As to the First; It having been observed (grosly) that those high Tides have used to happen about the Spring and Autumn; it hath been generally taken for granted (without any more nice observation) that the two Æquinoxes are the proper times, to which these Annual high Tides are to be referred; And such causes sought for, as might best sute with such a Supposition.

But it is now, the best part of twenty years, since I have had frequent occasions to converse with some Inhabitants of Rumney-marsh in Kent; where the Sea being kept out with great Earthen walls, that it do not at high water overflow the Levell;

and the Inhabitants livelyhood depending most on grazing, or feeding Sheep; they are (as you may believe they have reason to be) very vigilant and observant, at what times they are most in danger of having their Lands drowned. And I find them generally agreed, by their constant Observations, (and Experience dearly bought) that their times of danger are about the beginning of February and of November; that is, at those Spring Tides which happen near those times; to which they give the names of Candlemass-stream and Allhallond-stream; And if they scape those Spring-tides, they apprehend themselves out of Danger for the rest of the year. And as for March and September (the two Æquinoxes) they are as little solicitous of them, as of any other part of the year.

This, I confess, I much wondred at, when I first heard it; and suspected it to be but a mistake of him, that first told me, though he were indeed a person not likely so to be mistaken, in a thing wherein he was so much concerned: But I soon found, that it was not onely his, but a general observation of others too; both there, and elsewhere along the Sea coast. And though they did not pretend to know any reason of it, (nor so much as to enquire after it;) Yet none made doubt of it; but would rather laugh at any that should talk of March and September, as being the dangerous times. And since that time, I have my self very frequently observed (both at London and elsewhere, as I have had occasion), that in those months of February and November, (especially November), the Tides have run much higher, than at other times: Though I confess, I have not been so diligent to set down those Observations, as I should have done. Yet this I do particularly very well remember, that in November 1660. (the same year that his Majesty returned) having occasion to go by Coach from the Strand to Westminster, I found the Water so high in the middle of King-street, that it came up, not onely to the Boots, but into the Body of the Coach; and the Pallace-yard (all save a little place near the West-End) overflow'd; as likewise the Market-place; and many other places; and their Cellars generally filled up with Water. And in November last, 1665. it may yet be very well remembred, what very high Tides there were, not onely on the Coasts of England, (where much hurt was

done by it) but much more, in Holland, where by reason of those Inundations, many Villages and Towns were overflow'd. And though I cannot so particularly name other years, yet I can very safely say, that I very often observed Tides strangely high about those times of the year.

This Observation did for divers years cause me much to wonder, not only because it is so contrary to the received opinion of the two Æquinoxes; but because I could not think of any thing signal at those times of the year: as being neither the two Æquinoxes, nor the two Solstices, nor the Sun's Apogæum and Perigæum: (or Earths Aphelium and Perihelium;) nor indeed, at contrary times of the year, which at least, would seem to be expected. From Alhollandtide to Candlemass being but three months; and from thence to Alhollandtide again nine months.

At length it came into my mind, about four years since, that though there do not about these times happen any single signal Accident, which might cast it on these times, yet there is a compound of two that may do it; Which is the Inequality of the Natural day (I mean that of 24. hours, from noon to noon) arising at least from a double cause; either of which singly would cast it upon other times, but both joyntly on those.

It's commonly thought, how unequal soever the length be of the Artificial dayes as contradistinguished to nights, yet that the Natural Days, reckoning from noon to noon, are all equal: But Astronomers know well, that even these dayes are unequal.

For, this Natural Day is measured not onely by one intire conversion of the Æquinoctial, or 24. Æquinoctial hours, (which is indeed taken to be performed in equal times,) but increases by so much, as answers to that part of the Sun's (or Earths,) Annual motion as is performed in that time. For, when that part of the Æquinoctial, which (with the Sun) was the Meridian yesterday at noon, is come thither again to day, it is not yet Noon (because the Sun is not now at the place where yesterday he was, but is gone forward about one degree, more or less) but we must stay till that place, where the Sun now is, comes to the Meridian before it be now Noon.

Now this Additament (above the 24 Æquinoctial hours, or intire conversion of the Æquinoctial) is upon a double account