Knowledge, VOLUME XXKIV iJ9ll). 



1 ,1 fiue pa^e 204. 



CHRONOMETRICAL CHART OF THE DE^i 



Period. 



A.D. 



1500 



Time of— 

 Heno- VIII. 

 Edward VI. 



1550. 



(Mary, 

 Elizabeth.) 



1600. 



'James 1. 

 Charles I. 

 Commonwealth.) 



1650. 



(Charles II. 

 James II. 

 William III. 

 and Mary.) 



1700. 



I.Anne, 

 George 1. 

 George 1 1. 1 



1750. 



'George 111.) 



1800. 



(George I\'. 

 William I\'. 

 Victoria.) 



1850. 



(Victoria. 



1900. 



'Victoria, 

 Edward VII. 

 George V.) 



BlOGR.^PHIC.A.L. 



Copernicus. 1473-1543 



(Works in Polish Prussia). 

 TvcHO Brahe, 1546-1601 



(Denmark and Bohemia). 



Galileo. 1564-1642 (Italy). 

 Kepler, 1571-1630 



(Bohemia and Germany) 

 ScHEiNEK, 1575-1650 (Germany). 



Hevelius. 1611-16SS (Germany). 

 HORROX. 1619-1641 (England). 

 HuYGENS, 1629-1695 (Holland). 

 Newton, 1642-1727 (England). 

 Flamsteed, 1646-1719 (England). 



Halley, 1656-1741 (England). 

 Bradley, 1693-1762 (England! 



Wm. Herschel. 1738-1822 



(England). 

 Laplace, 1749-1827 (France). 



Bessel, 1784-1846 (Germany). 

 Frauenhofer. 1787-1826 (Germany). 

 JNO. Herschel, 1792-1871 



(England and S. .Africa/. 



Theoretical. 



Le Verrier, 1811-1877 (France). 

 Adams, 1819-1892 (England). 

 Schiaparelli, 1835-1910 (Italy). 

 Secchi, 1S1S-187S (Italy). 

 HuGGlN'S, 1824-1910 (Engl.uull. 

 Janssen, 1824-1907 (France). 

 LocKYER. 1836- (England). 



VOGEL, 1842-1907 (Germany). 

 E.G. Pickering, 1846- (America). 



Gill, 1843- (England and S. .-Xfrica) 



Young, 1834-1908 (America). 

 Campbell, 1852- (.America). 



Hale, 1868- (.America). 



The Geocentric Syste.m of Ptolciiiy. dominant for fourteen centuries, is brought to 

 renewed prominence by Piirbach (d. 1461) and Rcgioinontanns )d. 1476). but the 

 Heliocentric System is definitely revived by Copernicus in 1543. 



Tycho, by collecting a vast mass of valuable observations, prepares the way for the 

 theories of Kepler, who introduces the Dynamic Conception into A.stronomy by 

 his Three Laws of the planetary motions, which form the connecting link between 

 the theories of Copernicus and the discoveries of Neictoii. 



Galileo, by his telescopic discovery in 1610 of Jupiter's Satellites and the Phases 

 of Venus, firmly estabhshes the Copernican doctrine, and lays th(! foundation of 

 Observ.ational Astronomy. 



Scheiner, from the observation of Sunspots, discovered in 1610 by Fabricius and 

 Galileo, determines the Sun's rotation. Horrox predicts on dynamical principles, 

 and is the first to observe (with Crabtree) a Transit of Venus in 1639. 



Riccioli. Hevelius and GriinnUli lay the foundation of SELENOGRAPin by constructing 



lun.ar charts. 

 Hnygeiis discovers the true nature of Saturn's King in 1659. 

 Newton, by the publication of the " Principia" in 1687, establislies the L'miication 



OF Celestial and Terrestrial Science, and shows Kepler's Laics to proceed 



from the action of Gravitation. 

 Flamsteed, whose lunar observations aid Newton's calculations, forms the First 



Modern Star Catalogue. 



Halley predicts on Newtonian Principles the Return of the Comet of 1682, makes 

 the first determination of Stellar proper Motion, and the first Southern Star ' 

 Catalogue. 



Bradley discovers the Aberration of Light and the Nutation of the Earth's 

 -Axis, thus laying the foundation of accurate stellar astronomy. 



Wm. Herschel. by his discover)' of Binary Stellar Systems, shows Newton's 

 Laws to extend tln'oughout the universe. He discovers Ukanus in 1781. and by 

 his telescopic researches becomes the pioneer of Descriptive Astronomy. 



Laplace summarizes Astronomical Mathematics in his "Mecanique Celeste," 1799, and 

 publishes the Nebular Hypothesis, 1796. 



Bessel first Measures the Distance of a Star by determining the Parallax of 

 Si.xty-one Cygiii, and furthers accurate Astronomy by his Star Catalogue, 1818, 

 founded on Bradley's observations. Jno- Herschel extends his father's Survey 

 OF THE Heavens to the S. Hemisphere. .Adams and Le Verrier give to 

 gravitational .-Vstronomy its crowning distinction by the Theoretical Discovery 

 OF Neptune in 1846. 



Draper, Bond, Dc la Rue and Rutherford U840-1864) are pioneers in Celesti.\L 

 Photography. 



The Science of Astro-Physics is established on the interpretation b\- Knxlilioff of the 

 Frauenhofer-lines in the Solar Spectrum, 1859. Secchi forms the first 

 classification of Stellar Spectra in 1863. Huggins inaugurates Spectroscopic 

 Photography in 1863 and discovers CiASEOus Nebulae in 1864. 



Janssen, Lockyer. Young, Hale and Deslaudres advance Solar Physics. 



Schiaparelli demonstrates the Connection between Comets and Meteors, 1866, and 

 discovers the Martian "Canals," 1877. Vogel publishes the First Spectroscopic 

 Star Catalogue in 1883. Gill and Moucliez inaugurate the International 

 Photographic Chart of the Heavens in 1887. Pickering, Vogel and Campbell 

 demonstrate Spectroscopicallv the existence of Binary Stellar Systems. 



Vogel at Potsdam. Lockyer at London, and Hale at Mount Wilson, affiliate the 

 work of the .Astronomical Observatory with that of the Chemical Laboratory in their 

 Study of the Physical Elements of Stellar Evolution. 



