of the fame from that of Q; which could by no means happen if the Line BPQ was not circular. 3. In like manner all the Stars when they come to the Meridian ABC, have their Distances from the Zeniths of P, Q, B, in the fame Proportion as the Distances QP, PB, Q B. Moreover when our Mariners fail towards the South, the Stars which before were depreffed under the Horizon, and could not be seen, begin to appear,and by degrees are elevated in proportion to their Course. 4. If feveral Places be obferved in the fame Meridian, and the Stars that pass thro' their Zeniths be noted; the Distances of thefe Places have the fame Proportion one to another, as the Distances of the meridional Points, wherein the feveral vertical Stars make their fouthing. ALSO to prove that the Line of Longitude EBFC is circular, and that the Earth rifes into a globular Figure, according to that other Dimension, we need but obferve that the Sun and Stars rife and fet fooner to those that inhabit eaftward of us, but later to them that are more to the weft; and alfo that the Difference of Time is in proportion to the Distances of their Meridians from ours. Thus, if we fuppose two Places directly Eaft, the one diftant from us 225 Miles, the other 450, twice as much; we shall find that in this laft Place the Sun rifeth two Hours fooner, and in the other one Hour fooner than with us. The Argument will be more clear, if it be proposed about the Sun's approaching the Meridians of divers Places; for their Distances in refpect of ours are in Proportion to the Time of the Sun's apparent Motion (or an Arch of the Equator intercepted between our Meridian and theirs) as is evident in Eclipfes. Thefe Facts agree precifely to the Demonftrations upon the Artificial Globe : which could not happen if the Earth had any other Figure. SO that the Earth is found to have a spherical Form, both in Longitude and Latitude. BUT fince there feems to be a Difficulty in handling the Longitude, all this may be proved by the Latitude only. For it is manifeft, that the Figure of the Earth is spherical, fince all the Sections, or Lines of Latitude, are circular; and pafs thro' the fame Point or Pole. Because any folid Body whatsoever being cut with innumerable Planes, all paffing thro' the fame Point; if the Peripheries of thefe Sections are circular, the Body itself must be spherical: as is known and allowed by all Geometricians. THERE is another Reafon of no less Force, taken from the Shadow of the Earth upon the Face of the Moon in Lunar Eclipfes. For fince the obfcured Part of the Moon, caufed by the conical Shadow of the Earth, feems always to be bounded with a circular Line; the Earth itself, for that Reason, must needs be spherical (d). Because it is manifest from Optics that a folid Body being every way oppofed to the Sun; if the Shadow be always conical, the Body itself is spherical. IF these Arguments are not fufficient, we might produce a great many more, from the confideration of the Earth itself, which perfectly prove the Earth's Rotundity: fuch as these; (d) Tacquet (in his Aftronomy Lib. iv.) hath demonftrated that the Shadow of the Earth never reaches fo far as the Moon; fo that the Moon is darkened not by the Shadow of the Earth, but by that of it's Atmofphere only; which was obferved, tho' not fo exactly demonftrated, by Kepler and Riciolus. But whether the Sha dow proceed from the Earth itfelf, or the Atmosphere, (tho the latter indeed be the Truth) the Thing is the fame in the prefent Cafe: for if the Shadow of the Atmosphere be circular, the Shadow of the Earth which is enclosed on every Side therebymust be circular too. Whifton's Aftron. Lect. Pag. 2 J. FROM 1. FROM Circumnavigation; for the Europeans have several times fet Sail from Europe, and fteer'd their Course directly South and Weft, 'till they came to the Magellanic Sea; and from thence to the North and Weft 'till they returned to Europe from the East; and all the Phænomena, which fhould naturally arise from the Earth's Rotundity, happened to them. Their Method of failing alfo was founded upon this Hypothesis; which could never have fucceeded fo happily if the Earth had been of any other Figure*. 