Hydraulic Architecture, Volume 2, Part 2

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with raising works of consequence there, since it is only by taking precautions against its troublesome effects, and by a continual attention to profiting from favorable weather to build, that one succeeds in doing so solidly. Maritime works require great attention to safeguard against and overcome the diverse obstacles that arise, both in laying foundations and in raising structures above the waters. It is not enough to take advantage of locations intended for the safety of vessels, or to direct their entrances according to the course of the tides so that they may maneuver freely; one must also, as far as possible, take precautions against the furies of an element that sometimes topples the most solid buildings in a few hours. Otherwise, it is dangerous to commit faults that make one regret the expenses incurred. It is therefore because of the connection that hydraulic architecture has with this phenomenon that we believed we could not dispense with providing more accurate ideas of it than are held by those who, knowing little of maritime affairs, would have difficulty understanding several parts of this work where it was necessary to use the language proper to the subjects treated.

§ 82. Before entering into the matter, it is appropriate to be aware that in 1701 the Royal Academy of Sciences The Académie Royale des Sciences, founded in 1666, was the primary scientific institution of the French Enlightenment., wanting to demonstrate more and more its zeal for everything that could be useful to society in general, took advantage of the favorable disposition shown by the Count of Pontchartrain to contribute to its progress. The Academy engaged this minister to send a memorandum it had prepared to the most skilled individuals in the French ports along the Ocean. This memorandum concerned the manner of observing the precise time of the tides and their height during new and full moons, in order to see the relationship they would have with astronomical observations, and whether the ebb and flow original: "flux & reflux" were as linked to the daily course of that planet Referring to the Moon, which was often categorized with planets in older astronomical terminology. as had been noticed for a long time, but not with enough exactness to know precisely what to believe. The observations made for more than a year by Messrs. Baert and du Bocage, professors of hydrography The science of surveying and charting bodies of water.—the first at original: "Dunkerque" Dunkirk, and the second at original: "Havre de Grace" Le Havre—were handed over to M. Cassini Jacques Cassini (1677–1756), a famous French astronomer who succeeded his father at the Paris Observatory.. After having examined them thoroughly, he gave the result to the Academy in 1710, accompanied by learned reflections which have shed much more light on this subject than had yet been perceived, showing in an evident manner all