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.
Day and night cycles are easily explained on a flat earth. The sun moves in circles around the North Pole. When it is over your head, it's day. When it's not, it's night. The light of the sun is confined to a limited area and its light acts like a spotlight upon the earth. The picture below illustrates how the sun moves and also how seasons work on a flat earth. The apparent effect of the sun rising and setting is usually explained as a perspective effect.

Mr. J.M. Lockyer says: Because the Sun seems to rise in the east and set in the west, the Earth really spins in the opposite direction; that is, from west to east," Now, this is no better than though we were to say - Because a man seems to be coming up the street, the street really goes down to the man! And since true science would contain no such nonsense as this, it follows that the so-called science of theoretical astronomy is not true, and, we have another proof that the Earth is not a globe.
19.) Every man in his senses goes the most reasonable way to work to do a thing. Now, astronomers (one after another – following a leader), while they are telling us that Earth is a globe, are cutting off the upper half of this suppositious globe in their books, and, in this way, forming the level surface on which they describe man as living and moving! Now, if the Earth were really a globe, this would be just the most unreasonable and suicidal mode of endeavoring to show it. So that, unless theoretical astronomers are all out of their senses together, it is, clearly, a, proof that the Earth is not a globe.

As the mariners' compass points north and south at one time, and as the North, to which it is attracted is that part of the Earth situated where the North Star is in the zenith, it follows that there is no south "point" or "pole" but that, while the centre is North, a vast circumference must be South in its whole extent. This is a proof that the Earth is not a globe.

Astronomers tell us that, in consequence of the Earth's "rotundity," the perpendicular walls of buildings are, nowhere, parallel, and that even the walls of houses on opposite sides of a street are not! But, since all observation fails to find any evidence of this want of parallelism which theory demands, the idea must be renounced as being absurd and in opposition to all well-known facts. This is a proof that the Earth is not a globe.