L "5 ] 
thefe Variations of the height of the MercuYjy for in the 
places above named, there is always an eafy Gale of Wind 
blowing nearly upon the fame point, viz,^ E.N.E. dit Bar- 
lpadoes2indE.S.E2it ?>i, Helena^ fb that there being no 
contrary Currents of the Jir, to exhauft or accumulate it, 
the Almofphere continues much in the fame State : However 
upon Hurricanes^ the moft Violent of Storms, the Mercury 
has been obferved very low, but this is but for once iri two 
or three years,and it foon recovers its letled ftate of about 29 
I Inches. I doubt not but the fame thing is in the Eail: 
Coaft of Africa and in India^ where the Monfoonsor Winds 
are Trade for half the year one way, a^nd half the year ano- 
ther ; only tis probable, that there^may ibmething wortii 
noting happen, about the times of the Change or ihifting 
of the Winds, which might be obtained if any body had 
the curiofity to keep the li^rc?;^^^'!^^ at our Fattories in hi- 
dia. ^ 
I doubt not but this Doftriae will find fome Oppofers, 
and that one principal Objection wdll be, That I fuppofc the 
Jir Ibmetimes to move from thofe parts where it is already 
evacuated below the Eqs^Jlibriiim^ and fbmetimes again to- 
ivards thofe parts, where it is condeafed and crouded above 
the mean ftate, which mav be thought contradidory to the 
laws of Staticks and the rules of the Equilihrimn of Fluids. 
But thofe that fliall confider how, when once an Impetus is 
given to a fluid body, it is capable of mounting above its 
level, and checking others that have a contrary tendency to 
defcendby their own gravity, will no longer regard this as 
a material Obftacle ; but will rather conclude , that the 
Great Andogy there is between the rifing and falling of tlie 
Water upon the Flux and Rep.x of the Seiz^ and this of tiie 
accumulating and extenuating the Air^ is a great Argument 
for the truth of this Hyfothefts. For as the Ssa, over againft 
the Coaft of E^ex^ rifes and Pa^cIIs by the meeting of the 
two contrary Tides of floods v/hereof the one comes from 
the 6\ W, along the Chanel of England^ and tl:e other from 
CL the 
