The evidence for a flat earth is derived from many different facets of science and philosophy. The simplest is by relying on ones own senses to discern the true nature of the world around us. The world looks flat, the bottoms of clouds are flat, the movement of the Sun; these are all examples of your senses telling you that we do not live on a spherical heliocentric world. This is using what's called an empirical approach, or an approach that relies on information from your senses. Alternatively, when using Descartes' method of Cartesian doubt to skeptically view the world around us, one quickly finds that the notion of a spherical world is the theory which has the burden of proof and not flat earth theory.
86.) If the Earth were a globe, rolling and dashing through "space" at the rate of "a hundred miles in five seconds of time," the waters of seas and oceans could not, by any known law, be kept on its surface – the assertion that they could be retained under these circumstances being an outrage upon human understanding and credulity! But as the Earth – that is, the habitable world of dry land – is found to be "standing out of the wafer and in the water" of the "mighty deep," whose circumferential boundary is ice, we may throw the statement back into the teeth of those who make it and flaunt before their faces the flag of reason and common sense, inscribed with a proof that the Earth is not a globe.

The only explanation which has been given of this phenomenon is the refraction caused by the earth’s atmosphere. This, at first sight, is a plausible and fairly satisfactory solution; but on carefully examining the subject, it is found to be utterly inadequate; and those who have recourse to it cannot be aware that the refraction of an object and that of a shadow are in opposite directions. An object by refraction is bent upwards; but the shadow of any object is bent downwards, as will be seen by the following very simple experiment. Take a plain white shallow basin, and place it ten or twelve inches from a light in such a position that the shadow of the edge of the basin touches the centre of the bottom. Hold a rod vertically over and on the edge of the shadow, to denote its true position. Now let water be gradually poured into the basin, and the shadow will be seen to recede or shorten inwards and downwards; but if a rod or a spoon is allowed to rest, with its upper end towards the light, and the lower end in the bottom of the vessel, it will be seen, as the water is poured in, to bend upwards–thus proving that if refraction operated at all, it would do so by elevating the moon above its true position, and throwing the earth’s shadow downwards, or directly away from the moon’s surface. Hence it is clear that a lunar eclipse by a shadow of the earth is an utter impossibility.
10) Ship captains in navigating great distances at sea never need to factor the supposed curvature of the Earth into their calculations. Both Plane Sailing and Great Circle Sailing, the most popular navigation methods, use plane, not spherical trigonometry, making all mathematical calculations on the assumption that the Earth is perfectly flat. If the Earth were in fact a sphere, such an errant assumption would lead to constant glaring inaccuracies. Plane Sailing has worked perfectly fine in both theory and practice for thousands of years, however, and plane trigonometry has time and again proven more accurate than spherical trigonometry in determining distances across the oceans. If the Earth were truly a globe, then every line of latitude south of the equator would have to measure a gradually smaller and smaller circumference the farther South travelled. If, however, the Earth is an extended plane, then every line of latitude south of the equator should measure a gradually larger and larger circumference the farther South travelled. The fact that many captains navigating south of the equator assuming the globular theory have found themselves drastically out of reckoning, more so the farther South travelled, testifies to the fact that the Earth is not a ball.
153) Quoting Reverend Thomas Milner’s “Atlas of Physical Geography,” we find that, “Vast areas exhibit a perfectly dead level, scarcely a rise existing through 1,500 miles from the Carpathians to the Urals. South of the Baltic the country is so flat that a prevailing north wind will drive the waters of the Stattiner Haf into the mouth of the Oder, and give the river a backward flow 30 or 40 miles. The plains of Venezuela and New Granada, in South America chiefly on the left of the Orinoco, are termed Ilanos, or level fields. Often in the space of 270 square miles the surface does not vary a single foot. The Amazon only falls 12 feet in the last 700 miles of its course; the La Plata has only a descent of one thirty-third of an inch a mile.”
moving in all manner of directions – yes, and frequently, in different directions at the same time – from west to east being as frequent a direction as any other. . Now, if the Earth were a globe, revolving through space from west to east at the rate of nineteen miles in a second, the clouds appearing to us to move towards the east would have to move quicker than nineteen miles in a second to be thus seen; whilst those which appear to be moving in the opposite direction would have no necessity to be moving at all, since the motion of the Earth would be more than sufficient to cause the appearance. But it only takes a little common sense to show us that it is the clouds that move just as they appear to do, and that, therefore, the Earth is motionless. We have, then a proof that the Earth is not a globe.
Amazing. I posted this video a little over two weeks ago. In two weeks it has as many views as all of my posts did over an 8 year period of time. Why? I have noticed that I had way more likes than dislikes for the first two weeks. Now the tilt is to dislikes. Why? Because the globe earthers don't like this. It is too simple. "We have to kill this!" they think. But, you cannot kill truth. Flat earth is true. Your moon landing and your pictures of earth, Jupiter, and the moon are false. NASA's images are computer generated images and are false. The tide is turning. Truth is prevailing!
96.) If we refer to the diagram in "Cornell's Geography," page 4, and notice the ship in its position the most remote from the observer, we shall find that, though it is about 4,000 miles away, it is the same size as the ship that is nearest to him, distant about 700 miles! This a an illustration of the way in which astronomers ignore the laws of perspective. This course is necessary, or they would be compelled to lay bare the fallacy of their dogmas. In short, there is, in this matter, a proof that the Earth is not a globe.
25.) The surveyor's plans in relation to the laying of the first Atlantic Telegraph cable, show that in 1665 miles – from Valentia, Ireland, to St . John's, Newfoundland – the surface of the Atlantic Ocean is a LEVEL surface – not the astronomers' "level," either! The authoritative drawings, published at the time, are a standing evidence of the fact, and form a practical proof that Earth is not a globe.
The common sense of man tells him - if nothing else told him - that there is an "up" and a "down" in -nature, even as regards the heavens and the earth; but the theory of modern astronomers necessitates the conclusion that there is not: therefore, 'the theory of the astronomers is opposed to common sense - yes, and to inspiration - and this is a common sense proof that the Earth is not a globe.
61) If the Earth were actually a big ball 25,000 miles in circumference, the horizon would be noticeably curved even at sea-level, and everything on or approaching the horizon would appear to tilt backwards slightly from your perspective. Distant buildings along the horizon would all look like leaning towers of Piza falling away from the observer. A hot-air balloon taking off then drifting steadily away from you, on a ball-Earth would slowly and constantly appear to lean back more and more the farther away it flew, the bottom of the basket coming gradually into view as the top of the balloon disappears from sight. In reality, however, buildings, balloons, trees, people, anything and everything at right angles to the ground/horizon remains so regardless the distance or height of the observer.
As previously mentioned, the reaction of bodies of water with sunlight is very different from that of land. Being largely transparent, light penetrates deeply into water, so that the sun’s light is absorbed throughout a thick layer from the surface to some depth rather than just on the surface, as with land. Additionally, water has a high specific heat, which means that its temperature increases very slowly as heat is added. Consequently, water exposed to sunlight does not change temperature appreciably throughout the day, so there is no heating of air in contact with the water. If anything, during summer afternoons, when land is rapidly heating, bodies of water frequently are cooler than air temperature. The cooler water chills the air in direct contact with it, so the air lying just above water often is cooler than air higher up. Since air temperature normally decreases with height, this temperature reversal from the norm is called a temperature inversion. Temperature inversions are common over bodies of water during late spring and into summer. Since this temperature structure is the reverse of what causes inferior mirages, inferior mirages are far less commonly noticed over water. This happens particularly during the summer, when inferior mirages are common over land.