C*y*3 
a letter; 
fT/vtfw ty-Dr. John Wailis ^ ^ Publifher, concerning the r*- 
rietyofthe Annual High- fides, as to fcveral places ; with 
refpefftohis own Hypothefis, deliver W N°. i6> touching 
the Flux and Reflux of the Sea. 
SI R, In my Hypothecs for Tydes 5 you may remember 5 that I caft 
the Annual High-Tydes not on the Tnw Equinoxes, about 
the I I . of March and September nor yet on the Apogaum and Pf- 
£^0/0 of the Sun, about the middle of $nne and December 5 but 
(as proceeding from a Complication of thofe two Caufes) on a 
Midle time between the Perigmm and the two Equinoxes, (like 
as is the greateft Inequality of the Natural dates, proceeding from 
a Complication of the fame Caufes.) And particularly 3 for the 
Coaft of Kent (and confequently the Rivers of Thames and Med- 
my) about the beginning of November and February : which 
agrees with Obfervations on thofe Coafts, and particularly with 
that of yours of Febr. 5 . this year. 
The laftyear, when I was prefent in the R, Society, I rem em- 
ber, an account was brought us of the Annual High-Tydes on 
the Severn, and at Chep flow- bridge, to be about the beginning 
of March, and the end ot September. Which though they agree 
not with the particular times on the coaft of Kent, yet in the 
general they agree thus far, That the one is about as much before 
the one ^Equinox, as the other is after the other ifiquinox. You 
now acquaint me with High-Tides about February 22. about the 
coaft of Plimouthy which is later than that of the coaft of Kent, 
but fooner than that on the Severn. And I doubt not but in 
other parts of the world will be found other Varieties. 
The reafons of thefe Varieties are (as I have formerly fignifi- 
ed) to be. attributed to the particular Pofition of thofe parts ; ra- 
ther than to the general Hyporhefis. Of which this, in brief, 
may ferve for fome account at prefent. The General Hypothe- 
fis of the Earths diurnal Motion from Weft toEaft, would caft 
that of the W aters, not following fo faft, from Eaft to Weft; 
which caufeth the conftant Current within the Tropicks, 
where the Circles are greateft, wfft-ward from the Coaft of 
