Summarily, the line of the pendula must be 25 meters in length to get the minimum effect, and so by necessity, Leon Focault's original experiments between latitudes were conducted outside hung from a tree exposed to the elements.
As you can clearly see, of the 3 experiments, none were conducted from a tree, none were exposed to the elements and 2 of the 3 experiments had lines shorter that what is declared as the necessary length.
Tom and John, I believe that the parts in bold are the relevant errors that the OP is pointing out.
The experiments in the OP's link isn't testing variation by latitude. That's why his link and his argument is invalid. It does not address the subject matter: Variations by Latitude.
His complaint about line length is also invalid. The pendulums in exhibits have shorter line lengths because they tend to be powered pendulums, and thus are not comparable to Focault's original experiments. Short line pendulums are unstable and inaccurate, which is why the original variations by latitude experiments were done with lines of 25 meters or more.
In the OP's link the one in Paris had a line length of
67 meters.