66) “Dr. Rowbotham conducted several other experiments using telescopes, spirit levels, sextants and “theodolites,” special precision instruments used for measuring angles in horizontal or vertical planes. By positioning them at equal heights aimed at each other successively he proved over and over the Earth to be perfectly flat for miles without a single inch of curvature. His findings caused quite a stir in the scientific community and thanks to 30 years of his efforts, the shape of the Earth became a hot topic of debate around the turn of the nineteenth century.”

More of not-a-Dr. Rowbotham

We won't discuss more of his level experiments; we know that those examined by scientific scrutiny showed that the earth is curved.

Here, Mr Dubay claims N.D. Rowbotham "caused quite a stir in the scientific community" and "the shape of the earth became a hot topic of debate around the turn of the 19th century". Of course, this didn't happen. Wikipedia informs us that a pop-science magazine spoke had it as a regular feature. The scientific community at large wasn't impressed or involved.

No, what it mostly did was this:

 ... Hampden, who had embarked on an extraordinary 15-year campaign of abuse and libel that landed him in both jail and court several times. [Scientific American Blog]

http://blog.daimonie.com/2015_11_01_archive.html

A botched experiments;

Again, and again: Ask any qualified surveyor. These people don't have to put quotation marks around the word "theodolite" because they use it everyday, they know how it works and how to conduct geodesic measurements. 

Any surveyor will tell you that and explain to you why Mr Rowbotham’s experiments involved phony calculations (#65), ignored geometrical basics (#64), did not factor in sources of error like refraction (#62-65), are non-verifiable using today's standards and therefore absolutely worthless from a scientific point of view.

http://200proofsearthisnotflat.blogspot.co.uk/2016/02/debunking-dubay-60-69200.html