Out of Galileo

348 Book Reviews TECHNOLOGY AND CULTURE Out ofGalileo: The Science ofWaters, 1628-1718. By Cesare S. Maffioli. Rotterdam: Erasmus, 1994. Pp. xx+509; illustrations, tables, notes, bibliography, index. Hfl. 125.00. Although now complemented by relativistic and quantum fluid mechanics, the study ofwater flow phenomena has remained a lively field ofclassical physics tied to many technological applications. This is an area that relatively few historians have entered and one in which many of the models offered by philosophers of science may not be applicable. In his epilogue to Out of Galileo, Cesare Maffioli states that “the patterns in early modern science that are brought to light are rather unusual for the student of the scientific revolu­ tion.” He concludes this exhaustive study by asking, “Why then should we wonder that the story of the science of water does not fit the standard image of the scientific revolution or that it is inaccessi­ ble to the various philosophical -isms that have been coined by the historians of ideas?” This wise blending of external and internal history, an illuminat­ ing and magnificently documented book, should be seriously stud­ ied, with special attention to the many interacting cultural forces it considers. Readers familiar with applied mathematics, hydraulic and ecological engineering, and their general internal history may better understand the intrinsic reasons for some insurmountable problems faced by the adherents to a Galilean inspiration, at the root ofwhich they will see a misleading analogy. Fluvial and coastal engineers may learn about sociopolitical historical patterns that are not dissimilar to the ones they are now living through. Moreover, some of the dif­ ficult technoscientific problems of water-transported sedimentary phenomenology that faced Italian scholars from Castelli to Poleni (1628-1718) still seem intractable today, when the confusion about the powers of kinematics without dynamics has dissipated but other difficulties persist. The internal history of water science requires solid knowledge of several areas, rarely considered. Among them are the appropriate constitutive model as well as the need for a complete system ofpostu­ lates, including geometry, kinematics and dynamics, and, more re­ cently, thermodynamics, chemistry, and other sciences. For instance, the choice between continuum or discrete models is easier now than some centuries ago. Discrete models were a temptation leading to purgatory, if not hell, and Manfredi, in notes to Guglielmini’s book, mentioned the wisdom of abandoning such models. However, if the continuum model is preferred, the introduction ofan ad hoc notion of pressure, or the absence of it, as Maffioli emphasizes, plays an essential role. In this connection, the usual, convenient assumption of incompressibility constitutes a fluid-mechanical singularity with historical consequences which should be discussed. Inexperience in the use ofanalogies (in the Keynesian sense) in the mathematization technology and culture Book Reviews 349 of physical problems created difficulties even for Newton when he ventured into fluid mechanics. Maffioli refers briefly to Leonardo da Vinci, and this seems appro­ priate. However, some interesting conclusions could perhaps be achieved by examining fully Leonardo’s manuscripts (avoiding the published anthologies, including Arconati’s, and resorting instead to the originals). It seems unlikely that his notes about the kinemat­ ics and dynamics of air, water, and the “aridi” were exclusively his own creation and did not reflect his intellectual surroundings. Ideas that seem to spring forth for the first time in subsequent centuries probably existed already in a nonmathematized form. For instance, did Leonardo formulate out of nothing the kinematics of incom­ pressible continua in geometrized form, or were there already re­ lated notions floating around him? Was conservation of volume in water flow already understood, in empirical calculations and estima­ tions, much more than it appears to most historians of hydraulics, such as Fasso and Garbrecht? Maffioli shows that hydraulics in Italy remained active and strongly related to physics and technology during a period that seems not well known. During this time, the patronage of its study shifted from one seat of power and intrigue to another, a situation that fostered gradual rather than abrupt advance of hydraulics and its applica­ tions. The author has made good use not only of books and other publications, but also ofan impressive volume of letters and archival documents left by

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