Johannes Hevelius (1611-1687)-from Dantzig, who advanced astronomy by his accurate description of the face and the spots of the moon.1714 - Halley gave his views as to the origin and composition of these mysterious visitors in the earths atmosphere.1721 - Halley succeeded Flamsteed as astronomer royal at the Greenwich Observatory1758 - Halley predict correctly the return of a comet
1728 - Bradley thought, and afterwards demonstrated, was the result of the combination of the motion of light with the annual motion of the earth1748 - twenty years of continuous struggle and observation by him--that he was prepared to communicate the results of his efforts to the Royal Society. This remarkable paper is thought by the Frenchman, Delambre, to entitle its author to a place in science beside such astronomers as Hipparcbus and Kepler.
1751 - Nicolas Louis de Lacaille (1713-1762), went to the Cape of Good Hope for the purpose of determining the suns parallax by observations of the parallaxes of Mars and Venus, and incidentally to make observations on the other southern hemisphere stars.1763 – Lacaille published Coelum australe stelligerum, etc., due to the success of the results of his undertakings.1754- Jean Le Rond dAlembert (1717-1783) published the first two volumes of his Researches on the Systems of the World
1727 - Leonard Euler (1707-1783) was invited by Catharine I, to reside in St. Petersburg, and on accepting this invitation he was made an associate of the Academy of Sciences.1733 – Euler was made a professor of Mathematics1735 – he solved a problem in three days which some of the eminent mathematicians would not undertake under several months.
1741 - Frederick the Great invited him to Berlin, where he soon became a member of the Academy of Sciences and professor of mathematics1747 - Eulers first memoir, transmitted to the Academy of Sciences of Paris, was on the planetary perturbations. This memoir carried off the prize that had been offered for the analytical theory of the motions of Jupiter and Saturn.1766 - he returned to St. Petersburg
Great German philosopher Immanuel Kant (born at Konigsberg in 1724, died in 1804)This so-called "nebular hypothesis" assumes that in the beginning all space was uniformly filled with cosmic matter in a state of nebular or "fire-mist" diffusion, "formless and void."
1600- Bruno was burned at the stake for teaching that our earth is not the centre of the universe• 1700 - Newton was pronounced "impious and heretical" by a large school of philosophers for declaring that the force which holds the planets in their orbits is universal gravitation.
1800- Laplace and Herschel are honored for teaching that gravitation built up the system which it still controls; that our universe is but a minor nebula, our sun but a minor star, our earth a mere atom of matter, our race only one of myriad races peopling an infinity of worlds.closing years of the eighteenth century- Laplace took up the nebular hypothesis of cosmogony, to which we have just referred, and gave it definite proportions; in fact, made it so thoroughly his own that posterity will always link it with his name.
January 1, 1801- Italian astronomer, Piazzi, observed an apparent star of about the eighth magnitude (hence, of course, quite invisible to the unaided eye), which later on was seen to have moved, and was thus shown to be vastly nearer the earth than any true star.the very next year- Dr. Olbers, the wonderful physician astronomer of Bremen, while following up the course of Ceres, happened on another tiny moving star, similarly located, which soon revealed itself as planetary.
1804- The explosion theory was supported by the discovery of another asteroid, by Harding, of Lilienthal1845 - a Prussian amateur astronomer named Hencke found another asteroid, after long searching, and opened a new epoch of discovery.
1840- general predication of a trans-Uranian planet was made by Bessel, the great Konigsberg astronomer; the analysis that revealed its exact location was undertaken, half a decade later, by two independent workers--John Couch Adams, just graduated senior wrangler at Cambridge, England, and U. J. J. Leverrier, the leading French mathematician of his generation.
September 23, 1846- Dr. Galle turned his telescope to the indicated region, and there, within a single degree of the suggested spot, he saw a seeming star, invisible to the unaided eye, which proved to be the long- sought planet, henceforth to be known as Neptune.
1850 - The discovery of the inner or crape ring of Saturn, made simultaneously by William C. Bond, at the Harvard observatory, in America, and the Rev. W. R. Dawes in England1851 - Professor Peirce, of Harvard, showed the untenability of this conclusion, proving that were the rings such as Laplace thought them they must fall of their own weight.
1853 - Professor Adams of Neptunian fame, with whom complex analyses were a pastime, reviewed Laplaces calculation, and discovered an error which, when corrected, left about half the moons acceleration unaccounted for.1879- Professor G. H. Darwin showed that tidal friction, in retarding the earth, must also push the moon out from the parent planet on a spiral orbit.
1758 – Newton proved that the great comet of 1680 obeyed Keplers laws in its flight about the sun1822- German astronomer Encke, showed that one which he had rediscovered, and which has since borne his name, was moving in an orbit so contracted that it must complete its circuit in about three and a half years.
1832 - Bielas comet passed quite near the earth, as astronomers measure distance, and in doing so created a panic on our planet. It did no greater harm than that, of course, and passed on its way as usual.1852 - when the comet was due again, astronomers looked for it in vain. It had been completely shattered.
1872 - the earth crossed the orbit of the ill- starred Biela, and a shower of meteors came whizzing into our atmosphere in lieu of the lost comet.
1802- greatest of observing astronomers announced to the Royal Society his discovery that certain double stars had changed their relative positions towards one another1832 - When Bielas comet gave the inhabitants of the earth such a fright, it really did not come within fifty millions of miles of us.
1827 - M. Savary, of Paris, showed, that the observed elliptical orbits of the double stars are explicable by the ordinary laws of gravitation, thus confirming the assumption that Newtons laws apply to these sidereal bodies.
1838 - Bessel announced from the Konigsberg observatory that he had succeeded, after months of effort, in detecting and measuring the parallax of a star.
