y-eight years, whilst the more distant
third star, of almost similar magnitude, accomplishes a wide orbital
ellipse round the other two in 500 or 600 years. These stars have been
closely observed by astronomers during the past forty years, with the
result that their motions have appeared most perplexing, and complicated
beyond precedent. 'If this be really a ternary system,' wrote Sir John
Herschel, 'connected by the mutual attraction of its parts, its
perturbations will present one of the most intricate problems in
physical astronomy.' The second star revolves round its primary, whilst
the third pursues a retrograde course, but its path, instead of being
even, presents the appearance of a series of circular loopings, in
traversing which the star alternately quickens and slackens its pace,
or at times appears to be stationary.

Astronomers have arrived at the conclusion that these perturbations are
produced by the presence of a fourth member, which, though invisible, is
probably the most massive of the system--perhaps a magnificent world
teeming with animated beings, and attended by three suns which gravitate
round it, dispensing light and heat to meet the requirements of the
various forms of life which exist on its surface. In this system we have
an arrangement the reverse of what exists in the solar system, where all
the planets revolve round a predominant sun; but here there is a strange
verification of the old Ptolemaic belief with regard to the path of a
sun, though in this instance there are three suns circling round a dark
globe which they illumine and vivify.

Triple stars occur with comparative frequency throughout the heavens. In
Monoceros there is a fine triple star, discovered by Herschel, which he
describes as 'one of the most beautiful sights in the heavens.' The
stars Xi and Beta Scorpii form triple systems in which the components
are differently arranged. In Xi the primary and secondary consist of two
revolving stars which control the movements of a distant attendant; in
Beta the primary and secondary stars are in mutual revolution, whilst
round the former there circles a very close minute companion. There are
doubtless many binary stars which, if examined with adequate telescopic
power, would resolve themselves into triple and multiple systems, but
the profound distances of those objects render the detection of their
components a most difficult task.

Quadruple stars are usually arranged in pairs, _i.