But the first that I know of, who took in the consideration of the _Earth's_ motion, (_Diurnal_ and _Annual_) was _Galilaeo_; who in his _Systeme of the World_, hath a particular discourse on this subject: Which, from the first time I ever read it, seemed to me so very rational, that I could never be of other opinion, but that the true Account of this great _Phaenomenon_ was to be referred to the Earths motion, as the _Principal_ cause of it: Yet that of the Moon (for the reasons above mentioned) not to be excluded, as to the determining the _Periods of Tides_, and other circumstances concerning them. And though it be manifest enough, that _Galilaeo_, as to some particulars, was mistaken in the account which there he gives of it; yet that may be very well allowed, without any blemish to so deserving a person, or prejudice to the _main Hypothesis_: For that Discourse is to be looked upon onely as an _Essay_ of the _general Hypothesis_; which as to _particulars_ was to afterwards adjusted, from a good _General History of Tides_; which it's manifest enough that he had not; and which is in a great measure yet wanting. For were the matter of Fact well agreed on, it is not likely, that several Hypotheses should so far differ, as that one should make the Water _then_ and _there_ at the Highest, _where_ and _when_ the other makes it at the Lowest; as when the Moon is Vertical to the place. {266} And what I say of _Galilaeo_, I must in like manner desire to be understood of what I am now ready to say to you. For I do not profess to be so well skilled in the History of Tides, as that I will undertake presently to accommodate my _general Hypothesis_ to the _particular cases_; or that I will indeed undertake for the certainty of it, but onely as an _Essay_ propose it to further consideration; to stand or fall, as it shall be found to answer matter of Fact. And truly had not your importunity (which is to me a great Command) required me to do it, I should not so easily have drawn up any thing about it, till I had first satisfied my selfe, how well the Hypothesis would answer Observation: Having for divers years neglected to do it, waiting a time when I might be at leisure throughly to prosecute this design.