254. One would expect here ‘lime of travertine,’ for what Vasari must mean is lime prepared by burning this stone, which he recommends elsewhere, e.g. ‘Architettura,’ cap. iv, and ‘Scultura,’ cap. vi (calce di trevertino). The cement here given is a lime cement mixed with water. A sort of putty mixed with boiled oil is also employed, and is said to have been introduced by Girolamo Muziano of Brescia, a contemporary of Vasari. Each mosaic worker seems to have his own special recipe for this compound.

255. The process described by Vasari of building up the mosaic in situ, tessera by tessera, according to the design pounced portion by portion on the soft cement, is the most direct and by far the most artistic, and was employed for all the fine mosaics of olden time. In modern days labour-saving appliances have been tried, though it is satisfactory to know that they are all again discarded in the best work of to-day, such as that of Sir W. B. Richmond in St. Paul’s. One of the methods referred to, which can be carried out in the studio, is to take a reversed tracing of the design, covered with gum, and place the cubes face downwards upon it according to the colour scheme. When they are all in position, as far as can be judged when working from the back, a coating of cement is laid over them and they are thus fixed in their places. The whole sheet is then lifted up and cemented in its proper place on the wall, the drawing to which the faces of the cubes are gummed being afterwards removed by wetting. A better plan than this is called by the Italians ‘Mosaico a rivoltatura.’ For this process the tesserae are laid, face upwards, in a bed of pozzolana, slightly damp, which forms a temporary joint between the adjacent cubes. Coarse canvas is pasted over the face of the work; it is lifted up, and the pozzolana brushed out of the interstices. The whole is then applied to the wall surface and pressed into the cement with which this has been coated. When the cement has set the canvas is removed from the face.

256. The Duomo of Siena is a veritable museum of floor decorations in incised outlines and in black and white, in the various processes described by Vasari. There is a good notice of them in Labarte, Histoire des Arts Industriels. None of the work is as early as the time of Duccio, but Beccafumi executed a large amount of it. See the Life of that artist by Vasari.

It is worthy of notice that Dante had something of this kind in his thoughts, when in the 12th Canto of the Purgatorio he describes the figure designs on the ground of the first circle of Purgatory.

257. See Note on ‘Tuscan Marble Quarries,’ ante, p. 119.

258. The Appartamento Borgia still contains a good display of these variegated tiles; the original ones are however rather the worse for wear. In the Life of Raphael, Vasari says they were supplied by the della Robbia of Florence. In the Castle of S. Angelo there is a collection of interesting specimens of the tiles Vasari goes on to mention. They are in cases in the Sala della Giustizia, and exhibit the devices of Alexander VI, Julius II, Leo X, Paul III, and other Popes. The pavement of the Laurentian Library at Florence is laid with tiles showing a very effective design of yellow upon red. They are ascribed to Tribolo.

259. Was this the road from Seravezza seawards which Michelangelo had begun? See Note on ‘Tuscan Marble Quarries,’ ante, p. 119. Specimens of these Stazzema breccias are shown as C, D, on the Frontispiece.

260. Lat. Evonymus Europaeus. The only English example of the family is the spindle tree.

261. The Lemonnier editors say that this work is lost. Of course Vasari is speaking of the Old St. Peter’s, not the present structure.

262. Fra Damiano of Bergamo is mentioned by Vasari in his Life of Francesco Salviati (Opere, ed. Milanesi, VII).

263. Inlays of different coloured woods, forming what is known as tarsia work, and sometimes as marqueterie, compose an easily understood kind of decoration that has been practised especially in the East from time immemorial. There is however a special interest attaching to this work in the Italy of the fifteenth century, in that it was connected with the studies in perspective that had so potent an influence on the general artistic progress of the time. For some reason that is not clearly apparent the designs for this work often took the form of buildings and city views in perspective, and artists amused themselves in working out in this form problems in that indispensable science. The history of the craft is so instructive that it is worth a special Note, which the reader will find at the end of this ‘Introduction,’ postea, p. 303.

