Rowbotham's 'Earth Not a Globe' (1881): why the 'experiments' don't repeat

"Rowbotham's book contains 'experiments' that prove the Earth is flat - for example, that the horizon always rises to eye level."

MCToon has read the entire book and gone over the 'experiments' several times: they are all quite poor quality. Take experiment 15, the origin of 'the horizon is at eye level': it uses an unspecified instrument called a 'clinometer' that Rowbotham never describes (theodolites that measure vertical angles accurately existed in 1881). Because the device is unknown, the exercise is not repeatable - so it is not an experiment. Rowbotham observed from a hotel but never stated its elevation (the hotel still stands; the height works out to no more than 150 feet above sea level). He expected a 'considerable angle downwards' - but the globe model predicts a slight dip at 150 feet (at most 0.217 degrees, no refraction). No weather data, no time of day, no tide, no third-party attestation.

Experiment 15 (page 172 of the 1881 edition); the unspecified 'clinometer'; the 150-foot elevation implies a 0.217-degree dip, not a 'considerable angle'; no controls of any kind. Today the same claim is testable with a sub-$10 vinyl-tube clinometer - and the dip is measured, every time.