FOREWORD.

...of boats at locations where there are drops in elevation, the construction of aqueducts, spillwaysoriginal: "déversoirs." Structures or channels designed to release surplus water safely to prevent flooding., locksoriginal: "écluses." Enclosures with gates at each end used in canals and rivers for raising or lowering boats between different water levels. for the entry and exit of water, as well as swing bridgesoriginal: "ponts-tournants." Movable bridges that rotate horizontally on a pivot to allow ships to pass. suited to locks and canals, and masonry bridges belonging to the main highways. Finally, we provide the method for draining marshes and irrigating arid lands. One will better judge the subjects included in this volume by reading the table of contents, which will show at a glance that nothing has been neglected to meet what was expected from our long and arduous research.

If young engineers have even the slightest occasion to put into practice what we report, they will make marked progress in hydraulic architecture through the manner in which we have treated it. They will find drawings and specificationsoriginal: "devis." Detailed technical descriptions and cost estimates for a construction project. that they need only follow, modifying them to apply to the project at hand, as it is difficult to encounter works that do not have some relation to those we cite. Will it not be a great advantage for them to have their minds prepared by the knowledge of what the most skilled people have executed, even profiting from their mistakes by preventing those they would be in danger of making? To believe one can draw everything from one’s own resources without the help of others would be an unbearable vanity; if any were found susceptible to this weakness, they would only need to find themselves left to their own devices in difficult situations to have cause for humiliating reflections.

I shall be happy if this work fulfills its intended purpose by offering our descendantsoriginal: "neveux." While literally "nephews," in 18th-century French this term was frequently used to refer to future generations or successors. principles fit to push much further the models they find here! This is what they will achieve if they con-