264. ‘The onyx marbles of Algeria, Mexico, and California (which are of the same nature as the Oriental alabasters) can be cut and ground sufficiently thin for window purposes’ (Mr W. Brindley in Transactions, R.I.B.A., 1887, p. 53). See also ante, p. 43.

265. The ‘occhi’ of Vasari correspond to the old-fashioned ‘bull’s-eyes’ which are still to be seen surviving in cottage windows. The ‘bull’s eye’ pane was the middle part of a sheet of so-called ‘crown’ glass where was attached the iron rod or tube with which the mass of molten glass was extracted from the furnace, before, by rotation of the rod, it was spread out into the form of a sheet. When the rod was ultimately detached a knob remained, and this part of the sheet was used for glazing as a cheap ‘waste product.’ In connection with the modern revival in domestic architecture, for which Mr Norman Shaw deserves a good deal of the credit, these rough panes have come again into fashion, and manufacturers make them specially and supply them at the price of an artistic luxury! In Vasari’s time they were evidently quite common, and we find numerous specimens represented in the pictures of the fifteenth and sixteenth centuries. The bedroom of S. Ursula in Carpaccio’s picture at Venice; the cell of S. Jerome in Dürer’s engraving; the room in which van Eyck paints Arnolfini and his wife, those in which Jost Amman’s ‘Handworkers’ are busy, etc., etc., have casements glazed in this fashion, the knob, called in English ‘bullion,’ in French ‘boudine,’ in German ‘Butzen,’ being distinctly represented as in relief.

266. The ‘telajo di legno’ is a window frame of wood such as we are familiar with in modern days, only in olden times these were often made detachable and taken about from place to place when lords and ladies changed their domicile. When Julius II wanted Bramante to fill some windows of the Vatican with coloured glass, it was found that the French ambassador to the Papal court had brought a painted window in such a frame from his own country, and the sight of this led to the invitation to Rome of French artists in this material. See infra, Note 5.

267. See Note on ‘The Stained Glass Window’ at the close of this ‘Introduction,’ postea, p. 308.

268. Vasari wrote the life of this artist, who had been his own teacher in early years at Arezzo (Opere, IV, 417). Gaye, Carteggio, II, 449, gives documentary evidence that he was the son of a certain Pierre de Marcillat, and was born at S. Michel in the diocese of Verdun in France. His name therefore has nothing to do with Marseilles, which moreover is not in a glass-painting locality, whereas Verdun, between France and Germany, is just in the region where the art was developed and flourished. Guglielmo and another Frenchman named Claude came to Rome about 1508 in the circumstances described in the foregoing Note, and made some windows for the Sala Regia of the Vatican and other parts of the Palace. These have all perished, but there still survive two windows from their hands in the choir of S. Maria del Popolo, on which are the name and arms of Pope Julius II. They are placed north and south behind and above the high altar, and have each three lights. They contain scenes from the lives of Christ and the Madonna, in which the figures are carefully drawn but the colour is patchy. Though the reds are clear and strong, there is a good deal of grey and the architectural backgrounds are rather muddy in hue. The artist was invited from Rome to Cortona and from thence to Arezzo, which as Vasari notices in the beginning of his Life remained his home to the end. He executed many windows there, in the cathedral and in S. Francesco, some of which still remain; and also works in fresco. Vasari declares that he owed to his teaching the first principles of art.

On the whole subject of the glass-painting craft see the Note on ‘The Stained Glass Window,’ postea, p. 308, where the curious confusion of two different processes, between which Vasari’s treatment oscillates, is elucidated.

269. The significance of Vasari’s demand for transparency in glass is explained in the Note, postea, p. 308.

270. It is somewhat remarkable that the Venetians, who practised the art of glass mosaic from about the ninth century, and in the thirteenth began their famous glass works, never achieved anything in the technique of the stained glass window. Venetian glass vessels, like the glorious lamps from the Cairo Mosques, owe much of their beauty to the fact that the material is not clarified but possesses a beautiful warm tone. It is indeed more difficult to get clear glass than tinted.

