Empirical Earth · Shape, Curvature & the Horizon

The Bedford Level experiment

The claim

“The Bedford Level experiment proved six miles of canal water is perfectly flat.”

What is true

Rowbotham ran the experiment and got the result he reported. He was not lying about what he saw down the telescope.

What is measured

Done right (Wallace, 1870), the six-mile canal test puts the middle marker about 1.5 m above a straight line. That is the size of bulge an Earth of 6,371 km radius gives. More on refraction and the curve.

What would show this is wrong

a careful multi-marker sightline that shows the middle marker level with the ends, instead of riding higher.

Sources

  1. Refraction, Snell's law & refractive index of air/water. Standard optics; refractive index of air via the Ciddor/Edlén equations. E. Hecht, Optics ; NIST refractive-index references. Snell's link
  2. The Bedford Level experiment. S. Rowbotham, Zetetic Astronomy (1865, flat result); A. R. Wallace's 1870 three-marker repetition and the Hampden wager (Royal Geographical / Wallace correspond link
  3. The Bedford Level wager and its replication. In the 1870 Old Bedford River wager, the neutral referee (John Henry Walsh of The Field) ruled that Alfred Russel Wallace’s raised three-marker s link
  4. Thompson v. Garcia (2019), Barrow County, Georgia. William Thompson sued flat-earther Zen Garcia for a contest reward after Garcia refused to pay. Garcia’s rules required proof matching the link
  5. The 2019 ruling does not support a flat Earth. In the magistrate case (Barrow County, Winder, Georgia; case 2019-MV-1104), Thompson sought $15,000 and submitted software models, which the co link
  6. Hampden v Walsh (1877): the wager ruled void. After Wallace won the Bedford experiment, Hampden repudiated the bet and sued the stakeholder. The Queen’s Bench held the agreement was a wager, link
  7. Samuel Rowbotham (“Parallax”), Zetetic Astronomy: Earth Not a Globe , 1865. The founding text of the modern flat-Earth movement, and the source of most of the arguments answered in this refe link
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