1859 - the spectroscope came upon the scene, perfected by Kirchhoff and Bunsen, along lines pointed out by Fraunhofer almost half a century before.1860 - it was shown that such common terrestrial substances as sodium, iron, calcium, magnesium, nickel, bariu m, copper, and zinc exist in the form of glowing vapors in the sun, and very soon the stars gave up a corresponding secret.
1895 - two new terrestrial elements were discovered; but one of these had for years been known to the astronomer as a solar and suspected as a stellar element, and named helium because of its abundance in the sun.
nineteenth century - "astronomy of the invisible" is another of the great achievement1840 – Bessel definitely predicated the existence of such "dark stars.“Twenty years later- The correctness of the inference was shown when Alvan Clark, Jr., the American optician, while testing a new lens, discovered the companion of Sirius, which proved thus to be faintly luminous.
1880 - Dr. Henry Draper, at Hastings-on-the- Hudson, made the first successful photograph of a nebula.
1844 - Lord Rosses great six-foot reflector-- the largest telescope ever yet constructed- was turned on the nebulae1864 - when the spectroscope was first applied to a nebula, by Dr. Huggins, it clearly showed the spectrum not of discrete stars, but of a great mass of glowing gases, hydrogen among others.
Eighteenth century- Sir Norman Lockyer, of London, has in recent years elaborated what is perhaps the most comprehensive cosmogonic guess that has ever been attempted. His theory, known as the "meteoric hypothesis," probably bears the same relation to the speculative thought of our time that the nebular hypothesis of Laplace
seventeenth century (Robert Hooke and Steno) and eighteenth century (Moro,Leibnitz, Buffon, Whitehurst, Werner, Hut ton) – had vaguely conceived the importance of fossils as records of the earths ancient history, but the wisest of them no more suspected the full import of the story written in the rocks than the average stroller in a modern museum suspects the meaning of the hieroglyphs on the case of a mummy.
William Smith - the English surveyor, drew the commonsense inference that the earth had had successive populations of creatures, each of which in its turn had become extinct
1769 - George Cuvier was born1816 – the famous Ossements Fossiles, describing these novel objects, was published, and vertebrate paleontology became a science.1821 - In England the interest thus aroused was sent to fever-heat by the discovery of abundant beds of fossil bones in the stalagmite-covered floor of a cave at Kirkdale, Yorkshire which went to show that England, too, had once had her share of gigantic beasts.
1823 - other gigantic creatures, christened ichthyosaurus and plesiosaurus by Conybeare, had been found in deeper strata of British rocks1827 - books were published denouncing Buckland, doctor of divinity though he was, as one who had joined in an "unhallowed cause," and reiterating the old cry that the fossils were only remains of tropical species washed thither by the deluge.
Charles Lyell, the Scotchman, who was soon to be famous as the greatest geologist of his time. As a young man he had become imbued with the force of the Huttonian proposition, that present causes are one with those that produced the past changes of the globe, and he carried that idea to what he conceived to be its logical conclusion. To his mind this excluded the thought of catastrophic changes in either inorganic or organic worlds.
1809 – Jean Baptiste Lamarck, who had studied the fossil shells about Paris while Cuvier studied the vertebrates, and who had been led by these studies to conclude that there had been not merely a rotation but a progression of life on the globe. He found the fossil shells in deeper strata; and he believed that there had been long ages when no higher forms than these were in existence, and that in successive ages fishes, and then reptiles, had been the highest of animate creatures, before mammals, including
1859 - appeared a book which, though not dealing primarily with paleontology, yet contained a chapter that revealed the geological record in an altogether new light. The book was Charles Darwins Origin of Species, the chapter that wonderful citation of the "Imperfections of the Geological Record."
1826 - MM. Tournal and Christol had made independent discoveries of what they believed to be human fossils in the caves of the south of France1827 - Dr. Schmerling had found in the cave of Engis, in Westphalia, fossil bones of even greater significance.1833 – Schmerling bad published a full account of his discoveries in an elaborate monograph
1859 - Dr. Falconer, the distinguished British paleontologist, made a visit to Abbeville, in the valley of the Somme, incited by reports that for a decade before bad been sent out from there by M. Boucher de Perthes. These reports had to do with the alleged finding of flint implements, clearly the work of man, in undisturbed gravel- beds, in the midst of fossil remains of the mammoth and other extinct animals.
1865 - two associated workers, M. Edouard Lartet and Mr. Henry Christy, in exploring the caves of Dordogne, unearthed a bit of evidence against which no such objection could be urged.
between the years 1870 and 1876 - Professor Professor Marsh, who was first in the field, found three hundred new tertiary species- He also has discovered a series of mammalian remains, occurring in successive geological epochs, which are held to represent beyond cavil the actual line of descent of the modern horse; tracing the lineage of our one-toed species back through two and three toed forms, to an ancestor in the eocene or early tertiary that had four functional toes and the rudiment of a fifth.
• "It is a well-known fact," says Professor Marsh, "that the Spanish discoverers of America discovered no horses on this continent, and that the modern horse (Equus caballus, Linn.) was subsequently introduced from the Old World.
1862 – Professor Huxley admitted candidly that the paleontological record as then known, so far as it bears on the doctrine of progressive development, negatives that doctrine.1870- he was able to "soften somewhat the Brutus-like severity" of his former verdict, and to assert that the results of recent researches seem "to leave a clear balance in favor of the doctrine of the evolution of living forms one from another
1891 - The ape-man fossil found in the tertiary strata of the island of Java by the Dutch surgeon Dr. Eugene Dubois, and named Pithecanthropus erectus, may have been a direct descendant of the American tribe of primitive lemurs, though this is only a conjecture.• 1877 -
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