1492. Leonardo's opinions as to the shortcomings of plastic works

when compared with paintings are given under No. 655 and 656.] Notes on the casting of the Sforza monument (710-715). 710. Three braces which bind the mould. [If you want to make simple casts quickly, make them in a box of river sand wetted with vinegar.] [When you shall have made the mould upon the horse you must make the thickness of the metal in clay.] Observe in alloying how many hours are wanted for each hundredweight. [In casting each one keep the furnace and its fire well stopped up.] [Let the inside of all the moulds be wetted with linseed oil or oil of turpentine, and then take a handful of powdered borax and Greek pitch with aqua vitae, and pitch the mould over outside so that being under ground the damp may not [damage it?] [To manage the large mould make a model of the small mould, make a small room in proportion.] [Make the vents in the mould while it is on the horse.] Hold the hoofs in the tongs, and cast them with fish glue. Weigh the parts of the mould and the quantity of metal it will take to fill them, and give so much to the furnace that it may afford to each part its amount of metal; and this you may know by weighing the clay of each part of the mould to which the quantity in the furnace must correspond. And this is done in order that the furnace for the legs when filled may not have to furnish metal from the legs to help out the head, which would be impossible. [Cast at the same casting as the horse the little door] [Footnote: The importance of the notes included under this number is not diminished by the fact that they have been lightly crossed out with red chalk. Possibly they were the first scheme for some fuller observations which no longer exist; or perhaps they were crossed out when Leonardo found himself obliged to give up the idea of casting the equestrian statue. In the original the first two sketches are above l. 1, and the third below l. 9.] 711. THE MOULD FOR THE HORSE. Make the horse on legs of iron, strong and well set on a good foundation; then grease it and cover it with a coating, leaving each coat to dry thoroughly layer by layer; and this will thicken it by the breadth of three fingers. Now fix and bind it with iron as may be necessary. Moreover take off the mould and then make the thickness. Then fill the mould by degrees and make it good throughout; encircle and bind it with its irons and bake it inside where it has to touch the bronze. OF MAKING THE MOULD IN PIECES. Draw upon the horse, when finished, all the pieces of the mould with which you wish to cover the horse, and in laying on the clay cut it in every piece, so that when the mould is finished you can take it off, and then recompose it in its former position with its joins, by the countersigns. The square blocks _a b_ will be between the cover and the core, that is in the hollow where the melted bronze is to be; and these square blocks of bronze will support the intervals between the mould and the cover at an equal distance, and for this reason these squares are of great importance. The clay should be mixed with sand. Take wax, to return [what is not used] and to pay for what is used. Dry it in layers. Make the outside mould of plaster, to save time in drying and the expense in wood; and with this plaster enclose the irons [props] both outside and inside to a thickness of two fingers; make terra cotta. And this mould can be made in one day; half a boat load of plaster will serve you. Good. Dam it up again with glue and clay, or white of egg, and bricks and rubbish. [Footnote: See Pl. LXXV. The figure "40," close to the sketch in the middle of the page between lines 16 and 17 has been added by a collector's hand. In the original, below line 21, a square piece of the page has been cut out about 9 centimetres by 7 and a blank piece has been gummed into the place. Lines 22-24 are written on the margin. l. 27 and 28 are close to the second marginal sketch. l. 42 is a note written above the third marginal sketch and on the back of this sheet is the text given as No. 642. Compare also No. 802.] 712. All the heads of the large nails. [Footnote: See Pl. LXXVI, No. i. This drawing has already been published in the "_Saggio delle Opere di L. da Vinci_." Milano 1872, Pl. XXIV, No. i. But, for various reasons I cannot regard the editor's suggestions as satisfactory. He says: "_Veggonsi le armature di legname colle quali forse venne sostenuto il modello, quando per le nozze di Bianca Maria Sforza con Massimiliano imperatore, esso fu collocato sotto un arco trionfale davanti al Castello_." 713. These bindings go inside. 714. Salt may be made from human excrements, burnt and calcined, made into lees and dried slowly at a fire, and all the excrements produce salt in a similar way and these salts when distilled, are very strong. [Footnote: VASARI repeatedly states, in the fourth chapter of his _Introduzione della Scultura_, that in preparing to cast bronze statues horse-dung was frequently used by sculptors. If, notwithstanding this, it remains doubtful whether I am justified in having introduced here this text of but little interest, no such doubt can be attached to the sketch which accompanies it.] 715. METHOD OF FOUNDING AGAIN. This may be done when the furnace is made [Footnote: this note is written below the sketches.] strong and bruised. Models for the horse of the Sforza monument (716-718). 7l6. Messer Galeazzo's big genet 717. Messer Galeazzo's Sicilian horse. [Footnote: These notes are by the side of a drawing of a horse with figured measurements.] 