Page:Popular Science Monthly Volume 11.djvu/600

582 If formed of cement, they must have time to harden, and for that purpose must be removed from the mould on which they were formed, to prevent cracking by contraction; and here the cloth bandage becomes a necessity. But this cloth is a costly article, requiring a great expenditure of hand-labor and time. It must not be allowed to fasten



to the vessel as the cement hardens. To prevent this, a simple, natural device has been adopted. The pottery shows a laminated texture. No doubt every fresh layer of the cement has been hardly compressed on the previous one; for at hand we find the primitive tools that were used for the purpose, scattered over the site of this ancient