E. B. Hunt on the Dynamics of Ocean Currents. 171 
the expansion at each point. Thus from the pole to the equator 
a spheroidal meniscus would be spread equal to the ocean expan- 
sion under the solar heat. It isa remarkable feature that the 
heating leaves each vertical ocean column of its original weight, 
and there is thus a perfect mechanical equilibrium between these 
columns considered as joined by their interior bases. Thus con- 
sidering the grand ocean masses, there is no disturbance of static 
stability from the heating agency of the sun, hence there is no 
formation of massive currents due to this cauise. 
If now we regard the heated ocean in its hydrodynamic aspect, 
we find that the bounding surface having everywhere a slope 
polewards. This gives manifestly but a slight disturbance of 
normal level, amounting in the meridian quadrant only to the. 
Vertical expansion at the equator, and being diffused over the 
essentially modified in direction by the earth’s rotation. 
. the equatorial evaporation greatly exceeds the correspond- 
ing rain fall, this operates to counteract in part the regular out- 
With the normal level. It is clear that this saltness could not 
fully compensate for the expansion by heating, or we should 
have the surface reduced to the normal level, when all would 
either be in stable equilibrium, or below it when the currents 
bee be reversed aa 
t thus a pears that the expansion due to equatorial heats in- © 
duces a superficial derangement tending soles outflow towards 
