—" 
E. B. Hunt on the Dynamics of Ocean Currents. 178 
This consideration of the effect of inertia in storing the living 
force of this immense equatorial current, and thus enabling it to 
sweep through the cycles of the seas, has not been duly consid- 
ered. ese currents, in such a place as Florida Straits, move 
in a closed channel, and are subject to the hydrodynamic rules 
for this case. The gradual changes of direction and velocity 
there imposed, produce less absolute resistance than is generally 
imagined, by reason of the great mass of waters relative to the 
area of frictional surfaces. 
The problem of ocean currents is of very great complexity, 
not only on account of the difficult hydrodynamic questions in- 
volved, but because the effect of the winds on the ocean surface 
can searcely be subjected to estimation. The permanent eleva- 
tion of the equatorial waters above the normal level traced from 
the pole, might be approximately determined by knowing the 
deficiency of weight in the vertical equatorial column, relative 
to an aretic one, connected by their bases at the same deep level, 
t 
.~ Jére are numerous secon ints which might enter this 
discussion, but which need aottor be considered. I will notice 
a oa Oceanic oscillation which is practically unimportant; but 
pees I believe has not before been noticed. The sun in its 
“aly round must heat the waters of the sea, at a given locality, 
Mech a manner that there shall be a daily maximum and mini- 
The Sea temperature due to absorption and radiation combined. 
‘S Must give a maximum and minimum of expansion, or a 
_ Thus if a current be moving through a sea other- 
arena, it will by this lateral diag carry forward such 
counten  °f Water in addition to its own proper mass, that a 
wane “current must set in to restore the level. This is, I sup- 
ND ee XXVII, No. 80.—MARCH, 1859. 
