3. 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 earth's
atmosphere.
1721 - Halley succeeded Flamsteed as astronomer royal
at the Greenwich Observatory
1758 - Halley predict correctly the return of a comet

4. 1728 - Bradley thought, and afterwards
demonstrated, was the result of the combination
of the motion of light with the annual motion of
the earth
1748 - 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.

5. 1751 - Nicolas Louis de Lacaille (1713-1762), went to the
Cape of Good Hope for the purpose of determining the
sun's 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 d'Alembert (1717-1783) published
the first two volumes of his Researches on the Systems
of the World

6. 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 Mathematics
1735 – he solved a problem in three days which some
of the eminent mathematicians would not undertake
under several months.

7. 1741 - Frederick the Great invited him to Berlin, where he
soon became a member of the Academy of Sciences and
professor of mathematics
1747 - Euler's 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

9. 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."

10. 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.

11. 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.

12. 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.

13. 1804- The explosion theory was supported by
the discovery of another asteroid, by
Harding, of Lilienthal
1845 - a Prussian amateur astronomer named
Hencke found another asteroid, after long
searching, and opened a new epoch of
discovery.

14. 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.

15. 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.

16. 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 England
1851 - 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.

17. 1853 - Professor Adams of Neptunian
fame, with whom complex analyses were a
pastime, reviewed Laplace's calculation, and
discovered an error which, when
corrected, left about half the moon's
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.

18. 1758 – Newton proved that the great comet
of 1680 obeyed Kepler's laws in its flight
about the sun
1822- 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.

19. 1832 - Biela's 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.

20. 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.

21. 1802- greatest of observing astronomers
announced to the Royal Society his discovery
that certain double stars had changed their
relative positions towards one another
1832 - When Biela's comet gave the
inhabitants of the earth such a fright, it really
did not come within fifty millions of miles of
us.

22. 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 Newton's laws apply to these sidereal
bodies.

23. 1838 - Bessel announced from the Konigsberg
observatory that he had succeeded, after
months of effort, in detecting and measuring
the parallax of a star.

24. 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.

25. 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.

26. nineteenth century - "astronomy of the
invisible" is another of the great achievement
1840 – 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.

27. 1880 - Dr. Henry Draper, at Hastings-on-the-
Hudson, made the first successful photograph
of a nebula.

28. 1844 - Lord Rosse's great six-foot reflector--
the largest telescope ever yet constructed-
was turned on the nebulae
1864 - 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.

29. 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

31. 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 earth's 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.

32. 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

33. 1769 - George Cuvier was born
1816 – 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.

34. 1823 - other gigantic creatures, christened
ichthyosaurus and plesiosaurus by
Conybeare, had been found in deeper strata of
British rocks
1827 - 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.

35. 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.

36. 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

37. 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 Darwin's Origin of
Species, the chapter that wonderful citation of
the "Imperfections of the Geological Record."

38. 1826 - MM. Tournal and Christol had made
independent discoveries of what they
believed to be human fossils in the caves of
the south of France
1827 - 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

39. 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.

40. 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.

41. 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.

42. • "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.

43. 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

44. 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 -