be no more than the three hundred and sixtieth part of what it is? The more this preposterous system is considered, the more does it appear to be replete with sophisms, absurdities, and impossibilities. When, however, they find their untempered mortar insufficient to cement the parts of their miserable fabric, they immediately have recourse to the name of their Creator for assistance. "It is not necessary," say they, "that the inhabitants of Mercury, and the Georgium Sidus, should be of the same nature as those of this earth, the Almighty can fit them for the extremes of heat, cold, &c." No doubt He can do any thing that is consistent with the plans of His divine wisdom, but He never will realize the dreams of idle philosophers; for, most certainly, if the system were formed upon their wild principles, the heavens would no longer declare the glory of God, nor would the firmament exhibit everlasting proofs of his unbounded wisdom!

CHAPTER X.

DISTANCES OF THE HEAVENLY BODIES; THE METHODS PROPOSED BY ASTRONOMERS TO ASCERTAIN THEM SHOWN TO BE INAPPLICABLE AND THEREFORE USELESS;-CONTRADICTORY ACCOUNTS OF PHILOSOPHERS RESPECTING THE DISTANCES OF JUPITER'S SATELLITES FROM HIS BODY, AND LIKEWISE RESPECTING THE DIURNAL REVOLUTIONS OF THE PLANETS ;—THE CHARACTER GIVEN BY DIODORUS SICULUS OF THE GREEK PHILOSOPHERS STRICTLY APPLICABLE TO THE MODERN ONES;-NATURAL EVIDENCES OF THE DEITY STATED BY ST. PAUL, AND EXEMPLIFIED IN THE CONDUCT OF SOCRATES;POETICAL CONCLUSION.

To calculate the destinies of individuals and empires; to discover the causes of motion in the heavenly bodies; or to measure the distances and magnitudes of the sun, moon and stars; have, in all nations from time immemorial been, to astronomers and mathematicians, objects of unceasing pursuit; though God, in the Holy Scriptures, has so pointedly set their vain efforts at defiance. "Let now the observers of the heavens, the lookers on the stars, stand up."-"My hand founded the earth, and my right hand spanned the heaven."-"Who among them has declared these things?" &c. But there is no occasion to multiply quotations, because the constant disagreement and war of opinions amongst philosophers, sufficiently prove that they are utterly ignorant of these

matters, and that all such attempts are impositions, unless they are grounded upon what God himself has been pleased to reveal.

The distance which Posidonius, Ptolemy and other ancient astronomers, assigned to the moon has, with some small variations, been adopted by the moderns; namely about 60 semidiameters of the earth; which is I think evidently founded upon the apparent dimensions of the earth's shadow in a lunar eclipse. Ptolemy and some others of the ancients seem to have had a tolerably correct idea of the magnitude of the earth, and as they, like the moderns, agreed in imagining the sun to move at the distance of many millions of miles, they likewise imagined, that the diameter of the conical shadow of the earth could not be much diminished at the moon; and that as the moon appeared to be about one-third the breadth of the shadow, they concluded that the moon itself must bear nearly a like proportion to the diameter of the earth, and that therefore the real diameter of the moon must be about 2200 miles. That this estimate is formed from the appearance, is evident from the mathematical consideration, that an object of a third of an inch in diameter placed one yard from the eye, or of 16 yards in diameter placed at the distance of a mile, appears equal to the diameter of the moon, which at the distance of 240,000 miles must be about 2200 miles in diameter in order to appear of an equal magnitude; on the supposition of its not being affected by the medium through which it is viewed. Though it is evidently upon this shadowy foundation that astronomers have estimated the distance and magnitude of the moon, they, I believe, generally, if not altogether, keep it out of sight, and endeavour to make their readers believe, that the problem may be solved by geometrical principles.

As they mostly copy from each other, it will be sufficient to quote what one or two of them have advanced upon the subject.

"We will begin with the moon; this planet is nearer to us than any of the rest, and the method of finding her distance from the earth being once known, it will be easy to perceive that the distance of an yother planet may be determined in nearly the same manner. The first thing to be done in the method I am about to describe is to find the moon's horizontal parallax, or the difference between the place of the moon when she appears in the horizon to a spectator on the earth's surface; and her place as it would appear to a spectator placed at the earth's centre. This problem is no less curious than the one it is meant to elucidate; it is the same thing as to find the angle under which the semidiameter of the earth would appear, at a certain time, to an observer placed at the centre of the moon. That this can be done, must appear very extraordinary to a person unacquainted with astronomical principles: but the determination, singular as it may seem, is far from being impracticable."

"Let us suppose an observer to be placed upon any point A, of the equator BAC (Fig. 2,) at the time the moon moves in the equinoctial DMP, then as this latter circle is in the plane of the former the moon will pass directly over his head, and descend perpendicularly to the horizon EN. In this situation of the spectator upon the earth's surface A, the moon will appear to have described a quarter of a circle, or 90 degrees, in passing from the zenith M to the sensible horizon at N; but to a spectator placed at the centre of the earth O, she would appear to have described a quarter of a circle when she came to the rational horizon at P. But the moon revolves

round the earth, from the meridian to the meridian again, in about 24 hours and 48 minutes; she will therefore revolve from M to P in six hours and twelve minutes; and if the time she takes in moving from M to N, be found, by observation, and taken from six hours twelve minutes, the time of moving from M to P, the remainder will be the time employed in describing the arc NP.

66 Having thus found the measure of the arc NP in time, we can convert it into degrees and minutes, as follows: as the time of describing the arc MN, which is found, by observation, is to 90 degrees, so is the time of describing the arc NP, to the degrees and minutes in that arc. But this arc is the measure of the angle NOP, or of its equal ONA; for, since the lines AN and OP are parallel to each other, it is a known property of geometry, that the angle NOP will be equal to the angle ONA. This angle ONA, is called the moon's horizontal parallax, and as that is now found, we can easily determine the distance of the moon from the earth's centre. For it is a maxim in trigonometry, that when any three things, in a plain triangle, are known, except the three angles, the rest may be found by calculation.

"Now, in the triangle AON, we have the side OA, equal to the diameter of the earth, which from an actual mensuration of the circumference," (part, only, of the circumference,) "has been found to be about 3960 miles: the angle ONA, or the moon's horizontal parallax, has also been found by observation; and the angle OAN is a right angle, because OA is perpendicular to the sensible horizon EN. These three things, therefore, are known, and are sufficient data for determining the rest. The side of the triangle ON, is the distance of the moon from the centre of the earth O; and this distance, by a