and prove this Hypothefis to be very confiftent with Reason itself, and the Experience of all Obfervers.

Now if any Body will ftill infift further upon what I hinted upon before, viz. That the Tide is occafioned by a ConAuence of Water arifing at the Mael-ftream, or Navel of the Sea, and preceding from thence, &c. and for Confirmation thereof will alledge that they have seen and obferved this regular Rifing and Sinking of the Water (before spoken of) at that Place; I anfwer, I can eafily approve of this Opinion, without denying mine own hitherto afferted; for they are very eafily reconcileable; fince it is poffible, and very probable, that this Ebbing and Flowing at the Maelftream, may be occafioned by fome fubterraneous Cavern, whereby this Place hath fome Communication with the Eaftern Seas, and fis fupplied from thence; which being granted, it will follow, that while the Tide (whose general Motion is Weftwards) is interrupted by the Continent of Norway, &c. and thereby is forced to find a Way about the North Cape; yet by the Way, finding this Paffage under Ground, and the Tide, by Virtue of the Moon's Attraction, inclining that Way, there may be fuppofed to be so much Water conveyed that Way as that obfcure Paffage can contain, though far fhort of fo much as to occafion that Flowing and Ebbing that is obferved; and this being granted, it is evident, that this Rifing and Falling at the Mealftream, muft needs keep Time with the Motion of the Moon, and of the teft of the Tide; because it proceeds from the fame Original, and is a fmall Brance thereof; and this we may fee illuftrated by our common Rivers, whose Natural Motion, when interrupted by Bank, or other Impediments, caufeth the main Body of the Water to find a Paffage fome other Way; yet if at the fame Time any small Holes be found in the faid Banks, there will always fo much Water pass thereby as the faid Holes can contain; though the main Body of Water is forced another Way: Hence, from what has been faid, it is plain, that this fmall Flood and Ebb obferved at the Mael-stream, must needs have the fame regular Motion with the rest of the Tide, which I fuppofe has at firft occafioned, and fince feemed

to

to confirm that Opinion that the Tide proceeds only from thence.

To what has been faid I fhall only add, that this that I have here inferted feems yet to be further confirmed by our Obfervations abroad; for it is obferved, that there is little or no Tide at the Straits of Gibraltar, nor upon the Coast of Guiney; nor can it be expected, according to this Hypothefis; for if the Tide comes from the Northward, it may be fuppofed, that by that Time that it hath paffed fo far along, and having fo many Vacancies to fill up, as the German Ocean, the Irish Sea, the British Channel, the Bay of Bifcay, &c. its Power must be very much impaired, if not totally exhaufted, before it comes fo far as the Coast of Africa before mentioned.

Now it may be queftioned, what is the Reason that there is little or no Tide in the Baltick Sea, feeing there are strong Tides almoft on every Side of it, viz. upon the Coast of Norway on the North of it, on the Coast of Holland on the South, and on the Coaft of England on the Weft of it, &c.

I answer, it is hard to determine absolutely what is the Caufe thereof; but I fhall lay down fome Conjectures, which may conclude very much that Way; for if it was High-Water at the Naze and Coaft of Norway, at the fame Time that it is High-Water upon the Coaft of Jutland Southward from the Baltick Sea, it must needs force a Tide into the Baltick Sea, as well as High-Water upon any Coast forces a Tide up the Inland Rivers there; but this cannot reafonably be expected, if we confider, that the Tide along the Coaft of France, Holland, and Jutland, proceeds from the British Channel, and comes from thence Northwards, along the faid Coaft of Holland, &c. but the Tide upon the Coaft of Norway lies to the Southward, as hath been largely proved, the two Tides both terminating at the Mouth of the Baltick Sea; hence it is very probable, that it may be High-Water upon the Coaft of Jutland, when it may perhaps be LowWater, or some intermediate Tide at the Naze, or South Coaft of Norway; and if fo, it cannot force a Tide into the Baltick Sea, but rather a fucking Current, or Inclination of

the

the Sea from that Place on one Side of the Mouth of the Baltick Sea where it is High-Water, to that Coaft on the other Side where it is Low-Water, and hence it will neceffarily follow, that this Current muft fet fometimes one Way, and fometimes another. And this may be affigned as a Reason why many have found themselves deceived in their Reckonings, when intending to make the Naze, or other Lands thereabouts; and when they have imputed their Mistake to a Current setting towards the Point of the Compafs, towards which they have found themselves unexpectedly carried, thinking thereby to regulate their future Reckonings, they have found themselves at another Time under a quite contrary Error, and hence have concluded that there was no Currenr at all, but fome other Thing hath been the Caufe of their Error; whereas, if the Tides upon the Coaft of Norway and Jutland, viz. on each Side. of the Mouth of the Baltick Sea, were carefully observed and determined, and the Current allowed to run or fet from the Highest Water to the Loweft, (upon which of these Coafts foever it were) and to be at a Stand only when the Water upon both the faid Coafts were of equal Height (whether Rifing or Falling) I queftion not but that the Motion of this Current might thereby be limitted and determined, as well as the Motion of the Tides elsewhere, and due Allowance might be given for the Current there, as well as for the Ebbs and Floods in other Places, to the great Satisfaction and Advantage of those that use the EastCountry Trade.

