Arizona republican., 1910-01-24
THE HAIRY STAR

t foregoing observations were published to refer to the meaning of the ap- 5 pearance of comets, and their influ- ence on human affairs. At this time there were striking events enough in | Europe to prove any influence of com cts on human life. He realized, how | ever, that comets are very numerous, [ for he states. there are as many argu- ments to prove the motion of the Il earth around the sun as there are
 comets in the heavens
 The motion of the comets was also studied by Calico as a part of the motion of the earth in the Co., pernican theory of the solar system.
 But the first and most important con- tribution to the true explanation came | from Dorfef of SaXony, who proved | from the comet of 1881 that the orbits ! of comets are either very elongated
 osals or parabolas. and that the sun ] occupies a focus of the curve New
 ton discussed this subject in hIs 'Prin- l cipia,' and reached independently this | same conclusion few years later and
 established it as a universal law by incontrovertibie mathematical proof. ! By the seventeenth century a con- , siderable number of comets had been : recorded. John Hevel of Danzig pub- { lished two large books on-~~comets, which contained the first systematic account of all recorded comets. Tt was a brilliant thought of New |! tons that led him to consider whether , gravitation toward the sun could not : explain comets motion just as well as that of planet. and if so. as he took pains to prove in the beginning of his Principal such a body must
 move either along an ellipse or in
 one of two. other allied curves. the par1 bOla or the hyperbola
 Edmund Haley Oc56-I742). who
 had been a friend and active associate of Newton. and had assisted him sex eral years in the preparation of the
 Principal followed NewtOn's prindi- ! ples in the observation of comets. He 1 computed the paths of the comets of | l6sO and 1882. and especially one Of | 153l. whose appearance was recorded | by Appian. His studies contributed | much to the material dealing with this | subject in the 'Principia.' especially in | the later editions. In l705 he pub | lished a synopsis of Cometary As- i
 
 ty-four cometary orbits. Discussing in detail a number of these, he was struck with the resemblance of the paths described by the comets of l53I. 1907 and 1882, and the approximate equality in the intervals between their respective appearances and that of fourth comet. observed in 1856. More over. there was historical record of a comet in 1880. as well as in 1905. He at once concluded that all four comets were. really different appearances of the same comet. which moved sroundo| the sun in an elongated ellipse in a period of about seventyfive or seven- ty-six years. and he accounted for the small differences in the different in between the appearances of the comet by perturbations caused by planets in whose neighborhoods the comets passed. He then made the first prediction of the probable reap Dearance of the comet in 175S, when next it would be seen after a seventy six-year interval Haley. no less than modern astronomers, was aware of he disturbance that the presence of he planets might work in a comet and it's orbit. and how its time might De altered. He confidently announced the reappearance of the comet, but ! eft shortly before his death. at the age of S5 years, the following quaintly worded statement in regard to the 1 comet: Wherefore, if. according to { what we have already said. it should { -eturn again about the year 175S. can- { lid posterity will not refuse to ac- ( that this was first discov- l .red by an Englishman.' When the I .ime arrived the comet was looked for I oy astronomers. The French savant, Alexis Claude Clairaut, |. computed the I ;arious perturbations which might l nave affected it's journey. AS its path $ ay through the orbits Of Saturn and s Jupiter. and as it passed close to both I ,f these great planets, his calculations ' showed that there might be a retarda- g ion of 100 days on Saturn's account /, md SIS days for Jupiter On Christ 1 mas day. 1753. a month and day be- ore the date assigned by Clairaut. and n the year announced by Haley. the ! ,omet was actually discovered by , ieorge Palitzsch Of Saxony. and the |, ,reat astronomical prophecy was thus fulfilled new member was added ] O the solar system; the wandering z md inspiring comet was thus ,rought into harmony with the other members and made subject to the |,