Parallel
             and
             the
             right
             Ascention
             ,
             by
             the
             number
             of
             Vibrations
             of
             the
             Pendulum
             ,
             from
             the
             Western
             Limb
             of
             the
             Sun
             ,
             taken
             by
             the
             shadow
             of
             a
             Perpendicular
             Cross-line
             to
             the
             other
             3.
             by
             the
             same
             means
             ,
             also
             he
             measured
             the
             Diameter
             of
             the
             Sun
             and
             of
             Mercury
             .
          
           
             Then
             to
             the
             end
             he
             might
             give
             less
             cause
             of
             doubt
             ,
             according
             to
             his
             usual
             custom
             ,
             he
             procured
             several
             friends
             who
             were
             present
             and
             witnesses
             of
             all
             the
             observations
             after
             the
             fourth
             mentioned
             in
             the
             Table
             .
             During
             the
             observation
             he
             took
             notice
             of
             these
             remarkable
             accidents
             .
             First
             ,
             that
             Mercury
             through
             the
             long
             Tube
             was
             very
             black
             ,
             and
             of
             an
             Elliptical
             figure
             whose
             longest
             Diameter
             was
             Parallel
             to
             the
             Equator
             ,
             but
             in
             the
             Species
             through
             the
             lesser
             Telecope
             ,
             it
             appeared
             round
             and
             of
             a
             dusky
             red
             (
             like
             a
             spot
             observed
             by
             him
             in
             the
             Sun
             from
             the
             Ninth
             to
             the
             Fifteenth
             of
             
               April
               .
            
             )
             Secondly
             ,
             that
             the
             Diameter
             of
             mercury
             going
             out
             of
             the
             Disc
             of
             the
             Sun
             ,
             when
             it
             toucht
             the
             periphery
             seemed
             to
             be
             of
             four
             times
             the
             Diameter
             it
             appeared
             of
             through
             the
             whole
             Phase
             ,
             so
             that
             Mr.
             Beauchamp
             ,
             who
             watched
             the
             exit
             with
             the
             longer
             Tube
             ,
             whilst
             he
             himself
             minded
             the
             Quadrant
             in
             order
             to
             take
             the
             Altitude
             of
             the
             Sun
             ,
             at
             the
             time
             of
             the
             exit
             cried
             out
             ,
             O
             how
             large
             do
             
             I
             see
             the
             Diameter
             of
             Mercury
             now
             ,
             it
             does
             not
             only
             leave
             the
             Sun
             ,
             but
             is
             confused
             with
             it
             ,
             or
             as
             it
             were
             melts
             into
             it
             ,
             and
             presently
             it
             vanisht
             ,
             the
             Sun
             being
             then
             13.
             
             23′
             .
             high
             .
          
           
             He
             further
             adds
             that
             before
             he
             leaves
             to
             speak
             of
             the
             Sun
             ,
             he
             will
             here
             insert
             an
             observation
             that
             he
             had
             made
             of
             four
             spots
             he
             had
             seen
             in
             the
             Sun
             in
             the
             first
             of
             October
             last
             
               (
               St.
               No.
            
             )
             with
             this
             his
             longer
             Telescope
             ,
             one
             only
             of
             which
             was
             visible
             by
             the
             Species
             cast
             with
             the
             lesser
             Glass
             .
          
           
             
               
                 
                   Octob.
                   Die.
                   hora
                
                 
                   Decinat
                   .
                   maculae
                   principalis
                   à
                   paral
                   .
                   Centri
                   ☉
                   .
                
                 
                   Differentia
                   temp
                   .
                   inter
                   limbus
                   ☉
                   Occident
                   .
                   &
                   maculam
                   .
                
                 
                   Tempus
                   transitus
                   disci
                   Sonlaris
                   .
                
              
               
                 
                   1
                
                 
                   10
                
                 
                   0
                
                 
                   4
                
                 
                   44
                
                 
                   austr
                   .
                
                 
                   1
                
                 
                   4
                
                 
                   20
                
                 
                   2
                
                 
                   10
                
                 
                   0
                
              
               
                 
                   2
                
                 
                   10
                
                 
                   0
                
                 
                   2
                
                 
                   43
                
                 
                   aust
                   .
                
                 
                 
                   49
                
                 
                   0
                
                 
                   2
                
                 
                   10
                
                 
                   20
                
              
               
                 
                   3
                
                 
                   10
                
                 
                   30
                
                 
                   1
                
                 
                   21
                
                 
                   aust
                   .
                
                 
                 
                   34
                
                 
                   40
                
                 
                   2
                
                 
                   10
                
                 
                   20
                
              
               
                 
                   4
                
                 
                   10
                
                 
                   35
                
                 
                   0
                
                 
                   40
                
                 
                   aust
                   .
                
                 
                 
                   24
                
                 
                   40
                
                 
                   2
                
                 
                   10
                
                 
                   30
                
              
               
                 
                   6
                
                 
                   10
                
                 
                   0
                
                 
                   3
                
                 
                   0
                
                 
                   boreal
                   .
                
                 
                 
                   3
                
                 
                   20
                
                 
                   2
                
                 
                   10
                
                 
                   4
                
              
            
          
           
             Thus
             submitting
             his
             method
             to
             the
             judgment
             of
             the
             Learned
             Cassini
             ,
             and
             earnestly
             desiring
             his
             thoughts
             thereon
             ,
             he
             ends
             his
             Letter
             ,
             and
             Dates
             it
             from
             
               Avignon
               ,
               Nov.
            
             21.
             1677.
             
          
           
             To
             this
             Letter
             he
             subjoins
             the
             observation
             it self
             ,
             Intituled
             ,
          
           
             Mercurius
             sub
             Sole
             visus
             Avenione
             die
             7.
             
             
               Novemb
               .
               1677.
            
             
             Observante
             me
             
               Joanne
               Carolo
               Gallet
            
             ,
             J.
             V.
             D.
             Praeposito
             Ecclesiae
             Sancti
             Symphoriani
             Avenionensis
             .
          
           
             The
             Contents
             of
             which
             are
             ,
          
           
             That
             designing
             to
             observe
             this
             passage
             of
             ☿
             under
             ☉
             he
             with
             his
             Tube
             watchfully
             looked
             for
             it
             in
             the
             Suns
             place
             ,
             from
             the
             5th
             to
             the
             7th
             .
             day
             ,
             with
             a
             Telescope
             of
             
             23
             foot
             (
             as
             above
             )
             he
             observed
             a
             spot
             of
             an
             elliptical
             figure
             which
             had
             already
             gotten
             a
             16th
             .
             part
             of
             the
             semidiameter
             of
             the
             Sun
             within
             the
             limb
             ,
             and
             declined
             a
             little
             to
             the
             South
             in
             respect
             of
             the
             parallel
             of
             the
             Aequator
             drawn
             through
             the
             Suns
             center
             ,
             at
             10
             hours
             26
             min.
             but
             the
             Clouds
             hindering
             he
             could
             not
             observe
             its
             motion
             till
             it
             had
             ascended
             as
             high
             as
             the
             parallel
             :
             when
             the
             Suns
             altitude
             was
             27.
             45.
             or
             10
             a
             Clock
             54
             minutes
             .
             From
             the
             quickness
             of
             its
             motion
             he
             soon
             found
             it
             to
             be
             ☿
             and
             not
             a
             spot
             ,
             and
             therefore
             he
             forsook
             not
             his
             Quadrant
             to
             which
             was
             fitted
             his
             three
             foot
             Telescope
             and
             Table
             to
             receive
             the
             figure
             of
             the
             ☉
             but
             observed
             the
             times
             of
             the
             Immersions
             and
             the
             Emersion
             of
             ☿
             by
             the
             help
             thereof
             ,
             being
             assisted
             by
             several
             of
             his
             friends
             who
             were
             witnesses
             of
             what
             passed
             ,
             and
             particularly
             by
             the
             Illustrious
             Monsieur
             
               De
               Beauchamp
            
             ,
             who
             with
             the
             twenty
             three
             foot
             Glass
             determined
             the
             Exit
             of
             Mercury
             ,
             whilest
             he
             himself
             took
             the
             Altitude
             of
             the
             Sun
             with
             his
             Quadrant
             ,
             as
             in
             the
             tenth
             Observation
             .
          
           
           
             
               
                 The
                 Order
                 of
                 the
                 Observations
                 of
                 Mercury
                 seen
                 under
                 the
                 Sun.
                 
              
               
                 
                   The
                   number
                   of
                   the
                   Phases
                   observed
                   .
                
                 
                   The
                   north
                   Declination
                   of
                   ☿
                   from
                   the
                   Parallel
                   of
                   the
                   equat
                   .
                   through
                   the
                   Center
                   .
                
                 
                   The
                   difference
                   of
                   the
                   time
                   between
                   the
                   Transit
                   of
                   West
                   Limb
                   of
                   the
                   Sun
                   ,
                   and
                   the
                   body
                   of
                   ☿
                   under
                   the
                   same
                   Meridian
                   collected
                   from
                   the
                   Pendulum
                   Vibrating
                   1
                   /
                   ●
                   of
                   a
                   second
                   .
                
                 
                   The
                   distant
                   of
                   ☿
                   from
                   the
                   Center
                   of
                   the
                   Sun.
                   
                
                 
                   The
                   apparent
                   altitude
                   of
                   the
                   Sun.
                   
                
                 
                   The
                   hour
                   Collected
                   by
                   the
                   Altitude
                   .
                
              
               
                 
                    
                
                 
                   M.
                   
                
                 
                   S.
                   
                
                 
                   vib
                   .
                   Pend.
                   
                
                 
                   M.
                   
                
                 
                   S.
                   
                
                 
                   T.
                   
                
                 
                   M.
                   
                
                 
                   S.
                   
                
                 
                   T.
                   
                
                 
                   G.
                   
                
                 
                   M.
                   
                
                 
                   H.
                   
                
                 
                   M.
                   
                
                 
                   S.
                   
                
              
               
                 
                   1
                
                 
                   0
                
                 
                   0
                
                 
                   345
                
                 
                   1
                
                 
                   55
                
                 
                   ●
                
                 
                   1
                
                 
                   20
                
                 
                   37
                
                 
                   2●
                
                 
                   45
                
                 
                   10
                
                 
                   53
                
                 
                   58
                
              
               
                 
                   2
                
                 
                   2
                
                 
                   3
                
                 
                   276
                
                 
                   1
                
                 
                   32
                
                 
                   0
                
                 
                   6
                
                 
                   0
                
                 
                   55
                
                 
                   29
                
                 
                   36
                
                 
                   12
                
                 
                   0
                
                 
                   0
                
              
               
                 
                   3
                
                 
                   2
                
                 
                   45
                
                 
                   258
                
                 
                   1
                
                 
                   26
                
                 
                   0
                
                 
                   5
                
                 
                   9
                
                 
                   20
                
                 
                   29
                
                 
                   34
                
                 
                   0
                
                 
                   9
                
                 
                   55
                
              
               
                 
                   4
                
                 
                   3
                
                 
                   40
                
                 
                   224
                
                 
                   1
                
                 
                   14
                
                 
                   40
                
                 
                   4
                
                 
                   7
                
                 
                   30
                
                 
                   29
                
                 
                   03
                
                 
                   0
                
                 
                   35
                
                 
                   50
                
              
               
                 
                   5
                
                 
                   5
                
                 
                   30
                
                 
                   164
                
                 
                   0
                
                 
                   54
                
                 
                   40
                
                 
                   7
                
                 
                   13
                
                 
                   7
                
                 
                   25
                
                 
                   0
                
                 
                   1
                
                 
                   44
                
                 
                   1●
                
              
               
                 
                   6
                
                 
                   6
                
                 
                   30
                
                 
                   148
                
                 
                   0
                
                 
                   49
                
                 
                   20
                
                 
                   8
                
                 
                   15
                
                 
                   0
                
                 
                   24
                
                 
                   5
                
                 
                   1
                
                 
                   55
                
                 
                   22
                
              
               
                 
                   7
                
                 
                   6
                
                 
                   53
                
                 
                   132
                
                 
                   0
                
                 
                   44
                
                 
                   00
                
                 
                   9
                
                 
                   16
                
                 
                   45
                
                 
                   22
                
                 
                   30
                
                 
                   2
                
                 
                   11
                
                 
                   58
                
              
               
                 
                   8
                
                 
                   8
                
                 
                   14
                
                 
                   100
                
                 
                   0
                
                 
                   33
                
                 
                   20
                
                 
                   12
                
                 
                   1
                
                 
                   45
                
                 
                   19
                
                 
                   30
                
                 
                   2
                
                 
                   39
                
                 
                   14
                
              
               
                 
                   9
                
                 
                   8
                
                 
                   55
                
                 
                   80
                
                 
                   0
                
                 
                   26
                
                 
                   40
                
                 
                   14
                
                 
                   5
                
                 
                   30
                
                 
                   17
                
                 
                   17
                
                 
                   2
                
                 
                   57
                
                 
                   28
                
              
               
                 
                   10
                
                 
                   9
                
                 
                   28
                
                 
                   29
                
                 
                   0
                
                 
                   13
                
                 
                   00
                
                 
                   16
                
                 
                   20
                
                 
                   0
                
                 
                   13
                
                 
                   23
                
                 
                   3
                
                 
                   26
                
                 
                   56
                
              
            
             
               
                 
                    
                
                 
                   The
                   time
                   of
                   the
                   Transitus
                   .
                
                 
                   The
                   Diameter
                   in
                   the
                   Parallel
                   .
                
                 
                   The
                   Diameter
                   in
                   a
                   great
                   Circle
                   .
                
              
               
                 
                   of
                   the
                   Sun.
                   
                
                 
                   414
                
                 
                   2
                
                 
                   18
                
                 
                    
                
                 
                   34
                
                 
                   30
                
                 
                   0
                
                 
                   43
                
                 
                   0
                
                 
                   0
                
              
               
                 
                   of
                   Mercury
                   .
                
                 
                   3
                   ½
                
                 
                   0
                
                 
                   1
                
                 
                   10
                
                 
                   0
                
                 
                   17
                
                 
                   30
                
                 
                    
                
                 
                    
                
                 
                    
                
              
            
          
           
             From
             this
             Observation
             he
             had
             the
             Declination
             of
             Mercury
             in
             respect
             of
             the
             Parallel
             through
             the
             Center
             of
             the
             Sun
             ,
             and
             thence
             its
             absolute
             Declination
             from
             the
             Equator
             ,
             supposing
             the
             place
             of
             the
             Sun
             according
             to
             Hecker
             ,
             and
             the
             obliquity
             of
             the
             Ecliptick
             ,
             23
             ,
             30′
             the
             right
             Ascension
             also
             of
             ☿
             appeared
             by
             the
             difference
             of
             time
             between
             the
             Transit
             of
             ☿
             and
             the
             West
             limb
             of
             the
             Sun
             by
             the
             same
             meridian
             .
             Then
             from
             the
             Declination
             and
             right
             Ascension
             of
             ☿
             given
             by
             Trigonometrical
             Calculation
             ,
             he
             found
             out
             the
             Longitude
             and
             Latitude
             of
             it
             in
             every
             ▪
             Observation
             ,
             and
             the
             time
             of
             its
             true
             Conjunction
             .
          
           
           
             
               
                 
                    
                
                 
                   The
                   time
                   of
                   the
                   phases
                   observed
                   .
                
                 
                   Heckers
                   place
                   of
                   the
                   ☉
                   in
                   ♏
                
                 
                   The
                   Decl.
                   of
                   ☿
                   South
                   ascen
                   .
                
                 
                   The
                   right
                   Ascension
                   of
                   Mercury
                   .
                
                 
                   The
                   N.
                   Lat.
                   of
                   ☿
                   ascen
                   .
                
                 
                   The
                   Long.
                   of
                   Mercury
                   in
                   ♏
                
              
               
                 
                    
                
                 
                   H.
                   
                
                 
                   M.
                   
                
                 
                   S.
                   
                
                 
                   G.
                   
                
                 
                   M.
                   
                
                 
                   S.
                   
                
                 
                   G.
                   
                
                 
                   M.
                   
                
                 
                   S.
                   
                
                 
                   G.
                   
                
                 
                   M.
                   
                
                 
                   S.
                   
                
                 
                   M.
                   
                
                 
                   S.
                   
                
                 
                   G.
                   
                
                 
                   M.
                   
                
                 
                   S.
                   
                
              
               
                 
                   1
                
                 
                   10
                
                 
                   53
                
                 
                   58
                
                 
                   15
                
                 
                   33
                
                 
                   55
                
                 
                   16
                
                 
                   32
                
                 
                   33
                
                 
                   223
                
                 
                   16
                
                 
                   40
                
                 
                   3
                
                 
                   10
                
                 
                   15
                
                 
                   44
                
                 
                   48
                
              
               
                 
                   2
                
                 
                   12
                
                 
                   0
                
                 
                   0
                
                 
                   15
                
                 
                   36
                
                 
                   41
                
                 
                   16
                
                 
                   31
                
                 
                   38
                
                 
                   223
                
                 
                   13
                
                 
                   43
                
                 
                   3
                
                 
                   14
                
                 
                   15
                
                 
                   40
                
                 
                   40
                
              
               
                 
                   3
                
                 
                   0
                
                 
                   9
                
                 
                   55
                
                 
                   15
                
                 
                   37
                
                 
                   6
                
                 
                   16
                
                 
                   30
                
                 
                   43
                
                 
                   223
                
                 
                   12
                
                 
                   37
                
                 
                   3
                
                 
                   53
                
                 
                   14
                
                 
                   40
                
                 
                   30
                
              
               
                 
                   4
                
                 
                   0
                
                 
                   35
                
                 
                   50
                
                 
                   15
                
                 
                   38
                
                 
                   11
                
                 
                   16
                
                 
                   30
                
                 
                   7
                
                 
                   223
                
                 
                   10
                
                 
                   51
                
                 
                   3
                
                 
                   55
                
                 
                   15
                
                 
                   38
                
                 
                   27
                
              
               
                 
                   5
                
                 
                   1
                
                 
                   44
                
                 
                   10
                
                 
                   15
                
                 
                   41
                
                 
                   3
                
                 
                   16
                
                 
                   29
                
                 
                   7
                
                 
                   223
                
                 
                   8
                
                 
                   54
                
                 
                   4
                
                 
                   15
                
                 
                   15
                
                 
                   36
                
                 
                   3
                
              
               
                 
                   6
                
                 
                   1
                
                 
                   55
                
                 
                   22
                
                 
                   15
                
                 
                   41
                
                 
                   31
                
                 
                   16
                
                 
                   28
                
                 
                   12
                
                 
                   223
                
                 
                   7
                
                 
                   59
                
                 
                   4
                
                 
                   55
                
                 
                   15
                
                 
                   35
                
                 
                   6
                
              
               
                 
                   7
                
                 
                   2
                
                 
                   11
                
                 
                   58
                
                 
                   15
                
                 
                   42
                
                 
                   13
                
                 
                   16
                
                 
                   28
                
                 
                   4
                
                 
                   223
                
                 
                   7
                
                 
                   36
                
                 
                   4
                
                 
                   56
                
                 
                   15
                
                 
                   34
                
                 
                   40
                
              
               
                 
                   8
                
                 
                   2
                
                 
                   39
                
                 
                   14
                
                 
                   15
                
                 
                   43
                
                 
                   22
                
                 
                   16
                
                 
                   27
                
                 
                   4
                
                 
                   223
                
                 
                   7
                
                 
                   4
                
                 
                   5
                
                 
                   48
                
                 
                   15
                
                 
                   34
                
                 
                   5
                
              
               
                 
                   9
                
                 
                   2
                
                 
                   57
                
                 
                   58
                
                 
                   15
                
                 
                   44
                
                 
                   8
                
                 
                   16
                
                 
                   26
                
                 
                   36
                
                 
                   223
                
                 
                   6
                
                 
                   10
                
                 
                   5
                
                 
                   57
                
                 
                   15
                
                 
                   33
                
                 
                   0
                
              
               
                 
                   10
                
                 
                   3
                
                 
                   26
                
                 
                   56
                
                 
                   15
                
                 
                   45
                
                 
                   23
                
                 
                   16
                
                 
                   26
                
                 
                   15
                
                 
                   223
                
                 
                   5
                
                 
                   50
                
                 
                   6
                
                 
                   12
                
                 
                   15
                
                 
                   32
                
                 
                   37
                
              
            
          
           
             Therefore
             the
             time
             of
             the
             true
             conjunction
             of
             the
             Sun
             and
             Mercury
             at
             Avignon
             ,
             was
             
               Nov.
               7.
               
