his harness rather than be retarded. The pressure of the difficulty is somewhat lightened by the fact, that the bright ring is divided into two halves, so that the inner half can go at a more rapid pace without being retarded by the outer one. Still, notwithstanding this relief, the difficulty is great; for the outer bright ring is 11,000 miles broad, while the inner is 17,000. We must also keep in view the fragile structure of these rings. If we take the whole system of rings, it may be represented by a strip of tissue paper, a foot long, and an inch broad. This strip, in the form of a ring, is to maintain a state of equilibrium; and it is obvious that its stability is not consistent with powerful internal forces, tending to rend it asunder, as there must be, if the substance is solid, and the rings broad. We can conceive that internal rupture would be avoided by reducing the breadth of the rings; and observation has given indications that the rings are very numerous. A structure, something like the coil of a mainspring of a watch, and a pretty broad division in the outer bright ring, have been detected. This would, in one way, relieve the difficulty of rigidity; but, in another, would increase it. A system of close, narrow rings, packed the one within the other, each with its own period of rotation, would be subject to constant collisions among its constituent parts. Besides all this, the system, as a whole, would be in a
