BOOK FIRST

...equal the temperament of all these three metals; and these species have been since variously imitated by men. I have thus far explained what seemed necessary of those things that must be considered and prepared before one begins to build: it remains now that we say something of the foundations, from which the prepared material begins to be put to work.

ON THE QUALITIES OF THE GROUND WHERE

the foundations must be placed.

Chapter VII.

Ornamental woodcut initial 'L' depicting a landscape with classical architecture and a seated figure.
Foundations are properly called the base of the building; that is, the part which is under the ground: which supports the whole edifice that is seen above ground. Therefore, among all the errors into which one can fall while building, those committed in the foundations are the most harmful, because they bring with them the ruin of the entire work, and they cannot be amended without the greatest difficulty: wherefore the Architect must apply his every diligence there: for in some places the foundations are provided by Nature, and elsewhere there is a need to use art. From nature we have foundations when one has to build upon rock, tufa A type of rock made of volcanic ash or limestone deposits, and scarantò A hard, stony subsoil common in the Venetian region, which is a kind of earth that partly consists of stone: because these, without the need for digging or other help of art, are in themselves the best foundation, and most fit to support any large building, whether on land or in rivers. But if Nature does not provide the foundations, it will be necessary to seek them with art; and then one will either have to build in solid ground, or in a place where there is gravel, or sand, or loose earth, or soft and marshy ground. If the ground is solid and firm, the Architect will dig down as far as his judgment suggests is required by the quality of the building and the solidity of that ground; which excavation will for the most part be a sixth part of the height of the edifice, unless one wishes to make cellars or other subterranean places. To recognize this solidity, it will be helpful to observe the precautions taken for wells, cisterns, and other similar places: and it will also be known by the herbs that grow there, if they are of the sort that usually grow only in firm and solid ground: and besides this, it will be a sign of solid ground if, when a heavy weight is thrown upon it, it does not resound or tremble: which can be known by the skins of drums placed on the ground, if at that stroke, moving slightly, they do not resound; and by water placed in a vessel, if it does not move. The neighboring places will also give an understanding of the solidity and firmness of the ground.

But if the place is sandy or gravelly, one must note whether it is on land or in rivers: because if it is on land, one shall observe what was said above regarding solid ground. And if one builds in rivers, the sand and gravel will be entirely useless: because the water, with its continuous course and with floods, continuously changes its bed: therefore one must dig until the solid and firm bottom is found: or, if that should be difficult, one shall dig somewhat into the sand and gravel, and then make palificate piling systems or foundations of driven stakes, so that the tips of the oak piles reach the good and solid ground, and upon those one shall build. But if one has to build in loose ground and not solid, then one must dig until the solid ground is found, and as far into it as the thickness of the walls and the size of the building require.

This solid ground, and fit to support buildings, is of various sorts: for (as Alberti Leon Battista Alberti (1404–1472), a foundational Renaissance architectural theorist rightly says) in some places it is so hard that iron can hardly cut it, elsewhere more solid, elsewhere it turns black, elsewhere it turns white (and this is considered the weakest), elsewhere it is like clay, elsewhere it is of tufa. Of all these, the best is that which is cut with difficulty, and that which, when wet, does not dissolve into mud. One should not found upon ruins, unless one first knows how they are sufficient to support the building, and how deep they go. But if the ground is soft and sinks deep, as in marshes, then palificate shall be made: the piles of which shall be long for the eighth part of the height of the wall, and thick for the twelfth part of their length. The piles must be driven so close that others cannot enter between them: and they should be struck with blows rather frequent than heavy, so that the ground may be better consolidated and firmed. These pilings shall be made not only under the outside walls placed over the canals, but also under those which are between the land and divide the buildings: because if foundations are made for the middle walls different from those of the outside—putting beams side by side lengthwise, and others across the top—it will often happen that the middle walls will sink, and the outside ones, being upon piles, will not move: whereby all the walls will come to open; which makes the building ruinous and is very ugly to see. Therefore this danger shall be avoided, primarily by spending less on the pilings; because according to the proportion of the walls, the said middle pilings shall be thinner than those on the outside.

C