               Hor.
               2.
               
               Min.
               39.
               
               Sec.
            
             14.
             
             Afternoon
             .
          
           
             To
             this
             he
             hath
             adjoyned
             this
             ensuing
             Table
             ,
             to
             shew
             how
             much
             the
             Heavens
             do
             differ
             from
             the
             Astronomical
             Tables
             .
          
           
             
               
                 
                   Tempus
                   datum
                   ex
                   Tabulis
                   Novemb.
                   
                
                 
                   Differentia
                   ab
                   observata
                   conjunctione
                   .
                
              
               
                 
                    
                
                 
                   D.
                   
                
                 
                   H.
                   
                
                 
                   M.
                   
                
                 
                   D.
                   
                
                 
                   H.
                   
                
                 
                   M.
                   
                
                 
                    
                
              
               
                 
                   Rudolphinis
                   Reyneri
                   .
                
                 
                   7
                
                 
                   8
                
                 
                   3
                
                 
                   9
                
                 
                   7
                
                 
                   24
                
                 
                   excessus
                   .
                
              
               
                 
                   Calculis
                   Heckeri
                   .
                
                 
                   7
                
                 
                   6
                
                 
                   9
                
                 
                   0
                
                 
                   5
                
                 
                   0
                
                 
                   excessus
                   .
                
              
               
                 
                   Lansbergianis
                   .
                
                 
                   6
                
                 
                   1
                
                 
                   12
                
                 
                   0
                
                 
                   23
                
                 
                   27
                
                 
                   defectus
                   .
                
              
               
                 
                   Philolaicis
                   Bullialdi
                
                 
                   7
                
                 
                   4
                
                 
                   18
                
                 
                   0
                
                 
                   3
                
                 
                   39
                
                 
                   excessus
                   .
                
              
               
                 
                   
                     
                       Riccilinis
                       juxta
                       calculum
                       .
                    
                     
                       R.
                       admodum
                       Patris
                       Bonifa
                       .
                       Societatis
                       Jesu
                       .
                    
                  
                
                 
                   7
                
                 
                   8
                
                 
                   17
                
                 
                   0
                
                 
                   7
                
                 
                   38
                
                 
                   excessus
                   .
                
              
            
          
           
           
             These
             Observations
             are
             delineated
             in
             the
             23.
             
             Figure
             .
          
        
         
           
             Vpon
             this
             Observation
             I
             find
             in
             the
             twenty
             third
             Journal
             de
             Scavans
             of
             the
             Year
             1677.
             
             Mr.
             Cassini
             made
             these
             Reflections
             .
          
           
             THat
             having
             compared
             this
             Observation
             of
             Monsieur
             Gallet
             ,
             of
             1677.
             with
             that
             of
             Mr.
             Gassendus
             ,
             of
             1631.
             the
             same
             day
             of
             the
             year
             ,
             to
             wit
             the
             seventh
             of
             November
             ,
             he
             found
             that
             the
             Latitudes
             of
             ☿
             at
             its
             leaving
             the
             Disc
             of
             the
             Sun
             ,
             determined
             by
             these
             two
             Astronomers
             were
             equal
             ,
             even
             to
             the
             sixth
             part
             of
             a
             minute
             .
             And
             by
             consequence
             that
             ☿
             was
             both
             in
             the
             one
             and
             the
             other
             Observation
             at
             the
             same
             distance
             from
             its
             North
             node
             ,
             and
             that
             it
             traced
             in
             the
             Disc
             of
             the
             Sun
             an
             equal
             line
             :
             And
             for
             that
             ☿
             was
             here
             at
             the
             like
             distance
             from
             its
             Apoge
             ;
             as
             the
             Sun
             was
             also
             pretty
             near
             ,
             the
             swiftness
             of
             its
             apparent
             motion
             in
             the
             Sun
             was
             equal
             .
             By
             the
             Observation
             of
             Mr.
             Gallet
             it
             is
             found
             considerably
             more
             slow
             than
             that
             which
             Mr.
             Gassendus
             hath
             supposed
             from
             the
             Rudolphin
             Tables
             of
             which
             he
             made
             use
             for
             the
             determining
             of
             it
             ,
             not
             having
             been
             able
             to
             make
             Observation
             immediately
             by
             reason
             of
             the
             Clouds
             .
             He
             believes
             then
             that
             ☿
             spent
             more
             then
             five
             hours
             in
             running
             through
             the
             Disc
             of
             the
             Sun
             ,
             since
             by
             the
             Observation
             of
             Mr.
             Gallet
             ,
             it
             hath
             spent
             5
             hours
             and
             35
             minutes
             ,
             which
             may
             serve
             for
             an
             Advertisement
             for
             determining
             more
             exactly
             the
             time
             of
             the
             true
             conjunction
             of
             ☿
             with
             the
             ☉
             in
             the
             year
             1631.
             
          
           
             The
             same
             equality
             of
             Latitude
             at
             Mercury's
             leaving
             the
             Sun
             shews
             that
             the
             Sun
             was
             equally
             distant
             from
             the
             Node
             of
             Mercury
             at
             the
             time
             of
             these
             two
             Observations
             .
             And
             as
             the
             Sun
             was
             more
             advanced
             in
             that
             of
             this
             year
             from
             63
             to
             64
             minutes
             ,
             than
             in
             that
             of
             the
             year
             1631
             ,
             So
             it
             follows
             that
             the
             septentrional
             
             Node
             of
             ☿
             is
             advanced
             from
             63
             to
             64
             minutes
             in
             the
             space
             of
             46
             years
             ,
             as
             precisely
             as
             by
             the
             Rudolphin
             Tables
             ,
             which
             agree
             also
             exactly
             in
             the
             Epochas
             of
             the
             Nodes
             :
             a
             matter
             of
             no
             small
             Importance
             in
             Astronomy
             ,
             which
             hath
             not
             a
             little
             difficulty
             to
             determine
             with
             preciseness
             the
             Nodes
             of
             the
             Planets
             and
             their
             motions
             .
          
           
             But
             having
             compared
             the
             observation
             of
             Mr.
             Gallet
             ,
             with
             that
             of
             Mr.
             Hevelius
             ,
             in
             1661.
             which
             hapned
             the
             third
             of
             May
             ,
             in
             a
             place
             of
             the
             Zodiac
             opposite
             to
             that
             of
             this
             year
             ,
             he
             hath
             found
             the
             septentrional
             Node
             of
             ☿
             less
             advanced
             than
             the
             Meridional
             was
             in
             the
             preceding
             Observation
             ;
             so
             that
             if
             the
             Nodes
             of
             ☿
             in
             regard
             of
             the
             Sun
             are
             precisely
             opposite
             the
             one
             to
             the
             other
             ,
             it
             appears
             that
             they
             have
             gone
             backward
             since
             the
             year
             1661.
             as
             do
             those
             of
             the
             Moon
             ,
             and
             by
             consequence
             their
             motion
             is
             sometimes
             direct
             ,
             sometimes
             retrograde
             :
             But
             if
             their
             motion
             is
             supposed
             uniform
             ,
             it
             will
             follow
             that
             the
             Line
             of
             the
             Nodes
             of
             ☿
             doth
             not
             pass
             at
             all
             through
             the
             center
             of
             the
             Sun
             ,
             but
             that
             it
             is
             removed
             from
             it
             towards
             the
             septentrional
             limit
             about
             a
             two
             hundredth
             part
             of
             the
             Semidiameter
             of
             the
             Orb
             of
             Mercury
             .
          
           
             Thus
             far
             this
             knowing
             and
             accurate
             Astronomer
             Monsieur
             Cassini
             ,
             who
             we
             hear
             hath
             since
             farther
             discoursed
             concerning
             this
             matter
             ,
             which
             we
             hope
             to
             procure
             so
             soon
             as
             he
             shall
             make
             it
             publick
             ;
             and
             to
             add
             some
             other
             curious
             Observations
             made
             by
             other
             hands
             ,
             I
             have
             as
             yet
             been
             able
             to
             procure
             but
             one
             more
             ;
             but
             that
             is
             one
             so
             considerable
             ,
             that
             it
             will
             excite
             the
             skilful
             Astronomers
             anew
             to
             ply
             their
             Calculations
             ,
             to
             see
             what
             the
             comparing
             of
             this
             with
             the
             rest
             will
             produce
             ;
             which
             as
             they
             come
             to
             my
             hands
             ,
             I
             design
             to
             publish
             ,
             as
             I
             shall
             also
             somewhat
             of
             my
             own
             Observations
             thereupon
             :
             and
             therefore
             I
             omit
             to
             make
             any
             reflections
             at
             present
             .
             This
             Letter
             is
             of
             Mr.
             
               Edmund
               Hally
            
             ,
             now
             residing
             at
             St.
             Helena
             ,
             directed
             to
             Sir
             
               Jonas
               Moore
            
             ,
             Surveyor
             of
             his
             Majesties
             Ordnance
             ;
             a
             person
             to
             whom
             
             the
             Learned
             world
             is
             very
             much
             obliged
             for
             his
             patronizing
             and
             promoting
             these
             Coelestial
             enquiries
             ;
             who
             hath
             not
             been
             sparing
             of
             his
             own
             pains
             and
             purse
             in
             providing
             the
             best
             apparatus
             of
             instruments
             and
             other
             conveniences
             for
             such
             Observations
             the
             world
             ever
             had
             ;
             from
             whom
             we
             may
             with
             good
             reason
             hope
             a
             great
             advancement
             towards
             the
             perfecting
             thereof
             .
          
        
         
           
             
               
                 St.
                 Helena
                 ,
                 
                   Novemb.
                   22.
                   1677.
                   
                
              
               
                 HOnored
                 Sir
                 ,
                 You
                 may
                 with
                 reason
                 wonder
                 that
                 I
                 should
                 so
                 long
                 be
                 negligent
                 to
                 write
                 to
                 your
                 Worship
                 ,
                 to
                 give
                 you
                 an
                 account
                 of
                 my
                 proceedings
                 since
                 my
                 departure
                 from
                 you
                 ,
                 seeing
                 that
                 in
                 the
                 business
                 I
                 am
                 now
                 engaged
                 upon
                 ,
                 the
                 Honorable
                 Sir
                 
                   Joseph
                   Williamson
                
                 ,
                 his
                 Majesties
                 Principal
                 Secretary
                 of
                 State
                 ,
                 and
                 your self
                 are
                 my
                 only
                 Patrons
                 :
                 but
                 I
                 have
                 not
                 been
                 unmindful
                 of
                 my
                 Duty
                 in
                 this
                 particular
                 ,
                 only
                 I
                 delayed
                 ,
                 that
                 what
                 I
                 sent
                 you
                 might
                 not
                 be
                 altogether
                 inconsiderable
                 .
                 I
                 hoped
                 still
                 that
                 we
                 might
                 have
                 some
                 clear
                 weather
                 when
                 the
                 Sun
                 came
                 near
                 our
                 Zenith
                 ,
                 that
                 so
                 I
                 might
                 give
                 you
                 an
                 account
                 that
                 I
                 had
                 near
                 hand
                 finished
                 the
                 Catalogue
                 of
                 the
                 Southern
                 Stars
                 ,
                 which
                 is
                 my
                 principal
                 concern
                 ;
                 but
                 such
                 hath
                 been
                 my
                 ill
                 fortune
                 ,
                 that
                 the
                 Horizon
                 of
                 this
                 Island
                 is
                 almost
                 always
                 covered
                 with
                 a
                 Cloud
                 ,
                 which
                 sometimes
                 for
                 some
                 weeks
                 together
                 hath
                 hid
                 the
                 Stars
                 from
                 us
                 ,
                 and
                 when
                 it
                 is
                 clear
                 ,
                 is
                 of
                 so
                 small
                 continuance
                 ,
                 that
                 we
                 cannot
                 take
                 any
                 number
                 of
                 Observations
                 at
                 once
                 ;
                 so
                 that
                 now
                 ,
                 when
                 I
                 expected
                 to
                 be
                 returning
                 ,
                 I
                 have
                 not
                 finished
                 above
                 half
                 my
                 intended
                 work
                 ;
                 and
                 almost
                 despair
                 to
                 accomplish
                 what
                 you
                 ought
                 to
                 expect
                 from
                 me
                 .
                 I
                 will
                 yet
                 try
                 two
                 or
                 three
                 months
                 more
                 ,
                 and
                 if
                 it
                 continue
                 in
                 the
                 same
                 constitution
                 ,
                 I
                 shall
                 then
                 ,
                 I
                 hope
                 be
                 excusable
                 if
                 in
                 that
                 time
                 I
                 cannot
                 make
                 an
                 end
                 .
                 However
                 it
                 will
                 be
                 a
                 great
                 grief
                 to
                 be
                 so
                 far
                 frustrated
                 in
                 my
                 first
                 undertaking
                 :
                 I
                 have
                 notwithstanding
                 had
                 the
                 opportunity
                 of
                 observing
                 the
                 ingress
                 
                 and
                 egress
                 of
                 ☿
                 on
                 the
                 ☉
                 ,
                 which
                 compared
                 with
                 the
                 like
                 Observations
                 made
                 in
                 England
                 ,
                 will
                 give
                 a
                 demonstration
                 of
                 the
                 Suns
                 Parallax
                 ,
                 which
                 hitherto
                 was
                 never
                 proved
                 ,
                 but
                 by
                 probable
                 arguments
                 .
                 Likewise
                 I
                 have
                 seen
                 those
                 two
                 Eclipses
                 ,
                 one
                 of
                 the
                 Sun
                 ,
                 the
                 other
                 of
                 the
                 Moon
                 in
                 May
                 last
                 ,
                 both
                 which
                 I
                 send
                 you
                 ,
                 but
                 the
                 
                   mighty
                   winds
                   ,
                   and
                   extraordinary
                   swift
                   motion
                   of
                   the
                   Clouds
                
                 hindred
                 the
                 exactness
                 of
                 the
                 Observations
                 .
                 That
                 of
                 the
                 Moon
                 may
                 help
                 for
                 the
                 difference
                 of
                 our
                 Meridians
                 ,
                 which
                 is
                 about
                 7
                 degrees
                 to
                 the
                 Westwards
                 of
                 London
                 :
                 but
                 it
                 may
                 more
                 curiously
                 be
                 found
                 by
                 
                   Mercury
                   sub
                   Sole
                
                 .
                 There
                 are
                 three
                 Stars
                 of
                 the
                 first
                 Magnitude
                 that
                 never
                 appear
                 in
                 England
                 ,
                 but
                 none
                 near
                 the
                 South
                 Pole
                 of
                 any
                 brightness
                 ,
                 except
                 one
                 of
                 the
                 third
                 Magnitude
                 ,
                 which
                 is
                 about
                 ten
                 degrees
                 distant
                 from
                 it
                 .
                 The
                 two
                 Nubeculae
                 called
                 by
                 the
                 Saylors
                 the
                 Magellanick
                 Clouds
                 ,
                 are
                 both
                 of
                 them
                 exactly
                 like
                 the
                 whiteness
                 of
                 the
                 milky
                 way
                 lying
                 within
                 the
                 Antartick
                 Circle
                 ;
                 they
                 are
                 small
                 ,
                 and
                 in
                 the
                 Moon
                 shine
                 ,
                 scarce
                 perceptible
                 ;
                 yet
                 in
                 the
                 dark
                 the
                 bigger
                 is
                 very
                 notable
                 .
                 I
                 need
                 not
                 relate
                 unto
                 you
                 the
                 temperature
                 of
                 the
                 Weather
                 for
                 heat
                 and
                 cold
                 here
                 in
                 the
                 Torrid
                 Zone
                 ,
                 you
                 your self
                 having
                 long
                 since
                 had
                 experience
                 of
                 a
                 Latitude
                 little
                 different
                 :
                 only
                 this
                 I
                 shall
                 certifie
                 you
                 ,
                 that
                 ever
                 since
                 I
                 came
                 to
                 this
                 Island
                 ,
                 we
                 have
                 had
                 no
                 weather
                 that
                 is
                 hotter
                 than
                 the
                 Summer
                 of
                 England
                 is
                 ordinarily
                 .
                 Mr.
                 Clark
                 is
                 a
                 person
                 wonderfully
                 assistant
                 to
                 me
                 ,
                 in
                 whose
                 company
                 all
                 the
                 good
                 fortune
                 I
                 have
                 had
                 this
                 Voyage
                 consisteth
                 ,
                 to
                 me
                 all
                 other
                 things
                 having
                 been
                 cross
                 :
                 nevertheless
                 I
                 despair
                 not
                 of
                 his
                 Honors
                 and
                 your
                 Worships
                 favour
                 ,
                 which
                 alone
                 is
                 sufficient
                 to
                 encourage
                 me
                 to
                 bear
                 with
                 patience
                 these
                 disappointments
                 ,
                 and
                 expect
                 some
                 fitter
                 opportunity
                 .
              
               
                 
                   I
                   am
                   your
                   Worships
                   most
                   obliged
                   Servant
                   ,
                   and
                   true
                   Honorer
                   ,
                   
                     Edmund
                     Halley
                  
                   .
                
              
            
          
           
           
             
               
                 St.
                 Helenae
                 ,
                 Latitudo
                 Australis
                 ,
                 15.
                 55.
                 
                 Anno
                 1677.
                 
              
               
                 Octobris
                 28.
                 die
                 ☉
                 mane
                 ☿
                 apparuit
                 intra
                 ☉
                 .
              
               
                 
                   h.
                   
                
                 
                   m.
                   
                
                 
                   s.
                   
                
                 
                    
                
              
               
                 
                   9
                
                 
                   26
                
                 
                   17
                
                 
                   Pars
                   aliqua
                   corporis
                   ☿
                   ii
                   intrasset
                   Solem
                   decem
                   gradus
                   à
                   nadir
                   ad
                   dextram
                   circiter
                   .
                
              
               
                 
                   9
                
                 
                   27
                
                 
                   30
                
                 
                   Formabat
                   angulum
                   contactus
                   totus
                   ☿
                   scilicet
                   .
                   intus
                
              
               
                 
                   2
                
                 
                   38
                
                 
                   39
                
                 
                   Limbus
                   ☿
                   ii
                   proximus
                   dissiti
                   à
                   limbo
                   Solis
                   sui
                   Diametro
                   .
                
              
               
                 
                   2
                
                 
                   40
                
                 
                   8
                
                 
                   Limbus
                   ☿
                   ii
                   tetigit
                   limbum
                   ☉
                   .
                
              
               
                 
                   2
                
                 
                   41
                
                 
                   0
                
                 
                   Centrum
                   ☿
                   exiit
                   è
                   Sole
                   30
                   grad
                   .
                   circiter
                   à
                   Nadir
                   ad
                   dextram
                   .
                
              
               
                 
                   2
                
                 
                   41
                
                 
                   54
                
                 
                   ☉
                   limbus
                   integer
                   factus
                   .
                
              
            
          
           
             
               
                 Longitudo
                 &
                 Latitudo
                 trium
                 Stellarum
                 illustrium
                 prope
                 polum
                 austrinum
                 .
              
               
                 
                    
                
                 
                   Long.
                   
                
                 
                   Latit
                   .
                
              
               
                 
                   Canopus
                
                 
                   11
                
                 
                   3
                   ♋
                
                 
                   75
                
                 
                   49
                
              
               
                 
                   Centauri
                   pes
                
                 
                   25
                
                 
                   24
                   ♏
                
                 
                   42
                
                 
                   22
                
              
               
                 
                   Alcarnar
                   .
                
                 
                   10
                
                 
                   31
                   ♓
                
                 
                   59
                
                 
                   18
                   1
                   /
                   3.
                   
                
              
            
          
        
         
           
           
             The
             Period
             of
             the
             Revolution
             of
             Jupiter
             upon
             it
             Axis
             ;
             verified
             by
             new
             Observations
             made
             by
             Monsieur
             Cassini
             :
          
           
             Extracted
             out
             of
             the
             Journal
             de
             Scavans
             .
          
           
             THE
             Globe
             of
             Jupiter
             ,
             whose
             Revolution
             about
             its
             Axis
             was
             determined
             by
             the
             Observations
             of
             Monsieur
             Cassini
             ,
             in
             the
             Year
             1665.
             to
             be
             9
             hours
             ,
             
             and
             56
             minutes
             ,
             is
             as
             it
             were
             a
             watch
             for
             visibly
             pointing
             the
             hours
             and
             minutes
             to
             half
             the
             Earth
             at
             once
             ;
             so
             that
             it
             shews
             the
             same
             time
             to
             all
             under
             the
             same
             Meridian
             ,
             and
             a
             different
             time
             to
             different
             Meridians
             ,
             according
             as
             they
             differ
             in
             Longitude
             .
          
