Show the planet mercury any irregularity in the elliptical movement I 1 of a planet when it is accelerated retarded or deviates from its prescribed orbit in any direction is due to the presence and attract 1 tion of some other body should the body exercising this disturbing force have never yet been seen yet may assurance be attained of its existence and from the very degree decree of its t perturbations the exact spot herein wherein it should be sought may be indicated its masa I 1 estimated and all the elements of its orbit be as correctly assigned as though it had been I 1 present to our vision the long mysterious i perturbations of crinus uranus which could only be accounted for in buch such a manner occasioned that research which issued in the discovery of the planet neptune the genius of leverrier foresaw its existence and succeeded in pointing I 1 I 1 it out to an admiring world and doubling I 1 the extent of the solar system the same great astronomer has lately communicated to the academy of sciences the result of a long series of observations made by him of certain similar perturbations of the planet mercury hitherto unno unnoticed tided of all the planets meri 1 cury is the least known from its proximity to I 1 the radiance of the sun I 1 from the observations alluded to it appears I 1 that its actual motion does not coi col correspond respond to that theoretically assigned to it by sir isaac i newton ewton thirty six seconds should be adi ded to its perihelion ary motion that its theory may coincide with that of the sun ba M leverrier infers from a number of asteroids of equal mass interposed between it and the sun the research of neptune was rendered difficult by its vast distance and its tardy movement in the present case the rapidity of motion of mercury and the facts of its being f always immersed in the suns beams will be obstacles to a speedy solution of the mystery should the perturbations be caused by asi steroids iter lter olds two methods 0 of observation are open I 1 I 1 to astronomers photographing the suns buhs disk every day and by comparison detecting changes on eclipses it the conclusion that that disturbing influence is due to asteroids that the celebrated le monnier observed during an eclipse which took place towards the close of the last century a number of small opaque bodies passing in a continuous line across the disk of the sun for several successive minutes of the forty five asteroids already know to us the largest is somewhat less than forty miles in diameter while the smallest is only four |