OUTLINE OF 18TH CENTURY ASTRONOMY
-------------------------------
John Pazmino
NYSkies Astronomy Inc
nyskies@nyskies.org
www.nyskies.org
2003 August 5 initial
2021 July 23 current
At the Observing Group meeting of 12 July 2003 I presented an
overview of astronomy during the 1700s. I had hand-written notes to
cue me. Here are my notes in finished form, with many additional
items suggested since then. I confine to items distinctly 'astronomy',
leaving out collateral fields like chemistry, industry, biography,
and general world affairs.
Apart from minor editing and some addition of new items, the
major change is the collapse of the categories for the entires. It got
too fiddly to put an entry in a one category where it could be valid
for several. Here, entries are now listed seriatim and divided by
decade. I update this article irreguarly as readers advise me of new
items of interest.
The year for each item is sometimes uncertain in the litterature.
It may be the year the work was actually done or that when the work was
published or announced.
1700-1709
---------
1700 - Roemer invents meridian transit telescope
1700 - Boyle, Lord of Orrery, invents hand-driven model of solar
system
1700 - Delisle perfects celestial geodesy
1701 - ENGLAND issues charts with compass variation contours
1702 - Hauksbee shows that electrcity makes rarified air glow,
hints at cause of aurora
1702 - Halley issues first map of geomagnetic field, first use of
contour lines in cartography
1702 - Gregory writes first astronomy textbook with Newton gravity
1704 - Newton issues corpuscular theory of light
1705 - Halley proposes periodic comets, predicts return of
'Halley's comet'
1705 - Flamsteed issues 1st part of most accurate star catalog
1706 - Stannyan discovers prominences during solar eclipse
1708 - Jupiter's 'great red spot' reappears, gone since 1680s
1710-1719
---------
1710 - end of Maunder sunspot drought on Sun
1712 - bootleg unverified Flamsteed catalog is issued
1713 - Newton issues updated 'Principia'
1714 - ENGLAND opens contest for finding longitude at sea
1714 - Whiston & Ditton propose contest for finding longitude
1714 - Leibniz proposes space & time can not be absolute
1715 - Halley discovers 'Baily's beads' during solar eclipse
1715 - Halley does first accurate calcs of solar eclipse path
1716 - Halley shows aurora rays converge by perspective effect
and align with Earth magnetic field
1716 - France opens contest for determining longitude
1716 - Halley proposes Venus transit for fixing Earth-Sun distance
1718 - Cassini proposes Earth is prolate (it's really oblate)
1718 - Halley discovers proper motion of stars
1719 - Maraldi makes first detailed Mars map, fixes rotation
1719 - Maraldi explains changes of Mars polar caps as ice
1719 - Whiston issues first map of magneic inclination
1719 - Stupendous aurora erupts over Europe starting modern
scientific study of northern lights
1720-1729
---------
1720 - Halley studies 'Olber's paradox'
1721 - Berkeley proposes matter-space interaction
1721 - Whiston shows magnetic incliantion to find longitude
1722 - Graham discovers daily shift of geomagnetic feild
1722 - Hadley makes first practical reflector telescope
1724 - Maraldi shows corona is part of Sun, not Moon
1724 - Graham, also Celsius, discovers geomagnetic storm by
violent agitation of marine compass
1725 - Flamsteed posthumously issues most accurate staratlas, uses
'Flamsteed' designations
1725 - Thiout builds clock for true, not mean, solar time
1727 - Schulze discoveres photochemical effect in silver nitrate.
1727 - Bradley discovers aberration as effect of light speed
1728 - Bianchini fixes Venus rotation (wrong, until spacecraft
measurements in 1960s.)
