...As the earth's surface curves at approximately 8 inches per mile (RE theory)
Really, RET math gives us an eight inch drop per mile? I never bothered to figure this out myself (never had a reason), but I never would have thought it to be that much.
If this is the case, couldn't one simply construct a simple apparatus consisting of a long tube say an eighth of a mile long (this is only about two football fields or so, right?) with a center tap. With both ends and the center tap held up in the air a bit, fill the tube with water. The level of the water in the three tube ends can be lined up with each other and sighted with a scope to check all three levels in the tube ends.
According to RET, the water level in the center tap should be a bit higher than the two ends, right? And likewise, according to FET, the three levels should all line up exactly.
Am I explaining this well enough?