"(About the Great Wall of China) All walled with square stones, strong enough to withstand any torment of air and water; and, whether true or plausible, it is nevertheless rumoured among the Chinese that King Cin ordered the execution of the master builders of the work if, where one stone meets and fits together with another, the joints were so loose that a nail could be driven into them: which, even if it is nothing more than an expression of exaggeration, would still have no reason to be feigned, if the squaring and fitting of the marble were not exquisitely executed."