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PREFACE.

part, the reason for their dimensions, the degree of speed that was appropriate for them, how much water should pass to the reservoir original: "réſervoir"; a storage basin for water, often at height to provide pressure., whether it was not possible to make more of it ascend by the action of a limited power Referring to a fixed source of energy, such as a waterwheel, a team of horses, or a specific amount of manual labor., while accounting for friction original: "frottemens"; the resistance encountered when one body moves over another, a major factor in machine efficiency.; whether the same objective could not be achieved with more simplicity and at less cost: in a word, whether I could flatter myself with having nothing to fear from the examination of an enlightened Judge, inclined to show no mercy.

Not feeling myself capable of fulfilling all these circumstances, I will ingenuously admit that I was disconcerted to find myself so destitute; I had, however, long ago learned the Principles of Mechanics and the movement of Waters original: "mouvement des Eaux"; the study of hydraulics. from our best Authors, and even written on these matters, which I believed I possessed passably; but often one imagines having in the mind a chain of knowledge, and when the occasion arises to make use of it, one finds only traces without order and without connection; it even happens that the good opinion we have of our own weak lights A common 18th-century metaphor for intellectual understanding or reason. is an obstacle that prevents us from acquiring more extensive ones, because we believe we know much, for lack of knowing what would still be necessary to us; and supposing that we feel what we lack, that is still not enough, one must know where to acquire it, and that was my embarrassment, no one having written on Machines in the style that I have just suggested; this is why I formed the design to apply myself seriously to it, and to communicate my research to those who might be in the same case as I found myself; thus I thought of nothing more but instructing myself, to put myself in a state to instruct others, being unable to resolve to leave behind a subject so interesting, and which was missing from my Treatise to make it complete. I therefore resolved