           
             It
             hath
             for
             an
             Index
             of
             its
             motion
             one
             principal
             spot
             ,
             which
             is
             very
             neatly
             distinguished
             from
             the
             rest
             of
             its
             surface
             ,
             and
             seems
             from
             its
             figure
             and
             situation
             to
             have
             some
             resemblance
             to
             the
             Caspian
             Sea
             of
             the
             Terraqueous
             Globe
             .
             By
             the
             help
             of
             good
             Glasses
             it
             may
             be
             seen
             passing
             the
             under
             Hemisphere
             of
             it
             ,
             from
             the
             East
             to
             the
             West
             ,
             with
             a
             velocity
             so
             sensible
             ,
             that
             one
             may
             determine
             to
             one
             or
             two
             minutes
             ,
             the
             time
             that
             it
             comes
             to
             the
             middle
             of
             the
             Disc
             ,
             which
             is
             the
             place
             the
             most
             fit
             for
             establishing
             of
             the
             Epochas
             ,
             and
             for
             finding
             the
             difference
             of
             Longitude
             .
             There
             may
             be
             a
             great
             number
             of
             such
             Revolutions
             observed
             ,
             since
             in
             one
             year
             of
             365
             
             days
             there
             are
             made
             882
             Revolutions
             .
             But
             it
             doth
             not
             appear
             in
             every
             year
             ,
             but
             as
             if
             it
             were
             some
             kind
             of
             Marish
             which
             is
             dried
             at
             certain
             times
             ,
             and
             so
             disappears
             during
             two
             or
             3000
             Revolutions
             ;
             and
             after
             it
             hath
             remained
             thus
             imperceptible
             for
             some
             years
             ,
             it
             returns
             again
             to
             its
             former
             state
             .
             After
             it
             had
             been
             observed
             the
             last
             six
             months
             of
             the
             year
             1665.
             and
             some
             months
             of
             1666.
             it
             became
             invisible
             till
             the
             beginning
             of
             the
             year
             1672.
             then
             being
             returned
             to
             its
             former
             appearance
             ,
             Monsieur
             Cassini
             compared
             the
             intervals
             of
             the
             six
             years
             ,
             and
             limited
             the
             revolution
             to
             be
             made
             in
             9
             hours
             ,
             55
             minutes
             ,
             51
             seconds
             ;
             and
             continuing
             his
             Observations
             to
             the
             end
             of
             the
             year
             1674.
             he
             found
             by
             these
             two
             years
             that
             it
             was
             too
             slow
             by
             two
             seconds
             and
             a
             half
             :
             so
             that
             it
             appeared
             to
             be
             in
             9
             hours
             ,
             55
             minutes
             ,
             53
             ½
             seconds
             .
          
           
             This
             spot
             hath
             been
             invisible
             in
             1675.
             and
             1676.
             during
             which
             space
             there
             happened
             other
             very
             considerable
             changes
             in
             the
             body
             of
             Jupiter
             ;
             for
             the
             clear
             interstice
             which
             was
             between
             the
             two
             dark
             belts
             of
             Jupiter
             was
             separated
             into
             many
             little
             parts
             ,
             in
             the
             manner
             like
             so
             many
             Islands
             ;
             as
             if
             the
             two
             obscure
             belts
             had
             been
             two
             great
             Rivers
             broken
             one
             into
             the
             other
             ,
             and
             had
             left
             these
             parts
             which
             appeared
             like
             Islands
             ,
             which
             yet
             were
             at
             last
             all
             effaced
             ,
             and
             the
             two
             dark
             belts
             ,
             and
             the
             interjacent
             space
             at
             length
             all
             coalesced
             into
             one
             large
             belt
             .
             But
             after
             the
             coming
             of
             Jupiter
             out
             of
             the
             Rays
             of
             the
             Sun
             in
             the
             year
             1677.
             the
             belts
             again
             took
             their
             form
             ,
             and
             situation
             which
             they
             had
             heretofore
             ;
             to
             wit
             ,
             the
             same
             which
             is
             described
             in
             the
             24
             figure
             .
             The
             principal
             spot
             appeared
             anew
             after
             the
             beginning
             of
             July
             last
             .
             Monsieur
             Cassini
             found
             this
             spot
             in
             the
             middle
             of
             Jupiter
             the
             night
             after
             the
             eighth
             of
             the
             said
             month
             ,
             at
             13
             minutes
             after
             one
             at
             night
             ;
             and
             hath
             hitherto
             ever
             since
             observed
             it
             at
             the
             hours
             proper
             to
             its
             revolution
             .
             Having
             compared
             many
             Observations
             of
             this
             year
             with
             as
             many
             others
             made
             the
             same
             days
             of
             the
             year
             1665.
             for
             avoiding
             the
             scruples
             which
             may
             arise
             
             from
             the
             inequality
             of
             times
             ,
             he
             hath
             found
             by
             the
             intervals
             of
             twelve
             years
             that
             those
             revolutions
             compared
             the
             one
             with
             the
             other
             ,
             complete
             themselves
             in
             9
             hours
             ,
             55
             minutes
             ,
             52
             seconds
             ,
             and
             5
             or
             6
             thirds
             .
             And
             because
             that
             in
             the
             years
             1672
             ,
             1673.
             they
             appeared
             more
             slow
             by
             2
             seconds
             and
             a
             half
             ,
             during
             the
             time
             that
             Jupiter
             was
             in
             its
             greatest
             elevation
             from
             the
             Sun.
             Monsieur
             Cassini
             inclines
             to
             suppose
             that
             these
             revolutions
             have
             some
             little
             inequality
             depending
             on
             the
             variation
             of
             the
             distance
             of
             ♃
             from
             the
             ☉
             ,
             and
             that
             they
             are
             a
             little
             slower
             when
             ♃
             is
             more
             removed
             ,
             and
             somewhat
             faster
             when
             nearer
             approached
             that
             body
             ;
             the
             same
             which
             several
             great
             Astronomers
             have
             supposed
             to
             happen
             to
             the
             Diurnal
             Revolutions
             of
             the
             Earth
             in
             the
             Copernican
             Hypothesis
             .
          
           
             In
             this
             account
             he
             hath
             separated
             the
             inequality
             which
             doth
             result
             from
             the
             variation
             of
             the
             two
             equations
             of
             Jupiter
             (
             as
             he
             hath
             explained
             in
             divers
             Letters
             in
             1665.
             )
             the
             which
             may
             amount
             to
             one
             half
             hour
             ,
             besides
             the
             inequality
             of
             natural
             days
             ,
             which
             according
             to
             his
             Hypothesis
             may
             amount
             to
             16
             minutes
             .
          
           
             For
             the
             finding
             then
             of
             the
             return
             of
             the
             principal
             spot
             to
             the
             middle
             of
             ♃
             for
             many
             years
             to
             half
             an
             hour
             or
             thereabout
             ,
             there
             needs
             nothing
             but
             adding
             still
             the
             time
             of
             the
             period
             to
             the
             Epoche
             of
             the
             8.
             of
             
               July
               ,
               1677.
            
             and
             for
             the
             finding
             precisely
             ,
             even
             to
             some
             minutes
             ,
             the
             two
             inequalities
             of
             Jupiter
             must
             be
             observed
             according
             to
             the
             following
             Rule
             .
          
           
             Differentiam
             inter
             medium
             locum
             Jovis
             &
             appar●ntem
             converte
             in
             tempus
             dando
             singulis
             gradibus
             min.
             
             1.
             hoc
             tempus
             adde
             tempori
             restitutionis
             maculae
             supputato
             ,
             si
             locus
             apparens
             Jovis
             excesserit
             medium
             :
             subtrahe
             vero
             si
             defecerit
             à
             medio
             .
          
           
             We
             have
             then
             the
             mean
             time
             of
             the
             return
             of
             the
             spot
             ,
             and
             to
             get
             the
             apparent
             time
             the
             ,
             equation
             of
             days
             according
             to
             the
             method
             of
             Monsieur
             Cassini
             (
             of
             which
             a
             Table
             is
             inserted
             in
             the
             Ephemerides
             of
             Monsieur
             
               Flaminio
               de
               Mezzavachi
            
             )
             must
             be
             made
             use
             of
             .
          
        
      
       
         
         
           MICROSCOPIVM
           :
           OR
           ,
           Some
           new
           Discoveries
           made
           with
           and
           concerning
           Microscopes
           .
        
         
           A
           Letter
           of
           the
           Ingenious
           and
           Inquisitive
           Mr.
           Leeuwenhoeck
           of
           Delft
           ,
           sent
           to
           the
           Secretary
           fo
           the
           Royal
           Society
           ,
           
             October
             5.
             1677.
             
          
        
         
           IN
           this
           Letter
           after
           the
           Relation
           of
           many
           curious
           Observations
           made
           with
           his
           Microscope
           ,
           he
           adds
           ,
        
         
           
             By
             some
             of
             my
             former
             Letters
             I
             have
             related
             what
             an
             innumerable
             company
             of
             little
             Animalcules
             ,
             I
             have
             discovered
             in
             waters
             ;
             of
             the
             truth
             of
             which
             affirmations
             ,
             that
             I
             might
             satisfie
             the
             Illustrious
             Philosophers
             of
             your
             Society
             ,
             I
             have
             here
             sent
             the
             Testimonials
             of
             eight
             credible
             persons
             ;
             some
             of
             which
             affirm
             they
             have
             seen
             10000
             ,
             others
             30000
             ,
             others
             45000
             little
             living
             Creatures
             ,
             in
             a
             quantity
             of
             water
             as
             big
             as
             a
             grain
             of
             Millet
             (
             92
             of
             which
             go
             to
             the
             making
             up
             the
             bigness
             of
             a
             green
             Pea
             ,
             or
             the
             quanitty
             of
             a
             natural
             drop
             of
             water
             )
             in
             the
             desiring
             of
             which
             Testimonials
             I
             made
             it
             my
             request
             that
             they
             would
             only
             justifie
             (
             that
             they
             might
             be
             within
             compass
             )
             half
             the
             number
             that
             they
             believed
             each
             of
             them
             saw
             in
             the
             water
             ,
             and
             even
             so
             the
             number
             of
             those
             little
             creatures
             that
             would
             thereby
             be
             proved
             to
             be
             in
             one
             drop
             of
             water
             would
             be
             so
             great
             ,
             that
             it
             would
             exceed
             belief
             .
             Now
             whereas
             by
             my
             Letter
             of
             the
             9th
             .
             of
             October
             ,
             1676.
             
             I
             affirmed
             that
             there
             were
             more
             than
             1000000
             living
             Creatures
             contained
             in
             one
             drop
             of
             Pepper-water
             .
             I
             should
             not
             
             have
             varied
             from
             the
             truth
             of
             it
             ,
             if
             I
             had
             asserted
             that
             there
             were
             8000000
             ;
             for
             if
             according
             to
             some
             of
             the
             included
             testimonials
             there
             might
             be
             found
             in
             a
             quantity
             of
             water
             as
             big
             as
             a
             millet
             seed
             ,
             no
             less
             than
             45000
             animalcules
             .
             It
             would
             follow
             that
             in
             an
             ordinary
             drop
             of
             this
             water
             there
             would
             be
             no
             less
             than
             4140000
             living
             creatures
             ,
             which
             number
             if
             doubled
             will
             make
             8280000
             living
             Creatures
             seen
             in
             the
             quantity
             of
             one
             drop
             of
             water
             ,
             which
             quantity
             I
             can
             with
             truth
             affirm
             I
             have
             discerned
             .
          
           
             This
             exceeds
             belief
             .
             But
             I
             do
             affirm
             ,
             that
             if
             a
             larger
             grain
             of
             sand
             were
             broken
             into
             8000000
             of
             equal
             parts
             ,
             one
             of
             these
             would
             not
             exceed
             the
             bigness
             of
             one
             of
             those
             little
             creatures
             ;
             which
             being
             understood
             ,
             it
             will
             not
             seem
             so
             incredible
             to
             believe
             that
             there
             may
             be
             so
             great
             a
             number
             in
             the
             quantity
             of
             one
             drop
             of
             water
             .
          
        
         
           Upon
           the
           perusal
           of
           this
           Letter
           ,
           being
           extremely
           desirous
           to
           examine
           this
           matter
           farther
           ,
           and
           to
           be
           ascertained
           by
           ocular
           inspection
           as
           well
           as
           from
           testimonials
           .
           I
           put
           in
           order
           such
           remainders
           as
           I
           had
           of
           my
           former
           Microscopes
           (
           having
           by
           reason
           of
           a
           weakness
           in
           my
           sight
           omitted
           the
           use
           of
           them
           for
           many
           years
           )
           and
           steeped
           some
           black
           pepper
           in
           River
           water
           ,
           but
           examining
           that
           water
           about
           two
           or
           three
           days
           after
           ,
           I
           could
           not
           by
           any
           means
           discover
           any
           of
           those
           little
           creatures
           mentioned
           in
           the
           aforesaid
           Letter
           :
           though
           I
           had
           made
           use
           of
           small
           glass
           canes
           drawn
           hollow
           for
           that
           purpose
           ,
           and
           of
           a
           Microscope
           that
           I
           was
           certain
           would
           discover
           things
           much
           smaller
           than
           such
           as
           the
           aforesaid
           Mr.
           Leeuwenhoeck
           had
           affirmed
           these
           creatures
           to
           be
           ;
           but
           whether
           it
           were
           that
           the
           light
           was
           not
           convenient
           (
           the
           reason
           of
           which
           I
           shall
           shew
           by
           and
           by
           )
           having
           looked
           only
           against
           the
           clear
           sky
           ,
           or
           that
           they
           were
           not
           yet
           generated
           ,
           which
           I
           rather
           suppose
           ,
           I
           could
           not
           discover
           any
           .
           I
           concluded
           therefore
           either
           that
           my
           Microscope
           was
           not
           so
           good
           as
           that
           he
           made
           use
           of
           ,
           or
           that
           the
           time
           of
           the
           
           year
           (
           which
           was
           in
           November
           )
           was
           not
           so
           fit
           for
           such
           generations
           ,
           or
           else
           that
           there
           might
           be
           somewhat
           ascribed
           to
           the
           difference
           of
           places
           ;
           as
           that
           Holland
           might
           be
           more
           proper
           for
           the
           production
           of
           such
           little
           creatures
           than
           England
           .
           I
           omitted
           therefore
           farther
           to
           look
           after
           them
           ,
           for
           about
           five
           or
           six
           days
           ,
           when
           finding
           it
           a
           warm
           day
           ,
           I
           examined
           again
           the
           said
           water
           ;
           and
           then
           much
           to
           wonder
           I
           discovered
           vast
           multitudes
           of
           those
           exceeding
           small
           creatures
           ,
           which
           Mr.
           Leeuwenhoeck
           had
           described
           ;
           and
           upon
           making
           use
           of
           other
           lights
           and
           glasses
           ,
           as
           I
           shall
           by
           and
           by
           shew
           ,
           I
           not
           only
           magnified
           those
           I
           had
           thus
           discovered
           to
           a
           very
           great
           bigness
           ,
           but
           I
           discovered
           many
           other
           sorts
           very
           much
           smaller
           than
           those
           I
           first
           saw
           ,
           and
           some
           of
           these
           so
           exceeding
           small
           ,
           that
           millions
           of
           millions
           might
           be
           contained
           in
           one
           drop
           of
           water
           .
           I
           was
           very
           much
           surprized
           at
           this
           so
           wonderful
           a
           spectacle
           ,
           having
           never
           seen
           any
           living
           creature
           comparable
           to
           these
           for
           smallness
           :
           nor
           could
           I
           indeed
           imagine
           that
           nature
           had
           afforded
           instances
           of
           so
           exceedingly
           minute
           animal
           productions
           .
           But
           nature
           is
           not
           to
           be
           limited
           by
           our
           narrow
           apprehensions
           ;
           future
           improvements
           of
           glasses
           may
           yet
           further
           enlighten
           our
           understanding
           ,
           and
           ocular
           inspection
           may
           demonstrate
           that
           which
           as
           yet
           we
           may
           think
           too
           extravagant
           either
           to
           feign
           or
           suppose
           .
        
         
           Of
           this
           ,
           A
           later
           Discovery
           of
           Mr.
           Leeuwenhoeck
           does
           seem
           to
           give
           good
           probabilities
           ;
           for
           by
           a
           Letter
           of
           his
           since
           sent
           (
           the
           which
           is
           hereunto
           annexed
           )
           it
           appears
           he
           hath
           discovered
           a
           certain
           sort
           of
           Eels
           in
           Pepper-water
           ,
           which
           are
           not
           in
           breadth
           above
           one
           thousandth
           part
           of
           the
           breadth
           of
           a
           hair
           ;
           and
           not
           above
           a
           hundredth
           part
           of
           the
           length
           of
           a
           vinegar
           Eel
           .
        
         
           
             
             
               Mr.
               Leeuwenhoecks
               Second
               Letter
               .
            
             
               SIR
               ,
               Yours
               of
               the
               thirtieth
               of
               November
               I
               received
               not
               till
               January
               ,
               whereby
               understanding
               the
               kind
               reception
               of
               my
               former
               by
               the
               R.S.
               I
               here
               return
               my
               acknowledgment
               to
               that
               illustrious
               Company
               for
               their
               great
               civility
               :
               but
               I
               wonder
               that
               in
               your
               Letter
               I
               find
               no
               mention
               made
               of
               my
               Observations
               of
               the
               second
               of
               
                 December
                 ,
                 St.
                 No.
              
               which
               makes
               me
               doubt
               whether
               the
               same
               came
               to
               your
               hands
               .
            
             
               Since
               you
               assure
               me
               that
               what
               I
               send
               of
               this
               nature
               will
               be
               acceptable
               to
               the
               renowned
               Society
               ,
               I
               have
               adventured
               again
               to
               send
               you
               some
               of
               my
               farther
               Enquiries
               ,
               to
               be
               communicated
               to
               that
               learned
               Philosophical
               Company
               .
               Since
               I
               wrote
               of
               the
               Blood
               of
               Eels
               ,
               and
               of
               young
               Eels
               ,
               I
               have
               not
               been
               idle
               to
               view
               Blood
               ,
               but
               especially
               my
               own
               ,
               which
               for
               some
               time
               I
               have
               indefatigably
               examined
               ,
               after
               that
               I
               had
               put
               it
               into
               all
               conceivable
               motions
               .
               Among
               which
               Observations
               I
               well
               saw
               that
               the
               globuli
               of
               my
               own
               blood
               took
               the
               same
               figure
               which
               I
               formerly
               mentioned
               ,
               that
               the
               Globules
               of
               the
               blood
               of
               Eels
               appeared
               of
               to
               the
               eye
               :
               upon
               seeing
               which
               I
               doubted
               again
               at
               the
               cause
               of
               the
               smart
               which
               the
               blood
               of
               the
               Eels
               causes
               in
               the
               eye
               .
            
