that in _Bayes_ and _In land-Channels_,
the position of the Banks and other like causes must needs make the times
to be much different from what we suppose in the open Seas: And likewise,
that even in the Open Seas, _Islands_, and _Currents_, _Gulfs_ and
_Shallows_, may have some influence, though not comparable to that of
_Bays_ and _Channels_. And moreover, though I think, that Seamen do
commonly reckon the time of High-water in the _Open Seas_, to be then, when
the Moon is there in the _Meridian_ (as this Hypothesis would cast it:) Yet
I do not take my self to be so well furnished with a _History of Tides_, as
to assure my self of it; much less to accommodate it to particular places
and cases.

Having thus dispatched the main of what I had to say {280} concerning the
Seas Ebbing and Flowing: Had I not been already too tedious, I should now
proceed to give a further reason, why I do introduce this consideration of
the _Common Center of Gravity_ in reference to _Astronomical Accounts_. For
indeed, that which may possibly seem at first to be an Objection _against_
it, is with me one reason _for_ it.

It may be thought perhaps, that if the Earth should thus describe an
_Epicycle_ about the Common Center of Gravity, it would (by this its change
of place) disturbe the _Caelestial_ motions; and make the _apparent_ places
of the Planets, especially some of them, different from what they would
otherwise be. For though so small a removal of the Earth, as the _Epicycle_
would cause (especially if its _Semidiameter_ should not be above 1-1/3 of
the Earths Semidiameter) would scarce be sensible (if at all) to the
remoter Planets; yet as to the nearer it might.

Now though what _Galilaeo_ answers to a like Objection in his _Hypothesis_;
(that its possible there may be some small difference, which _Astronomers_
have not yet been so accurate, as to observe) might here perhaps serve the
turn; Yet my answer is much otherwise; to wit, that such difference hath
been observed and hath very much puzzeled _Astronomers_ to give an account
of. About which you will find Mr. _Horrocks_ (in some of his Letters,
whereof I did formerly, upon the Command of the _Royal Society_, make an
_Extract_) was very much perplexed; and was fain, for want of other relief,
to have recourse to somewhat like _Keplers_ amicable _Fibres_, which did
according to the several positions of the Moon, accelerate or retard the
Moon's motion; which _amicable Fibres_ he