so, and not in any way connected with each other by attraction. Others of the stars are called "variable," they are those whose light gradually diminishes and after a time regains its former brightness; some of them not only vary in brilliancy but in colour; the cause of these phenomena is totally unknown, and fortunate will he be who discovers it; it will be a great stride in the science of astronomy, for at present everything proposed has been quite inadequate to account for such phenomena. About 60 of these variable stars are at present known, but others are constantly being added to the list. Hind has discovered twenty-one, Pogson seven, and other astronomers have taken their share in discerning them. But, of all the heavenly bodies, none have excited so much wonder, and in former times so much fear, as the Comets. The orbits of these are for the most part in very eccentric ellipses, some of them comprised within the limits of our solar system, while those of others extend millions of miles beyond it, so that they only reappear to us after hundreds of years. The matter of which these bodies is composed is certainly not solid, as the smallest telescopic stars may be seen through the very middle of it, although many thousand miles in thickness. When comets approach the sun, their substance appears to become more condensed, and therefore to possess a greater power of reflecting light. The cause of the "tails" which appear appended to comets when they approach the sun is not known, but this tail extends always in a direction from the sun, and passes over many degrees of the heavens' space. As comets obey strictly the law of gravitation, they must possess some amount of weight or mass, however small it may be, and that it is inconceivably small is proved by the fact of comets having passed close to Jupiter, right amongst his four moons, without in any way affecting or disturbing their well-known motions; the comets have, however, been terribly tossed about on such occasions, one having been totally lost to us by such an occurrence. Thus it is seen how the same laws of gravity exist throughout all the infinity of space. The comets traverse our system of suns, and passing onwards with incredible rapidity, for years upon years, through that great space beyond it, at last visit some other system--perhaps to be as much an object of regard and wonderment there as they were here. The same ray of light which emanated from one of the distant stars of some one of the clusters situated far out in space, and which has travelled for thousands of years at the rate of 200,000 miles for every second of time, serves us here on this globe to distinguish it--it enters the tube of our telescope and affects our optic nerve; and the Creator who caused it _there_ to be given off, has _here_ made our senses capable of perceiving it. Is not this a clear demonstration of the fact, that one hand has designed the whole; and one Creator provided for all? THE AIR.