             
               These
               my
               many
               times
               repeated
               Observations
               of
               my
               own
               blood
               I
               made
               to
               no
               other
               end
               ,
               than
               if
               it
               were
               possible
               ,
               to
               observe
               the
               parts
               out
               of
               which
               the
               Globules
               of
               the
               blood
               consisted
               :
               With
               observing
               this
               ,
               I
               found
               the
               globulous
               blood
               much
               more
               pliable
               than
               I
               did
               imagine
               the
               same
               before
               .
               I
               have
               at
               several
               times
               bended
               these
               Globules
               before
               my
               eyes
               ,
               that
               they
               were
               three
               times
               as
               long
               as
               broad
               ,
               without
               breaking
               the
               Vesicule
               of
               them
               :
               and
               besides
               I
               saw
               that
               the
               Globules
               of
               blood
               in
               passing
               by
               and
               through
               one
               another
               ,
               did
               by
               reason
               of
               their
               pliableness
               receive
               many
               sorts
               of
               figures
               ,
               and
               coming
               thence
               into
               a
               larger
               place
               ,
               they
               recovered
               their
               
               former
               globulosity
               which
               was
               a
               very
               great
               pleasure
               to
               observe
               :
               and
               withal
               ,
               that
               the
               Globules
               of
               blood
               coming
               many
               together
               ,
               and
               growing
               cold
               thereby
               ,
               came
               to
               unite
               ,
               and
               made
               a
               matter
               very
               smooth
               ,
               wherein
               there
               were
               no
               more
               parts
               distinct
               to
               be
               taken
               notice
               of
               ,
               much
               after
               the
               same
               manner
               as
               if
               we
               supposed
               a
               Dish
               filled
               with
               balls
               of
               wax
               set
               over
               a
               fire
               ,
               by
               which
               they
               would
               quickly
               be
               melted
               together
               ,
               and
               united
               into
               one
               mass
               ;
               by
               which
               uniting
               of
               the
               Globules
               ,
               I
               concluded
               this
               to
               be
               the
               reason
               of
               the
               accident
               which
               is
               called
               the
               
                 cold
                 fire
              
               ,
               and
               of
               that
               also
               which
               causes
               the
               hands
               or
               fingers
               to
               be
               lost
               by
               cold
               :
               but
               I
               leave
               this
               to
               others
               .
               And
               I
               did
               very
               clearly
               also
               discover
               that
               there
               were
               six
               other
               smaller
               Globules
               of
               blood
               contained
               within
               each
               of
               the
               former
               and
               larger
               Globulous
               Vesicles
               :
               and
               withal
               ,
               I
               took
               much
               pains
               to
               observe
               the
               number
               of
               the
               same
               very
               small
               globules
               ,
               out
               of
               which
               the
               greater
               Globules
               do
               consist
               :
               that
               at
               last
               I
               strongly
               imagined
               ,
               that
               every
               of
               the
               greater
               Globules
               consisted
               of
               six
               smaller
               Globules
               ,
               no
               less
               pliable
               than
               the
               aforesaid
               :
               for
               oftentimes
               I
               saw
               very
               clearly
               how
               the
               small
               Globules
               joyned
               and
               adapted
               themselves
               according
               to
               the
               figure
               the
               Vesicle
               or
               larger
               Globule
               stretched
               at
               length
               had
               taken
               ,
               being
               themselves
               stretched
               after
               the
               same
               manner
               :
               and
               thus
               made
               one
               of
               the
               larger
               Globules
               stretcht
               out
               ,
               to
               appear
               by
               the
               lesser
               within
               it
               stretched
               also
               with
               it
               ,
               as
               if
               it
               consisted
               of
               long
               threads
               .
               Moreover
               ,
               I
               put
               the
               greater
               Globules
               into
               so
               violent
               a
               motion
               ,
               that
               their
               Vesicles
               burst
               in
               pieces
               ,
               and
               then
               the
               lesser
               Globules
               appeared
               plainly
               to
               be
               scattered
               .
               This
               first
               Globule
               I
               can
               see
               as
               plainly
               and
               great
               ,
               as
               with
               the
               naked
               eye
               one
               should
               look
               upon
               the
               eggs
               or
               spawn
               of
               a
               Cod-fish
               .
            
             
               About
               nine
               or
               ten
               years
               since
               Dr.
               Graff
               opened
               in
               my
               presence
               the
               vein
               of
               a
               Dog
               ,
               and
               let
               out
               so
               much
               blood
               that
               the
               Dog
               grew
               faint
               ;
               then
               he
               opened
               the
               Artery
               of
               another
               Dog
               ,
               and
               by
               a
               pipe
               transfused
               the
               
               blood
               of
               this
               second
               into
               the
               first
               ,
               whereby
               the
               first
               was
               recovered
               ,
               the
               second
               was
               faint
               .
               Then
               the
               said
               Doctor
               injected
               back
               into
               the
               Artery
               of
               the
               second
               ,
               a
               quantity
               of
               Cows
               milk
               ,
               supposing
               thereby
               to
               preserve
               the
               second
               dog
               alive
               ,
               saying
               ,
               milk
               was
               blood
               :
               but
               no
               sooner
               was
               the
               milk
               put
               into
               the
               artery
               ,
               but
               the
               dog
               died
               .
               And
               whereas
               't
               is
               commonly
               said
               that
               milk
               is
               Blood
               ,
               therefore
               I
               shall
               relate
               of
               what
               parts
               the
               Milk
               consists
               ,
               so
               far
               as
               I
               have
               hitherto
               discovered
               .
               I
               have
               said
               heretofore
               that
               the
               Milk
               doth
               consist
               of
               Globules
               swimming
               in
               a
               thin
               clear
               watery
               matter
               which
               we
               call
               Whey
               :
               but
               as
               the
               great
               Globuli
               of
               Blood
               are
               all
               of
               the
               same
               bigness
               ,
               so
               in
               the
               Milk
               they
               are
               quite
               differing
               ,
               being
               of
               as
               many
               sizes
               and
               magnitudes
               as
               we
               can
               imagine
               ,
               between
               the
               smallest
               sand
               ,
               and
               a
               barely
               corn
               ;
               all
               of
               them
               being
               as
               clear
               as
               Crystal
               ;
               save
               only
               that
               through
               and
               between
               the
               same
               drive
               some
               irregular
               particles
               for
               the
               most
               part
               rounded
               :
               these
               had
               a
               fatty
               substance
               ,
               which
               I
               imagined
               to
               be
               the
               latter
               :
               their
               irregularity
               I
               imagined
               came
               from
               the
               impression
               of
               the
               encompassing
               Globules
               made
               on
               them
               ,
               in
               which
               posture
               they
               grew
               cold
               .
            
             
               Viewing
               the
               aforesaid
               differences
               of
               the
               Milk
               Globules
               ,
               I
               supposed
               that
               the
               Milk
               vessels
               have
               no
               other
               parts
               included
               but
               the
               matter
               out
               of
               which
               they
               are
               all
               made
               ;
               and
               that
               the
               same
               matter
               ,
               so
               long
               as
               included
               in
               the
               vessels
               ,
               consisted
               of
               one
               uniform
               matter
               ,
               so
               that
               one
               could
               not
               distinguish
               parts
               ;
               and
               that
               the
               same
               vessels
               discharging
               this
               uniform
               matter
               into
               other
               vessels
               ,
               containing
               a
               substance
               of
               a
               quite
               differing
               nature
               ,
               which
               I
               suppose
               to
               be
               the
               Whey
               ,
               comes
               to
               be
               separated
               into
               these
               Globules
               of
               so
               differing
               magnitudes
               .
               This
               may
               be
               represented
               by
               having
               two
               vessels
               filled
               ,
               the
               one
               with
               Fat
               ,
               representing
               Whey
               ;
               the
               other
               with
               Quicksilver
               ,
               resembling
               the
               uniform
               matter
               of
               the
               Milk
               :
               these
               blended
               together
               ,
               the
               Quicksilver
               will
               be
               separated
               into
               small
               Globules
               of
               differing
               magnitudes
               ,
               and
               kept
               distinct
               by
               the
               fat
               .
            
             
             
               Or
               further
               ,
               it
               may
               be
               explained
               by
               a
               dissolution
               of
               some
               gums
               in
               Spirit
               of
               Wine
               ,
               a
               drop
               of
               which
               being
               put
               into
               rain
               water
               (
               which
               I
               compare
               to
               Whey
               )
               the
               Gum
               becomes
               separated
               immediately
               into
               an
               incredible
               number
               of
               small
               clear
               Globules
               ,
               which
               makes
               it
               appear
               also
               as
               white
               as
               Milk
               it self
               :
               and
               thence
               I
               suppose
               that
               the
               whiteness
               of
               Milk
               hath
               the
               same
               cause
               .
            
             
               I
               have
               been
               often
               minded
               by
               some
               ,
               that
               flesh
               was
               nothing
               else
               but
               clodded
               blood
               ;
               yet
               for
               all
               my
               endeavours
               I
               was
               never
               able
               to
               find
               the
               first
               particles
               of
               blood
               in
               the
               fibers
               of
               the
               flesh
               ,
               but
               only
               such
               as
               are
               contained
               in
               the
               first
               Globules
               .
            
             
               The
               last
               Summer
               being
               sickly
               for
               some
               weeks
               ,
               I
               voided
               much
               Flegm
               ,
               which
               was
               green
               ,
               tough
               ,
               and
               acid
               in
               the
               throat
               ,
               which
               yet
               continues
               ;
               but
               nothing
               near
               so
               much
               as
               before
               :
               and
               some
               of
               it
               which
               I
               voided
               in
               the
               morning
               was
               of
               so
               heavy
               a
               matter
               ,
               that
               it
               sunk
               in
               the
               water
               :
               the
               ponderosity
               of
               it
               I
               found
               to
               proceed
               from
               its
               not
               being
               filled
               with
               airy
               bubbles
               ,
               which
               most
               Flegms
               are
               mixed
               with
               .
               By
               this
               means
               I
               observed
               my
               Flegm
               very
               often
               ,
               and
               found
               it
               to
               consist
               of
               tough
               slimy
               moisture
               ,
               mixt
               with
               many
               Globules
               ;
               and
               the
               tougher
               the
               Flegm
               was
               ,
               the
               greater
               was
               the
               quantity
               of
               Globules
               ;
               and
               from
               them
               also
               proceeded
               the
               green
               colour
               of
               it
               .
               All
               these
               Globules
               were
               of
               one
               and
               the
               same
               bigness
               with
               the
               first
               Globules
               of
               the
               blood
               ;
               and
               indeed
               the
               blood
               is
               of
               the
               same
               make
               ,
               but
               only
               of
               a
               different
               colour
               :
               for
               as
               I
               observed
               the
               greater
               blood
               Globules
               to
               consist
               of
               six
               lesser
               ,
               so
               here
               I
               could
               see
               them
               more
               plain
               ;
               only
               they
               seemed
               more
               slender
               and
               tender
               than
               in
               the
               blood
               :
               the
               reason
               whereof
               I
               suppose
               to
               be
               that
               the
               vesicules
               of
               the
               Flegm
               Globules
               had
               already
               received
               some
               kind
               of
               corruption
               :
               besides
               ,
               there
               was
               mixt
               with
               the
               tough
               part
               of
               the
               Flegm
               great
               quantity
               of
               very
               thin
               cuticles
               :
               and
               in
               the
               same
               manner
               as
               I
               have
               heretofore
               explained
               how
               our
               cuticle
               is
               supplied
               underneath
               ,
               as
               the
               upper
               part
               is
               rubbed
               off
               in
               scurf
               ,
               so
               I
               suppose
               the
               inner
               
               cuticles
               of
               the
               gullet
               
                 aspera
                 arteria
              
               ,
               and
               other
               vessels
               are
               taken
               off
               by
               the
               Flegm
               .
               There
               drove
               also
               ,
               through
               the
               Flegm
               some
               other
               particles
               ,
               which
               from
               their
               smallness
               I
               could
               not
               assign
               them
               a
               figure
               ,
               but
               I
               conceived
               them
               rather
               cubical
               than
               round
               .
               I
               did
               last
               Summer
               shut
               up
               some
               Caterpillers
               to
               spin
               Webs
               ,
               and
               within
               these
               few
               days
               I
               broke
               some
               of
               these
               Webs
               ,
               when
               from
               each
               of
               them
               came
               out
               a
               flie
               ,
               which
               from
               the
               cold
               were
               very
               weak
               ,
               and
               were
               unable
               to
               stand
               ;
               by
               which
               I
               conceive
               that
               those
               which
               came
               not
               out
               in
               the
               latter
               part
               of
               the
               year
               ,
               remain
               the
               whole
               Winter
               in
               their
               Webs
               ,
               till
               the
               warmth
               makes
               them
               come
               out
               .
               I
               was
               pleased
               to
               understand
               that
               your self
               and
               the
               Society
               had
               seen
               in
               so
               small
               a
               quantiy
               of
               water
               as
               a
               sand
               ,
               so
               great
               a
               number
               of
               Creatures
               ;
               as
               also
               ,
               that
               I
               shall
               be
               partaker
               of
               what
               you
               shall
               observe
               ,
               which
               I
               shall
               with
               longing
               desire
               expect
               .
               I
               cannot
               but
               mention
               that
               that
               small
               sort
               of
               Creature
               which
               I
               heretofore
               could
               give
               no
               description
               of
               ,
               I
               now
               see
               their
               figure
               .
               And
               for
               the
               pleasure
               I
               take
               in
               the
               various
               pleasing
               shapes
               ,
               with
               their
               motions
               ,
               which
               do
               now
               and
               then
               appear
               in
               the
               water
               ,
               I
               have
               the
               fourth
               of
               this
               month
               ,
               when
               it
               froze
               hard
               ,
               taken
               a
               third
               part
               of
               beaten
               pepper
               ,
               and
               2
               /
               3
               of
               high
               rain
               water
               in
               a
               clean
               glass
               ,
               which
               I
               set
               the
               first
               night
               in
               my
               Bed-chamber
               ;
               the
               next
               day
               ,
               the
               weather
               being
               milder
               ,
               I
               set
               it
               in
               my
               Counting-house
               ,
               and
               in
               three
               times
               24
               hours
               discovered
               so
               great
               a
               number
               ,
               and
               so
               unexpressible
               small
               Creatures
               ,
               that
               't
               is
               hard
               to
               be
               conceived
               ;
               and
               according
               to
               my
               judgment
               ,
               the
               most
               of
               them
               were
               much
               less
               than
               a
               thousandth
               part
               of
               the
               thickness
               of
               the
               hair
               of
               ones
               head
               ,
               and
               three
               or
               four
               times
               as
               long
               as
               thick
               ;
               the
               which
               made
               ,
               with
               the
               hinder
               part
               of
               their
               body
               ,
               oft-times
               so
               swift
               a
               progress
               ,
               as
               when
               we
               observe
               a
               Pike
               shooting
               through
               the
               water
               ,
               and
               every
               shoot
               was
               in
               length
               most
               times
               about
               half
               a
               hairs
               breadth
               ;
               the
               other
               sorts
               or
               kind
               of
               which
               were
               yet
               smaller
               ,
               whose
               shape
               for
               brevity
               I
               omit
               ;
               only
               I
               shall
               say
               ,
               that
               oft-times
               
               times
               in
               pepper-water
               which
               hath
               stood
               somewhat
               long
               ,
               among
               the
               very
               small
               Creatures
               ,
               I
               have
               seen
               a
               sort
               of
               small
               Eels
               which
               had
               their
               shapes
               and
               motions
               as
               perfect
               as
               great
               ones
               :
               these
               were
               to
               my
               appearance
               a
               thousand
               times
               thinner
               than
               the
               hair
               of
               ones
               head
               ,
               and
               that
               if
               100
               of
               these
               small
               Eels
               were
               laid
               in
               length
               one
               behind
               another
               ,
               the
               whole
               length
               would
               not
               extend
               to
               the
               length
               of
               the
               Eel
               in
               vinegar
               :
               Whether
               you
               have
               also
               observed
               these
               small
               Creatures
               with
               your
               Microscope
               ,
               I
               shall
               be
               glad
               to
               understand
               .
               I
               would
               willingly
               also
               be
               informed
               whether
               my
               Letter
               of
               the
               second
               of
               December
               mention'd
               above
               be
               come
               to
               your
               hands
               ,
               and
               how
               those
               Observations
               do
               please
               the
               Gentlemen
               of
               your
               Society
               ;
               and
               also
               to
               understand
               the
               receipt
               of
               this
               .
            
          
        
         
           The
           manner
           how
           the
           said
           Mr.
           Leeuwenhoeck
           doth
           make
           these
           discoveries
           ,
           he
           doth
           as
           yet
           not
           think
           fit
           to
           impart
           ,
           for
           reasons
           best
           known
           to
           himself
           ;
           and
           therefore
           I
           am
           not
           able
           to
           acquaint
           you
           with
           what
           it
           is
           :
           but
           as
           to
           the
           ways
           I
           have
           made
           use
           of
           ,
           I
           here
           freely
           discover
           that
           all
           such
           persons
           as
           have
           a
           desire
           to
           make
           any
           enquiries
           into
           Nature
           this
           way
           ,
           may
           be
           the
           better
           inabled
           so
           to
           do
           .
        
         
           First
           ,
           for
           the
           manner
           of
           holding
           the
           liquor
           ,
           so
           as
           to
           examine
           it
           by
           the
           Microscope
           ,
           I
           find
           that
           the
           way
           prescribed
           by
           Mr.
           Leeuwenhoeck
           is
           to
           include
           the
           same
           in
           a
           very
           fine
           pipe
           of
           glass
           ,
           and
           then
           to
           view
           it
           by
           the
           help
           of
           the
           Microscope
           ;
           for
           by
           placing
           that
           at
           a
           due
           distance
           ,
           whatever
           is
           contained
           in
           the
           said
           liquor
           will
           most
           easily
           be
           discovered
           :
           The
           liquor
           will
           most
           easily
           insinuate
           it self
           into
           the
           cavity
           of
           the
           said
           pipe
           ,
           if
           the
           end
           thereof
           only
           be
           just
           put
           within
           the
           liquor
           .
           This
           as
           it
           is
           exceedingly
           convenient
           for
           many
           trials
           ,
           so
           is
           it
           not
           very
           difficult
           to
           prepare
           ;
           but
           because
           every
           one
           is
           not
           instructed
           how
           to
           proceed
           in
           this
           matter
           ,
           and
           it
           may
           cause
           him
           more
           trouble
           than
           needs
           to
           procure
           them
           ,
           I
           will
           here
           describe
           the
           way
           ;
           and
           so
           much
           the
           rather
           ,
           because
           the
           same
           apparatus
           will
           
           serve
           for
           the
           preparing
           of
           Microscopes
           :
           as
           I
           shall
           afterwards
           shew
           .
        
         
           Provide
           then
           a
           box
           made
           of
           tin
           ,
           with
           a
           flat
           bottom
           ,
           and
           upright
           on
           all
           sides
           ;
           let
           this
           have
           fixed
           within
           it
           to
           the
           bottom
           a
           small
           piece
           of
           tin
           ,
           hollowed
           like
           a
           ridg
           tile
           ,
           so
           that
           the
           wiek
           of
           the
           Lamp
           may
           lie
           and
           rest
           upon
           it
           ,
           and
           let
           the
           Tin-man
           fix
           on
           it
           a
           cover
           of
           tin
           ,
           so
           that
           there
           may
           be
           only
           left
           one
           part
           of
           the
           aforesaid
           box
           open
           ,
           to
           wit
           ,
           where
           the
           bent
           tin
           piece
           and
           the
           wiek
           do
           lie
           and
           come
           above
           the
           sides
           :
           this
           cover
           may
           be
           turned
           back
           on
           its
           hinges
           when
           there
           is
           occasion
           to
           raise
           the
           wiek
           ,
           or
           put
           in
           more
           oyl
           ,
           &c.
           but
           for
           the
           most
           part
           ought
           to
           lie
           flat
           and
           covered
           ;
           for
           whilst
           it
           is
           using
           ,
           it
           is
           necessary
           to
           keep
           the
           flame
           from
           spreading
           too
           much
           ,
           and
           taking
           fire
           all
           over
           .
           This
           box
           must
           stand
           within
           another
           box
           of
           tin
           ,
           made
           large
           enough
           to
           contain
           it
           ;
           the
           use
           of
           which
           is
           to
           keep
           the
           former
           Lamp
           Box
           from
           fowling
           the
           board
           or
           table
           on
           which
           it
           stands
           :
           This
           stands
           upon
           a
           board
           about
           one
           foot
           square
           ,
           into
           which
           is
           fastned
           a
           standard
           or
           stick
           upright
           ,
           cleft
           so
           as
           to
           pinch
           and
           hold
           the
           sodering
           pipe
           between
           its
           clefts
           ,
           which
           may
           be
           fastned
           with
           a
           screw
           ,
           or
           a
           slipping
           ring
           ;
           through
           which
           pipe
           ,
           blowing
           with
           your
           breath
           ,
           the
           flame
           will
           be
           darted
           forward
           with
           great
           swiftness
           and
           brightness
           :
           if
           then
           into
           this
           flame
           you
           hold
           a
           small
           piece
           of
           a
           glass
           pipe
           ,
           made
           of
           white
           glass
           ,
           (
           for
           green
           glass
           ,
           or
           coarser
           glass
           will
           not
           be
           melted
           easily
           in
           this
           flame
           )
           and
           keep
           it
           turning
           round
           between
           your
           fingers
           and
           thumbs
           ,
           you
           shall
           find
           that
           the
           flame
           will
           in
           a
           very
           short
           time
           melt
           the
           middle
           part
           of
           the
           said
           pipe
           ;
           so
           that
           if
           you
           remove
           it
           out
           of
           the
           flame
           ,
           and
           draw
           your
           hands
           one
           from
           another
           ,
           you
           may
           easily
           draw
           the
           former
           pipe
           into
           a
           very
           small
           size
           ,
           which
           will
           yet
           remain
           hollow
           ,
           though
           drawn
           never
           so
           small
           .
           The
           best
           Oyl
           for
           this
           purpose
           is
           good
           clean
           Sallat
           Oyl
           ,
           or
           Oyl
           Olive
           ;
           but
           high
           rectified
           Spirit
           of
           Wine
           is
           yet
           better
           ,
           and
           cleanlier
           ,
           but
           much
           more
           chargeable
           ;
           and
           for
           most
           uses
           the
           Oyl
           Olive
           will
           serve
           .
           This
           I
           have
           set
           down
           ,
           because
           
           many
           who
           are
           far
           off
           in
           the
           Country
           cannot
           have
           the
           convenience
           of
           going
           to
           a
           Lamp-blower
           as
           oft
           as
           they
           have
           occasion
           for
           such
           pipes
           ;
           which
           if
           they
           provide
           themselves
           with
           small
           white
           glass
           pipes
           from
           the
           Potters
           ,
           they
           may
           accommodate
           themselves
           withal
           ,
           though
           they
           have
           nothing
           but
           a
           large
           candle
           ,
           and
           a
           tobacco-pipe
           ,
           instead
           of
           the
           aforesaid
           apparatus
           ,
           though
           not
           altogether
           so
           conveniently
           .
           But
           I
           would
           rather
           advise
           them
           to
           have
           a
           Lamp
           made
           ,
           which
           most
           Tin-men
           know
           how
           to
           fit
           and
           prepare
           ;
           and
           so
           it
           will
           not
           need
           much
           more
           description
           .
        
