The Day the Universe Changed - James Burke [32]
Toscanelli was born in 1397 to a well to do bourgeois family which owned nineteen servants, two horses and a mule. One evening, probably in 1424, Toscanelli was in Florence, having returned from Padua, where he had among other things studied under the great mathematician Biagio Pelecani of Parma. At a dinner party held in a friend’s garden, Toscanelli met the man with whom he was, as he himself said, to form ‘the greatest association of my life’. The man in question was Filippo Brunelleschi, a local architect and builder, who was at the time engaged by the comune on the construction of a dome for the unfinished cathedral. The difficulty Brunelleschi faced was one he had set himself: how to construct a circular structure over an octagonal base.
Brunelleschi’s experience was purely practical. He had studied no Latin. What little he read would have been limited to Dante and the Bible, both in the vernacular. At this time an architect was still a craftsman, rather than a theoretician. Buildings were still being planned and constructed empirically. The planners of Milan Cathedral had recently spurned the use of calculation because it did not fit the Aristotelian view of what could be done in building -which was simply to double the number first thought of when it came to designing for strength. Many buildings collapsed.
At the dinner in Florence, or soon after, Toscanelli opened Brunelleschi’s eyes to the geometrical possibilities of his university knowledge, and the two men probably joined in the task of designing the dome. Brunelleschi developed a method of constructing it with little use of wood for scaffolding, and without any centring. This had never been achieved before. The idea undoubtedly came partly from the weeks Brunelleschi had spent earlier in Rome with Donatello, meticulously examining and measuring the Roman ruins to see how triumphal arches, barrel vaults, tunnel vaults and coffered roofs could be built for their nouveau riche Florentine patrons. The two had spent so much time underground that the Romans presumed them to be treasure hunters. The trip to Rome was but one example of the general research into the past going on in various fields.
The civic aim, extolled by another architect, Leon Battista Alberti, in a remark about Brunelleschi’s dome, was revealed:
Who could ever be hard or envious enough to fail to praise Pippo [Filippo] the architect on seeing here such a large structure, rising above the skies, ample enough to cover with its shadow all the Tuscan people, and constructed without the help of centring or a lot of wood? Since this work seems impossible to achieve in our time, I reckon it was probably unknown and unthought of to the ancients.
The dome was not completed until 1436, but as it rose it served to remind the Florentines that they were doing something better than the ancient Romans and Greeks. They were not merely copying: they were fusing the old tradition with a new dynamism that was solely Florentine.
What was to prove the most dynamic act of all, however, was due to another facet of the Toscanelli-Brunelleschi relationship. While Toscanelli had been in Padua, his teacher Biagio da Parma had given a course on optics. In this he had drawn on the writings of the great Arab thinker Al Hazen.
Brunelleschi’s famous dome on Florence Cathedral. The construction, unequalled at the time in architectural genius and engineering skill, dwarfed the city and served to provide its citizens with the status symbol they so earnestly desired.
Born in Basra in AD 965, Al Hazen had written on every aspect of optical tradition, drawing on the earlier work of Aristotle, Galen, Euclid and Ptolemy. In the tenth century, theory held that the eye gave out a ray of light which acted in various ways, according to different schools of thought, to hit any object