Giovanni Branca (April 22 1571-January 24 1645) was an Italian engineer and architect, chiefly remembered today for what some commentators have taken to be an early steam engine.
Born in Sant'Angelo in Lizzola
, in 1616 Branca was employed at the Sacra Casa in Loreto
, where he carried out work typical for a Renaissance engineer. He supervised repairs to the structure, designed funeral monuments, and improved fortifications. He also took a role in the local government and acted as a land agent in the administration of the Sacra Casa’s properties. His work also took him frequently to Assisi
. He was made a citizen of Rome in 1622.
Branca designed many different mechanical inventions, a collection of which he dedicated to Cenci, the governor of Loretto. These were later published in book form at Rome in 1629, under the title Le machine
The work contains 63 engravings with descriptions in Italian and Latin and was an example of the Theater of machines
genre which had appeared in the 16th century, named for Jacques Besson
's Theatrum Instrumentorum
of 1571. However, where Besson's book had been beautifully illustrated with engravings, Branca's book was a small octavo
volume illustrated with relatively shoddy woodcuts
Unlike earlier authors, Branca did not claim to be the creator of many of the machines and in one instance is even uncertain over how the machine in question is supposed to work. In the words of historian Alex Keller, his machines "look like armchair inventions which seldom ever had any three-dimensional working counterparts".
Branca's so-called steam engine appears as the 25th plate in Le Machine. It comprises a wheel with flat vanes like a paddlewheel, shown being rotated by steam produced in a closed vessel and directed at the vanes through a pipe. Branca suggested that it might be used for powering pestles and mortars, grinding machines, raising water, and sawing wood. It bears no relation to any later application of steam power and is not considered much of an advance over Hero of Alexandria's aeolipile, though Branca's engine was much more practical than the aeolipile.
Branca's Manuale d’Architettura
, published in 1629, was a practical guide for planning and construction and is considered the first "pocket" architectural handbook. Branca's experience as an architect was due to his posting as superintendent of works of the House of Santa Maria di Loreto
, to which he was appointed by the Duke of Urbino . Most of his architectural works are the detailed architectural renderings of Jacques Besson
and Androuet du Cerceau
. It was republished in 1772 by Leonardo de Vegni.
Branca communicated with Benedetto Castelli and references his work in the last chapter of the Manuale, a chapter about rivers. Castelli, often considered to be the founder of the field of hydrodynamics, wrote to Branca urging him to defend himself against naïve or interested parties such as the Venetians who had rejected Castelli’s opinions as to why their lagoons were silting. On another occasion, Branca wrote to Castelli regarding a design for a nozzle for an inverted siphon to be installed in a fountain. Castelli also witnessed the ecclesiastical innocence of Le Machine for the inquisition.
Influence of Branca's work
It is unclear how influential Branca’s work was. But it was known that Robert Hooke
owned a copy of Branca’s work.