         
           But
           this
           way
           of
           Mr.
           Leeuwenhoecks
           ,
           of
           holding
           the
           liquors
           in
           small
           glass
           pipes
           ,
           though
           it
           be
           exceedingly
           ingenious
           ,
           and
           very
           convenient
           for
           many
           examinations
           ,
           yet
           for
           divers
           others
           't
           is
           not
           so
           well
           accommodated
           as
           this
           which
           I
           contrived
           my self
           for
           my
           own
           trials
           ,
           at
           least
           for
           those
           Microscopes
           I
           make
           use
           of
           ;
           what
           it
           may
           be
           for
           those
           which
           Mr.
           Leeuwenhoeck
           uses
           I
           know
           not
           .
        
         
           I
           take
           then
           instead
           of
           a
           glass
           pipe
           a
           very
           thin
           plate
           of
           Muscovy
           glass
           ,
           this
           serves
           instead
           of
           the
           moveable
           plate
           which
           is
           usually
           put
           upon
           the
           pedestal
           of
           Microscopes
           ;
           but
           because
           the
           common
           pedestal
           hitherto
           made
           use
           of
           in
           Microscopes
           is
           generally
           not
           so
           convenient
           for
           trials
           of
           this
           nature
           ,
           I
           lay
           those
           by
           ,
           and
           instead
           thereof
           I
           fix
           into
           the
           bottom
           of
           the
           Tube
           of
           the
           Microscope
           ,
           a
           cylindrical
           rod
           of
           Brass
           or
           Iron
           .
           Upon
           this
           a
           little
           socket
           is
           made
           to
           slide
           to
           and
           fro
           ;
           and
           by
           means
           of
           a
           pretty
           stiff
           spring
           ,
           will
           stand
           fast
           in
           any
           place
           .
           This
           hath
           fastned
           to
           it
           a
           joynted
           arm
           of
           three
           or
           four
           joynts
           ,
           and
           at
           the
           end
           a
           plate
           about
           the
           bigness
           of
           a
           half
           crown
           ,
           with
           a
           hole
           in
           the
           middle
           of
           it
           about
           three
           quarters
           of
           an
           inch
           wide
           ;
           upon
           this
           plate
           I
           lay
           the
           Muscovy
           glass
           ,
           and
           upon
           that
           I
           spread
           a
           very
           little
           of
           the
           liquor
           to
           be
           examined
           ;
           then
           looking
           against
           the
           flame
           of
           a
           Candle
           ,
           or
           a
           Lamp
           ,
           or
           a
           small
           reflection
           of
           the
           Sun
           from
           a
           globular
           body
           ;
           all
           such
           parts
           of
           the
           liquor
           as
           have
           differing
           refraction
           will
           manifestly
           appear
           .
           By
           this
           means
           I
           examined
           the
           water
           in
           which
           
           I
           had
           steeped
           the
           pepper
           I
           formerly
           mentioned
           ;
           and
           as
           if
           I
           had
           been
           looking
           upon
           a
           Sea
           ,
           I
           saw
           infinite
           of
           small
           living
           Creatures
           swimming
           and
           playing
           up
           and
           down
           in
           it
           ,
           a
           thing
           indeed
           very
           wonderful
           to
           behold
           .
        
         
           If
           the
           flame
           of
           the
           candle
           were
           directly
           before
           the
           Microscope
           ,
           then
           all
           those
           little
           Creatures
           appeared
           perfectly
           defin'd
           by
           a
           black
           line
           ,
           and
           the
           bodies
           of
           them
           somewhat
           darker
           than
           the
           water
           ;
           but
           if
           the
           candle
           were
           removed
           a
           little
           out
           of
           the
           axis
           of
           vision
           ,
           all
           those
           little
           Creatures
           appeared
           like
           so
           many
           small
           pearls
           ,
           or
           little
           bubbles
           of
           air
           ,
           and
           the
           liquor
           in
           which
           they
           swimmed
           appeared
           dark
           ;
           but
           when
           the
           water
           began
           to
           dry
           off
           ,
           the
           bending
           of
           the
           superficies
           of
           the
           liquor
           over
           their
           backs
           ,
           and
           over
           the
           tops
           of
           other
           small
           motes
           which
           were
           in
           the
           water
           made
           a
           confused
           appearance
           ,
           which
           some
           not
           used
           to
           these
           kind
           of
           examinations
           ,
           took
           to
           be
           quite
           differing
           things
           from
           what
           they
           were
           really
           ;
           and
           the
           appearances
           here
           are
           so
           very
           strange
           ,
           that
           to
           one
           not
           well
           accustomed
           to
           the
           phaenomena
           of
           fluids
           of
           differing
           figures
           and
           refractions
           ,
           the
           examinations
           of
           substances
           this
           way
           will
           be
           very
           apt
           to
           mis-inform
           ,
           rather
           than
           instruct
           him
           ;
           especially
           of
           such
           substances
           as
           are
           not
           perfectly
           fluid
           ,
           and
           will
           not
           readily
           and
           naturally
           smooth
           their
           own
           superficies
           ,
           such
           as
           Tallow
           ,
           concreted
           Oyls
           ,
           Marrow
           ,
           Brains
           ,
           Fat
           ,
           inspissated
           juyces
           ,
           &c.
           for
           if
           those
           substances
           be
           so
           examined
           by
           spreading
           them
           upon
           this
           plate
           ,
           and
           be
           looked
           upon
           against
           the
           candle
           ,
           or
           other
           small
           defined
           light
           ,
           all
           the
           inequalities
           left
           on
           the
           surface
           by
           the
           spreading
           do
           by
           the
           refractions
           of
           the
           rays
           of
           light
           render
           such
           odd
           appearances
           ,
           that
           they
           will
           easily
           deceive
           the
           examinator
           ,
           and
           make
           him
           to
           conceive
           that
           to
           be
           in
           the
           texture
           of
           the
           part
           which
           is
           really
           no
           where
           but
           in
           the
           make
           of
           the
           superficies
           of
           it
           .
           This
           therefore
           as
           another
           great
           inconvenience
           to
           be
           met
           with
           in
           Microscopical
           Observations
           ,
           I
           prevent
           by
           these
           ensuing
           methods
           :
           First
           ,
           all
           such
           bodies
           as
           Fat
           ,
           Oyl
           ,
           Brains
           ,
           Rhobs
           ,
           Pus
           ,
           tough
           concreted
           Flegm
           ,
           and
           the
           like
           ,
           whose
           surfaces
           
           are
           irregular
           ,
           and
           ought
           to
           be
           reduced
           to
           smoothness
           before
           they
           can
           be
           well
           examined
           ,
           I
           order
           in
           this
           manner
           :
           First
           ,
           I
           provide
           a
           very
           clear
           and
           thin
           piece
           of
           looking-glass
           plate
           very
           smooth
           and
           plain
           on
           both
           sides
           ,
           and
           clean
           from
           foulness
           :
           upon
           the
           surface
           of
           this
           I
           lay
           some
           of
           those
           substances
           I
           last
           mentioned
           ,
           then
           with
           such
           another
           piece
           of
           Looking-glass
           plate
           laid
           upon
           the
           said
           substance
           I
           press
           it
           so
           thin
           as
           not
           only
           to
           make
           the
           surfaces
           of
           it
           very
           smooth
           ,
           but
           also
           to
           make
           the
           substance
           of
           it
           very
           thin
           ;
           because
           otherwise
           ,
           if
           the
           substance
           be
           pretty
           thick
           ,
           as
           suppose
           as
           thick
           as
           a
           piece
           of
           Venice
           paper
           ,
           if
           it
           be
           a
           whitish
           substance
           ,
           the
           multitudes
           of
           parts
           lying
           one
           upon
           another
           in
           such
           a
           thickness
           ,
           do
           so
           confound
           the
           sight
           ,
           that
           none
           of
           them
           all
           can
           be
           distinctly
           seen
           :
           but
           if
           by
           squeezing
           the
           said
           plates
           hard
           ,
           and
           close
           together
           ,
           it
           be
           reduced
           to
           a
           twentieth
           part
           perhaps
           of
           that
           thickness
           ,
           the
           substance
           may
           be
           well
           looked
           through
           ,
           and
           the
           constituent
           parts
           may
           be
           very
           plainly
           discovered
           .
           Thus
           also
           't
           is
           very
           visible
           in
           the
           Globules
           of
           milk
           and
           blood
           ,
           discovered
           by
           the
           ingenious
           Mr.
           Leeuwenhoeck
           ,
           for
           when
           either
           of
           those
           substances
           are
           thick
           ,
           the
           multitude
           of
           those
           little
           Globules
           confound
           and
           thicken
           the
           liquor
           so
           as
           one
           cannot
           perceive
           any
           thing
           until
           it
           be
           run
           very
           thin
           ;
           for
           then
           all
           the
           remaining
           Globules
           with
           their
           motions
           may
           very
           distinctly
           be
           apprehended
           .
           This
           therefore
           is
           an
           expedient
           by
           which
           thousands
           of
           substances
           may
           be
           examined
           ;
           and
           therefore
           the
           more
           fit
           to
           be
           communicated
           ,
           that
           there
           may
           be
           the
           greater
           number
           of
           observers
           well
           accommodated
           for
           such
           trials
           .
           These
           plates
           therefore
           may
           be
           contrived
           so
           as
           to
           be
           pinched
           together
           by
           the
           help
           of
           screws
           ,
           and
           a
           frame
           ,
           that
           thereby
           they
           may
           be
           forced
           the
           closer
           and
           the
           evener
           together
           ,
           as
           there
           shall
           be
           occasion
           ;
           and
           may
           be
           kept
           firm
           and
           steady
           in
           that
           posture
           ,
           and
           then
           ,
           that
           it
           may
           some
           ways
           or
           other
           be
           conveniently
           fastned
           to
           the
           former
           plate
           ,
           so
           as
           to
           be
           moved
           this
           way
           or
           that
           way
           steadily
           ,
           as
           there
           shall
           be
           occasion
           .
        
         
         
           But
           there
           are
           other
           substances
           which
           none
           of
           these
           ways
           I
           have
           yet
           mentioned
           will
           examine
           ,
           and
           those
           are
           such
           parts
           of
           animal
           or
           vegetable
           bodies
           as
           have
           a
           peculiar
           form
           ,
           figure
           ,
           or
           shape
           ,
           out
           of
           which
           if
           it
           be
           put
           ,
           the
           principal
           thing
           looked
           after
           is
           destroyed
           :
           such
           are
           the
           Nerves
           ,
           Muscles
           ,
           Tendons
           ,
           Ligaments
           ,
           Membranes
           ,
           Glandules
           ,
           Parenchymas
           ,
           &c.
           of
           the
           body
           of
           Animals
           ,
           and
           the
           Pulps
           ,
           Piths
           ,
           Woods
           ,
           Barks
           ,
           Leaves
           ,
           Flowers
           ,
           &c.
           of
           Vegetables
           .
           Some
           of
           these
           which
           are
           not
           made
           by
           dissection
           or
           separation
           from
           other
           parts
           may
           be
           viewed
           alone
           ;
           but
           there
           are
           others
           which
           cannot
           be
           well
           examined
           unless
           they
           be
           made
           to
           swim
           in
           a
           liquor
           proper
           and
           convenient
           for
           them
           :
           as
           for
           instance
           ,
           the
           parts
           of
           flesh
           ,
           muscles
           and
           tendons
           :
           for
           if
           you
           view
           the
           fibres
           of
           a
           muscle
           encompassed
           only
           with
           the
           air
           ,
           you
           cannot
           discover
           the
           small
           parts
           out
           of
           which
           it
           is
           made
           :
           but
           if
           the
           same
           be
           put
           into
           a
           liquor
           ,
           as
           water
           ,
           or
           very
           clear
           oyl
           ,
           you
           may
           clearly
           see
           such
           a
           fabrick
           as
           is
           truly
           very
           admirable
           ,
           and
           such
           as
           none
           hitherto
           hath
           discovered
           that
           ever
           I
           could
           meet
           with
           ;
           of
           which
           more
           hereafter
           ,
           when
           I
           shew
           the
           true
           mechanical
           fabrick
           thereof
           ,
           and
           what
           causes
           its
           motion
           .
           Thus
           if
           you
           view
           a
           thred
           of
           a
           Ligament
           ,
           you
           shall
           plainly
           see
           it
           to
           be
           made
           up
           of
           an
           infinite
           company
           of
           exceeding
           small
           threads
           smooth
           and
           round
           ,
           lying
           close
           together
           ;
           each
           of
           which
           threads
           is
           not
           above
           a
           four
           hundredth
           part
           of
           the
           bigness
           of
           a
           hair
           :
           for
           comparing
           those
           of
           Beef
           with
           a
           hair
           of
           my
           head
           ,
           which
           was
           very
           fine
           and
           small
           ,
           viz.
           about
           a
           640.
           part
           of
           an
           inch
           ,
           I
           found
           the
           Diameter
           thereof
           to
           be
           more
           than
           twenty
           times
           the
           Diameter
           of
           these
           threads
           ;
           so
           that
           no
           less
           than
           163
           millions
           ,
           besides
           840
           thousands
           of
           these
           must
           be
           in
           a
           ligament
           one
           inch
           square
           .
           I
           shall
           not
           here
           enlarge
           upon
           the
           admirable
           contrivance
           of
           Nature
           in
           this
           particular
           ,
           nor
           say
           any
           thing
           farther
           of
           the
           reason
           of
           the
           greater
           strength
           of
           the
           same
           substance
           drawn
           into
           smaller
           than
           into
           greater
           threads
           ;
           but
           only
           this
           in
           general
           ,
           that
           the
           mechanical
           operations
           of
           these
           minute
           
           bodies
           are
           quite
           differing
           from
           those
           of
           bodies
           of
           greater
           bulk
           ,
           and
           the
           want
           of
           considering
           this
           one
           thing
           hath
           been
           the
           cause
           of
           very
           great
           absurdities
           in
           the
           Hypotheses
           of
           some
           of
           our
           more
           eminent
           modern
           Philosophers
           :
           For
           he
           that
           imagines
           the
           actions
           of
           these
           lesser
           bodies
           the
           same
           with
           those
           of
           the
           larger
           and
           tractable
           bodies
           ,
           will
           indeed
           make
           but
           Aristotles
           wooden
           hand
           at
           best
           .
           This
           put
           me
           in
           mind
           likewise
           of
           advertising
           the
           Experimenter
           that
           he
           provide
           himself
           with
           instruments
           ,
           by
           which
           ,
           to
           stretch
           and
           pull
           in
           pieces
           any
           substance
           whilst
           the
           same
           is
           yet
           in
           view
           of
           the
           Microscope
           ,
           of
           which
           there
           may
           be
           many
           which
           any
           one
           will
           easily
           contrive
           ,
           when
           he
           hath
           this
           hint
           given
           him
           of
           the
           usefulness
           thereof
           in
           the
           examination
           of
           the
           texture
           of
           several
           substances
           ;
           as
           of
           Tendons
           ,
           Nerves
           ,
           Muscles
           ,
           &c.
           those
           I
           have
           made
           use
           of
           were
           made
           to
           open
           like
           a
           pair
           of
           Tobacco
           Tongues
           ,
           by
           two
           angular
           plates
           of
           thin
           brass
           rivetted
           together
           ,
           which
           by
           pinching
           the
           opposite
           end
           ,
           would
           either
           open
           or
           shut
           at
           the
           other
           ,
           as
           I
           had
           occasion
           .
           These
           having
           a
           part
           extended
           between
           the
           two
           tops
           ,
           were
           fixt
           at
           a
           due
           distance
           from
           the
           object-glass
           that
           the
           body
           extended
           between
           them
           might
           be
           distinctly
           seen
           ;
           then
           with
           my
           finger
           squeezing
           together
           the
           opposite
           ends
           ,
           the
           other
           ends
           opened
           ,
           by
           which
           means
           how
           the
           parts
           stretched
           and
           shrunk
           might
           be
           plainly
           discovered
           .
           Now
           as
           this
           is
           of
           use
           for
           some
           kind
           of
           substances
           ,
           so
           the
           two
           glass
           plates
           are
           for
           others
           ,
           and
           particularly
           for
           squeezing
           of
           several
           substances
           between
           them
           ,
           so
           as
           to
           break
           them
           in
           pieces
           ,
           as
           those
           little
           Creatures
           in
           pepper-water
           ,
           or
           the
           Globules
           in
           blood
           ,
           milk
           ,
           flegm
           ,
           &c.
           whereby
           the
           parts
           within
           them
           may
           yet
           farther
           be
           enquired
           into
           ,
           as
           Mr.
           Leeuwenhoeck
           I
           find
           hath
           done
           by
           his
           latest
           Observations
           .
           Whether
           he
           makes
           use
           of
           this
           way
           ,
           or
           some
           other
           ,
           I
           know
           not
           .
        
         
           Having
           thus
           given
           a
           description
           of
           the
           appurtenances
           ,
           it
           remains
           that
           I
           come
           to
           the
           description
           of
           the
           Microscope
           
           it self
           ,
           which
           is
           the
           principal
           instrument
           ,
           and
           without
           which
           all
           the
           rest
           are
           insignificant
           .
        
         
           The
           Microscopes
           then
           I
           design
           here
           to
           describe
           ,
           are
           only
           of
           two
           kinds
           ,
           either
           single
           or
           double
           .
        
         
           The
           single
           Microscope
           I
           call
           that
           which
           consisteth
           only
           of
           one
           glass
           ,
           though
           it
           have
           a
           double
           refracting
           superficies
           ;
           and
           the
           double
           one
           I
           call
           that
           which
           is
           compounded
           of
           two
           glasses
           ,
           though
           it
           hath
           for
           the
           most
           part
           a
           quadruple
           refraction
           of
           the
           Rays
           .
        
         
           The
           single
           Microscope
           then
           consisteth
           of
           one
           small
           lens
           so
           fastened
           into
           a
           cell
           ,
           that
           the
           eye
           may
           come
           conveniently
           to
           look
           through
           the
           middle
           part
           or
           Axis
           of
           it
           ;
           of
           these
           there
           are
           various
           sorts
           ,
           as
           double
           Convexes
           ,
           or
           plain
           Convexes
           ,
           or
           perfectly
           spherical
           .
        
