Aristotle (who made quite a lot of observations about the spherical nature of the Earth) noticed that during lunar eclipses (when the Earth’s orbit places it directly between the Sun and the Moon, creating a shadow in the process), the shadow on the Moon’s surface is round. This shadow is the planet's, and it’s a great clue about the spherical shape of the Earth.
Planets (from Ancient Greek ἀστὴρ πλανήτης [astēr planētēs, "wandering star"], or just πλανήτης [planḗtēs, "wanderer"]) are orbiting astronomical objects. The Earth is not a planet by definition, as it sits at the center of our solar system above which the planets and the Sun revolve. The earths uniqueness, fundamental differences and centrality makes any comparison to other nearby celestial bodies insufficient - Like comparing basketballs to the court on which they bounce.

32.) It is often said that, if the Earth were flat, we could see all over it! This is the result of ignorance. If we stand on the level surface a plain or a prairie, and take notice, we shall find that the horizon is formed at about three miles all around us: that is, the ground appears to rise up until, at that distance, it seems on a level with the eye-line or line of sight. Consequently, objects no higher than we stand – say, six feet – and which are at that distance (three miles), have reached the "vanishing point," and are beyond the sphere of our unaided vision. This is the reason why the hull of a ship disappears (in going away from us) before the sails; and, instead of there being about it the faintest shadow of evidence of the, Earth's rotundity, it is a clear proof that Earth is not a globe.
Millennials, the generation that thinks they know it all. Yes, we have unlocked all the secrets of the universe, including the REAL shape of the earth. According to a study by YouGovUS, millennials between the ages of 18 and 24 are more likely than any answer the question 'Is the earth flat or round?' with an answer flat (4%). Honestly, our ancient selves did not think that the shape of earth is still debatable...
23.) If astronomical works be searched through and through, there will not be found a single instance of a bold, unhesitating, or manly ,statement respecting a proof of the Earth's " rotundity." Proctor speaks of "proofs which serve to show … that the Earth is not flat," and says that man "finds reason to think that the Earth is not flat," and speaks of certain matters being "explained by supposing" that the Earth is a, globe; and says that people have "assured themselves that it is a globe;" but he says, also, that there is a " most complete proof that the Earth is a globe:" just as though anything in the world could possibly be wanted but a proof – a proof that proves and settles the whole question. This, however, all the money in the United States Treasury would not buy; and, unless the astronomers are all so rich that they don't want the cash, it is a sterling proof that the Earth is not a globe.
50.) We read in the inspired book, or collection of books, called THE BIBLE, nothing at all about the Earth being a globe or a planet, from beginning to end, but hundreds of allusions there are in its pages which could not be made if the Earth were a globe, and which are, therefore, said by the astronomer to be absurd and contrary to what he knows to be true! This is the groundwork of modern infidelity. But, since every one of many, many allusions to the Earth and the heavenly bodies in the Scriptures can be demonstrated to be absolutely true to nature, and we read of the Earth being "stretched out" "above the waters," as "standing in the water and out of the water," of its being "established that it cannot be moved," we have a store from which to take all the proofs we need, but we will just put down one proof – the Scriptural proof – that Earth is not a globe.
32.) It is often said that, if the Earth were flat, we could see all over it! This is the result of ignorance. If we stand on the level surface a plain or a prairie, and take notice, we shall find that the horizon is formed at about three miles all around us: that is, the ground appears to rise up until, at that distance, it seems on a level with the eye-line or line of sight. Consequently, objects no higher than we stand – say, six feet – and which are at that distance (three miles), have reached the "vanishing point," and are beyond the sphere of our unaided vision. This is the reason why the hull of a ship disappears (in going away from us) before the sails; and, instead of there being about it the faintest shadow of evidence of the, Earth's rotundity, it is a clear proof that Earth is not a globe.
50) If the Earth were truly a globe, the Arctic and Antarctic polar regions and areas of comparable latitude North and South of the equator should share similar conditions and characteristics such as comparable temperatures, seasonal changes, length of daylight, plant and animal life. In reality, however, the Arctic/Antarctic regions and areas of comparable latitude North/South of the equator differ greatly in many ways entirely inconsistent with the ball model and entirely consistent with the flat model.
It has been shown that the meridians are, necessarily, straight lines; and that it is impossible to travel round the Earth in a north or south direction: from which it follows that, in the general acceptation of the word "degree" - the 360th - part of a circle - meridians have no degrees: for no one knows anything of a meridian circle or semicircle, to be thus divided. But astronomers speak of degrees of latitude in the same sense as those of longitude. This, then, is done by assuming that to be true which is not true. Zetetic philosophy does not involve this necessity. This proves that the basis of this philosophy is a sound one, and, in short, is a proof that the Earth is not a globe.
102) Some heliocentrists have tried to suggest that the Pole Star’s gradual declination overhead as an observer travels southwards is proof of a globular Earth. Far from it, the declination of the Pole Star or any other object is simply a result of the Law of Perspective on plane (flat) surfaces. The Law of Perspective dictates that the angle and height at which an object is seen diminishes the farther one recedes from the object, until at a certain point the line of sight and the seemingly uprising surface of the Earth converges to a vanishing point (i.e. the horizon line) beyond which the object is invisible. In the ball-Earth model the horizon is claimed to be the curvature of the Earth, whereas in reality, the horizon is known to be simply the vanishing line of perspective based on the strength of your eyes, instruments, weather and altitude.
199) From “Foundations of Many Generations” by E. Eschini, “The one thing the fable of the revolving Earth has done, it has shown the terrible power of a lie, a lie has the power to make a man a mental slave, so that he dares not back the evidence of his own senses. To deny the plain and obvious movement of the Sun he sees before him. When he feels himself standing on an Earth utterly devoid of motion, at the suggestion of someone else he is prepared to accept that he is spinning furiously round. When he sees a bird flying, and gaining over the ground, he is prepared to believe that the ground is really travelling a great number of times faster than the bird, finally, in order to uphold the imagination of a madman, he is prepared to accuse his Maker of forming him a sensiferous lie.”
Besides the above difficulties or incompatibilities, many cases are on record of the sun and moon being eclipsed when both were above the horizon. The sun, the earth, and the moon, not in a straight line, but the earth below the sun and moon–out of the reach or direction of both–and yet a lunar eclipse has occurred! Is it possible that a “shadow” of the earth could be thrown upon the moon, when sun, earth, and moon, were not in the same line? The difficulty has been met by assuming the influence of refraction, as in the following quotations:– 
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