make choice of no better an argument to conclude his book withal, than that which we read at the latter end of Al. Rosse, where he infers, that the earth does not move, because then the shadow in a sun-dial would not be altered.

2. As for the difference of months, we say, that the diverse illumination of the moon, the different bigness of her body, her remaining for a longer or shorter time in the earth's shadow, when she is eclipsed, &c. may well enough be solved by supposing her to move above our earth, in an eccentrical epicycle. Thus,

In which kind of hypothesis, there will be a double difference of motion; the one caused by the different situations of the moon's body, in its own eccentric; the other by the different situations of the moon's orb, in the earth's eccentric which is so exactly answerable to the motions and appearances of this planet, that from hence Lansbergius draws an argument for this system of the heavens, which in the strength of his confidence he calls, demonstrationem ex σTиpovinny, cui nulla ratione potest contradici.

4. As for the difference betwixt winter and summer; betwixt the number and length of days, which appertain to each of those seasons; the seeming motion of the sun from one sign to another in the zodiac: all this may easily be

solved, by supposing the earth to move in an eccentrical orb about the sun. Thus,

Suppose the earth to be at C, then the sun at A will seem to be in the sign, and at the greatest distance from us, because the earth is then in the farthest part of its eccentric. When after by its annual motion it hath passed successively by the signs 8, at length it comes to the other solstice at B, where the sun will appear in W, and seem biggest, as being in its perige, because our earth is then in the nearest part of its eccentric.

As for all other appearances of the sun which concern the annual motion, you may see by the following figure, that they are exactly agreeable to this hypothesis.

.it.

Where you have the earth described about the sun at A, in the four chief points of the zodiac; namely, the two

equinoctials at y and, and the solstices at W and . Through all which points the carth does pass in his annual motion from west to east.

The axis upon which our earth does move, is represented by the line B C, which axis does always decline from that of the ecliptic, about 23 degrees, 30 minutes. The points B C are imagined to be the poles, B the north-pole, and C the south.

Now if we suppose this earth to turn about its own axis by a diurnal motion, then every point of it will describe a parallel circle, which will be either bigger or lesser, according to its distance from the poles. The chief of them are the equinoctial D, E. The two tropics, F, G; and H, I, the two polar circles. M, N, the arctic, and K, L, the antarctic; of which the equinoctial only is a great circle, and therefore will always be equally divided by the line of illumination M, L, whereas the other parallels are thereby distributed into unequal parts. Amongst which parts, the diurnal arches of those that are towards B, the north pole, are bigger than the nocturnal, when our earth is in and the sun appears in : insomuch, that the whole arctic circle is enlightened, and there is day for half a year together under that pole.

Now when the earth proceeds to the other solstice at 5, and the sun appears in W, then that hemisphere must be involved in darkness, which did before partake of light. And those parallels towards the north and south poles will still be divided by the same inequality. But those bigger parts which were before enlightened, will not be darkened, et vice versa. As when the earth was in N, the arctic circle M, N, was wholly enlightened, and the antarctic, K, L, altogether in the dark. So now, when it is in A, the antarctic K, L, will be wholly in the light, and the other M, N, altogether obscured. Whereas the sun before was vertical to the inhabitants at the tropic F, G; so now is he in the same situation to those that live under the other tropics H, I. And whereas before the pole did incline 23 degrees 30 minutes towards the sun, so now does it decline

as much from him. The whole difference will amount to 47 degrees, which is the distance of one tropic from the other.

But now in the two other figures, when the earth is in either of the equinoctials, the circle of illumination will pass through both the poles, and therefore must divide all the parallels into equal parts. From whence it will follow, that the day and night must then be equal in all places of the world.

As the earth is here represented in, it turns only the enlightened part towards us: as it is in y we see its nocturnal hemisphere.

So that according to this hypothesis, we may easily and exactly reconcile every appearance concerning the difference betwixt days and nights, winter and summer, together with all those other varieties which depend upon them.

If you would know how the planets (according to the system of the heavens) will appear direct, stationary, retrograde; and yet still move regularly about their own centres, you may plainly discern it by this following diagram.

!

Where suppose the sun to be at A, the circle (B, G, M) to be the orb of the earth's motion, and that above it noted with the same letters, to be the sphere of Jupiter; and the uppermost of all, to be a part of the zodiac in the starry heaven.

Now if you conceive the letters ABCDEFGHIKL M, and bcdefghiklm, to divide the earth's orb and that of Jupiter, into several parts, proportionable to the slowness or swiftness of their different motions (Jupiter finishes his course in twelve years, and the earth in one) then supposing the earth to be at the point (B) and Jnpiter likewise in his orb to be situated at (b,) he will appear unto us to be in the zodiac at the point (r.) But afterwards both of them moving forwards to the letter (C c) Jupiter will seem to be in the zodiac at (v,) as having passed di