IL di Milano – The

The Floor Plan‘s External Perimeter Layout: Ad Quadratum

In this post of 1 Feb 2020 a detailed floor plan of the Milan Cathedral [ref.1] has been compared to the floor plan of Chartres Cathedral in search of possible comparable principles underpinning their designs. It is shown here in this post that the overall external plan of the Milan Cathedral has been shaped and laid out in “Ad Quadratum” fashion. Two adjacent squares, a large and a smaller, circumscribe the outer edges of the buttresses surrounding the walls and the Cathedral’s inner space. The large square surrounds the and Apse and the smaller square surrounding the . Together they encompass the entire plan. The sides of each of these respective squares are proportioned according to the square root of two to one, V2 : 1 (1.4142 : 1). The overall dimensions given in meters hint at other proportioning methods involved as well when compared with Chartres Cathedral. A pdf version is given at the end of this post

When you read about the Milan Cathedral you see it described as a “massive” building, of a grand scale and of “immense” size. It is counted among the five largest (gothic) churches in the world [ref.2]. It is an edifice with a long building history that started in 1386 and was completed around 1900. There is a vast volume of literature around the art history of the Duomo. My interest got piqued when I came across the “Duomo di Milano” floor plan that not only showed the overall dimensions in meters, but also their ‘marking points’. That prompted to look closer into the overall layout as the Eastern side has an Apse and Chevet (without radial chapels) that is shaped very different from Chartres’ and other major French . It ‘nudged’ me to draw a large (blue) square around the East side through the 93 meter markings on the plan. This newly drawn square, now circumscribing the North and South part of the Transept, passed on the Eastern side along the outside of the two buttresses supporting the Chevet and Apse. This drawn-in square hence runs on three sides along the external perimeter of the cathedral in particular along its widest part containing the Transept! See Fig.1 (click on image to enlarge)

DUOMO di MILANO -- The Milan Cathedral Ad Quadratum and the External Layout of the Plan

~178 Coudee overall width 93 m

chartresconceptualplan.wordpress.com by A.E. post of Feb 2020 Fig.1

Pondering this Figure 1, questions then arose in my mind: what about the Western part with the Cathedrals’ Nave and Façade that shows to be much less wide? Does a –smaller- square fit here too? How big ? Can its size be scaled from the plan (see the bar with scale-measure drawn onto the plan)? Rather then tedious measurement on my version of the plan, the large blue square was copied and reduced by a factor 1/1.4142 or 0.7071. And ‘lo and behold’ this smaller blue square tightly runs along the outer perimeter of north and south solid buttresses placed along the Façade and Nave as you can see in Fig.1!

A second small square of identical size can be drawn adjacent to the small square that extends over transept and crossing within the large blue square. For the Chartres Cathedral plan two equal (large) squares could be drawn surrounding the and the entire Nave and Towers as I found and earlier reported in previous posts. See for example and for ease of comparison see Fig 11a of post ….[ref. 3].

If you furthermore take into consideration that, in addition to the two squares surrounding the external perimeter of buttresses and walls, the floor plan of the Duomo of Fig. 1, features a square pattern of piers at the meeting of aisles and nave bays and that the Chevet with ambulatory and choir-end, the Apse, are laid out in a half- octagonal form one cannot escape the conclusion that the “Ad Quadratum” method plays the major role in the design or at least a very dominant role ! But wait. Perhaps this is a jumping to conclusions here. The plan of Fig 1 gives one more piece of information that had piqued my interest namely the dimensions in meters written on the plan. Having read earlier about the elevation of the cathedral and its recorded discussions about the design of the elevation i.e. the question of: how high to build [ref. 1] and being an Italian gothic church the measurements showing up in the discussions and literature around the Duomo were always quoted in “braccia”. The “braccio” is the local unit of length measurement used in Milan at the time. A measurement system I was not familiar with at all. Having now some dimensions in meters I could try and see if the old French measurement system that was found to reveal insights into the design of Chartres Cathedral could perhaps provide some insights here too?

