2Both species should be built of the smallest sized stones, that the walls, by sucking up, and attaching themselves to, the mortar, may last the longer. For as the stones are of a soft and porous nature, they absorb, in drying, the moisture of the mortar, and this, if used plentifully, will consequently exercise a greater cementing power; because from their containing a larger portion of moisture, the wall will not, of course, dry so soon as otherwise; and as soon as the moisture is absorbed by the pores of the stone from the mortar, the lime, losing its power, leaves the sand, so that the stones no longer adhere to it, and in a short time the work becomes unsound.
2Both kinds should be constructed of the smallest stones, so that the walls, being thoroughly puddled with the mortar, which is made of lime and sand, may hold together longer. Since the stones used are soft and porous, they are apt to suck the moisture out of the mortar and so to dry it up. But when there is abundance of lime and sand, the wall, containing more moisture, will not soon lose its strength, for they will hold it together. But as soon as the moisture is sucked out of the mortar by the porous rubble, and the lime and sand separate and disunite, the rubble can no longer adhere to them and the wall will in time become a ruin.