VOL. I.J PHILOSOPHICAL TRANSACTIONS. IQ$ 



ther, even at Chatham or Greenwich ; but rather at some place in the open 

 sea, or at the Land's End in Cornwall, or on the west parts of Ireland ; or at 

 St. Helen's, or the Bermudas, &c. would do more to the resolving of thig 

 point than any verbal discourse without it. 



3. To the third objection, that supposing the earth and moon to move 

 about a common centre of gravity ; if that the highest tides be at the new 

 moon, when the moon being nearest to the sun, the earth is farthest from it, 

 and its compound motion at the swiftest ; and that the tides abate as the earth 

 approaches nearer, till it comes into the supposed circle of her annual motion : 

 it may be demanded why do they not still abate as the earth comes yet nearer 

 to the sun, and the swiftness of its compound motion still slackens ? And so, 

 why have we not spring tides at the new moon, when the motion is swiftest, 

 and neap tides at full moon, when the motion is slowest, but spring tides at 

 both ? — the answer, if observed, is already given in my hypothesis itself. Be- 

 cause the effect is indifferently to follow either upon a sudden acceleration, or 

 a sudden retardation. (Like as a loose thing lying on a moving body ; if the 

 body be thrust suddenly forward, that loose thing is cast back or rather left 

 behind, not having yet obtained an equal impetus with that of the body on 

 which it lies ; but if stopped or notably retarded, that loose incumbent is 

 tlirown forward by its formerly contracted impetus not yet qualified, or accom- 

 modated to the slowness of the body on which it lies.) Now both of these 

 happening, the one at the new moon, the other at the full moon, do cause 

 high tides at both. 



4. To the fourth objection, that the highest tides are not at all places 

 about the new moon and full moon ; and particularly, that in some places of 

 the East Indies the highest tides are at the quadratures : I must first answer 

 in general, that as to the particular varieties of tides in several parts of the 

 world, I cannot pretend to give a satisfactory account, for want of a competent 

 history of tides, &c. Because, as is intimated in what I wrote in the general, 

 the various positions of channels, bays, promontories, gulfs, shallows, cur- 

 rents, trade-winds, &c. must needs make an innumerable variety of accidents 

 in particular places, of which no satisfactory account is to be given from the 

 general hypothesis, though never so true, without a due consideration of all 

 those : which is a task too great for me to undertake, being so ill furnished 

 with materials for it. And then as to the particular instance of some places in 

 the East Indies, where the highest tides are at the quadratures, I suppose it 

 may be chiefly intended of those about Cambaia and Pegu ; at which places, 

 beside that they are situated at the inmost parts of vast bays or gulfs, they 

 have also vast in-draughts of some hundred miles within land ; which when 



