Professor Kemp was presenting the 2013 Murray Memorial lecture at Birkbeck College. He was an appropriate person to deliver this lecture because he was taught by Peter Murray at the Courtauld Institute in the 60s. The Murray Bequest is an important part of the History of Art department which provides student financial support, acquisition of books for the library and public engagement with free lectures like this one.
He opened with a quote from a Murray lecture from 1966;
...the great change which takes place soon after 1500 is to be associated with Leonardo and Bramante, and it seems to me that Leonardo's theoretical drawings, which can never surely have meant as serious projects for building, ... were invented as a new means of rendering all the information one could require about an exceedingly complex structure in two drawings only. This approach is, I believe, the result of his interest in anatomy, while the idea of producing such information, rather than pictorial drawings of architectural almost certainly arises from his connection with Bramante. (p604)(Murray, Peter, 'The Italian Renaissance Architect', Journal of the Royal Society for the Encouragement of Arts, Manufactures and Commerce,114:5119 (Jun 1, 1966), 589-607)
Prior to 1500, Kemp states, clear architectural plans were not de rigour and he drew our attention to Murray's simple yet obvious insight into the workings of Leonardo's mind. The curious Leonardo designs for Christian temples that appear in Manuscript B (1480s) are purely his invention, certainly no mention are made of designs like this in Vitruvius. They are not real buildings but a series of geometric forms with no scale, demonstrating the mental process of iteration and manipulation of simple geometric forms. They are developments of squares, rounds, octagonal shapes, some vaguely byzantine in places, all examples of the concept of demonstrazione - 'a commitment to test knowledge through, experience, persistence, and a willingness to learn from mistakes'. One of the buildings, Leonardo notes in the manuscript, could be sliced in two and turned into two buildings which tells us a lot about his abilities to manipulate solid buildings as if they were plastic objects. It is this ability to model and produce 3D images which was the focus of this lecture.
He opened with the iconic image of Vitruvian man and the well documented contrivances within Leonardo's sketch. Vitruvius describes the human dimensions of his temples and there were many attempts to square the circle and to circle the square but even Leonardo's attempt failed. Although at first glance he appeared to make it work, as soon as you try to animate the figure digitally, glaring contrivances appear; his legs are in profile, his hips are too narrow and not symmetrical, his arms aren't right. When you try to work out where the hips move, the maths is all wrong. Leonardo was good at geometry and would have realised this - Kemp acknowledged this is an area of further study and one day he would look into Leonardo's ingenious contrivance which, at first glance isn't obviously contrived!
Leonardo leaves us with no full scale drawings of architectural interiors, though there are some which show garden furniture and temporary architecture, so ephemeral that it has disappeared. However the interior of the body is a different matter - in the same period as these architectural drawings (1489)his investigation in to skulls reveal structures which demonstrate the workings of a mind trained in sculpture - the eye sectioned like an onion. He recognised that his sketches needed instructions because readers would have been unfamiliar with this new diagrammatic technique. He pulls the moulding of the sculpture away, just like he separates off a part of skull section.
Professor Kemp then outlined the various graphic/drafting techniques which Leonardo invented, tested, perfected in the course of his demonstrazione. With examples he showed us the Cut Away, the Explosion, the Transparency, the Sequential View - all of which seem entirely familiar/normal to us but these were the result of a mind which could envisage the interior of bodies, buildings, gadgets and get it down on paper - as if it was being modelled. Some images sit side by side rather incongruously, eg., a double helix staircase and a spine. However the images demonstrate unity, not diversity which is precisely what Peter Murray meant regarding the connection Leonardo made between the building and the body. One single piece at Windsor demonstrated all these drafting techniques so it is extremely complicated - the female torso is a stunning piece of work.
With that he moved from form to time...and I get rather confused. The problem arises out of a lecture I went to by Adam Hart Davies on inventions last week and he talked about Ibn al-Haytham and optics. This gentleman didn't come up in this lecture but when I did a search for Kemp and al-Haytham and da Vinci, of course this rather interesting paper came up, as well as various art historical textbooks. All relevant stuff.
In this section of the lecture he focused on
Leonardo's efforts to make static drawing move. Leonardo was constantly trying to prove the infinite potential of movement in space, eg., his rearing horse with flailing hooves and thrashing head is animated by a going over and over with lines to show movement. Also fascinating his hammering man where he was able to halt the movement in time, sketch it and then start time again. Not only did he draw movement he wrote about in his De Pittura, talking about camera obscura and other optical effects. It's as if his sketches prefigure the art of the animator - which is precisely what Kemp asked Steve Mayer to do when collaborating for the V&A exhibition. By doing this they were able to show Leonardo's understanding of the fulcrum and levers of the body and how it is affected by the movement of the head.
Another way of animating Leonardo is actually to recreate some of his sketches in a physical way. This is precisely what they did and demonstrated that his visualisation of the effects of the ox heart valves is quite accurate. Using his observations of water flow, he transferred this knowledge to anatomy. His way of transferring 'plastic vision' (way of seeing the movement within objects) on to paper was extraordinary. Not only that but he seemed to show the heart valves as a collection of clustered architectural forms, as well as adding a design for a mace because of the similarity in geometric forms.
The breadth of application of how he could visualise movement in the mind's eye and how it could be transferred to a plan is demonstrated by the map of the irrigation/canal of the Arno. The fact that his contour line study of the area reflects the path of the modern day motorway is well documented. He even worked out how the canal was to be funded and how many labourers would be required, which seems quite an excursion into the practical for Leonardo.
This interest in the geophysical was profound. He imagined that there were lakes in the Arno valley in pre-historic times and understood that all great European rivers were once massive bodies of water. This understanding of great changes over time is documented in the Codex Leicester and it describes radical ideas such as erosion, internal collapses at the centre of earth, upheavals of mountains, inundations, shifting of earthly balances and extraordinary visions of the earth moving. Certainly no ancients had thought of this. Kemp suggests that these imagined expanses of time are reflected in his art, building on Walter Pater, he says the large lakes and river beds in Mona Lisa represent the evolution of the mutable female body. They show the potential for change and give the portrait picture a form of narrative.
Other images also portray time and space. The Last Supper he states is not a frozen moment in time but a series of moments in the present and things to come. Judas and the dipping bowl, Thomas and his finger and Christ sat with his hands outstretched in a prefiguring of the crucifixion holding out his hands, an event to come. As Kemp iterated, not a snapshot but a quantità continua - “Ogni quantità continua intellettualmente è divisibile in infinito.” - Every quantity is intellectually conceivable as infinitely divisible.
He concluded with the most recently discovered Leonardo painting; the Salvator Mundi. In this he sees the spiritual otherness of Christ, the miraculous ineffable outsider. It was a common subject but Leonardo makes it uncommon by having Christ holding the rock crystal sphere, rather than an earthly symbol of kingship - an orb. This crystalline sphere reflects the universe of Aristotle and Ptolemy and in the Aristotelian conception there was an outermost sphere that was the domain of the "Prime Mover". Leonardo understands Christ to be divine and shows him out of time and space, infinite, beyond time and quantity.
Finally, I just want to mention that Kemp referred to various digitisation projects where certain of Leonardo's sketches were animated. It turns out that these are now inaccessible because of changing technologies. This is so pertinent to digital art development and shows how important continuous investment - it is an alarming proposition...