271. For the most part this description, with the exception of the part about scaling-off glass in order to introduce a variety in colour, corresponds closely with the technical directions which Theophilus gives so fully and clearly in his Schedula Diversarum Artium of about 1100 A.D. It is pretty clear that Vasari is telling us here what he learned from William of Marcillat who would have inherited the traditions of the great French glass-painters of the thirteenth century.

272. The ‘scaglia’ is the thin scale that comes off heated iron when cooling under the hammer, and is collected from the floors of smithies. Vasari thinks of it as a ‘rust’ ‘ruggine,’ because rusty iron scales off in much the same way, the cause in both cases probably being oxidization. Hence the expression ‘another rust.’

273. The pigments or pastes that are to be fused on to the coloured glass, to modify its hue or to indicate details, are powdered and mixed with gum for convenience in application. The gum is not to serve as permanent binding material as the pastes are subsequently fused and burnt in on the glass.

274. It will be understood that the glass subjected to this treatment is not coloured in the mass, or what is called ‘pot-metal,’ but has a film of colour ‘flashed’ or spread thinly on a clear sheet. This is done with certain colours, such as the admired ruby red, because a piece coloured in the mass would be too opaque for effect. Economy may also be a consideration, as the ruby stain is a product of gold.

275. The composition, which when fused stains the glass yellow, may before fusion be of a red hue. As a rule the yellow stain on glass is produced by silver. Vasari does not say what his composition is.

276. The red film is what Vasari understands by the ‘painting.’ This might fuse and run with the heat required to fuse the yellow.

277. That is, the space where the yellow leaf is to come may be cleared of the red film after the yellow leaf has been painted on the back, as well as before that process. The process Vasari describes of introducing small details of a particular colour into a field of another hue is a good deal employed by modern workers in glass, but it was not known to Theophilus, or much used in the palmy days of the art, the twelfth and thirteenth centuries.

278. In Theophilus’s time these convenient leads grooved on both sides, which are still in use, were not invented. He directs the worker to bind strips of lead round each piece of glass and then solder together the leads when the pieces so bound are brought into juxtaposition.

279. ‘Niello’ is from the mediaeval Latin ‘nigellum,’ ‘black,’ and refers to the black composition with which engraved lines in metal plates were filled, according to the process detailed by Vasari.

280. It is curious that the chapter ends without any discussion of the chasing of gold and silver plate.

281. To some small extent the ancients do seem to have filled the engraved lines in their bronze or silver plates with colouring matter, and the known examples are described in Daremberg et Saglio, Dictionnaire des Antiquités, art. ‘Chrysographia,’ p. 1138. Pliny, Hist. Nat., XXXIII, 46, gives a recipe, as used by the Egyptians, for a material for colouring silver that corresponds with the composition used for niello work, though the use he indicates seems rather that of an artificial patina than a filling for incisions. In any case the use of such a filling in antiquity was quite uncommon, for the innumerable incised designs on the backs of Greek and Etruscan mirrors and on caskets like the Ficeronian Cista show no indication of the process, though of course in the lapse of time the incisions have acquired a darker tinge than the smooth surfaces of the metal, and Vasari may have seen them filled with accidental impurities.

282. A burin is shown in Fig. 2, D, ante, p. 48.

283. Vasari makes no mention here of sulphur, which in the recipes given by Pliny, Theophilus, and Cellini, is a constant constituent of the black amalgam. Silver and lead alone would not give the black required.

284. The ‘Pax,’ Italian ‘pace,’ was a little tablet of metal or some other material used in churches to transmit the kiss of peace from the priest to the people. Certain paxes once in the Baptistry of Florence have now found their way through the Uffizi to the Museum in the Bargello, but experts are not agreed as to the ascription of particular examples to Finiguerra. See Milanesi’s note on this artist at the close of Vasari’s Life of Marc Antonio Raimondi (Opere, V, 443).

