84 0. E. SCHIOTZ. [NORW. POL, EXP. 
LINES OF FORCE 
Ocean Continent 
EARTH’S CRUST 
force the higher they rise, while on the other hand, the lines of force in the 
space beyond, under the ocean, will be thinned out (see fig.). This holds 
good until the level of the ocean bottom is reached, when the density 
becomes greatest on the side of the continents, and the difference of density 
is considerably greater than below. As a consequence of this, the lines 
