They immediately set about the task, and commenced hewing large blocks of stone and dragging them to the mouth of the gap, but not so near as to obstruct it. The whole body of workmen that had come from the Mound-builders' villages had labored at this task for a week, and they found that in that time sufficient stone had been hewn to build the wall from base to summit. Each block was more than twelve feet square, and through its centre was drilled a hole of some six inches diameter, in which to insert bars of metal, to bind them more firmly together.

Part Second, page 119-120