285. In Vasari’s first edition, of 1550, there is a notice of Finiguerra in the Life of Antonio Pollaiuolo (p. 498) and he there celebrates only the skill of Maso as a niellist, but in the edition of 1568 there is another notice of him in connection with Marc Antonio (Opere, ed. Milanesi, V, 395), and here Vasari claims for him the credit of being the first to make the advance from niello work to copper-plate engraving. This second passage is a famous one, and describes how Finiguerra moulded his silver plate, incised with a design, in clay, and then cast it in sulphur, and subsequently filled the hollow lines in the sulphur cast (which reproduced the incisions on the silver plate) with lamp-black, so that they showed up more clearly. He then seems, according to Vasari, to have pressed damp paper against the sulphur plaque so treated, and obtained a print by extracting the black from the lines. Benvenuto Cellini however, a better authority than Vasari on Finiguerra, praises him as the best niello worker of his time, but says nothing about this further development of his craft, and on the contrary ascribes the invention of copper-plate engraving to the Germans. Cellini tells us at the end of his ‘Introduzione,’ that in 1515, when fifteen years old, he began to learn the goldsmith’s trade, and that then, though the art of niello work had greatly declined, the older goldsmiths sang in his ears the praise of Maso Finiguerra, who had died in 1464. Hence, Cellini says, he gave special attention to niello work, and he describes the process, at rather greater length than Vasari, in the first chapter of his Treatise on Gold-work (I Trattati, etc. di Benvenuto Cellini, ed. Milanesi, Firenze, 1893).

The question of the origin of copper-plate engraving need not be here discussed. Any of the incised silver or bronze plaques of the ancients might have been printed from; and as a fact some incised bronze discs that are placed at the bottoms of the towers in the great crown-light of the twelfth century in the Minster at Aachen have actually been put through the printing press and the impressions published, though no one at the time they were made can have thought of printing from them. In the same way wooden stamps in relief were used by Egyptians and Romans for impressing the damp clay of their bricks, though no one seems to have thought of multiplying impressions on papyrus or parchment. So trial impressions of niello plates, before the lines were filled in permanently, may often have been made, and not by Finiguerra alone. The idea of multiplying such impressions on their own account is now universally credited to the Germans, and this seems also to have been the opinion of Cellini. See his ‘Introduzione.’

286. That is to say, the bottoms of cups or chalices. There are notices of armorial insignia, enamelled at the bottom of cups of gold used by some of the French kings, in Labarte, Histoire des Arts Industriels.

287. Giulio: a piece coined under Pope Julius II, of the same value as the ‘paolo,’ and equivalent to 56 centesimi, or about 5½d. of our money.

288. That is, the outlines of the different figures, ornaments, or other objects executed in low relief on the metal. See the Note on ‘Vasari’s Description of Enamel Work’ at the close of the ‘Introduction’ to Painting, postea, p. 311.

289. ‘The other kind’ probably refers to the incisions on the niello plates of which he has been speaking. These are hollow, or in intaglio, whereas the work he is here describing is in relief.

290. ‘Si fermino col martello.’ The only practicable use of the hammer in connection with enamels is to pound the lumps of vitreous paste to a more or less fine powder, in which form they are placed over the metal. Theophilus, in chapter 53 of his third Book, ‘de Electro,’ ‘on Enamel,’ introduces the hammer in a similar connection: ‘Accipiensque singulas probati vitri ... quod mox confringas cum rotundo malleo donec subtile fiat;’ ‘take portions of the glass you have tested ... and break up each lump with a round headed hammer till it be finely powdered.’ Cellini also says the pastes are to be pounded in a mortar ‘con martello.’ Trattati, p. 30. It is not easy however to see how any sense of ‘pounding’ can be extracted from the verb ‘fermare’ which Vasari uses.

