is not a quarter of the motion of the fixed stars, which is performed exactly in twenty-four hours; but a quarter of the moon's diurnal motion. * PRECEPTS AND ADMONITIONS FOR THE BETTER PRO- BEFORE this matter can be fully and demonstratively settled, there are several lesser enquiries to be made; and in particular we recommend the following to future diligence. 1. Enquire whether the hour of flood about the coast of Afric precede the hour of flood about the Streights of Gi braltar; and in like manner whether the hour of flood about Norway, precede the hour of flood about Sweden; and whether this precede the hour of flood about Graveling. 2. Enquire whether the hour of flood about Brazil, precede the hour of flood on the coast of New Spain, and Florida. 3. Enquire whether the hour of flood on the coast of China, do not nearly coincide with the hour of flood on the coast of Peru; and again with the hour of ebb on the coasts of Africa and Forida. 4. Enquire how the hour of flood on the coast of Peru, differs from that on the coast of New Spain; and particularly how the differences of the hours of flood stand in both the shores of the isthmusses in America; and again * See Sir Isaac Newton's Theory of the Tides. A R how the hour of flood on the coast of Peru, corresponds with that on the coast of China. 5. Enquire into the heights of the tides on different shores, as well as their times: for although high tides are generally caused by low shores; yet they still participate of the true motion of the sea; according as that proves favourable or opposite. 6. Enquire, particularly, into the state of the Caspian sea, which is a large collection of waters, excluded from a free communication with the ocean; to see if it has any flux or reflux; and in what manner they happen; for we conjecture that this sea may have a single, but not a double tide, in a day: whilst the water forsakes the eastern shore, and rises to the western of that sea. 7. Enquire whether the tides in the new and full moon, and in the equinoxes prove high, and large, in different parts of the world at once: not understanding by once, the same hour; for the hours differ according to the appulse of the waters to the shores; but on the same day. 8. For want of fuller information, this general enquiry of the ebbing and flowing of the sea, cannot be justly continued down to an explanation of the consent of the menstrual motion of the sea-tides with the motion of the moon; whether these motions proceed from a subordination to the moon; or, whether they both have one and the same cause: which should be farther examined. 9. The present enquiry is connected with that relating to the earth's diurnal motion; which should therefore be cleared up, before any thing is determined upon this head. For if the tides of the sea, be, as it were, the last extremity of the diurnal motion; it will follow that the globe of the earth is fixed; or at least that its motion is much slower than the motion of the water. * *This beginning of an enquiry about the cause of the tides, is a posthumous piece, that occurs among the Scripta published by Gruter and seems not intended to have come abroad, till, in the author's usual manner, it had been brought nearer to perfection. But imperfect as it is, it may deserve the place here assigned it, among other imperfect pieces, designedly wrote, not in the inductive, but ordinary manner. |
