Thank you for your recent email.
The two towers are build vertical to a tangent to the earth, i.e. radial to the centre of the earth, thus, theoretically, the shape between the two towers is an inverted trapesium rather than a rectangle with the length between the bottom of the towers being 36mm less than the length at the top of the towers.
The gap at the base is, of course, the one that was actually "measured" with the apparent increase being a result of building the towers "vertically".
Regards
Peter Hill
General Manager & Bridgemaster
So there you have it, straight from the horse's bridgemaster's mouth. I'm man enough to admit I backed a wrong 'un, so can we let this one go now?
If the two Towers are vertical (as respect to their local position), and yet they are further apart at the top than the bottom, then this
is proof that the Earth is indeed Round.
As the diagram I provided shows, only on a Round Earth can the Towers be both vertical and create an inverted trapezoid between them. On a Flat Earth the shape between the towers has to be a rectangle. This is a mathematical imperative, so unless the FEers can prove the 1 + 1 does not equal 2, then this evidence is
absolute proof that the Earth is
in fact Round.