ii6 
The American Geologist. 
February, 1901. 
yet easily recognizable owing to its influence on the distribution 
of land and water. As the centres of the flattened faces are 
nearer the earth's center of mass than the edges, the water will 
collect upon them. The ratio of the area of land to that of 
FIG. 4. RELATIONS OF .\ TETRAHEDKAL LITHOSPHERE TO ITS 
HYDROSPHERE. FIG. 4a REPRESENTS THE ARRANGEMENT IN 
A SIMPLE TETRAHEDRON. FIG. 4b ILLUSTRATES THE CASE OF 
A MODIFIED TETRAFlEDROiV (SUCH AS SHOWN FIG. 5b) BY A 
SECTION PASSING ON THE LEFT THROUGH A TETRAHEDRAL 
COIGN, AND ON THE RIGHT THROUGH THE OPPOSITE TETRA- 
HEDRAL FACE. THE SHADED AREAS REPRESENT WATER. 
water on the globe is as 2 to 5. If on a model of a tetrahedron 
we color the five-sevenths of the surface that is nearest the 
centre, the colored areas would show where the water would 
collect if the earth were a stationary tetrahedron. On the 'up- 
per face there is a large central colored area in the position of 
the Arctic ocean. It is surrounded by a land belt, 
from which three projections run southward down the 
three lateral edges. These three land areas taper 
southward to a point, below which is a complete belt 
of . sea. South of that, again, is our fourth projecting 
corner, which is above the water-level, and is the Antarctic con-- 
tinent. Sc» that on the model the general plan of the arrange- 
ment of land and water is identical with its actual distribution 
on the globe. For the land occurs as three triangular equidistant 
continents, united alxwe into a ring and tapering southwards ; 
there is a great excess of water in the southern and of land in 
the northern hemisphere ; and land and water are antipodal, 
since in a tetrahedron a corner is ahyays opposite a flat face. 