291. The difference in colour between gold and silver will naturally affect the choice of the transparent vitreous pastes that are to cover them, and there are also considerations of a chemical kind which prevent the use of certain pastes on certain metal grounds. For example tin has the property of rendering transparent enamels opaque, and transparent pastes cannot be used over metal grounds wherein tin enters into the composition. Cellini, who gives the same caution as Vasari, takes as an illustration transparent ruby coloured enamel, which he says cannot be used over silver, for a reason which has about it a reminiscence of the ancient alchemy, namely, that it is a product of gold and must be employed only over its kindred metal! On the other hand he forbids for use with gold yellow, white, and turquoise blue. We are indebted for some special information on this highly technical subject to the kindness of Mr H. H. Cunynghame, C.B., who writes: ‘There are two distinct reasons why different enamels are used on silver and gold respectively. The first is an artistic reason. Transparent reds do not show well over silver, the rays reflected from a silver surface not being well calculated to show off the colours of the gold. In fact silver absorbs those rays on the transmission of which the beauty of gold-red largely depends, whence then it follows that transparent blues and greens should be used on silver, and reds, browns, and the brighter yellows on gold. In addition to this, silver has its surface disturbed by the silicic acid in the enamel. The consequence is that ordinary enamels put on a silver surface are stained. To prevent this it is desirable to add some ingredient that dissolves and renders colourless the stain. For this purpose therefore special fluxes or clear enamels are made for silver. They usually contain manganese and arsenic. The first of these has such a property of “clarifying” enamels and glazes that it used to be called the potter’s “soap,” for it cleaned the glazes on china. The other is also used for the same purpose.... As silver alloy is more easy to melt than gold alloy, fluxes, i.e. clear enamels for silver, are much more fusible than those for gold.’

292. This is a practice of modern enamellers. Cellini however is against it, as if the enamels begin again to run there is a danger of losing the truth of the surface. He recommends polishing by hand alone (Trattati, ed. Milanesi, 35).

293. This may have been the so-called Venetian enamel used in Vasari’s time. This was a form of opaque painted enamel over copper, extremely decorative, but coarse as compared with the translucent enamel over reliefs. We owe this suggestion to Sir T. Gibson Carmichael.

294. The word ‘Tausia,’ and its connection with ‘Tarsia,’ the term used for wood inlays, has given rise to some discussion. The explanation in Bucher’s Geschichte der Technischen Künste, III, 14, is probably correct, and according to this the Italian ‘Tausia’ comes from the Spanish ‘Tauscia’ or ‘Atauscia,’ which is derived from an Arabic root meaning ‘to decorate.’ The art of inlaying one metal in another is one of great antiquity in the East, and was no doubt brought to Spain by the Moors, from which country, perhaps by way of Sicily, it spread to Italy. The word ‘Tarsia,’ applied as we have already seen to inlays in wood, may have been derived by corruption from ‘Tausia,’ though, as the form ‘Intarsia’ is also common, a derivation (unlikely) has been suggested from the Latin ‘Interserere.’ The ‘in’ is probably only the preposition, that has become incorporated with the word it preceded.

295. ‘Cavasi il ferro in sotto squadra.’

296. If the sinkings be undercut the further process of roughening the sunk surfaces is hardly necessary, but the roughening or puncturing may suffice to hold the inlaid metal when there is no actual undercutting of the sides of the sinkings.

297. The ‘filiera,’ or iron plate pierced with holes of various sizes for drawing wires through, was known to Theophilus. See chapter 8 of Book III of the Schedula, ‘De ferris per quae fila trahuntur.’

298. Vasari does not attempt to deal with the art of wood engraving in general nor need this Note traverse the whole subject. In all these later chapters of the ‘Introduction’ to Painting he is dealing with forms of the decorative art in which various materials are put together so as to produce something of the effect of a picture. Hence all that he envisages in the department of wood engraving are what are called chiaroscuri, or engravings meant to produce the effect of shaded drawings by tints rather than by the lines which constitute engravings proper. It has been noticed that some writers on engraving, (ante, p. 20) have denied to these imitated light-and-shade drawings the character of true engravings.

