12. “ The Manchester Ship Canal Company published in the Earth Review stated, “It is customary in Railway and Canal constructions for all levels to be referred to a datum which is nominally horizontal and is so shown on all sections. It is not the practice in laying out Public Works to make allowances for the curvature of the earth”

Yes, it’s the same argument from Point 7 again!  

It was wrong then, so it’s wrong here to. 

And it is based on a quote that can’t be found anywhere but other flat earth publications. 

The quote says it’s not the practice to take account of the negligible difference of 8 inches over a mile, and that’s probably true, because it doesn’t matter when building a canal. When building an accelerator, it does matter, so engineers do take it into account.