718. Measurement of the Sicilian horse the leg from behind, seen in front, lifted and extended. [Footnote: There is no sketch belonging to this passage. Galeazze here probably means Galeazze di San Severino, the famous captain who married Bianca the daughter of Ludovico il Moro.] Occasional references to the Sforza monument (719-724). 719. Again, the bronze horse may be taken in hand, which is to be to the immortal glory and eternal honour of the happy memory of the prince your father, and of the illustrious house of Sforza. [Footnote: The letter from which this passage is here extracted will be found complete in section XXI. (see the explanation of it, on page 2).] 720. On the 23rd of April 1490 I began this book, and recommenced the horse. 721. There is to be seen, in the mountains of Parma and Piacenza, a multitude of shells and corals full of holes, still sticking to the rocks, and when I was at work on the great horse for Milan, a large sackful of them, which were found thereabout, was brought to me into my workshop, by certain peasants. 722. Believe me, Leonardo the Florentine, who has to do the equestrian bronze statue of the Duke Francesco that he does not need to care about it, because he has work for all his life time, and, being so great a work, I doubt whether he can ever finish it. [Footnote: This passage is quoted from a letter to a committee at Piacenza for whom Leonardo seems to have undertaken to execute some work. The letter is given entire in section XXL; in it Leonardo remonstrates as to some unreasonable demands.] 723. Of the horse I will say nothing because I know the times. [Footnote: This passage occurs in a rough copy of a letter to Ludovico il Moro, without date (see below among the letters).] 724. During ten years the works on the marbles have been going on I will not wait for my payment beyond the time, when my works are finished. [Footnote: This possibly refers to the works for the pedestal of the equestrian statue concerning which we have no farther information in the MSS. See p. 6.] The project of the Trivulzio monument. 725. THE MONUMENT TO MESSER GIOVANNI JACOMO DA TREVULZO. [2] Cost of the making and materials for the horse [5]. [Footnote: In the original, lines 2-5, 12-14, 33-35, are written on the margin. This passage has been recently published by G. Govi in Vol. V, Ser. 3a, of _Transunti, Reale Accademia dei Linea, sed. del 5 Giugno, 1881,_ with the following introductory note: _"Desidero intanto che siano stampati questi pochi frammenti perche so che sono stati trascritti ultimamente, e verranno messi in luce tra poco fuori d'Italia. Li ripubblichi pure chi vuole, ma si sappia almeno che anche tra noi si conoscevano, e s'eran raccolti da anni per comporne, quando che fosse, una edizione ordinata degli scritti di Leonardo."_ The learned editor has left out line 22 and has written 3 _pie_ for 8 _piedi_ in line 25. There are other deviations of less importance from the original.] A courser, as large as life, with the rider requires for the cost of the metal, duc. 500. And for cost of the iron work which is inside the model, and charcoal, and wood, and the pit to cast it in, and for binding the mould, and including the furnace where it is to be cast ... duc. 200. To make the model in clay and then in wax......... duc. 432. To the labourers for polishing it when it is cast. ....... duc. 450. in all. . duc. 1582. [12] Cost of the marble of the monument [14]. Cost of the marble according to the drawing. The piece of marble under the horse which is 4 braccia long, 2 braccia and 2 inches wide and 9 inches thick 58 hundredweight, at 4 Lire and 10 Soldi per hundredweight.. duc. 58. And for 13 braccia and 6 inches of cornice, 7 in. wide and 4 in. thick, 24 hundredweight....... duc. 24. And for the frieze and architrave, which is 4 br. and 6 in. long, 2 br. wide and 6 in. thick, 29 hundredweight., duc. 20. And for the capitals made of metal, which are 8, 5 inches in. square and 2 in. thick, at the price of 15 ducats each, will come to...... duc. 122. And for 8 columns of 2 br. 7 in., 4 1/2 in. thick, 20 hundredweight duc. 20. And for 8 bases which are 5 1/2 in. square and 2 in. high 5 hund'.. duc. 5. And for the slab of the tombstone 4 br. io in. long, 2 br. 4 1/2 in. wide 36 hundredweight....... duc. 36. And for 8 pedestal feet each 8 br. long and 6 1/2 in. wide and 6 1/2 in. thick, 20 hundredweight come to... duc. 20. And for the cornice below which is 4 br. and 10 in. long, and 2 br. and 5 in. wide, and 4 in. thick, 32 hund'.. duc. 32. And for the stone of which the figure of the deceased is to be made which is 3 br. and 8 in. long, and 1 br. and 6 in. wide, and 9 in. thick, 30 hund'.. duc. 30. And for the stone on which the figure lies which is 3 br. and 4 in. long and 1 br. and 2 in., wide and 4 1/2 in. thick duc. 16. And for the squares of marble placed between the pedestals which are 8 and are 9 br. long and 9 in. wide, and 3 in. thick, 8 hundredweight . . . duc. 8. in all. . duc. 389. [33]Cost of the work in marble[35]. Round the base on which the horse stands there are 8 figures at 25 ducats each ............ duc. 200. And on the same base there are 8 festoons with some other ornaments, and of these there are 4 at the price of 15 ducats each, and 4 at the price of 8 ducats each ....... duc. 92. And for squaring the stones duc. 6. Again, for the large cornice which goes below the base on which the horse stands, which is 13 br. and 6 in., at 2 due. per br. ...... duc. 27. And for 12 br. of frieze at 5 due. per br. ........... duc. 60. And for 12 br. of architrave at 1 1/2 duc. per br. ....... duc. 18. And for 3 rosettes which will be the soffit of the monument, at 20 ducats each .......... duc. 60. And for 8 fluted columns at 8 ducats each ......... duc. 64. And for 8 bases at 1 ducat each, duc. 8. And for 8 pedestals, of which 4 are at 10 duc. each, which go above the angles; and 4 at 6 duc. each .. duc. 64. And for squaring and carving the moulding of the pedestals at 2 duc. each, and there are 8 .... duc. 16. And for 6 square blocks with figures and trophies, at 25 duc. each .. duc. 150. And for carving the moulding of the stone under the figure of the deceased .......... duc. 40. For the statue of the deceased, to do it well .......... duc. 100. For 6 harpies with candelabra, at 25 ducats each ......... duc. 150. For squaring the stone on which the statue lies, and carving the moulding ............ duc. 20. in all .. duc. 1075. The sum total of every thing added together amount to ...... duc. 3046. 726. MINT AT ROME. It can also be made without a spring. But the screw above must always be joined to the part of the movable sheath: [Margin note: The mint of Rome.] [Footnote: See Pl. LXXVI. This passage is taken from a note book which can be proved to have been used in Rome.] All coins which do not have the rim complete, are not to be accepted as good; and to secure the perfection of their rim it is requisite that, in the first place, all the coins should be a perfect circle; and to do this a coin must before all be made perfect in weight, and size, and thickness. Therefore have several plates of metal made of the same size and thickness, all drawn through the same gauge so as to come out in strips. And out of [24] these strips you will stamp the coins, quite round, as sieves are made for sorting chestnuts [27]; and these coins can then be stamped in the way indicated above; &c. [31] The hollow of the die must be uniformly wider than the lower, but imperceptibly [35]. This cuts the coins perfectly round and of the exact thickness, and weight; and saves the man who cuts and weighs, and the man who makes the coins round. Hence it passes only through the hands of the gauger and of the stamper, and the coins are very superior. [Footnote: See Pl. LXXVI No. 2. The text of lines 31-35 stands parallel 1. 24-27. Farther evidence of Leonardo's occupations and engagements at Rome under Pope Leo X. may be gathered from some rough copies of letters which will be found in this volume. Hitherto nothing has been known of his work in Rome beyond some doubtful, and perhaps mythical, statements in Vasari.] 727. POWDER FOR MEDALS. The incombustible growth of soot on wicks reduced to powder, burnt tin and all the metals, alum, isinglass, smoke from a brass forge, each ingredient to be moistened, with aqua vitae or malmsey or strong malt vinegar, white wine or distilled extract of turpentine, or oil; but there should be little moisture, and cast in moulds. [Margin note: On the coining of medals (727. 728).] [Footnote: The meaning of _scagliuolo_ in this passage is doubtful.] 728. OF TAKING CASTS OF MEDALS. A paste of emery mixed with aqua vitae, or iron filings with vinegar, or ashes of walnut leaves, or ashes of straw very finely powdered. [Footnote: The meaning of _scagliuolo_ in this passage is doubtful.] The diameter is given in the lead enclosed; it is beaten with a hammer and several times extended; the lead is folded and kept wrapped up in parchment so that the powder may not be spilt; then melt the lead, and the powder will be on the top of the melted lead, which must then be rubbed between two plates of steel till it is thoroughly pulverised; then wash it with aqua fortis, and the blackness of the iron will be dissolved leaving the powder clean. Emery in large grains may be broken by putting it on a cloth many times doubled, and hit it sideways with the hammer, when it will break up; then mix it little by little and it can be founded with ease; but if you hold it on the anvil you will never break it, when it is large. Any one who grinds smalt should do it on plates of tempered steel with a cone shaped grinder; then put it in aqua fortis, which melts away the steel that may have been worked up and mixed with the smalt, and which makes it black; it then remains purified and clean; and if you grind it on porphyry the porphyry will work up and mix with the smalt and spoil it, and aqua fortis will never remove it because it cannot dissolve the porphyry. If you want a fine blue colour dissolve the smalt made with tartar, and then remove the salt. Vitrified brass makes a fine red. 729. STUCCO. Place stucco over the prominence of the..... which may be composed of Venus and Mercury, and lay it well over that prominence of the thickness of the side of a knife, made with the ruler and cover this with the bell of a still, and you will have again the moisture with which you applied the paste. The rest you may dry [Margin note: On stucco (729. 730).] [Footnote: In this passage a few words have been written in a sort of cipher--that is to say backwards; as in l. 3 _erenev_ for _Venere_, l. 4 _oirucrem_ for Mercurio, l. 12 _il orreve co ecarob_ for _il everro (?) co borace_. The meaning of the word before _"di giesso"_ in l. 1 is unknown; and the sense, in which _sagoma_ is used here and in other passages is obscure.-- _Venere_ and _Mercurio_ may mean 'marble' and 'lime', of which stucco is composed.