         
           I
           shall
           not
           need
           to
           describe
           the
           common
           lenses
           which
           are
           every
           where
           made
           use
           of
           for
           this
           purpose
           ,
           being
           plano-convexes
           of
           Spheres
           about
           half
           an
           inch
           Diameter
           ,
           save
           only
           this
           ,
           that
           't
           is
           best
           to
           turn
           the
           plain
           side
           towards
           the
           object
           ,
           and
           the
           convex
           to
           the
           eye
           :
           nor
           shall
           I
           say
           much
           concerning
           those
           double
           Convex
           Glasses
           ,
           there
           being
           no
           great
           difficulty
           in
           the
           making
           or
           using
           of
           them
           ;
           but
           that
           the
           smaller
           the
           sphere
           is
           in
           which
           they
           are
           made
           ,
           the
           nearer
           do
           they
           bring
           the
           object
           to
           the
           eye
           ;
           and
           consequently
           the
           more
           is
           the
           object
           magnified
           ,
           and
           the
           better
           and
           truer
           they
           are
           polisht
           in
           the
           Tool
           ,
           the
           more
           clear
           and
           distinct
           doth
           the
           object
           appear
           ,
           but
           to
           make
           any
           of
           a
           Sphere
           less
           than
           1
           /
           10
           of
           an
           inch
           in
           Diameter
           is
           exceeding
           difficult
           ,
           by
           reason
           that
           the
           glass
           becomes
           too
           small
           to
           be
           tractable
           ;
           and
           't
           is
           very
           difficult
           to
           find
           a
           cement
           that
           will
           hold
           it
           fast
           whilst
           it
           be
           completed
           ;
           and
           when
           't
           is
           polisht
           ,
           't
           is
           exceeding
           difficult
           to
           handle
           and
           put
           into
           its
           cell
           :
           besides
           ,
           I
           have
           found
           the
           use
           of
           them
           offensive
           to
           my
           eye
           ,
           and
           to
           have
           much
           strained
           and
           weakened
           the
           sight
           ,
           which
           was
           the
           reason
           why
           I
           omitted
           to
           make
           use
           of
           them
           ,
           though
           in
           truth
           they
           do
           make
           the
           object
           appear
           much
           more
           clear
           and
           distinct
           ,
           and
           magnifie
           as
           much
           as
           the
           double
           Microscopes
           :
           nay
           ,
           to
           those
           whose
           eyes
           can
           
           well
           endure
           it
           ,
           't
           is
           possible
           with
           a
           single
           Microscope
           to
           make
           discoveries
           much
           better
           than
           with
           a
           double
           one
           ,
           because
           the
           colours
           which
           do
           much
           disturb
           the
           clear
           vision
           in
           double
           Microscopes
           is
           clearly
           avoided
           and
           prevented
           in
           the
           single
           .
           The
           single
           Microscope
           therefore
           which
           I
           shall
           here
           describe
           ,
           as
           it
           is
           exceeding
           easie
           to
           make
           ,
           so
           is
           it
           much
           more
           tractable
           than
           the
           double
           Convex
           glasses
           made
           the
           common
           way
           by
           working
           them
           in
           a
           hollow
           Hemisphere
           with
           water
           and
           sand
           ;
           for
           those
           ,
           supposing
           them
           made
           with
           all
           the
           accurateness
           imaginable
           ,
           will
           be
           far
           short
           from
           being
           so
           well
           polisht
           as
           these
           ;
           and
           wanting
           the
           stem
           or
           handle
           which
           these
           have
           ,
           they
           are
           infinitely
           troublesome
           to
           remove
           ,
           or
           place
           ,
           or
           to
           cleanse
           when
           there
           shall
           be
           occasion
           .
        
         
           Take
           then
           a
           small
           rod
           of
           the
           clearest
           and
           cleanest
           glass
           you
           can
           procure
           ,
           free
           if
           possible
           from
           blebbs
           ,
           sands
           ,
           or
           veins
           ;
           then
           by
           melting
           it
           in
           the
           flame
           of
           a
           Lamp
           made
           with
           Spirit
           of
           Wine
           ,
           or
           the
           cleanest
           and
           purest
           Sallet
           Oyl
           ,
           draw
           it
           out
           into
           exceeding
           fine
           and
           small
           threads
           ;
           then
           take
           a
           small
           piece
           of
           these
           threads
           ,
           and
           in
           the
           same
           flame
           of
           the
           aforesaid
           Lamp
           melt
           the
           end
           of
           it
           ,
           till
           you
           perceive
           it
           to
           run
           into
           a
           little
           ball
           or
           globule
           of
           the
           bigness
           desired
           ;
           then
           suffer
           it
           to
           cool
           ,
           and
           handling
           it
           by
           the
           aforesaid
           thread
           of
           glass
           ,
           which
           is
           as
           it
           were
           a
           handle
           to
           it
           ,
           fix
           it
           with
           a
           little
           wax
           upon
           the
           side
           of
           a
           thin
           plate
           of
           Brass
           ,
           Silver
           ,
           or
           the
           like
           ,
           that
           the
           middle
           of
           it
           may
           lie
           directly
           over
           the
           middle
           of
           a
           small
           hole
           pricked
           through
           the
           said
           thin
           plate
           with
           a
           needle
           :
           then
           holding
           this
           plate
           close
           to
           the
           eye
           ,
           look
           through
           the
           said
           little
           hole
           ,
           and
           thereby
           you
           may
           also
           see
           very
           clearly
           through
           the
           aforesaid
           Globule
           ,
           fixed
           with
           wax
           on
           the
           side
           that
           is
           from
           the
           eye
           :
           if
           then
           either
           by
           a
           little
           joynted
           arm
           ,
           or
           by
           a
           little
           soft
           wax
           ,
           and
           a
           needle
           ,
           or
           a
           thin
           plate
           of
           Muscovy
           glass
           ,
           you
           fix
           the
           object
           you
           would
           examine
           ;
           so
           that
           it
           may
           be
           at
           a
           due
           distance
           from
           the
           said
           little
           Globule
           ,
           you
           will
           perceive
           the
           minute
           parts
           thereof
           very
           distinct
           .
           The
           focus
           of
           a
           sphere
           looked
           on
           by
           the
           naked
           eye
           ,
           is
           about
           half
           the
           radius
           of
           the
           
           sphere
           ,
           without
           the
           superficies
           of
           it
           ;
           but
           this
           is
           varied
           much
           by
           the
           age
           of
           the
           eye
           that
           looks
           through
           it
           ,
           by
           the
           imagination
           also
           of
           the
           person
           ,
           and
           by
           the
           differing
           specifique
           refraction
           of
           the
           glass
           made
           use
           of
           .
        
         
           By
           this
           means
           I
           have
           prodigiously
           magnified
           some
           small
           bodies
           ,
           insomuch
           that
           I
           have
           been
           able
           to
           see
           and
           distinguish
           the
           particles
           of
           bodies
           ,
           not
           only
           a
           million
           of
           times
           smaller
           than
           a
           visible
           point
           ,
           but
           even
           to
           make
           those
           visible
           ,
           whereof
           a
           million
           of
           millions
           of
           them
           would
           hardly
           make
           the
           bulk
           of
           the
           smallest
           visible
           sand
           ;
           so
           prodigiously
           do
           these
           exceeding
           the
           little
           Globules
           of
           glass
           inlarge
           the
           prospect
           of
           humane
           sight
           into
           the
           more
           private
           recesses
           of
           nature
           .
        
         
           If
           the
           things
           to
           be
           viewed
           be
           liquors
           ,
           they
           may
           be
           included
           either
           in
           those
           little
           pipes
           of
           Mr
           Leeuwenhoeck
           I
           newly
           mentioned
           ,
           or
           else
           they
           may
           be
           put
           upon
           exceeding
           thin
           plates
           of
           Muscovy
           glass
           or
           Selenites
           ,
           and
           the
           other
           side
           of
           the
           plate
           may
           be
           made
           to
           touch
           the
           Globule
           ,
           or
           at
           least
           be
           fixed
           at
           such
           distance
           ,
           as
           may
           make
           the
           parts
           of
           the
           liquor
           distinct
           :
           If
           you
           make
           use
           of
           a
           Looking-glass
           plate
           to
           spread
           the
           liquor
           upon
           you
           would
           examine
           ,
           you
           may
           turn
           the
           liquor
           towards
           the
           Globule
           ,
           and
           you
           may
           therein
           easily
           see
           all
           the
           parts
           very
           distinctly
           ,
           without
           at
           all
           hurting
           the
           prospect
           by
           the
           interposition
           of
           the
           Muscovy
           glass
           ;
           which
           though
           it
           be
           exceeding
           clear
           ,
           especially
           if
           the
           plates
           be
           very
           thin
           ,
           yet
           hath
           it
           some
           flaws
           ,
           and
           some
           opacousnesses
           in
           it
           ,
           which
           do
           somewhat
           cloud
           the
           prospect
           .
        
         
           If
           further
           ,
           you
           would
           have
           a
           Microscope
           with
           one
           single
           refraction
           ,
           and
           consequently
           capable
           of
           the
           greatest
           clearness
           and
           brightness
           that
           any
           one
           kind
           of
           Microscopes
           can
           possibly
           be
           imagined
           susceptible
           of
           ,
           when
           you
           have
           fixt
           one
           of
           these
           little
           Globules
           as
           I
           have
           directed
           ,
           and
           spread
           a
           little
           of
           the
           liquor
           upon
           a
           piece
           of
           Looking-glass
           plate
           ,
           then
           apply
           the
           said
           plate
           with
           the
           liquor
           ,
           next
           to
           the
           Globule
           ,
           and
           gently
           move
           it
           close
           to
           the
           Globule
           ,
           till
           the
           liquor
           touch
           ;
           which
           done
           ,
           you
           will
           find
           the
           liquor
           presently
           to
           adhere
           to
           the
           
           Globule
           ,
           and
           still
           to
           adhere
           to
           it
           though
           you
           move
           it
           back
           again
           a
           little
           ;
           by
           which
           means
           ,
           this
           liquor
           being
           of
           a
           specifique
           refraction
           ,
           not
           much
           differing
           from
           glass
           ,
           the
           second
           refraction
           is
           quite
           taken
           off
           ,
           and
           little
           or
           none
           left
           but
           that
           of
           the
           convex
           side
           of
           the
           Globule
           next
           the
           eye
           ;
           by
           which
           means
           as
           much
           of
           the
           inconvenience
           of
           refraction
           as
           is
           possible
           is
           removed
           ,
           and
           that
           by
           the
           easiest
           and
           most
           practicable
           expedient
           that
           can
           be
           desired
           .
           I
           could
           add
           various
           other
           ways
           of
           making
           these
           Globular
           bodies
           both
           of
           glass
           and
           other
           substances
           which
           will
           yet
           farther
           advance
           our
           prospect
           into
           nature
           ,
           and
           are
           pleasant
           to
           admiration
           ;
           but
           those
           I
           shall
           yet
           reserve
           till
           I
           see
           what
           effects
           the
           publishing
           of
           these
           may
           produce
           ,
           and
           to
           the
           end
           to
           excite
           other
           persons
           to
           be
           inquisitive
           into
           this
           matter
           :
           for
           let
           me
           assure
           them
           ,
           very
           much
           more
           may
           yet
           be
           done
           by
           a
           way
           I
           know
           ,
           than
           by
           this
           I
           have
           here
           published
           .
           And
           I
           confess
           I
           have
           very
           often
           wondered
           that
           no
           farther
           improvement
           had
           been
           made
           of
           this
           Principle
           ,
           since
           I
           publisht
           it
           in
           the
           year
           1664.
           in
           the
           20.
           page
           of
           my
           Preface
           to
           Micrographia
           :
           for
           though
           some
           other
           reasons
           discouraged
           me
           from
           prosecuting
           those
           enquiries
           ,
           yet
           I
           hoped
           that
           others
           might
           long
           before
           this
           have
           carried
           it
           much
           farther
           .
        
         
           The
           only
           inconvenience
           in
           these
           kinds
           of
           Microscopes
           ,
           is
           ,
           that
           the
           object
           is
           necessarily
           brought
           so
           near
           the
           glass
           ,
           that
           none
           but
           such
           as
           are
           transparent
           ,
           and
           to
           be
           viewed
           by
           a
           through
           light
           are
           capable
           of
           examination
           by
           them
           :
           such
           therefore
           are
           to
           be
           examined
           by
           the
           double
           Microscope
           ;
           which
           ,
           as
           it
           is
           abundantly
           more
           tractable
           ,
           so
           doth
           it
           much
           less
           strain
           the
           eye
           ;
           and
           from
           the
           easiness
           of
           its
           use
           ,
           when
           well
           fitted
           ,
           is
           much
           more
           pleasant
           :
           and
           if
           ordered
           as
           it
           ought
           ,
           will
           magnifie
           as
           much
           more
           than
           the
           common
           ones
           hitherto
           made
           ,
           as
           those
           did
           more
           than
           the
           naked
           eye
           .
        
         
           Both
           these
           Microscopes
           I
           have
           directed
           Mr.
           
             Christopher
             Cock
          
           ,
           in
           Long-Acre
           ,
           how
           to
           prepare
           ,
           that
           such
           as
           will
           not
           trouble
           themselves
           in
           the
           making
           of
           them
           ,
           may
           know
           
           where
           to
           be
           accommodated
           with
           such
           as
           are
           good
           .
        
         
           And
           of
           the
           improvement
           of
           this
           kind
           of
           Microscope
           ,
           I
           see
           no
           limits
           ,
           especially
           as
           to
           the
           augmenting
           the
           visible
           appearance
           of
           such
           objects
           as
           are
           capable
           of
           enduring
           the
           increase
           of
           light
           ;
           for
           since
           't
           is
           demonstrable
           that
           light
           may
           be
           augmented
           upon
           any
           one
           object
           susceptible
           to
           any
           given
           degree
           ,
           and
           that
           by
           the
           double
           Microscope
           the
           image
           can
           be
           augmented
           to
           any
           assigned
           magnitude
           ,
           what
           but
           the
           difficulty
           of
           making
           all
           things
           correspondent
           should
           limit
           the
           power
           of
           such
           an
           instrument
           .
           Now
           the
           making
           of
           this
           double
           Microscope
           ,
           though
           it
           be
           somewhat
           more
           difficult
           than
           of
           the
           single
           one
           ,
           yet
           the
           tractableness
           thereof
           when
           well
           fitted
           ,
           and
           its
           easiness
           to
           be
           cleansed
           ,
           and
           applied
           to
           use
           ,
           makes
           amends
           for
           the
           extraordinary
           charge
           ,
           especially
           the
           situation
           of
           the
           object
           ;
           which
           being
           capable
           of
           any
           reasonable
           distance
           from
           the
           object
           glass
           ,
           so
           as
           to
           be
           fit
           for
           examination
           ,
           makes
           it
           very
           desirable
           .
           Now
           as
           in
           all
           other
           mechanical
           contrivances
           ,
           that
           is
           best
           which
           is
           plainest
           ,
           and
           most
           simple
           :
           so
           is
           it
           in
           this
           ,
           wherein
           nothing
           more
           is
           required
           ,
           but
           two
           plano
           Convex
           glasses
           ,
           the
           one
           for
           the
           object-glass
           ,
           and
           the
           other
           for
           the
           eye-glass
           :
           the
           less
           the
           spheres
           of
           the
           glasses
           be
           ,
           the
           more
           do
           they
           magnifie
           the
           object
           ;
           and
           the
           thinner
           and
           clearer
           the
           substance
           of
           them
           be
           ,
           and
           the
           more
           exactly
           shaped
           ,
           and
           the
           brighter
           they
           are
           polisht
           ,
           the
           clearer
           do
           they
           represent
           it
           ;
           and
           the
           longer
           the
           glasses
           are
           distant
           from
           each
           other
           ,
           the
           more
           is
           the
           image
           magnified
           ,
           
             caeteris
             paribus
          
           ,
           though
           indeed
           the
           same
           thing
           is
           performed
           by
           glasses
           of
           very
           differing
           magnitudes
           ,
           due
           proportions
           of
           all
           things
           about
           it
           being
           kept
           and
           observed
           .
           For
           if
           as
           the
           distance
           of
           one
           object
           from
           the
           object-glass
           is
           to
           the
           distance
           of
           another
           object
           from
           another
           object-glass
           ,
           so
           the
           distance
           of
           the
           first
           image
           be
           to
           the
           distance
           of
           the
           second
           image
           ,
           the
           image
           in
           both
           must
           be
           equal
           :
           if
           therefore
           this
           image
           be
           viewed
           with
           equal
           glasses
           the
           image
           must
           be
           equally
           magnified
           at
           the
           bottom
           of
           the
           eye
           ;
           so
           that
           in
           this
           way
           the
           object
           is
           
           capable
           of
           a
           double
           way
           of
           augmenting
           ,
           viz.
           first
           ,
           the
           augmenting
           the
           figure
           in
           the
           Tube
           ,
           by
           the
           smallness
           of
           the
           object-Glass
           ,
           and
           length
           of
           the
           Tube
           :
           and
           secondly
           ,
           by
           the
           augmenting
           that
           image
           in
           the
           bottom
           of
           the
           eye
           ,
           and
           that
           is
           by
           the
           Eye-glass
           ;
           give
           therefore
           light
           enough
           to
           the
           object
           ,
           and
           you
           may
           increase
           the
           image
           at
           the
           bottom
           of
           the
           eye
           to
           what
           proportion
           you
           shall
           desire
           .
           And
           by
           a
           way
           I
           shall
           shortly
           shew
           ,
           the
           objects
           may
           be
           perceived
           distinct
           ,
           defined
           ,
           and
           colourless
           ,
           as
           if
           seen
           by
           the
           naked
           eye
           .
           In
           all
           these
           ways
           the
           manner
           of
           applying
           the
           light
           is
           very
           significant
           ,
           and
           provided
           it
           be
           very
           strong
           ,
           the
           smaller
           the
           point
           be
           it
           proceedeth
           from
           ,
           the
           more
           distinctly
           doth
           it
           exhibit
           the
           difference
           of
           refraction
           in
           the
           transparent
           bodies
           viewed
           by
           it
           ,
           and
           the
           plainer
           will
           their
           parts
           be
           discovered
           :
           The
           light
           therefore
           of
           the
           Sun
           either
           reflected
           from
           a
           Spherical
           Convex
           body
           ,
           or
           Spherical
           Concave
           body
           ,
           the
           object
           being
           placed
           beyond
           the
           focus
           ,
           or
           Refracted
           through
           a
           Concave
           or
           through
           a
           Convex
           ,
           if
           the
           object
           be
           placed
           beyond
           the
           focus
           ,
           do
           exceedingly
           well
           .
           But
           these
           with
           the
           help
           of
           a
           dark
           Room
           do
           yet
           better
           ,
           the
           object
           being
           placed
           in
           a
           Table
           against
           the
           Light
           ,
           and
           all
           other
           Light
           screen'd
           from
           the
           Eye
           by
           the
           Dark
           Room
           .
           Much
           the
           same
           thing
           is
           done
           by
           the
           Light
           of
           a
           Lamp
           or
           Candle
           in
           the
           Night
           ,
           which
           is
           indeed
           the
           most
           convenient
           Light
           ,
           where
           Colour
           is
           not
           so
           much
           looked
           after
           .
        
         
           Whilest
           this
           Discourse
           was
           Printing
           I
           casually
           met
           with
           a
           Treatise
           of
           
             P.
             Cherubine
          
           ,
           Printed
           at
           
             Paris
             ,
             1677.
          
           
           Entituled
           ,
           
             LAVISION
             PERFAITE
             ,
             ou
             les
             concours
             des
             deux
             axes
             de
             la
             Vision
             en
             un
             sceul
             point
             de
             l'
             object
          
           ;
           Wherein
           the
           Author
           pretends
           amongst
           other
           things
           to
           have
           promoted
           Microscopes
           extreamly
           by
           so
           joyning
           two
           together
           ,
           as
           through
           them
           to
           see
           the
           same
           object
           distinct
           with
           both
           the
           Eyes
           at
           once
           ,
           and
           to
           see
           a
           large
           object
           all
           at
           one
           view
           ,
           by
           which
           he
           affirms
           to
           have
           discovered
           some
           mistakes
           and
           untruths
           in
           some
           of
           those
           figures
           I
           have
           formerly
           published
           in
           my
           Micrography
           .
           But
           if
           he
           had
           pleased
           to
           have
           read
           
           the
           Description
           as
           well
           as
           looked
           on
           the
           Figure
           ,
           he
           might
           have
           been
           better
           informed
           than
           by
           his
           Preface
           he
           would
           seem
           to
           be
           .
           I
           deny
           not
           but
           that
           there
           are
           many
           failures
           in
           some
           of
           those
           draughts
           ,
           some
           of
           my
           own
           and
           some
           of
           the
           gravers
           committing
           .
           
