The Rev. D. Olmsted, in describing a diagram whish is supposed to represent the Earth as a globe, with a figure of a man sticking out at each side and one hanging head downwards, says "We should dwell on this point until it appears to us as truly up," In the direction given to these figures as it does with regard to a figure which he has placed on the top! Now, a system of philosophy which requires us to do something which is, really, the going out of our minds, by dwelling on an absurdity until we think it is a fact, Cannot be a system based on God's truth, which never requires anything of the kind. Since, then, the popular theoretical astronomy of the day requires this, it is evident that it is the wrong thing, and that this conclusion furnishes us with 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. 

The warm surface air that causes inferior mirages tends to expand. As air expands, it becomes less dense, producing buoyancy. Buoyant force causes the warm air to rise, and the air must be replaced somehow. This unstable condition leads to upward and downward motion of air (turbulence). Light passing through turbulent air is blurred. The constantly changing turbulence causes the images to shimmer. It is unusual for an inferior mirage to be steady.
22.) God's Truth never – no, never – requires a falsehood to help it along. Mr. Proctor, in his " Lessons," says: Men " have been able to go round and round the Earth in several directions." Now, in this case, the word " several will imply more than two, unquestionably: whereas, it is utterly impossible to circumnavigate the Earth in any other than an easterly or a westerly direction; and the fact is perfectly consistent and clear in its relation to Earth as a Plane.. Now, since astronomers would not be so foolish as to damage a good cause by misrepresentation, it is presumptive evidence that their cause is a bad one, and – a proof that Earth is not a globe.
The Flat Earth Society is a group actively promoting the Flat Earth Movement worldwide. Descending from Samuel Shenton's International Flat Earth Research Society, and the Universal Zetetic Society before it, we continue the age-old tradition of questioning the Round Earth doctrine and challenging authorities. Acknowledging the link between various unconventional beliefs, the Society also occasionally engages in other unconventional debates, striving to provide a voice for all free thinkers and Zeteticists.

66) Dr. Rowbotham conducted several other experiments using telescopes, spirit levels, sextants and “theodolites,” special precision instruments used for measuring angles in horizontal or vertical planes. By positioning them at equal heights aimed at each other successively he proved over and over the Earth to be perfectly flat for miles without a single inch of curvature. His findings caused quite a stir in the scientific community and thanks to 30 years of his efforts, the shape of the Earth became a hot topic of debate around the turn of the nineteenth century.

If the Earth were a globe, an observer who should ascend above its surface would have to took downwards at the horizon (if it be possible to conceive of a horizon at all under such circumstances) even as astronomical diagrams indicate that angles - varying from ten to nearly fifty degrees below the "horizontal" line of sight! (It is just as absurd as it would be to be taught that when we look at a man full in the face we are looking down at his feet!) But, as no observer in the clouds, or upon any eminence on the earth, has ever had to do so, it follows that the diagrams spoken of are imaginary and false; that the theory which requires such things to prop it up is equally airy and untrue; and that we have a substantial proof that Earth is not a globe.

26.) If the Earth were a globe, it would, if we take Valentia to be the place of departure, curvate downwards, in the 1665 miles across the Atlantic to Newfoundland, according to the astronomers' own tables, more than three hundred miles; but, as the surface of the Atlantic does not do so – the fact of its levelness having been clearly demonstrated by Telegraph Cable surveyors, – it follows that we have a grand proof that 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.