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fame Level from which it defeended. In other 
Cafes, however, the Afcent of the Centre of Gravity 
will be lefs than its Defcent, but is never greater. 
After demonftrating the ufual Rule for finding the 
Centre of Ofcillation, the Author treats of the Mo- 
tion of Water ifiuing from a cylindric Vefiel. The 
EiFed of the Gravitation of the whole Mafs of Wa- 
ter is confidered as Threefold. It accelerates, for 
lome time at leaft, the Motion with which the Wa- 
ter in the Vefiel defeendsj it generates the Excefs of 
the Motion with which the Water iflues at the Ori- 
fice above the Motion which it had in common with 
the reft of the Water ; and it atts on the Bottom of 
the Vefiel at the fame time. Then fuppofing the 
laftTwo Parts of the Force to be in any invariable 
Ratio to each other, when the Diameters of the 
Bafe and Orifice are given, he determines by Loga- 
rithms the Velocity with which the Water iflues at 
the Orifice ; and ftiews that this Velocity will ap- 
proach very near to its utmoft Limit in an exceeding 
fmall Time. When the Water is fuppofed to be 
fupplied in a Cylinder, lo as to ftand always at the 
fame Altitude above the Orifice, there is an Analogy 
between the Acceleration of the Motion of the Wa- 
ter that iflues at the Orifice, and the Acceleration of 
a Body that defeends by its Gravity in a Medium 
which refifts in the duplicate Ratio of the Velocity. 
For when the utmoft Velocities, or Limits, are equal 
in thofe two Cafes, the Time in which the ifiuing 
Water acquires any lefier Velocity, is to the Time in 
which the defeending Body acquires the fame Velo- 
city as the Area of the Orifice to the Area of the 
Bafe, and if a cylindric Column be fuppofed to 
