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elapsed; nor hear the report for two millions and seven hundred thousand years after the explosion.
Charles. Are the fixed stars at different distances from the earth ?
Tutor. Their magnitudes, as you know, ap pear to be different from one another, which difference may arise either from a diversity in their real magnitudes, or in their distances, or from both these causes acting conjointly. It is the opinion of Dr. Herschel that the different apparent magnitudes of the stars arise from the different distances at which they are situated, and therefore he concludes that stars of the seventh magnitude are at seven times the distance from us that those of the first magnitude are.
By the assistance of his telescopes he is able to discover stars at 497 times the distance of Sirius the Dog-Star; from which he infers that with more powerful instruments he should be able to discover stars at still greater distances.
James. I recollect that you told us once, that it had been supposed by some astronomers, that there might be fixed stars at so great a distance from us, that the rays of their light had not yet reached the earth, though they had been travelling at the rate of twelve millions of miles in a minute, from the first creation to the present time.
Tutor. I did ; it was one of the sublime speculations of the celebrated Huygens. Dr. Halley has also advanced, what he says seems to be a metaphysical paradox, viz. that the number of fixed stars must be more than finite, and some of them at a greater than a finite distance from others; and Mr. Addison has justly observed, that this thought is far from being extravagant, when we consider that the universe is the work of infinite power, promoted by infinite goodness, and having an infinite space to exert itself in; so that our imagination can set no bounds to it.
How distant some of the nocturnal suns!
Charles. What can be the use of these fixed stars ?-not to enlighten the earth, for a single additional moon would give us much more light than them all, especially if it were so contrived as to afford us its assistance at those intervals when our present moon is below the horizon.
Tutor. You are right: they could not have been created for our use, since thousands, and even millions, are never seen but by the assistance of glasses, to which but few of our race have
Your minds indeed are too enlightened to imagine, like children unaccustomed to reflection, that all things were created for the enjoyment of man. The earth on which we live
is but one of seven primary plapets circulating perpetually round the sun as a centre, and with these are connected eighteen secondary planets or moons, all of which are probably teeming with living beings, capable, though in different ways, of enjoying the bounties of the great First Cause.
The fixed stars then are probably suns, which, like our sun, serve to enlighten, warm, and sus. tain other systems of planets and their dependent satellites.
James. Would our sun appear as a fixed star at any great distance?
Tutor. It certainly would: and Dr. Herschel thinks there is no doubt, but that it is one of the heavenly bodies belonging to that tract of the heavens known by the name of the Milky Way.
Charles. I know the milky way in the heavens, but I little thought that I had any concern with it otherwise than as an observer.
Tutor. The milky way consists of fixed stars, too small to be discerned with the naked eye; and if our sun be one of them, the earth and other planets are closely connected with this part of the heavens.
But, Gentlemen, it is time that we take our leave of this subject for the present. For your attention to those instructions, which, on this and other topics, I have been able to communicate, accept my best thanks. For your future welfare and happiness, my heart is deeply interested. You will not, I flatter myself, very soon forget that connexion which has subsisted between us for a long course of years. From my mind the remembrance of your kindness can never be obliterated. Permit, me, then, as a testimony of my gratitude and sincere affection, to recommend to your future attention the works of nature and creation, by a careful investigation of which you will necessarily be led to the contemplation and love of the God of Nature.
Your knowledge, young as you yet are, of the fundamental principles of Geometry and Algebra, is such as to render scientific pursuits easy and pleasant. And your understandings are not more capable of entering into the sublime speculations of science, than your hearts are adapted to receive and cherish those impressions of gratitude, which are the natural consequences of enlarged and comprehensive views of the being and perfections of the Deity. In all your studies and pursuits, then, never for
-you cannot go
END OF VOLUME I.
CONTENTS OF VOL. I.
XV. Of the Lever
XVI. Of the Lever
XVII. Of the Wheel and Axis
XVIII. Of the Pulley
XIX. Of the Inclined Plane
XX. Of the Wedge
XXI. Of the Screw
XXII. Of the Fixed Stars
XXIII. Of the Fixed Stars
XXIV. Of the Fixed Stars and Ecliptic
XXV. Of the Ephemeris
XXVI. Of the Solar System