As we have seen to be the case with copper-plate engraving (ante, p. 275) priority is now claimed in these chiaroscuri for Germany over Italy, and Ugo da Carpi, who was born about 1450, near Bologna, becomes rather the improver of a German process than the inventor of a new one. On July 24, 1516, when resident in Venice he petitions the Signoria of that city for privilege for his ‘new method of printing in light and shade, a novel thing and not done before.’ Lippmann (The Art of Wood Engraving in Italy in the Fifteenth Century, trans., London, 1888) thinks that this claim may be true ‘in so far as he may have introduced further developments in the practice of colour printing with several blocks, which still survived in Venice, especially after the production of coloured wood-cuts by Burgkmair and Cranach in Germany had given fresh stimulus to a more artistic cultivation of that method’ (p. 69), and that ‘he gave the art an entirely new development based upon the principles which guided the profession of painting’ (p. 136). This last phrase explains the interest that Vasari here manifests in his work. In the older wood engraving only lines had been left on the block to take the ink, the rest of the surface being cut away, and whatever was to be shown in the print was displayed in the lines alone. In the new method broad surfaces of the wood were left, on which was spread a film of ink or pigment, and these printed a corresponding tint upon the paper which took off the film thus laid. The pigment might be of any colour desired, or might only represent a lighter tint of the ink that had been used all along for the lines. Hence either an effect of colour or one merely of gradations of light and shade could equally well be produced by the process Vasari describes. The work he contemplates is of the latter kind, and his explanation of the process by which it was produced is fairly clear. Plate XIV, from a print by Ugo da Carpi in the British Museum, gives a specimen of the result.

Critics of Ugo da Carpi’s work, which is sufficiently abundant, notice that he begins by merely adding tints of shading to outlines, which as in the earlier productions of the Germans, like those of Cranach or Dienecker, remained substantially responsible for the effect; but that he gives more and more importance to the tints, the pictorial element in the design, till the outlines end by merely reinforcing the chiaroscuro, like the touches ‘a tempera’ that give effect and decision to painting in fresco (Kristeller, Kupferstich und Holzschnitt in vier Jahrhunderten, Berlin, 1905, p. 300).

299. That is, he made three blocks A, B, C, each the full size of the design, but each containing only a part of the work. A has engraved on it all the lines of the design, and a print from it would be an old-fashioned engraving proper. Such a print with the ink on it still wet is pressed down on a clean block of wood, on which it leaves indications of all these lines. The broad tints of shading, in which gradations may be introduced, are then laid on the block by hand, the outlines being a guide, and so is constituted block B, an impression from which printed on a sheet already printed from block A, and made to register accurately with this, would add shading to the outlines. C would add by the same process a third tint, quite flat, for the background, and this might of course be of another colour. The high lights would be cut away in this block, C, and these parts come out white in the print, as is seen on Plate XIV. The uniform grey shade on the Plate is the background tint. In the actual process of printing this block, C, is first put into the press and produces an impression showing the tinted background but white spaces where the high lights are to come. B, with the shadows tinted but all the rest of the wood cut away, is printed over the impression from C, and lastly A comes to give the decided lines and sharpen up the whole effect.

300. The ‘oil colour’ is the pigment which is transferred from the block to the paper. The ‘water colour’ and the ‘white lead mixed with gum’ mentioned above are only put on by the artist to guide the wood-cutter in his work of cutting the block.

301. The text, in both the original editions, runs as follows: ‘E la terza che è la prima a formarsi, è quella dove il profilato del tutto è incavato per tutto, salvo che dove e’ non ha i profili tocchi dal nero della penna,’ and the negative is puzzling, for obviously the wood must be cut away everywhere but in those places where the outlines do come.

302. But Theophilus says practically nothing about design, and yet the mediaeval epoch was for the decorative arts one of the most glorious the world has ever seen. See on this subject the last part of the Introductory Essay, ante, p. 20 f.