1729 - Bouger invents photometer
1729 - Bouger describes light attenuation thru glass plates
1729 - Motte translates Newton's 'Principia' into English
1730-1739
---------
1731 - Hadley, and Geoffrey, invents marine quadrant
1731 - Bevis discovers Crab Nebula, later catalogued by Messier
1732 - duChatelet shows radiant heat behaves much like light
1733 - Hall invents achromatic refractor
1733 - Celsius explains aurora borealis
1734 - FRANCE finally accepts Newton gravitation theory
1735 - deCondamine fixes curvature of Earth
1735 - France sends teams to Ecuador and Lapland to measure
shape of the Earth
1735 - Harrison invents mechanical clock for longitude
1736 - Euler applies differential equations to Newton mechanics
1737 - Bevis observes first planet-planet occultation, Venus over
Mercury
1737 - deMaupertuis proposes Earth is oblate, not prolate
1738 - Smith issues 'Opticks', 1st book on telescpe making
1738 - Delisle invents heliographic coordinate system
1739 - Winthrop starts first routine monitoring of sunspots
1739 - deMaupertuis fixes oblatitude of Earth
1739 - Halley confirms secular acceleration of Moon, first
noticed in 1692
1740-1749
---------
1740 - Short starts selling first commercial reflectors
1740 - duChatelet explains relation of momentum, energy, mass
1740 - Stukely discovers solstice alignment at Stonehenge
1740 - Bouguer discovers gravity variation around world
1742 - Celsius invents inverse centigrade temperature scale
1742 - Maclaurin explains spherical shape of planets
1743 - Christin invents 'Celsius' temperature scale
1743 - d'Alembert uses energy concept in Newton gravity theory
1743 - Clairaut shows Mewton's theory of Earth shape is correct
1743 - Clairaut calcs variation of gravity on oblate Earth
1744 - Pope allows Galileo's 'Dialogue ...' to publish only with
his denial of Copernicus system in it
1744 - Cassini makes first national geodetic survey, in France
1744 - duCheseaux studies 'Olbers's paradox'
1745 - Laplace proposes Earth is splash of Sun after comet
collision
1745 - Bevis makes most detailed staratlas, never published
1746 - Euler explains refraction by wave theory of light
1747 - Clairaut first solves of 3-body problem for Moon
1747 - Clairaut proposes Newton's theory of Moon is deficient
1748 - Bradley discovers Earth nutation, predicted by Newton
1748 - Lomonosov discovers conservation of mass & energy
1749 - Clairaut realizes Newton's theory of Moon is correct
1749 - D'Alembert refines theory of precession and nutation
1749 - Dunthorne confirms secular acceleration of Moon
1749 - Melvill builds spectroscope, studies spectrum lines
1749 - duChatelet translates Princioia into French with comments
1750-1759
---------
1750 - Mayer invents selenographic coordinate system
1750 - Wirgentan finds magnetic disruptions coincide with
strong auroral activity
1750 - Michell discovers inverse square law for magnetism
1750 - Mayer designs first lunar globe, never built
1750 - Wright proposes island universes and plurality of worlds
1752 - Melvill studies brightline spectra in flames
1752 - Mayer improves lunar-distance method for finding longitude
1752 - LaCaille issues cluster & nebula catalog of south skies
1754 - Dolland invents heliometer
1754 - Mairan publishes first textbook on aurorae
1754 - Maclaurin posthumously proposes Jupiter is a fluid body
1754 - Kant proposes acceleration of Moon is due to Earth slowdown
1754 - Maclaurin papers show gravity of fluid planets
1755 - Kant proposes solar system formed from nebula
1755 - Kant proposes 'Oort cloud' for comet origin
1756 - Cantor discovers first disruptions in geomagnetic field
1756 - Lomonosov argues for wave nature of light
1757 - Dolland perfects achromatic refractor
1757 - Campbell, and Bird, invents marine sextant
1757 - Clairaut fixes best ever mass of Moon and planets
1758 - Palitzsch finds Halley's comet, first comet whose future
return path was predicted
1758 - Halley's comet returns, first periodic comet
1758 - Messier recovers Crab Nebula, starts catalog of nebulae
1759 - Cantor discovers seasonal shift of geomagnetic field
1759 - Cantor sets up 'C-number' rating for geomagnetism
1760-1769
---------
1760 - Lambert studies diffuse reflection, invents 'albedo'
1760 - Lambert makes first photometry of planet albedo
1768 - Euler proposes aether to carry light waves
1761 - Lambert proposes Milky Way is heaps of star clusters
confined within a disc
1761 - Lomonosov discovers atmosphere of Venus during transit
1761 - Maskelyne perfects lunar-distance method for longitude
1761 - Harrison invents sea-worthy clock for longitude
1761 - 1st of 18th century Venus transits
1761 - Lambert calculates transfer trajectories between planets
1764 - Lagrange explains lunar librations
1765 - Euler predicts Chandler motion of Earth poles
1765 - Winthrop makes first calculation of comet's mass
1766 - Titius explains gap in planet orbits, now 'asteroid belt'
1767 - Michell proposes binary star systems
1767 - Michell assesses Vega is ~460,000 AU (~7.2 LY) away
1767 - Maskelyne begins publishing 'Nautical almanac and
astronomical ephemeris'
1767 - Rittenhouse invents clock-driven model of solar system
1768 - Rittenhouse fields first American temam for Venus transit
1769 - 2nd of 18th century Venus transits
1770-1779
---------
1770 - Messier discovers comet Lexell, notes it as Earth threat
1772 - Messier issues 1st part of cluster & nebula catalog
1772 - Bode issues Titius-Bode relation of planet orbits
1772 - Lagrange discovers libration points in gravity field
1773 - Herschel starts study of proper motions of 13 stars
1773 - Capt Cook 1st European to observe aurora australis
1774 - Wilson discovers depression of sunspots below photosphere
1774 - Herschel builds own first telescope
1774 - Maskelyne measures gravity pull of nearby mountain
1775 - Mayer issues first topograohic map of Moon
1776 - Lexell, also Prosperin, calculate ellipse orbit for
Lexell's comet, first short-period comet
1776 - Lexell discovers 1767 Jupiter interaction with comet Lexell
1777 - Mudge invents remelt process for metal mirrors
1777 - Mudge perfects zonal test of parabolic mirrors
1778 - Herschel begins Jupitter studies, discovers three large
'SL9' spots
1778 - Franklin explains atmospheric circulation among climata
1778 - Franklin explains aurora as electrical discharges
1779 - Olbers invents new method to calculate comet orbits
1779 - Herschel invents filar micrometer
1779 - Darquier explains globular (planetary) nebulae
1779 - Lexell studies 1779 Jupiter-comet Lexell interacton, shows
comet mass less than 1/9,000 of Earth.
