The Four Books of Architecture

L I B R O

they ought to be made of clayey earth, whitish and malleable: one shall entirely avoid gravelly and sandy earth. The earth should be dug in the Autumn, and soaked in the Winter, and then the bricksoriginal: "quadrelli", referring to square-shaped bricks or tiles shall be conveniently formed in the Spring. But if necessity should force one to form them in the Winter or the Summer; they shall be covered in the Winter with dry sand, and in the Summer with straw. Once formed, they must be dried for a long time, and it is better to dry them in the shade, so that they are equally dry not only on the surface but also in the middle parts: which is not achieved in less than two years. They are made both larger and smaller according to the quality of the buildings to be made, and according to how we wish to use them: wherefore the Ancients made the bricks for public and large buildings much larger than those for small and private ones. Those that are made somewhat thick should be pierced in several places, so that they may dry and fire better.

OF SAND. Cap. IIII.

Decorative drop cap 'S' with floral scrollwork.Sand is found in three sorts; that is, pit sand, river sand, and sea sand. Pit sand is the best of all, and it is either black, white, red, or charcoal-likeoriginal: "carboncino", a type of volcanic or burnt earth, which is a kind of earth burnt by fire enclosed in the mountains, and is dug in Tuscany. There is also dug in Terra di LavoroA historical region of the Kingdom of Naples, in modern-day Campania in the territory of Baia and Pozzuoli, a powder called by Marcus Vitruvius Pollio, the Roman author of "De architectura"Vitruvius PozzolanaA volcanic ash that, when mixed with lime, creates a cement that can set underwater: which sets very quickly in water and makes buildings very strong. Through long experience, it has been seen that white is the worst among the pit sands, and that among the river sands the best is that from torrents, which is found below the cliff from which the water descends: because it is more purified. Sea sand is the least good of all the others; it should be blackish and shine like glass: but that which is closer to the shore and is coarser is better. Pit sand, because it is "fat" meaning clay-heavy or cohesive, is more tenacious: but it cracks easily: and therefore it is used in walls and continuous vaults. River sand is very good for plastering, or as we might say, for external rendering. Sea sand, because it dries quickly and wets quickly, and dissolves because of the salt; is less fit to sustain weights. Every sand will be excellent in its kind if, when pressed and handled with the hands, it crackles: and if, when placed upon a white garment, it does not stain it, nor leave earth behind. That will be bad which, when mixed in water, makes it turbid and muddy, and which has stayed for a long time in the Air, the Sun, the Moon, and the Frost: for it will have much soil and rotten moisture, fit to produce shrubs and wild figs, which are of the greatest harm to buildings.

OF LIME, AND THE MANNER OF MIXING IT. Cap. V.

Decorative drop cap 'L' depicting a seated figure holding a book or tablet.The stones to make lime are either dug from the mountains or taken from the rivers. Every mountain stone is good that is dry, purged of humors, and brittle, and that has no other matter in itself which, when consumed by the fire, leaves the stone smaller: wherefore that will be better which is made of very hard, solid, and white stone, and which when cooked remains a third lighter than its original stone. There are also certain sorts of spongy stones, the lime of which will be very good for the plastering of walls. In the mountains of Padua, some scaly stonesoriginal: "pietre scagliose", likely referring to limestone with a flaky or layered texture are dug, the lime of which is excellent in works made in the open air and in water; because it sets quickly and lasts a long time. Every stone dug to make lime is better than that which is collected, and from a shady and humid quarry rather than a dry one, and white is better used than brown. The stones taken from rivers and torrents; that is, pebbles or cobbles; make very good lime, which makes very white and polished work: wherefore it is mostly used in the plastering of walls. Every stone, both of the mountains and the rivers, is cooked more or less quickly according to the fire given to it: but regularly it is cooked in sixty hours. Once cooked, it must be wetted, and all the water should not be poured on at once; but in several times, continuously however, so that it does not burn, until it is well diluted. Then it should be stored in a humid place and in the shade, without mixing anything else into it, only covering it with light sand: and the more it is slakedoriginal: "macerata", the process of soaking lime in water to make it usable for mortar, the more tenacious and better it will be, except that which is made of scaly stone, like the Paduan; because once wetted, it must be put to use immediately: otherwise it consumes and burns itself: wherefore it does not set and becomes entirely useless. To make mortar, it must be mixed with sand in this manner; that taking pit sand, one puts three parts of it and one of lime: if of river or sea sand; two parts of sand and one of lime.

OF METALS. Cap. VI.

Decorative drop cap 'I' with intricate floral and scroll designs.The Metals that are used in buildings are iron, lead, and copper. Iron serves to make nails, hinges, and bolts, with which doors are closed: to make the doors themselves, the grates, and similar works. In no place is it found and dug pure: but once dug it is purged with fire; so that it liquefies in a way that it can be cast: and thus before it cools, the dross is removed: but after it is purged and cooled; it ignites well, and be...