As was demonstrated in the (conceptual) reconstruction of the Chartres Cathedral plan the use of the ancient French system of measurements called the “Quine” , ( the “Five”) played a role not only in the proportioning of the various parts and layout of the inner space but at the same time set the ‘measure’ to the ‘as built dimensions’ of the Cathedral. The French “Quine” measurement units are based on the golden –or mean- ratio (see earlier posts). As said, being not familiar with this Italian system of measurement and having now here shown on this floor plan a key measurement reported in modern meters, being 93m, it allowed this key dimension to be expressed in the largest unit of the ‘Quine’ which is the “Coudee” having a metric value of 0.5236 meter and found it yields an equivalent length of a (rounded) value of 178 Coudee! Not only is this number indicating that the Coudee measure fits nearly precisely 178 times in the 93 meters, the number ‘178’ itself is striking as it is a ‘double’ of the number ‘89’ which is part of the Fibonacci series of numbers that relate to the “Golden Ratio” or “Phi” and sometimes called the “Divine Ratio”. This is just a “lucky hit” you may say? This, after all, is an Italian church not a French one. Well let’s see if indeed that is the case or that instead it is flagging that other systems of measurement units and proportioning methods other than ‘Ad Quadratum’ have been involved in the design and construction of the Duomo di Milano.

In the next post this question will be further elaborated and looked at. It will be shown that it is not a lucky hit, that other dimensions also translate into significant numbers and that symbolic numbers are also involved! A clue to answering this is the realization that the internal shaping and dimensioning of the inner, sacred space and the spatial arrangement and placing of the High Altar of the cathedral is the main concern and focus of the architect / designer!

At the end of this post it maybe of interest to give a little bit of history. From its very beginnings in 1386 Antonio da Saluzzo, as the spiritual leader and , as worldly Lord of Milan, had grand visions of a very large church and cathedral to be built at the site of the former and their intentions were given a sure footing with the establishment of the “Fabbrica del Duomo di Milano” (Factory of the Cathedral of Milan) in the next year 1387 to be in charge of the supervision of the design, construction and building of the Cathedral. This organization is still operational today and active in the “upkeep” , the maintenance of structure and artwork and is known as the “Veneranda Fabbrica del Duomo”, the Venerable Factory of The cathedral. It has an extensive archive going back to the early days with records of contracts, transactions, payments, drawings and so on [ref. 4]. It is clear that from the very beginning architects, master-masons, artisans and laborers had to be recruited from faraway places even beyond the Alps and such central and supervising body as the ‘Fabbrica’ was a key requirement. Over the many hundreds of years a great number of architects have been involved. It is said [ref. 2 and 5] that some 78 lead architects have been employed over the hundreds of years, amazingly the name of the architect in the beginning phase of the design is not known !

A pdf version of this post is here

References and Links

Ref. 1. The Source of The plan of the Duomo del Milano shown above is retrieved form the study titled: “First principles: Gabriele Stornalco and Milan Cathedral” by Giulia Ceriani Sebregondi and Richard Schofield ; in which it is shown as Fig 2. “Survey plan of Milan Cathedral (after Ferrari da Passano, ‘Storia della veneranda fabbrica’, 1973” DOI: https://doi.org/10.1017/arh.2016.3 Published online by Cambridge University Press: 19 October 2016

https://www.cambridge.org/core/journals/architectural-history/article/first-principles- gabriele-stornaloco-and-milan-cathedral/A3B34E788582FF50D47EC204A009E017/core- reader

Ref. 2. Here are some of the many introductory and touristy links : http://architectism.com/the-stunning-duomo-di-milano-milan-cathedral/ https://en.wikipedia.org/wiki/Milan_Cathedral

Ref. 3. This blog post Fig 9 and Fig 11 a

Ref. 4. Veneranda Fabbrica del Duomo di Milano website and archive: https://www.duomomilano.it/en/infopage/archive-and-library/51/

Ref. 5. See the following link summing up ‘10 things etc.’ however in it no source references are given. https://theculturetrip.com/europe/italy/articles/10-things-you-never-knew-about-- cathedral/

Figure 9 post dated 27 Aug 2015 Source Pitt univ added red /blue lines and numbers by A.E