The daily morning journal and courier., 1896-07-31
THE TRAVELS OF A COMET.


 Facts About the Most Interesting Ce- lestial Wanderer-Brooks' Comet and Its Thraldom Under the Influence of the Bully of the Solar syDt1rn-Trac- ing Its Antecedents.
 The announcement has just been mand through the official center for such news in this country, Messrs Chandler and Ritchie of Boston, ii at Brooks periodical comet has been de- tected on its return to the sun by Ja- velio an assistant at the observatory at Nice. This comet, while not even visible without g telescope, Is the most interesting object of its kind. This in terest exists not only among astrono- Iners, but among those intelligent per- sons who are little familiar with the popular features of astronomy. MT. W. K. Brooks is an amateur astronomer at Geneva, N. r., who for quite number of years occupied his spare evenings searching for comets. In finding these he was very successful. and is sur passed only by Dr. Lewis Swift in point of number of such objects seen for the first time. In July 1889, he found this comet the fifth one discovered during that year, faint patch of light, which seemed to have no particular interest to people in general. But the earliest orbits computed, those by Drs Cham dler and Searle, gave evidence that the object was moving in an elliptical orbit, the period of revolution about the sun being seven or eight years. Of course, astronomers at once priclSed up their ears and pointed their telescopes toward the object, for when comet Is known to be periodical every effort is made to get observations, so that as accurate an orbit as possible may be computed, and its motions before and after it's current apparition be deter mined as closely as possible. Upon such work as this is dependent all that we have learned about these travellers of the skies, which come we know not whence, and go away again, many of them, we know not whither
 The reader will at once inquire, of course, What can there be about this Insignificant comet, which we can not ever see unless we have telescope, to make it so interesting to us?" There are several reasons for this: CD It is possible that 1t is indeed Lexell's com ct, which was lost very many years ago; CD it is the only comet that to our knowledge has been entangled in the satellites of the great planet Jupiter. and, (3) it is one of the few comets which we know to be groups instead of Individuals, having several members which move through space in almost the same path, and are together in close company in the same parts of their orbits. One of these reasons alone would be delight to the astron- omer, but to have them united in the same object is exceedingly noteworthy
 The Brooks comet is one of the Jupi- ter group of comets. These are little family of comets which have been made members of our company through the attractive influence of Ju- piter. the .bully of the solar system" as he has been appropriately termed. The way in which we acquire comets is this: From out in space these little masses of gas come within the attrac- ton of the sun, and about our central luninary they move in regular orbit, usually the geometrical figure called the ayperbola, and having passed the sun they go out again into space in all most a straight line, never to return. The sun has disturbed it's motion through space by altering it's direction. But if 1t should happen that after the comet has decided to 9swing partners" with the sun there is one of the large planets near Its track, this planet will exercise it's attraction and on its own account make some changes in the path of the traveller. Mathematicians understand the laws which regulate this disturbance, and it is usually the case that the disturbed comet is forced into an orbit which Is an ellipse, the sun being at once of its foci and the ex- 'tremity of the orbit away from the sun extending out to near the place where the disturbance was effected. Jupiter is an enormous planet, more than three hundred times as heavy as the earth, and it moves in it's orbit at a very fast rate for so large planet. The region that is patrolled by it, therefore, is very large. and it's attraction has brought in as members of our system more than thirty comets, which for the present, at least, are moving in orbits about the sun, reporting to that luminary by a close approach every few years, and will continue to do so until they are dissipated, or until, coming again in the vicinity of Jupiter, they are ordered away on some other errand. For it should be remembered the conditions under which the path of the comet was changed from parabola to an ellipse may at some time be exactly reversed and the comet may be set free again after centuries of captivity by a per turbation from the very planet that caught it.
 Very soon after the discovery by Brooks of he fifth comet of 1889, when observations enough had been secured by astronomers, Dr. s. 0. Chandler computed the track over which the comet had come before 1t was discov- cred, to see if he could find out what had been it's past history. In doing this he came across some curious facts which inclined him to the belief that this comet was truly the lost Lexell which in the interim of fifty years had met with a variety of fortunes Of course 1t would be understood that such computation is of the most deli cate nature and requires most accurate observations as a basis. What Dr. Chandler was able to do, therefore, was not in the nature of absolute proof, but