2. WHEN we take our Departure from high Mountains and Towers; firft the lower Parts, then thofe that are higher, and laftly, their Tops are by degrees depreffed, as it were, and hid from us: On the other Hand, when we approach towards them, from a Place at a great Distance, firft the Top appears, then the middle Part, and laftly, when we come pretty near, the very Foot of the Mountain is discovered. So that this gradual Appearance and Occultation, is fuch as muft neceffarily happen from the spherical Figure of the the Earth. 3. IF we measure the Altitude of any Mountain upon this Suppofition, that the Earth is globular; the Practice is always found to justify the Truth of the Theory. WE might demonftrate many of thefe Arguments geometrically; but (because it would be both *Ferdinando Magellan was the first who failed round the Earth, in the Year 1519. he performed it in 1124 Days. Sir Francis Drake was the next, in the Year 1577. and he performed it in 1056 Days. The fame was afterwards done by Sir Thomas Cavendish, in the Year 1586; in the Space of 777 Days. I was done again by Mynheer Simon Cordes in the Year 1590. D 3 laborious laborious and difficult to prove this, or that Line circular, from fuch Principles, &c.) we fhall content ourselves with thofe evident Proofs above delivered which being collected into one Sum, will fufficiently demonftrate the Earth to be globular. As, first, the celeftial Phænomena (viz. The different Elevation of the Pole; the unequal Altitude of the Sun, at the fame Inftant, in different Countries; the Earth's Shadow on the Moon; the vaft Increase of the longest Day towards the Poles; the Rifing and Setting of the Stars; their perpetual Appearance near the Pole, &c.) do all equally prove the Earth's Rotundity. Alfo the terreftrial Appearances (viz. The Art of Navigation; the Appearance and Occultation of Mountains and Towers; the Distances of Places; the Winds and Points of the Compafs, &c.) can only be accounted for by this Figure and no other. Alfo the artificial Globe, which we make to represent the Earth, exhibits all these Things as they really are on the Earth; which would certainly, in fome Cafes, be different, except this was it's true Reprefentation. The Earth is not of a plane Figure, as is manifeft from the aforefaid Arguments; nor of a hollow Figure; for then the Sun and Stars would appear fooner to the western Inhabitants than to those of the Eaft: But we fee the Rifing Sun every Day illuminates the Vallies, before it fhines upon the back Parts of the oppofite Mountains *. A fpherical Body alfo is the only one that is fimilar, or hath all it's Parts alike among themselves; fo that they may be mutually applied one to another. For if two equal Parts of a Sphere be confidered, the Properties of each are the fame; which will not hold in any other Body. Thus in meafuring the Earth in different Places; if it be performed by the fame Method, it is always found of the fame Magnitude: which doth not a little contribute to the Proof of thefe Affertions. ANY impartial Perfon may eafily perceive of how little Weight their Reafons are, who believe the Earth to be of a plane Figure. For which they argue, 1. Because on a clear Day the Earth feems to be plane, as well as the Sea, if we look every way round about us (e). 2. If the Surface of it was not plane, it would be more easily moved, and more fubject to fall to pieces; whereas flat Figures are more firm and stable (f). 3. The Rifing or Setting Sun and Moon are cut, as it were, with right Lines; but if the Earth was fpherical, they ought to be divided by circular ones. Thus the Ancients reafoned, ridiculously, as Ariftotle tells us. 4. Some argue that the many high Mountains muft, of neceffity, deface it's Rotundity. 5. Others believe the Sea to be higher than the Earth. 6. Some again think it impoffible that Men should stand upon the oppofite (e) This Argument is confuted by what is faid above, about the Appearance and Difappearance of Mountains. Power of Attraction upon all the Matter in the Universe, whereby all Bodies, and all the Parts of Bodies, mutually (f) A fpherical Body is not attract themfelvés and one anofo liable to decay and fracture ther; which, as the Rev. Dr as another, because all the Parts Derham obferves, is the natural of the Surface are equidistant Caufe of the Sphericity of our from the Center. And we are common Globe. See New taught by Sir Ifaac Newton's ton's Principia, Lib. 3. Prop. Principles, that the Divine Being 7. Allo Derham's Phyfico Theol. at the Creation, bestowed the p. 40. D 4 Part |