The drop on the round earth is supposed to be as follows: 8 inches first mile, then 32 inches at the second mile, then at 90 miles it jumps to over a mile, then at 6,250 miles, the total drop becomes nearly 5,000 miles, which is about 1,000 miles too much on the round earth model, because the diameter of the earth on their model is less than 8,000 miles.

O.k., so if you accept that, then you aren't saying that the earth curves 8 inches per mile, because over 6,250 miles, that would only add up to a total drop of less than eight tenths of a mile and round earthers are claiming a drop of nearly 4,000 miles, over just 1/4 of the earth's circumference (assuming it is round).

Alright, so if your perspective is supposed to change, based on where you are on the ball and that model is actually correct (enough for government work), then you would only observe 8 inches of drop, for the first mile in any direction. Of course, with telephoto lenses, we don't.

http://www.sacred-texts.com/earth/za/za05.htm