The stars of which it is composed are easily distinguishable by a telescope of moderate power, and it is easily found from its vicinity to the very bright star adjacent to it. The small stars of which it is composed are situated nearly as represented in fig. 36. We might conceive of such a system of bodies revolving in a still more complex manner; the star V revolving round S, the star U revolving round T, the system of V and S revolving round a point a, and the system of U and Tround the same point or centre in a separate but more expansive orbit. But it is difficult to form diagrams of such complex systems. There are many different combinations by which we may conceive treble, quadruple, and multiple stars to revolve round their common centre of gravity, which it would be too tedious to describe, particularly as such motions have not yet been accurately ascertained. Sir W. Herschel describes one of these possible combinations, which is not a little singular. Suppose two equal stars, a and b (fig. 37), moving in a circu Fig. 37. απ lar orbit round their common centre of gravity, which will be the centre of the circle. From the centre of the circle, draw a line perpendicular to the plane of their orbit, extending to equal distances above and below this centre. Let us now suppose a third star, c, to fall from one extremity of this perpendicular from a state of rest; it will obviously descend with a gradually accelerated motion till it reaches the centre of gravity; and, passing onward with a motion gradually retarded, it will move to the other end of the perpendicular, where it will arrive at a state of rest, and again return and continue to oscillate between these two points. The two stars which move in a circular orbit may describe equal ellipses of any degree of eccentricity. In this case, however, the perturbations will affect not only the planes of their orbits, but also their figures; and the length of the oscillations of the third will be sometimes increased and diminished. A sun oscillating in a line perpendicular to the orbit of other two suns, and continuing its motion for ages in that line, is certainly a very strange idea; and yet, from the variety we perceive in the arrangements of the universe, it is not at all improbable that such combinations may exist among treble stars. The idea here intended to be conveyed may be illustrated by suspending a ring, and placing a wire perpendicular to it in its centre. The ring will represent the plane of the orbit in which the two equal stars move, and the perdendicular wire the line or course of the third star moving backward and forward with different degrees of accelerated and retarded motion. The motions connected with quintuple and multiple stars must be still more complex than those to which we have adverted; but it is difficult in the mean time to form any distinct ideas on the subject, till actual observation in the course of succeeding ages shall pave the way for deducing definite conclusions. The discoveries already made open to view new scenes of celestial mechanism, and new views of the diversified and admirable contrivances of Divine Wisdom; so that, in reference to such objects, we may apply to the almighty Architect the language of the sacred writer, "How unsearchable are thine operations, and thy ways past finding out!" When we consider that around each of these moving suns a retinue of planets must be supposed to wheel their courses, at different distances and in different periods of time, we cannot but feel astonished at the complexity of motions, perturbations, and other effects which must necessarily follow; yet we are bound to believe that everything moves onward, not only without confusion, but in the most perfect or der and harmony; for He who at first arranged the plan of the material world, and impressed upon matter the laws which now operate, is possessed of boundless intelligence, and foresees at one glance all the effects which those laws can possibly produce; and, so far as our observation extends, every object and movement in nature appears to be adjusted with the most perfect regularity. The solution of the "problem of three bodies" was considered as a work of so great nicety and difficulty, that none but such profound mathematicians as Clairaut, D'Alembert, and Euler could undertake such a delicate and laborious investigation. This problem was "to determine the curves described by three bodies projected from three points given in position, and with velocities given in quantity and direction; the force with which they gravitate being directly as their quantities of matter, and inversely as the squares of their distance. If the resolution of such a problem required so great acuteness of intellect, and so eminent skill in the science of analysis, what perspicacity of intellect, and what profound knowledge of everything connected with physical and mathematical investigations, must be requisite to determine the courses described and the perturbations produced by the complex motions of five, six, or seven suns all connected together, yet moving in different curves and in different directions, along with hundreds of planets, each connected with its own sun and pursuing its own distinct course, yet acted upon in succession with different degrees of force by the attractive influence of other suns! All our boasted powers of analysis are completely incompetent for such determinations. The faculties of an archangel, or of intelligences of a higher order than that of man, are alone adequate to such investigations; and this circumstance affords a presumptive evidence that such superior intelligences actually exist in the universe, and that man, in the present improvement of his powers, may be in the act of training for the employments and the society of such intellectual beings in a future scene of existence. The following brief list of treble and multiple stars, selected chiefly from Sir W. Herschel's catalogue, is given for the sake of those who may be disposed to inspect them with their telescopes.* *As the following and similar lists are inserted for the purpose of reference to amateur observers, the general reader, if he think proper, may pass over such lists and descriptions. π, or 42 Aries, in the ham, sixth magnitude. The three stars, which are all in a line, are excessively unequal; the largest is white, and the two smallest are mere points. With a power of 460, the two nearest are 1 diameter of the largest star. The third is about 25" from the largest. ε, or 4 or 5 Libra. This is a remarkable double-double star, or a double star, each star itself being a double star. The first set consists of stars that are considerably unequal. The largest is very white, and the smallest reddish. Their distance with 227 is one diameter of the larger one; the second set are white and equal, the preceding being rather the largest; their distance 1 diameter of either. The star appears of the fourth magnitude. o, or 48 Orion, a star of the fourth magnitude, a little below the lowest of the three stars in the belt. This is a doubletreble star, or two sets of treble stars, almost similarly situated. The two nearest of the preceding set are equal; the third larger, and pretty unequal when compared with the latter two. With a power of 222, the distance of the two nearest is 2 diameters of either. The two nearest of the following set are very unequal. The largest of the two and the farthest are considerably unequal, the largest being white and the smallest bluish. With a power of 222, their distance is about 2 diameters of the largest. The distance of the two farthest is 43". Right ascension 5b 30'; south declination 2° 43'. 0, or 41 Orion, the small telescopic trapezium in the nebula. Right ascension 5 26'; south declination 5° 32'. The stars composing this quadruple star are considerably unequal. The most southern star of the following side of the trapezium is the largest the star in the opposite corner is the smallest, the other two being nearly equal. The largest is pale red; the star preceding the largest inclined to garnet; and the star opposite to the largest, dusky. Distance of the two stars in the preceding side, 8 seconds; in the southern side, 12 secends; in the following side, 15 seconds; and in the northern side, 20 seconds. The first star (in right ascension) is of the seventh magnitude, the second of the eighth magnitude, the third of the fifth magnitude, and the fourth of the sixth or seventh magnitude. M. Struve found the angles of position in 1819 to be as follow: 3d and hth: 29° 45′ north following. 1st and 3d: |