In the careers of the four artist-engineers featured in “Mechanical Marvels,” we can see how technical drawing evolved hand in hand with the changing role of the engineer. Filippo Brunelleschi (1377-1446) was the first Renaissance builder to break from the engineer’s traditional and largely anonymous role as a provider of technical services. Best known today as the man who designed and built the dome of Santa Maria del Fiore, he earned greater renown among his fellow engineers for the construction machines he invented to build it, such as the revolving crane shown on page 54. The ambitious scale and complex nature of the construction projects that Brunelleschi undertook certainly must have required him to draw, but none of his drawings survive. Like his contemporaries, he may have destroyed them in accordance with the code of secrecy typical of medieval guilds. Nonetheless, the Florentine is credited, according to Eugene Ferguson, with discovering the mathematical laws of perspective and producing the first demonstrations of these principles around 1425. The rules he devised were later codified and published, providing a foundation for other artist-engineers who followed him.
Brunelleschi saw himself as a craftsman, not an author. It is in the work of two engineers who followed, Mariano di Iacopo (1382-1458?), known as Taccola, and Francesco di Giorgio (1439-1501), that we see the first big steps in the development of the engineer as author and illustrator. These engineers, both of Siena, were deeply engaged in a variety of the city’s ambitious military, construction, and hydraulic projects. But they also set out to distinguish themselves as authors, compiling technical writings with innovative illustrations. “The artist-engineers of Siena grasped the tremendous interpretative and expository potential of graphics,” Galluzzi says, and they consciously devised ways to turn it into a powerful tool in their writings.
Taccola set out to recover the technical wisdom of antiquity. He discovered that often the best way to understand a difficult text was to make a visual translation of it. The techniques of the cutaway and exploded views (still indispensable for assembly, operating, and repair manuals) originated in his notebooks. He did not stop at explicating the ancients, however, but went on to fill several volumes with drawings of machines and inventions, ranging from military weapons such as trebuchets (see facing page) and hull-piercing devices to advanced fishing technology and waterwheels designed to capture the energy of the tides-a compendium that blends engineering dreams and a search for practical solutions, Galluzzi observes. And in a touch that expresses the continuity of the Sienese tradition, he notes, the final pages of one of Taccola’s manuscripts were completed in the hand of Francesco di Giorgio.
Francesco’s own writings make clear that he studied Taccola’s texts closely. The so-called Vatican codicetto, a tiny notebook filled with notes and drawings modeled on Taccola’s manuscripts, illustrates the learning process that characterized the Renaissance workshop: observation, imitation, and refinement of a predecessor’s work. The codicetto was obviously “a compendium for personal use,” Galluzzi observes, “a pocket notebook whose only unusual feature is the parchment sheets, which would normally have been quite extravagant for such a purpose.” Then again, Francesco probably used-and reused-these pages for a decade or more.
Like Taccola, Francesco undertook an ambitious project of illustrating a vast catalogue of machines, the Trattato di architettura. What was distinctive in Francesco’s approach, however, was that he tried to order these machines according to general rules. He categorized devices as either mills, pumps, pulling and lifting machines, or wagons, and provided commentary on materials, construction, specific applications, and even hints on ways to reduce wear and tear. Moreover, within a basic category, such as mills, Francesco would present as subcategories water mills, windmills, human- and animal-powered mills.