             Humanum
             est
          
           .
           But
           those
           which
           he
           charges
           for
           such
           are
           not
           ,
           as
           he
           might
           have
           seen
           if
           he
           had
           made
           use
           of
           better
           glasses
           than
           those
           which
           he
           describes
           ,
           for
           they
           are
           so
           far
           short
           of
           equalling
           those
           I
           use
           ,
           that
           I
           can
           demonstrate
           from
           his
           own
           Description
           of
           them
           ,
           that
           those
           I
           made
           use
           of
           did
           magnifie
           10000
           times
           more
           than
           that
           with
           which
           he
           pretends
           to
           have
           made
           these
           great
           Discoveries
           .
           Nor
           is
           it
           any
           thing
           more
           than
           common
           to
           see
           as
           large
           an
           Area
           as
           he
           mentions
           ,
           with
           a
           glass
           that
           magnifies
           no
           more
           than
           his
           doth
           .
           But
           I
           could
           have
           shewed
           him
           how
           he
           might
           see
           the
           whole
           Creature
           at
           once
           ,
           and
           yet
           much
           more
           magnifie
           than
           that
           which
           I
           have
           described
           ,
           nay
           though
           the
           Creature
           were
           twice
           as
           big
           ,
           and
           that
           with
           one
           Eye
           only
           ,
           which
           is
           much
           to
           be
           preferred
           before
           that
           with
           two
           .
           However
           I
           should
           be
           very
           glad
           to
           hear
           what
           Discoveries
           he
           doth
           make
           with
           his
           binocular
           Microscope
           more
           than
           was
           seen
           before
           .
           As
           also
           that
           he
           would
           please
           to
           demonstrate
           the
           truth
           of
           Parallelogram
           prescribed
           for
           certain
           uses
           ,
           pag.
           of
           Dioptrique
           Oculaire
           ,
           and
           in
           the
           Fourth
           Chapter
           of
           the
           Fourth
           Part
           of
           this
           Book
           .
           But
           to
           digress
           no
           farther
           from
           what
           I
           was
           describing
           .
           I
           must
           add
           that
           with
           both
           these
           kinds
           of
           Microscopes
           have
           I
           examined
           several
           substances
           ;
           as
           particularly
           the
           steepings
           of
           several
           grains
           and
           seeds
           in
           rain-water
           .
           And
           though
           I
           have
           not
           yet
           found
           any
           one
           tincture
           more
           prolific
           than
           this
           of
           Pepper
           ;
           yet
           't
           is
           not
           the
           only
           tincture
           in
           which
           they
           do
           both
           breed
           and
           increase
           .
           I
           have
           seen
           several
           sorts
           in
           the
           steeping
           of
           Wheat
           ,
           Barly
           ,
           Oats
           ,
           Coffee
           ,
           Anniseeds
           ,
           Pease
           ,
           &c.
           some
           not
           above
           a
           third
           part
           of
           a
           hair
           in
           thickness
           ;
           others
           not
           above
           the
           twentieth
           part
           of
           the
           breadth
           of
           a
           hair
           ,
           and
           some
           not
           more
           than
           a
           thirtieth
           part
           of
           that
           breadth
           ;
           so
           that
           no
           less
           than
           900
           of
           these
           least
           must
           go
           to
           make
           an
           
           area
           as
           big
           as
           that
           of
           an
           hair
           cut
           transversly
           ,
           and
           27000
           to
           make
           a
           Cylinder
           as
           big
           as
           the
           hair
           of
           ones
           head
           ,
           and
           of
           equal
           height
           with
           the
           Diameter
           of
           that
           hair
           ,
           which
           one
           may
           just
           call
           a
           visible
           point
           ,
           and
           no
           more
           ;
           few
           eyes
           seeing
           things
           distinctly
           much
           smaller
           :
           Now
           the
           Diameter
           of
           a
           hair
           of
           my
           head
           being
           by
           examination
           found
           but
           the
           640
           part
           of
           an
           inch
           ,
           it
           follows
           that
           no
           less
           than
           19200
           or
           to
           use
           a
           round
           summ
           about
           20000
           of
           them
           may
           lie
           in
           the
           length
           of
           an
           inch
           ,
           and
           consequently
           ,
           that
           a
           circle
           an
           inch
           Diameter
           will
           be
           to
           the
           area
           of
           one
           of
           these
           cut
           transversly
           as
           400000000
           to
           1.
           four
           hundred
           millions
           to
           1
           and
           a
           Cylinder
           one
           inch
           Diameter
           ,
           and
           one
           inch
           high
           ,
           will
           be
           to
           one
           of
           these
           mites
           ,
           as
           8000000000000
           to
           one
           ,
           eight
           millions
           of
           millions
           to
           one
           .
           If
           therefore
           we
           compare
           the
           magnitude
           of
           one
           of
           these
           animals
           to
           the
           magnitude
           of
           other
           creatures
           living
           in
           the
           water
           ,
           we
           shall
           find
           that
           these
           will
           be
           found
           much
           smaller
           in
           comparison
           to
           the
           body
           of
           an
           ordinary
           Whale
           ,
           than
           the
           body
           of
           the
           same
           Whale
           will
           be
           to
           the
           body
           of
           the
           whole
           Earth
           ;
           which
           may
           prove
           an
           argument
           for
           an
           
             anima
             mundi
          
           perhaps
           to
           some
           .
           But
           let
           every
           one
           make
           his
           own
           inferences
           ,
           and
           believe
           his
           own
           eyes
           ,
           for
           they
           will
           make
           the
           best
           impression
           on
           his
           reason
           and
           belief
           .
           Now
           if
           the
           Creature
           be
           so
           exceeding
           small
           ,
           what
           must
           we
           think
           of
           the
           Muscles
           ,
           Joynts
           ,
           Bones
           ,
           Shells
           ,
           &c.
           certain
           it
           is
           ,
           that
           the
           Mechanism
           by
           which
           Nature
           performs
           the
           muscular
           motion
           is
           exceedingly
           small
           and
           curious
           ,
           and
           to
           the
           performance
           of
           every
           muscular
           motion
           in
           greater
           Animals
           at
           least
           ,
           there
           are
           not
           fewer
           distinct
           parts
           concerned
           than
           many
           millions
           of
           millions
           ,
           and
           these
           visible
           ,
           as
           I
           shall
           hereafter
           shew
           through
           a
           Microscope
           ;
           and
           those
           that
           conceive
           in
           the
           body
           of
           a
           muscle
           ,
           little
           more
           curiosity
           of
           mechanism
           than
           in
           a
           rope
           of
           the
           same
           bigness
           ,
           have
           a
           very
           rude
           and
           false
           notion
           of
           it
           ;
           and
           no
           wonder
           if
           they
           have
           recourse
           to
           Spirits
           to
           make
           out
           the
           Phaenomena
           :
           but
           of
           this
           hereafter
           more
           .
        
         
           Further
           ,
           I
           have
           examined
           the
           constitution
           of
           Blood
           ,
           
           Milk
           ,
           Flegm
           ,
           &c.
           and
           found
           them
           much
           the
           same
           with
           what
           Mr.
           Leeuwenhock
           has
           declared
           .
           A
           little
           fat
           laid
           upon
           the
           glass
           plate
           whilst
           warm
           ,
           melts
           ,
           and
           becomes
           transparent
           ,
           but
           observed
           in
           a
           convenient
           posture
           against
           the
           light
           of
           a
           candle
           ,
           &c.
           till
           it
           congeals
           ,
           and
           shrinks
           ,
           make
           a
           pleasant
           fluid
           ,
           and
           shews
           how
           considerably
           a
           fluid
           and
           solid
           body
           do
           vary
           ,
           and
           may
           give
           us
           a
           good
           hint
           to
           conjecture
           at
           the
           reason
           of
           the
           swelling
           and
           greater
           lightness
           of
           Ice
           than
           of
           Water
           .
           The
           first
           beginnings
           also
           of
           the
           shooting
           or
           crystallising
           of
           Sugar
           into
           rectangular
           parallelipipeds
           ,
           Alum
           ,
           Salt
           ,
           Vitriol
           ,
           &c.
           are
           strangely
           surprizing
           and
           instructive
           ,
           I
           could
           enumerate
           multitudes
           of
           these
           .
        
         
           But
           (
           that
           I
           may
           not
           detain
           the
           Reader
           toolong
           in
           the
           perusal
           of
           these
           anatomical
           descriptions
           of
           the
           minute
           and
           invisible
           parts
           of
           animal
           substances
           )
           to
           ease
           both
           his
           eyes
           and
           imagination
           I
           shall
           proceed
           to
           acquaint
           him
           with
           some
           Anatomical
           Observations
           more
           sensible
           ,
           and
           which
           do
           seem
           more
           nearly
           to
           concern
           us
           .
           And
           those
           are
           contained
           in
           the
           ensuing
           Discourse
           ,
           being
        
         
           
             
             
               A
               Relation
               communicated
               to
               me
               in
               a
               Letter
               by
               that
               ingenious
               and
               experienced
               Chirurgion
               Mr.
               James
               Young
               of
               Plimouth
               ,
               in
               the
               beginning
               of
               January
               last
               ,
               of
               the
               fatal
               Symptoms
               caused
               by
               a
               Bullet
               swallowed
               into
               the
               Lungs
               .
            
             
               SIR
               ,
               In
               the
               beginning
               of
               April
               ,
               1674.
               one
               Mr.
               
                 Anthony
                 Williamson
              
               of
               Liscard
               in
               Cornwal
               ,
               aged
               about
               65
               years
               ,
               of
               a
               brisk
               ,
               firm
               habit
               ,
               became
               (
               after
               a
               too
               liberal
               drinking
               of
               Cyder
               )
               afflicted
               with
               the
               Colick
               ,
               of
               which
               in
               four
               days
               he
               cured
               himself
               ,
               by
               swallowing
               two
               Musket
               Bullets
               ,
               and
               receiving
               some
               Carminative
               Clysters
               .
               On
               the
               12.
               of
               the
               same
               month
               ,
               his
               pain
               returning
               somewhat
               smarter
               than
               before
               ,
               he
               attempted
               to
               swallow
               three
               Pistol
               Shot
               ,
               and
               supposing
               it
               the
               easiest
               way
               ,
               he
               lay
               on
               his
               back
               ,
               and
               threw
               them
               all
               at
               once
               into
               his
               throat
               ;
               where
               they
               choaking
               ,
               had
               almost
               strangled
               him
               ;
               constraining
               him
               to
               vomit
               ,
               &c.
               
               When
               they
               were
               past
               down
               ,
               he
               became
               seized
               immediately
               with
               a
               violent
               Cough
               ,
               Wheasing
               ,
               pain
               in
               the
               left
               side
               of
               his
               Breast
               ,
               a
               great
               noise
               in
               respiration
               ,
               more
               especially
               after
               a
               fit
               of
               Coughing
               for
               then
               his
               Breast
               would
               hiss
               ,
               like
               the
               sucking
               of
               a
               Pump
               ,
               when
               the
               Air
               descends
               through
               the
               boxes
               .
            
             
               These
               accidents
               so
               suddenly
               occurring
               ,
               without
               any
               manifest
               cause
               ,
               did
               much
               surprize
               him
               ,
               and
               the
               more
               ,
               because
               he
               was
               naturally
               of
               a
               sound
               breast
               ;
               the
               Colick
               was
               cured
               by
               Clysters
               ,
               Potions
               of
               Manna
               ,
               
                 ol
                 .
                 amyg
                 .
                 d.
                 &c.
              
               and
               two
               of
               the
               Shot
               were
               soon
               ejected
               ,
               
                 ex
                 ano
              
               ,
               and
               maugre
               the
               other
               accidents
               ,
               he
               became
               indifferently
               well
               ,
               and
               able
               to
               walk
               about
               house
               .
            
             
               Five
               or
               six
               weeks
               after
               this
               ,
               those
               symptoms
               became
               more
               fierce
               ,
               depaupering
               his
               spirits
               ,
               prostrating
               his
               appetite
               ,
               disquieting
               his
               sleep
               with
               dreams
               ,
               a
               Dyspnoea
               ,
               and
               rutling
               violent
               Cough
               ;
               a
               straitness
               and
               load
               in
               his
               Breast
               kept
               him
               in
               bed
               ,
               extenuated
               his
               body
               (
               which
               without
               help
               of
               Milk
               Clysters
               ,
               was
               costive
               )
               he
               frequently
               fainted
               with
               sweats
               ,
               and
               a
               tickling
               sleepiness
               in
               both
               legs
               .
            
             
             
               Under
               the
               tyranny
               of
               this
               legion
               of
               symptoms
               ,
               our
               Western
               Apollo
               ,
               Dr.
               Bidgood
               of
               Exeter
               was
               consulted
               ,
               who
               affirmed
               them
               all
               to
               be
               caused
               by
               the
               remaining
               Bullet
               ,
               which
               passing
               through
               the
               Larynx
               ,
               was
               fallen
               into
               one
               of
               the
               branches
               of
               the
               Trachea
               ,
               where
               it
               would
               abide
               ,
               in
               despight
               of
               any
               endeavours
               to
               eject
               it
               :
               yet
               to
               alleviate
               the
               violence
               of
               the
               accidents
               ,
               he
               directed
               to
               the
               use
               of
               emollient
               Eclegma's
               ,
               temperate
               Cordials
               ,
               &c.
               by
               help
               of
               which
               ,
               and
               some
               other
               propitious
               circumstances
               ,
               he
               not
               only
               recovered
               his
               legs
               ,
               becoming
               able
               to
               walk
               ,
               and
               ride
               a
               small
               Journey
               ,
               but
               also
               consummated
               Marriage
               with
               a
               young
               woman
               of
               25
               —
               who
               afterward
               brought
               him
               two
               Children
               ,
               whereof
               one
               is
               now
               alive
               ,
               and
               very
               lusty
               ;
               and
               was
               seven
               months
               gone
               with
               a
               third
               ,
               when
               he
               died
               :
               the
               more
               wonderful
               if
               the
               woman
               were
               just
               to
               him
               (
               of
               which
               there
               appeareth
               no
               reason
               to
               doubt
               )
               because
               a
               very
               little
               motion
               would
               so
               increase
               his
               difficulty
               of
               breathing
               ,
               as
               to
               make
               him
               faint
               .
            
             
               After
               Matrimony
               he
               had
               divers
               lucid
               Intervals
               ,
               at
               times
               would
               be
               very
               brisk
               ,
               and
               at
               others
               very
               languid
               ,
               and
               faint
               ,
               like
               a
               dying
               man
               :
               he
               continually
               expectorated
               ,
               sometimes
               grumous
               coagulated
               Blood
               ,
               otherwhiles
               very
               recent
               ;
               now
               purulent
               foetid
               matter
               ,
               then
               laudable
               pus
               .
               His
               natural
               aversion
               to
               Medicine
               caused
               him
               to
               reject
               what
               was
               advised
               by
               Dr.
               Bidgood
               ,
               Dr.
               Lower
               ,
               Dr.
               
                 Sprage
                 ,
                 &c.
              
               saving
               a
               few
               of
               the
               more
               slight
               mixtures
               :
               And
               although
               Sack
               had
               been
               formerly
               very
               familiar
               to
               him
               ,
               he
               was
               now
               forced
               to
               shun
               it
               ,
               and
               all
               strong
               Drinks
               ,
               because
               they
               would
               infallibly
               produce
               a
               Cardialgia
               ,
               a
               pulsant
               throbbing
               of
               the
               Heart
               ,
               and
               labouring
               in
               his
               Breast
               :
               the
               first
               of
               these
               perhaps
               proceeded
               from
               his
               Constitution
               ,
               which
               inclined
               to
               Choler
               ;
               but
               the
               latter
               undoubtedly
               ,
               from
               the
               effervescency
               ,
               and
               warm
               motion
               ,
               to
               which
               it
               enforced
               the
               Blood
               ,
               which
               the
               obstruction
               and
               pressure
               the
               Bullet
               occasioned
               in
               the
               Pneumatick
               organs
               ,
               could
               not
               peaceably
               admit
               of
               :
               wherefore
               he
               resolutely
               fixed
               to
               small
               Drink
               ,
               and
               shunned
               ,
               as
               much
               as
               possible
               ,
               all
               evitable
               Exercise
               ,
               saving
               that
               of
               
               his
               hands
               ,
               which
               he
               frequently
               employed
               in
               making
               Net-work
               .
            
             
               In
               the
               Year
               1676.
               he
               applied
               himself
               to
               our
               ingenious
               and
               learned
               Country-man
               ,
               Dr
               Mayow
               of
               Bath
               ,
               who
               agreed
               with
               Dr.
               Bidgood
               ,
               that
               the
               remaining
               Bullet
               lodging
               in
               the
               Lungs
               ,
               was
               the
               occasion
               of
               all
               those
               ill
               symptomes
               under
               which
               he
               laboured
               ;
               but
               seemed
               to
               dissent
               from
               his
               presage
               ,
               by
               hoping
               he
               might
               expectorate
               it
               :
               to
               atchieve
               which
               ,
               he
               directed
               to
               have
               the
               body
               suspended
               head
               downwards
               ,
               and
               fumes
               of
               Storax
               ,
               Benjamin
               ,
               &c.
               to
               induce
               expulsive
               Coughing
               ,
               together
               with
               concussions
               of
               the
               body
               ,
               and
               all
               preceded
               with
               an
               opening
               course
               ,
               to
               relax
               ,
               and
               dilate
               the
               vessels
               of
               the
               Breast
               ;
               all
               which
               were
               used
               to
               no
               purpose
               ,
               save
               to
               verifie
               Dr.
               Bidgoods
               Prognostick
               ,
               that
               no
               efflation
               ,
               how
               violent
               soever
               ,
               would
               be
               able
               to
               extrude
               it
               ,
               and
               inhaunce
               the
               Patients
               despair
               of
               being
               ever
               cured
               ;
               from
               which
               time
               he
               never
               attempted
               it
               :
               so
               that
               those
               symptomes
               before
               mentioned
               ,
               continuing
               until
               the
               Winter
               ,
               and
               then
               gaining
               considerably
               on
               him
               ,
               especially
               the
               
                 Haemoptysis
                 ,
                 &c.
              
               he
               languished
               till
               the
               ninth
               of
               December
               last
               ,
               and
               then
               died
               .
            
             
               The
               tenth
               Ditto
               (
               assisted
               by
               his
               Son-in-law
               )
               I
               opened
               the
               Thorax
               ,
               in
               presence
               of
               two
               other
               Chirurgions
               of
               the
               place
               ,
               together
               with
               divers
               persons
               of
               Quality
               ,
               whose
               curiosity
               led
               them
               to
               see
               the
               examination
               ;
               because
               the
               Bullets
               being
               there
               ,
               was
               so
               much
               doubted
               by
               many
               ,
               and
               disputed
               as
               impossible
               by
               others
               .
               In
               the
               disfection
               the
               following
               particulars
               were
               observable
               ,
            
             
               The
               Body
               was
               extenuate
               and
               tabid
               ,
            
             
               The
               right
               lobes
               of
               the
               Lungs
               were
               replete
               ,
               sound
               ,
               and
               well
               coloured
               .
            
             
               The
               Serum
               in
               the
               Pericardium
               was
               almost
               all
               absumed
               ,
            
             
               The
               Heart
               strangely
               shrivelled
               and
               very
               small
               .
            
             
               Under
               the
               Pericardium
               (
               the
               Body
               being
               supine
               )
               we
               found
               a
               lump
               of
               coagulated
               Blood
               ,
               as
               big
               as
               a
               Pigeons
               Egg
               ;
               near
               which
               lay
               also
               a
               substance
               ,
               shaped
               like
               an
               
               obtuse
               headed
               muscle
               ,
               having
               a
               Tendon-like
               tail
               ,
               which
               insinuated
               to
               the
               Pendant
               Lobe
               :
               Its
               body
               was
               above
               an
               half
               inch
               thick
               .
               It
               s
               other
               dimensions
               and
               shape
               exactly
               like
               that
               of
               the
               figure
               X
               ,
               of
               which
               A
               sheweth
               the
               head
               or
               upper
               end
               ,
               B
               the
               tail
               ,
               which
               in
               drawing
               out
               of
               the
               rotten
               Lungs
               (
               being
               also
               corrupted
               )
               broke
               asunder
               .
               It
               s
               Texture
               seemed
               fibrous
               ,
               like
               that
               of
               the
               Kidneys
               ,
               being
               white
               one
               half
               way
               through
               ,
               the
               rest
               of
               a
               dark
               red
               :
               it
               was
               very
               soft
               and
               plum
               ,
               having
               a
               firm
               smooth
               tegument
               ,
               and
               felt
               very
               much
               like
               a
               Sheeps
               kidney
               .
            
