I fear they will verify Lord Palmerston's saying, that nothing is so permanent as a temporary appointment, not improbably our grand-children, visiting the Cape on pleasure or on business, will see this astounding, this everlasting memento, of our foresight.
I presume that the attribution was apocryphal rather than a literal quote but why was Lord Palmerston chosen for the attribution? Was there a famous episode in his career that resulted in him being associated with temporary appointments? Or perhaps he really did use this phrase and was directly famous for it?
I tried checking Lord Palmerston's biography but couldn't find any relevant episodes.