The Four Books of Architecture

BOOK FIRST.

...becomes soft, and allows itself to be handled and stretched by the hammer. But it cannot easily be melted, unless it is put again into furnaces made for this purpose: if it is not worked while heated and glowing, and compressed with hammer blows, it spoils and consumes away. It will be a sign of the goodness of the iron if, when reduced to a mass, its veins are seen to be continuous and straight, and not interrupted: and if the ends of the mass are clean and without dross: because the said veins will demonstrate that the iron is without knots and without flakes; and by the ends one will know what it is like in the middle: but if it is reduced into square sheets, or of another figure, if the sides are straight, we shall say that it is equally good, having been able to equally resist the blows of the hammers.

With lead are covered magnificent Palaces, Temples, towers, and other public buildings: pipes or small channels are made, which we use to conduct water; and hinges and iron gratings are secured with lead in the jambs of doors and windows. It is found in three sorts; that is, white, black, and of a middle color between these two; wherefore by some it is called ash-grayoriginal: "Cineraccio". The black is so called, not because it is truly black; but because it is white with some blackness: wherefore in respect to the white, the Ancients rightly gave it such a name. The white is more perfect and more precious than the black: the ash-gray holds a middle place between these two. Lead is extracted either in large masses, which are found by themselves without anything else: or small masses are extracted from it, which shine with a certain blackness, or its very thin flakes are found attached to rocks, marble, and stones. Every sort of lead easily melts: because with the heat of fire it liquefies before it catches fire: but placed in very hot furnaces it does not preserve its nature, and does not last: because one part changes into lithargeoriginal: "litargirio", a lead oxide byproduct, another into molybdenumoriginal: "Molibdena"; in this period, the term referred to lead-ore dross or galena rather than the chemical element known today. Of these sorts of lead, the black is soft, and for this reason allows itself to be easily handled by the hammer, and to be stretched much, and is heavy and weighty: the white is harder, and is light: the ash-gray is much harder than the white, and as for weight it holds the middle place.

With Copper public buildings are sometimes covered, and the Ancients made from it the nails, which are commonly called doroniRefers to large bronze pins or dowels used to secure masonry: which, fixed in the stone below and in the one above, prevent the stones from being pushed out of order, and the clampsoriginal: "arpesi", metal irons used to join stones horizontally, which are placed to hold two stones together side by side; and we use these nails and clamps so that the whole building (which by necessity can only be made of many pieces of stone) being in such a way joined and tied together, becomes as if of one single piece, and thus much stronger and more durable. Nails and clamps are also made of iron, but they made them for the most part of copper, because it is less consumed by time, since it does not rust. They also made from it the letters for inscriptions, which are placed in the frieze of buildings, and one reads that of this metal were the hundred famous gates of Babylon, and in the Isles of GadesModern-day Cádiz, Spain two columns of Hercules eight cubits high. That copper is held to be most excellent and best which, cooked and extracted by way of fire from the minerals, is of a red color tending to yellow, and is well "flowered"; that is, full of holes: because this is a sign that it is purged and free from all dross. Copper catches fire like iron, and liquefies, wherefore it can be melted: but placed in very hot furnaces it does not tolerate the force of the flames, but is entirely consumed. Although it is hard, it nevertheless allows itself to be handled by iron tools, and to be stretched even into thin sheets. It is preserved excellently in liquid pitch, and although it does not rust like iron, it nevertheless still produces its own rust, which we call verdigrisoriginal: "verde rame", literally 'green copper', especially if it touches sharp and liquid things. Of this metal mixed with tin, or lead, or brass (which itself is also copper, but colored with calamine earthoriginal: "terra cadmia", a zinc-rich earth used to produce brass alloys), a mixture is made, commonly called Bronzeoriginal: "Bronzo": which Architects very often use: for bases, columns, capitals, statues, and other similar things are made of it. Four columns of Bronze are seen in Rome in Saint John LateranThe Archbasilica of Saint John Lateran: of which only one has its capital: and Augustus had them made from the metal that was on the prows of the ships he conquered in Egypt against Mark Antony. Four ancient gates have also remained in Rome until today; that is, that of the RotundaThe Pantheon, which was formerly the Pantheon: that of Saint Hadrian, which was the Temple of Saturn: that of Saints Cosmas and Damian, which was the Temple of Castor and Pollux, or else of Romulus and Remus: and that which is seen in Saint Agnes outside the Viminal gate, today called Saint Agnese, on the Via Nomentana. But the most beautiful of all these is that of Santa Maria Rotonda: in which those Ancients wished to imitate with art that kind of Corinthian metalA highly prized alloy of gold, silver, and copper, in which the yellow nature of gold prevailed: for we read that when Corinth (which is now called Coranto) was destroyed and burned, the gold, silver, and copper liquefied and united into one mass, and fortune tempered and made the mixture of three kinds of copper, which was later called Corinthian: in one of which silver prevailed, wherefore it remained white, and approached closely with its splendor to that [of silver]; in another gold prevailed, and therefore it remained yellow and the color of gold: and the third was that where there was...