I agree, they are both talking about the same thing. The southerly deviation.
Laplace and Gauss say it is "insensible"
in·sen·si·ble
adjective
3. too small or gradual to be perceived; inappreciable.
You cut out the first two definitions of insensible. The fact that the scientists of the time were looking for this "undetectable" thing shows that the matter was not agreed upon.
The link in reply #34 @edby
Just click on the link in the quote, but here it is https://forum.tfes.org/index.php?topic=1362.msg27395#msg27395 .
You were the one who wanted to know where it is. Am I missing something?
Possibly I am being very stupid. I didn't want to know where the link was. Why did you post "The link in reply #34 @edby"?
Because I thought you wanted to know where the link was. And so the cycle continues....
Ah this link http://adsabs.harvard.edu/full/1913PA.....21..208R ? Rigge.
Right. And as you say, Rigge never says ""The rotation of the earth has never been met with an experimental proof". Rather, he discusses the most famous proof (Foucault) and mentions some others.
Yet according to Tom, the paper says "The rotation of the earth has never been met with an experimental proof". Why would Tom say that?
Focault's Pendulum is explained by Mach's Principal. It is not enough to demonstrate that the earth rotates.
Mach's Principle explains that if the earth was still and the all the stars went around the Earth then the gravitational pull of the stars would pull the pendulum. As Mach said "The universe is not twice given, with an earth at rest and an earth in motion; but only once, with its relative motions alone determinable. It is accordingly, not permitted us to say how things would be if the earth did not rotate."
A rotating earth must do specific things, and this was addressed by Tycho Brahe, whose organization demonstrated that the earth did not rotate.