This Motion of the Tide thus granted, I fhall next fhew how to find the Time of the Moon's Southing, and (with a little Application) the Time of High-Water by a Sight of the Moon, at any Time of the Day or Night.

How

How to know the Time of the Moon's coming to South, only by a Sight of the Moon, at any Time of the Day or Night.

I

T is commonly known, that the New Moon being in Conjunction with the Sun, Souths at Noon, and the Full Moon being oppofite to the Sun, comes to the Fig. 61. South at Midnight; and at the Quarters, when fhe is just half full, viz. to the Line N. 6. S, which croffes the Figure directly in the Middle, then she is South at 6 o'Clock, and if the light Half be on the West Side N.W.S. and the half full, the Souths at 6 in the Evening, as at the firft Quarter; but if the light Half be on the Eaft-fide, N.E.S. fhe Souths at 6 in the Morning; which granted, the Moon's coming to the South upon any other Phafis, or at any intermediate Age, may be eafily gathered from the Figure, obferving this General Rule; when you fee the Moon at any Time of the Day or Night, obferve how much of the Moon is light, whether on the Eaft or Weft-fide, and compare it as near as you can with the Figure, confidering to which Line in the Figure you suppose the light Part will reach, and obferve what Number is upon that Line, for that is the Hour at which the Moon will come to the Meridian that Day or Night; as for Example;

Suppose I obferve the Moon, and find her fomewhat more than half light on the Eaft-fide, fo that comparing the Moon with the Figure, I fuppofe the light Part to appear like the light Part of the Figure; then I obferve to what Number the light Part reaches, and I obferve it reaches to the Number 5; and hence I conclude, that the Moon comes to the South about 5 o'Clock; and because the light Part is on the Eaft-fide, I conclude it is at 5 in the Morning fhe will be upon the Meridian.

Again, Suppofe I fee her in the Evening, and the light Part on the Weft-fide, as near as I can compute, to be like the darker Part of the Figure, towards the right Hand, then obferving how far the light Part ex

tends,

tends, I fee it comes to the Figure 5, and because the light. Part is on the Weft-fide, I conclude the will be South at Five in the Evening, &c.

And thus you obferve the Moon two or three Days after the Change to appear in the Weft in the Evening, with a very little Light on the Weft-fide, which by Computation may be fuppofed to come as far over the Moon's Body as the Figure 3, I conclude the has been upon the South that Afternoon about Three o'Clock, and the next Night you will obferve the Light to encrease, and come towards the Figure 4, conclude fhe was South that Afternoon between 3 and 4, or near 4, and then perhaps 5 or 6 Days after, I obferve the light Part increased beyond half the Body of the Moon, as far as the Arch N. 8. S. I conclude from hence, that the Moon is South about Eight that Night; and although this Method is not fufficient to find the Moon's Southing exactly to a Minute, yet it is of fufficient Exactnefs for Reckoning the Tides, where a Quarter of an Hour, or Half an Hour, make no material Error, it being generally impoffible to predict the Tides to the abfolute Exactnefs of a Minute, although you had the Moon's Southing exactly, becaufe Winds, or Land Floods, &c. may alter the Tides, and few that have the Charge of a Ship will truft to the first or laft Scruple of the Tide for going into an Harbour, or coming out, but will endeavour if poffible, to have the best of the Tide, and to be ready for it against it come, whether Ebb or Flood.

The Moon's Southing being thus found, the next Thing is to fhew how thereby to find the Time of High-Water, at any known Port; and for an Help thereunto, I have inferted a Tide-Table, in an Alphabetical Order, in which you need but find the Name of the Port, at which you would know the Time of High-Water, and againft it you have a Number of Hours and Minutes, which added to the Time of the Moon's Southing, gives the Time of High-Water at that Place that Day; as for Example,

Suppose I were lying before Tinmouth Bar, waiting for half Flood to go in, I happen to fee the Moon in the Morning, and I obferve the Eaft-fide of the Moon

to