Biographies & Memoirs

Architectural Projects

In 1487 the fabbriceria or works department of Milan cathedral was considering the crowning of the central part of the cathedral with a tiburio, or domed crossing-tower, and Leonardo was among those who submitted designs for this. He constructed a wooden model, with the help of a carpenter called Bernardo, and received small subventions from the fabbriceria to cover the expenses of making the model: there are seven payments listed between July 1487 and January 1488.61 (This circumstance may explain why he used discarded cathedral paper to write his ‘newsletter’ to Benedetto Dei.) Other architects tendering for the job included his friend Donato Bramante.

A drawing in Paris MS B shows a system of buttresses designed to give a broader base to the drum of the tiburio; the accompanying text describes an experiment to demonstrate the distribution of weight on an arch:

Let a man be placed on a weighing-device in the middle of a well-shaft, then have him push out his hands and feet against the walls of the well. You will find that he weighs much less on the scales. If you put weights on his shoulders you will see for yourselves that the more weight you put on him, the greater will be the force with which he spreads his arms and legs and presses against the wall, and the less will be his weight on the scales.62

This elegant if rather dangerous experiment illustrates the property of arches to distribute weight transversely rather than placing it all on the supporting columns. The spreadeagled figure in the well-shaft makes me think of Leonardo’s famous ‘Vitruvian Man’ – also of Zoroastro, whom I always imagine as the man who steps up to perform this sort of ‘demonstration’; I also imagine him as the test-pilot strapped in to the ornithopter.

Among Leonardo’s papers is a draft of a presentation speech connected with the tiburio project. It begins with a flourish, ‘Signori padri diputati’ – ‘My lords, fathers, deputies’. Its theme is an analogy between the visual and structural harmonies of architecture and the harmonious balance of the body. In buildings, as in bodies, ‘health is maintained by a balance or concord of elements, and is ruined and undone by a discord in them’. Thus the architect is like a kind of physician:

You know that medicines, when they are properly used, restore health to invalids, and that he who knows them thoroughly will make the right use of them if he understands the nature of man, of life and its constitution, and of health. He who knows these things thoroughly will know also what opposes them, and will be a more effective healer than any other. This too is what the sick cathedral needs – it needs a doctor-architect, who understands the nature of the building, and the laws on which correct construction is based…

This analogy is not original to Leonardo: it is found in the writings of Renaissance architects like Alberti and Filarete, and before them in Vitruvius.63 Leonardo develops the theme quite exhaustively in this draft, of which I have only quoted a fraction. Imagined as an actual speech it sounds flannelly, pedagogic, repetitive. One feels this sort of thing is not his forte. Then suddenly he is tired of the performance, and the draft ends with what is almost a linguistic shrug: ‘Choose me or choose another who demonstrates the case better than I do; set aside all sentiments.’

It is doubtful that the speech was ever delivered. The tiburio project entered the usual limbo of delay, and it was three years before the contract was awarded. Leonardo seems by then to have lost interest: he was not even on the final shortlist.64 The ‘consultation’ was held at the castle on 27 June 1490, with Ludovico and the Archbishop of Milan in attendance. The winning design was by the Lombard architects Amadeo and Dolcebuono.

Also from this time is a series of designs for ‘temples’ – churches based on a central altar.65 Leonardo could have found examples of these in the architectural tracts of Vitruvius and Alberti, though as this type of church design is particularly associated with Bramante’s later work, there may already have been an exchange of ideas between them. Bramante’s remodelling of Santa Maria delle Grazie (where Leonardo painted the Last Supper) employed a semi-centralized design.

The temple illustrated here (from one of the pages of MS B stolen by Libri, and now bound separately) is beautifully realized. It has been shown that the ground plan is based on a complex geometrical system called the theta progression. Again there is the influence of Alberti, who recommended ‘natural proportions’ in architecture ‘which are not borrowed from numbers but from the roots and powers of squares’, but again one suspects the personal influence of Bramante, who was undoubtedly more proficient in mathematics and geometry than Leonardo at this stage.66 A note at the lower left of this page shows Leonardo thinking about real churches as well as geometrical progressions. He wonders whether the campanile, or bell-tower, should be separate, as in the cathedrals at Florence and Pisa, where the bell-towers ‘show their perfection on their own’, or whether it should be incorporated into the church, ‘making the lantern serve as the bell-tower as at the church of Chiaravalle’. The medieval abbey of Chiaravalle was a few miles from Milan; Leonardo elsewhere mentions an astrological clock there, which ‘shows the moon, the sun, hours and minutes’.67

On a folio datable to early 1489 are drawings showing an elevation and ground-plan of a small domed edifice, but this is not a temple or church. The captions identify it as the ‘pavilion of the Duchess of Milan’s garden’.68


Design for a ‘temple’ based on a central altar.

This refers to the already existing pavilion in the park of the Sforza castle, described in an account of 1480 as a brick building ‘surrounded by running water and hedges in the form of a labyrinth’; it was probably used as a bagno or bath-house during the steamy Milanese summer. Perhaps the plan to remodel the pavilion was connected with the marriage of the young Duke of Milan to Isabella of Aragon, granddaughter of the King of Naples, in February 1489. A lost folio of Paris MS B may have had another design for the pavilion, and notes for the decor: walls of pink marble, white baths, mosaics with a representation of the goddess Diana, and ‘spouts in the form of eels’ heads for hot and cold water’ – all this on the testimony of the nineteenth-century French biographer Arsène Houssaye, who saw the notebook before its mutilation by Count Libri. A later note about the plumbing of ‘the Duchess’s bagno’ probably refers to the same building.69 I include this among Leonardo’s early architectural projects, but the latter note shades towards Leonardo the odd-job man.

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