An ornamental woodcut headpiece featuring symmetrical floral and foliate scrolls, with a central floral motif.

FOREWORD.

Although the first volume of this second part was accompanied by a preface giving a general idea of its contents, it seemed necessary to present at the beginning of this one the most interesting points it contains, in order to show that not only will one find the subjects we promised to treat, but also several others equally instructive, which could contribute to making this work complete.

Since the first part was divided into four books, the same division has been followed for the second, in order to include within each of these books the matters most closely connected to one another; thus, after including in the first and second books everything pertaining to sluicesFrench: écluses. In 18th-century engineering, these were complex gate systems or locks used to control water levels in canals and harbors., especially those that interact with the sea, we have included in the third and fourth—which are the subject of this final volume—the construction of all the other works that we have only previously announced in our earlier writings.

The third of these books, which concerns maritime locations, begins with a dissertation on the ebb and flowFrench: flux & reflux. Referring to the tidal cycles of the sea. of the sea, so as to understand its effects well enough to erect significant works within the Ocean. This dissertation is followed by a historical description of the most famous ports,