So the point is we have no idea what is below us. We can not dig down very far and find out. Or at least we have not dug down more than 7.5 miles so far… But if the earth is flat you could theoretically dig through it. But we have not dug down more than 7.5 miles, which is nothing compared to the 8,000 mile diameter they give for the earth…. So the point is we can’t dig down very far so we don’t know…
30) In his book “South Sea Voyages,” Arctic and Antarctic explorer Sir James Clarke Ross, described his experience on the night of November 27th, 1839 and his conclusion that the Earth must be motionless: “The sky being very clear … it enabled us to observe the higher stratum of clouds to be moving in an exactly opposite direction to that of the wind--a circumstance which is frequently recorded in our meteorological journal both in the north-east and south-east trades, and has also often been observed by former voyagers. Captain Basil Hall witnessed it from the summit of the Peak of Teneriffe; and Count Strzelechi, on ascending the volcanic mountain of Kiranea, in Owhyhee, reached at 4000 feet an elevation above that of the trade wind, and experienced the influence of an opposite current of air of a different hygrometric and thermometric condition … Count Strzelechi further informed me of the following seemingly anomalous circumstance--that at the height of 6000 feet he found the current of air blowing at right angles to both the lower strata, also of a different hygrometric and thermometric condition, but warmer than the inter-stratum. Such a state of the atmosphere is compatible only with the fact which other evidence has demonstrated, that the earth is at rest."
78) From Anchorage, Alaska at an elevation of 102 feet, on clear days Mount Foraker can be seen with the naked eye 120 miles away. If Earth were a ball 25,000 miles in circumference, Mount Foraker’s 17,400 summit should be leaning back away from the observer covered by 7,719 feet of curved Earth. In reality, however, the entire mountain can be quite easily seen standing straight from base to summit.