             
               The
               left
               Lobe
               of
               the
               Lungs
               was
               cadaverous
               ,
               and
               hollow
               ,
               by
               an
               abscess
               which
               had
               discharged
               near
               a
               pint
               of
               very
               foetid
               and
               purulent
               matter
               ,
               into
               that
               side
               of
               the
               trunk
               where
               it
               lay
               immured
               up
               ,
               by
               the
               adhesion
               of
               the
               Lungs
               on
               that
               side
               ,
               to
               the
               Pleura
               ,
               which
               with
               the
               Diaphragima
               ,
               as
               far
               as
               the
               matter
               extended
               ,
               was
               livid
               ,
               and
               eroded
               .
            
             
               We
               examined
               this
               rotten
               part
               of
               the
               Lungs
               ,
               with
               what
               exactness
               and
               curiosity
               we
               were
               capable
               of
               ,
               amidst
               such
               a
               crowd
               as
               were
               present
               ;
               and
               the
               more
               troublesome
               stench
               of
               the
               Cadaver
               ;
               and
               found
               though
               the
               whole
               Parenchyma
               were
               rotten
               ,
               and
               no
               firmer
               than
               coagulated
               Blood
               (
               with
               which
               it
               had
               very
               near
               resemblance
               )
               yet
               the
               branches
               of
               the
               Trachea
               continued
               into
               it
               were
               uncorrupt
               ,
               and
               sound
               ;
               nor
               in
               any
               of
               them
               could
               we
               find
               what
               we
               very
               confidently
               presumed
               to
               be
               there
               ,
               viz.
               the
               Bullet
               .
            
             
               Wherefore
               I
               resolved
               to
               seek
               it
               the
               way
               by
               which
               it
               must
               have
               entred
               ;
               and
               accordingly
               dividing
               the
               Trachea
               at
               its
               insertion
               to
               the
               Lungs
               ,
               I
               thrust
               in
               a
               bended
               Probe
               to
               the
               left
               branch
               ,
               and
               there
               felt
               him
               ,
               lying
               loose
               about
               two
               inches
               within
               it
               ,
               which
               with
               my
               fingers
               I
               easily
               expressed
               at
               the
               divided
               end
               of
               the
               pipe
               :
               to
               do
               which
               ,
               I
               laid
               it
               bare
               so
               far
               as
               where
               the
               Bullet
               had
               lodged
               ;
               and
               I
               protest
               ,
               to
               my
               wonder
               ,
               I
               found
               it
               not
               any
               way
               injured
               ,
               or
               altered
               ,
               by
               hardness
               ,
               erosion
               ,
               &c.
               though
               the
               Bullet
               had
               divers
               impressions
               from
               the
               later
               .
            
             
             
               The
               sanguiferous
               vessels
               ,
               though
               lacerated
               ,
               and
               cut
               in
               the
               dissection
               ,
               did
               yield
               little
               or
               no
               Blood
               ,
               either
               fluid
               or
               coagulate
               .
            
             
               Thus
               far
               is
               true
               History
               ,
               and
               matter
               of
               fact
               ;
               I
               must
               now
               beg
               your
               pardon
               ,
               if
               I
               presume
               to
               give
               my
               sense
               ,
               and
               apprehension
               of
               some
               of
               those
               Phaenomena
               here
               related
               .
            
             
               The
               extenuation
               of
               the
               body
               ,
               the
               absumption
               of
               the
               serum
               in
               the
               Heart-bag
               ,
               and
               the
               contraction
               of
               the
               Heart
               ,
               were
               the
               effects
               of
               the
               Tabes
               ;
               and
               that
               occasioned
               by
               the
               Bullets
               injuring
               the
               Lungs
               ,
               and
               pectoral
               vessels
               .
            
             
               The
               lump
               of
               coagulate
               blood
               found
               under
               the
               Heart-bag
               was
               extravasate
               from
               the
               rotted
               veins
               ,
               and
               arteries
               of
               the
               Lungs
               .
            
             
               That
               strange
               substance
               lodged
               between
               the
               Pericardium
               ,
               and
               the
               Bullet
               ,
               was
               either
               a
               Polypus
               ,
               and
               the
               excrescence
               of
               some
               part
               ,
               or
               it
               was
               generated
               by
               nature
               ,
               and
               substituted
               for
               a
               cushion
               to
               defend
               the
               Heart
               from
               injury
               ,
               by
               so
               uneasie
               a
               neighbour
               .
               That
               Polypuses
               have
               been
               found
               in
               the
               Heart
               ,
               is
               affirmed
               by
               
                 Nicolas
                 Tulpius
                 ,
                 Marcellus
                 Malpighius
                 ,
                 G.
                 Garnarus
                 ,
              
               &c.
               but
               their
               shape
               and
               texture
               differing
               vastly
               from
               that
               of
               ours
               ,
               giveth
               reason
               to
               believe
               this
               to
               be
               none
               ;
               especially
               considering
               that
               they
               all
               excrescing
               from
               the
               Heart
               ,
               or
               some
               carneous
               part
               ,
               are
               inseparably
               united
               and
               radicated
               to
               their
               original
               ,
               and
               are
               spungy
               ;
               whereas
               this
               was
               nothing
               less
               ,
               having
               no
               root
               ,
               nor
               so
               much
               as
               an
               adhesion
               any
               where
               ,
               saving
               at
               the
               tail
               ;
               the
               small
               end
               of
               which
               ,
               being
               rotted
               by
               the
               Lungs
               ,
               into
               which
               it
               continued
               ,
               did
               easily
               divide
               upon
               my
               endeavour
               to
               draw
               it
               out
               :
               the
               body
               of
               it
               also
               lay
               loose
               in
               the
               aforesaid
               interstice
               ,
               and
               as
               easily
               slipped
               out
               ,
               as
               a
               Wen
               ,
               or
               a
               Struma
               ,
               when
               the
               containing
               parts
               are
               opened
               .
               It
               s
               substance
               was
               not
               fungous
               ,
               but
               of
               a
               soft
               firmness
               ,
               like
               a
               Kidney
               ;
               and
               in
               what
               ever
               circumstances
               it
               may
               resemble
               a
               Polypus
               ,
               as
               it
               doth
               the
               figure
               of
               that
               of
               the
               Nose
               ,
               
                 vide
                 N.
                 Tulpii
                 ob
                 .
                 med
                 .
                 lib.
                 1.
                 obs
                 .
              
               26.
               yet
               it
               also
               differs
               from
               all
               other
               excrescences
               ,
               
               besides
               ,
               in
               what
               hath
               been
               mentioned
               ,
               in
               that
               it
               was
               not
               rooted
               in
               any
               fleshy
               ,
               bony
               ,
               or
               muculous
               part
               ;
               and
               such
               the
               Lungs
               are
               well
               known
               not
               to
               be
               :
               it
               must
               therefore
               be
               the
               stupendious
               effect
               of
               Natures
               industry
               ,
               and
               laid
               as
               a
               cushion
               to
               defend
               the
               Heart
               ,
               &c.
               
               It
               s
               composition
               being
               so
               delicately
               soft
               ,
               and
               yet
               firm
               enough
               for
               such
               a
               purpose
               :
               Its
               magnitude
               ,
               situation
               ,
               &c.
               concurring
               also
               to
               confirm
               this
               opinion
               concerning
               it
               ;
               besides
               which
               ,
               I
               do
               almost
               remember
               ,
               and
               believe
               (
               though
               I
               cannot
               be
               positive
               )
               that
               the
               pulsant
               pain
               he
               had
               so
               violently
               in
               his
               Breast
               ,
               toward
               the
               left
               side
               ,
               decreased
               gradatim
               ,
               from
               the
               time
               of
               the
               deglutition
               :
               if
               that
               be
               true
               ,
               whatever
               the
               substance
               were
               ,
               or
               its
               cause
               ,
               its
               effects
               were
               very
               propitious
               ,
               manifesting
               nature
               to
               be
               ,
               not
               only
               a
               diligent
               supplier
               of
               her
               own
               defects
               ,
               but
               as
               industrious
               to
               produce
               strange
               and
               unaccountable
               relief
               ,
               in
               such
               emergencies
               as
               this
               before
               us
               :
               A
               resembling
               story
               we
               have
               from
               
                 A
                 Pareus
                 ,
                 lib.
                 8.
                 cap.
              
               15.
               
            
             
               The
               abscess
               was
               without
               doubt
               from
               a
               Phlegmon
               of
               the
               Lungs
               ;
               and
               because
               for
               the
               most
               part
               it
               was
               below
               ,
               or
               beyond
               the
               Bullet
               ,
               it
               proceeded
               rather
               from
               its
               obstructing
               ,
               and
               so
               stagnating
               the
               Blood
               ,
               and
               recrements
               in
               that
               Lobe
               ,
               than
               from
               extravasation
               .
               What
               occurred
               of
               the
               latter
               ,
               was
               expectorated
               ,
               or
               remained
               in
               such
               Coagulums
               as
               that
               found
               under
               the
               Heart
               .
            
             
               The
               cause
               of
               the
               Bullets
               falling
               ,
               rather
               into
               the
               left
               than
               the
               right
               Ramus
               of
               the
               Trachea
               ,
               is
               obvious
               from
               the
               more
               supine
               and
               direct
               figure
               thereof
               ,
               corresponding
               with
               the
               trunk
               ,
               as
               the
               figure
               doth
               manifest
               :
               which
               consideration
               ,
               together
               with
               the
               Bullets
               being
               loose
               in
               the
               pipe
               ,
               renders
               the
               unsuccessfulness
               of
               Dr.
               
               Mayow's
               attempt
               very
               wonderful
               :
               I
               am
               inclined
               to
               believe
               it
               was
               so
               ,
               either
               for
               want
               of
               a
               more
               early
               trial
               ,
               or
               a
               more
               skilful
               tryer
               ,
               than
               him
               who
               was
               employed
               about
               it
               .
               The
               way
               was
               ingeniously
               contrived
               ,
               and
               (
               as
               the
               Doctor
               himself
               told
               me
               )
               had
               been
               successfully
               experienced
               in
               the
               like
               occasion
               .
               Certainly
               ,
               had
               not
               the
               distance
               of
               the
               Doctors
               abode
               ,
               and
               very
               important
               avocations
               ,
               
               denied
               his
               personal
               assistance
               :
               or
               had
               any
               other
               person
               skilled
               in
               Anatomy
               ,
               &c.
               been
               substituted
               ,
               the
               Bullet
               from
               his
               own
               favourable
               shape
               ,
               and
               more
               propitious
               gravity
               ,
               and
               particularly
               from
               the
               strong
               efflations
               they
               provoked
               ,
               together
               with
               the
               assistant
               posture
               of
               the
               body
               ,
               would
               have
               been
               extruded
               .
               Had
               they
               instead
               of
               hanging
               him
               perpendicular
               ,
               made
               him
               incline
               a
               little
               to
               the
               right
               side
               ,
               to
               have
               made
               the
               left
               Ramus
               more
               prone
               ;
               and
               at
               the
               same
               time
               made
               him
               distend
               the
               pipes
               by
               sucking
               in
               as
               much
               breath
               as
               they
               could
               contain
               ,
               their
               other
               means
               might
               have
               been
               effectual
               ;
               which
               I
               am
               induced
               to
               presume
               from
               the
               prosperous
               effects
               of
               the
               like
               attempt
               ,
               and
               yet
               wanting
               many
               of
               their
               advantages
               ;
               I
               mean
               the
               reversion
               of
               a
               Stone
               ,
               when
               sticking
               ,
               and
               not
               able
               ,
               to
               pass
               through
               the
               Urinary
               Channels
               .
               Let
               any
               Physicians
               seriously
               perpend
               the
               difficulty
               of
               this
               ,
               with
               the
               advantages
               for
               the
               former
               ,
               and
               they
               will
               justifie
               my
               opinion
               .
            
             
               The
               erosion
               of
               the
               Pleura
               ,
               and
               Diaphragme
               ,
               was
               from
               the
               acidity
               of
               the
               matter
               ,
               gnawing
               and
               corrupting
               them
               ;
               for
               though
               the
               Trachea
               wonderfully
               escaped
               such
               impressions
               ,
               the
               Bullet
               discovered
               on
               its
               superficies
               ,
               divers
               marks
               of
               erosion
               ,
               which
               all
               acids
               produce
               with
               much
               facility
               ,
               upon
               the
               saccharous
               or
               saline
               parts
               of
               Lead
               ;
               as
               is
               to
               be
               seen
               by
               immersing
               it
               in
               vinegar
               .
            
             
               And
               now
               Sir
               ,
               to
               relieve
               your
               patience
               (
               no
               less
               than
               my
               own
               )
               perhaps
               already
               wearied
               with
               the
               prolixity
               of
               this
               Narrative
               ,
               give
               me
               leave
               to
               conclude
               ,
               with
               suggesting
               ,
               that
               I
               am
               of
               a
               belief
               (
               having
               perused
               most
               of
               the
               publick
               accounts
               of
               this
               kind
               )
               that
               scarcely
               a
               rarer
               accident
               ,
               and
               accompanied
               with
               such
               stupendious
               circumstances
               ,
               hath
               occurred
               to
               the
               present
               age
               than
               this
               :
               that
               an
               extraneous
               body
               ,
               so
               large
               ,
               so
               heavy
               ,
               so
               hard
               ,
               should
               slip
               down
               that
               difficult
               ,
               and
               unusual
               way
               of
               the
               Weason
               ,
               and
               abide
               so
               long
               in
               the
               organs
               of
               respiration
               ,
               in
               so
               aged
               a
               person
               ,
               admitting
               after
               it
               such
               exercises
               ,
               as
               he
               performed
               ,
               Riding
               ,
               Marriage
               ,
               &c.
               that
               nature
               should
               so
               unaccountably
               provide
               such
               a
               pertinent
               
               sence
               against
               injuries
               accidentally
               accruing
               ,
               and
               that
               even
               the
               smallest
               Ramifications
               of
               the
               Trachea
               ,
               though
               immersed
               in
               such
               a
               Cadaver
               ,
               should
               be
               preserved
               from
               injury
               thereby
               .
               I
               am
               sure
               in
               the
               voluminous
               Observations
               of
               
                 Schenckius
                 ,
                 Horstius
                 ,
                 Riverius
                 ,
                 Bartholine
                 ,
                 Burnet
                 ,
              
               &c.
               nor
               among
               all
               the
               stories
               in
               Mr.
               
               Oldenburg's
               Transactions
               ,
               or
               the
               
                 Miscellanea
                 Curiosa
              
               of
               the
               Leipswick
               Doctors
               ,
               hath
               it
               a
               Parallel
               .
            
             
               
                 This
                 ,
                 and
                 whatever
                 is
                 else
                 contained
                 in
                 this
                 History
                 ,
                 as
                 my
                 
                   〈◊〉
                   〈◊〉
                   〈◊〉
                   〈◊〉
                   〈◊〉
                
                 ,
                 I
                 submit
                 to
                 the
                 better
                 sense
                 ,
                 and
                 reason
                 of
                 the
                 Learned
                 ,
                 not
                 presuming
                 to
                 be
                 positive
                 in
                 any
                 thing
                 ,
                 save
                 in
                 affirming
                 my self
                 ,
                 &c.
                 JAMES
                 YOVNG
                 .
              
            
             
               
                 P.
                 S.
                 
              
               
                 For
                 the
                 plainer
                 understanding
                 where
                 the
                 Bullet
                 lodged
                 in
                 the
                 Wind-pipe
                 ,
                 I
                 have
                 drawn
                 and
                 sent
                 you
                 an
                 exact
                 figure
                 of
                 the
                 Trachea
                 ,
                 excarnified
                 ;
                 as
                 it
                 s
                 to
                 be
                 be
                 found
                 in
                 
                   Gerrard
                   Blassius
                   ,
                   Syntagma
                   Anatomicum
                   J.
                   Veslingi
                   .
                
                 See
                 figure
                 Y
                 in
                 the
                 III.
                 Table
                 .
              
               
                 C
                 points
                 to
                 the
                 Trachea
                 divided
                 under
                 the
                 Larynx
                 .
              
               
                 D
                 the
                 right
                 Ramus
                 of
                 the
                 
                   Trachea
                   .
                   E
                
                 the
                 left
                 .
              
               
                 F
                 the
                 place
                 where
                 the
                 Lungs
                 adhered
                 to
                 the
                 Pleura
                 .
              
               
                 g
                 g
                 g
                 ,
                 &c.
                 the
                 extremities
                 of
                 those
                 branches
                 of
                 the
                 
                   Aspera
                   arteria
                
                 ,
                 divaricated
                 into
                 the
                 rotten
                 Lobe
                 .
              
               
                 H
                 the
                 Bullet
                 in
                 the
                 pipe
                 where
                 it
                 was
                 found
                 .
              
            
          
        
      
    
     
       
         
           ERRATA
           .
        
         
           
             PAge
             1.
             line
          
           17.
           foot
           .
           
             p.
             2.
             l.
          
           6.
           ioyned
           ,
           
             p.
             8.
             l.
          
           21.
           〈◊〉
           ,
           
             p.
             11.
             l.
          
           5.
           is
           diffused
           ,
           
             p.
             11.
             l.
          
           17.
           
           Fostor
           ,
           
             p.
             12.
             l.
          
           33.
           within
           the
           sphere
           of
           its
           activity
           ,
           
             p.
             12.
             l.
             34.
             dele
          
           as
           ,
           
             p.
             14.
             l.
          
           8.
           
             ether
             ,
             p.
             19.
             l.
          
           7.
           common
           sights
           ,
           
             p.
             22.
             l.
          
           31.
           〈◊〉
           ,
           
             p.
             23.
             l.
          
           19.
           been
           produced
           ,
           
             p.
             24.
             l.
             27.
             add
          
           see
           fig.
           4.
           
             p.
             27.
             l.
          
           5.
           of
           this
           orb
           ,
           
             p.
             27.
             l.
          
           21.
           ♏
           ,
           
             p.
             28.
             l.
          
           27.
           sixth
           figure
           ,
           
             p.
             29.
             l.
          
           18.
           &
           perige
           ,
           
             p.
             29.
             l.
          
           25.
           
           B
           ,
           B
           ,
           E.
           
             ib.
             l.
          
           26
           ,
           27.
           
           H
           ,
           H
           ,
           I
           
             p.
             31.
             l.
          
           9.
           for
           (
           .
           )
           
             put
             (
             ,
             )
             p.
             32.
             l.
          
           28.
           stream
           of
           bu●bles
           ,
           
             p.
             35.
             l.
             29.
             add
          
           fig.
           9.
           
             p.
             38.
             l.
          
           28.
           to
           get
           out
           of
           ,
           l.
           34.
           of
           finding
           the
           ,
           
             p.
             46.
             l.
          
           31.
           
           Baldwines
           
             p.
             49.
             l.
          
           17.
           downwards
           shall
           touch
           ,
           
             p.
             54.
             l.
          
           26.
           
           Scolopendra
           ,
           
             p.
             69
             l.
             ult
          
           .
           Suns
           phase
           ,
           
             p.
             71.
             l.
             25.
             for
             43
             put
             34
             ,
             p.
             83.
             l.
          
           8.
           to
           my
           wonder
           ,
           
             p.
             93.
             l.
             3.
             blot
             out
          
           first
           ,
           
             p
             96.
             l.
          
           14.
           plano
           c●nnexes
           ,
           
             p.
             101.
             l.
             22.
             for
          
           table
           put
           tube
           ,
           
             p.
             101.
             l.
          
           30.
           
           Seul
           ,
           
             p.
             102.
             l.
          
           17.
           magnified
           ,
           l.
           23.
           the
           paralellogram
           ,
           l.
           24.
           page
           241
           ,
           
             p.
             104.
             l.
             6.
             for
          
           fluid
           put
           feild
           .
        
         
         
         
      
       
         
         
           
        
         
         
         
           
        
         
         
         
           
        
         
      
       
         Notes, typically marginal, from the original text
         
           Notes for div A44321-e1350
           
             This
             Revolution
             of
             the
             body
             of
             ♃
             upon
             its
             Axis
             I
             first
             discovered
             in
             May
             1664.
             and
             published
             in
             the
             first
             Transaction
             ,
             which
             was
             a
             considerable
             time
             before
             it
             was
             discovered
             by
             Monsieur
             Cassini
             ;
             but
             we
             are
             obliged
             to
             him
             for
             the
             perfecting
             the
             Theory
             ,
             as
             we
             are
             also
             for
             many
             other
             rare
             Discoveries
             and
             excellent
             improvements
             in
             Astronomy
             .