1780-1789
---------
1780 - Williams rediscovers 'Baily's beads' in solar eclipse
1780 - Herschel discovers 'Encke's division' in Saturn B ring
1781 - Herschel discovers Uranus, first new planet since antiquity
1781 - Herschel shows Earth-Mars similarity of seasons
1781 - Herschel questions Earth as stable clock. based on
Jupiter's variable rotation.
1781 - Lexell, also Olbers, shows Uranus has a planet, not comet,
orbit
1781 - Maskelyne & Herschel stage telescope rally; Herschel wins
1781 - Messier discovers cluster of nebulae, Virgo galaxy cluster
1782 - Herschel discovers real binary stars, first is Castor
1782 - Goodricke discovers beta Persei & delta Cephei as variables
1782 - Goodricke proposes eclipsing binary stars
1782 - Herschel discovers Sun's motion thru local stars
1783 - Mechain shows many new nebulae in Virgo cluster, but
apparently never documented them
1783 - Michell proposes blackholes
1784 - Pigott discovers delta Cephei as variable
1785 - Hutton proposes Earth is several million years old
1785 - Herschel discovers millstone shape of Milky Way
1785 - vonZach searches for planet in Titius-Bode gap, gives up
with no finds by 1800
1785 - Laplace shows solar system has longterm dynamic stability
1785 - Schroeter discovers clouds on Mars
1785 - Laplace develops field description for gravity
1786 - Herschel publishes best catalog of nebulae & clusters,
becomes by late 19th 'New General Catalog'
1786 - Gilpin begins regular records of geomagnetic field
1787 - Laplace proposes Saturn has very many nested solid rings
1787 - Laplace proposes lunar acceleration is due to Earth orbit changes
1787 - Herschel discovers Uranus moons Titania & Oberon
1789 - Schroeter discovers solar photosphere granulation
1789 - Herschel builds 'Herschel' scope with 1.2m mirror
1789 - Russell builds first globe of Moon
1789 - Herschel discovers Saturn moons Mimas & Enceladus
1789 - Herschel measures Saturn ring thickness, ~500Km
1789 - Herschel discovers oblateness of Saturn
1789 - Herschel explains globular clusters
1789 - Herschel proposes Saturn has only two solid rings separated
by Cassini's division
1790-1799
---------
1790 - Michell builds first 'Cavendish' machine, never used
1791 - Banneker improves calculation of eclipses and Moon phases
1791 - Schroeter discovers lunar rimae (rilles)
1792 - Schroeter measures Venus atmosphere, about 14Km thick
1792 - Delambre & Mechain fix size of Earth, define the 'meter'
1793 - Schroeter discovers Venus phase-geometry discrepancy
1794 - Chladni proposes meteors fall from outer space
1795 - Bowditch issues 'American practical navigator'
1795 - France adopts metric system of measures
1795 - Pigott discovers R Coronae and R Scuti as variables
1796 - Laplace improves nebular origin of solar system
1797 - Olbers develops 'Olbers's' method of orbit calculation
1797 - Cavendish fixes Earth density by measuring Newton constant
1798 - Laplace, also Lagrange, shows stability of solar system
1798 - Laplace proposes blackholes
1798 - Brandes starts triangulation measures of meteors
1799 - Herschel measures rotation of Saturn ring, 10h 43m
1799 - vonHumboldt starts geomagnetic mapping of Atlantic OCean
1799 - vonHumboldt makes first detailed study of Leonid meteors
1799 - Brandes & Brenzenberg show Leonids are ~97Km above ground
1799 - Herschel disocvers infrared radiation in sun spectrum