ON SEISMOLOGICAL INVESTIGATIONS. 45 
above India Tibet, the highest land in the world, occupies nearly the 
centre of the triangle. The side KE runs through a well-known 
series of earthquake centres skirting the coast, of which perhaps the 
most important are at HE (Japan) and S (Borneo), one at the extremity 
and the other near the middle point. The continuation of KE is EC, 
since the angles FEK and FEC, though they are only 60° on the 
plane projections, are 90° on the sphere; and since there is a notable 
centre U (Alaska) near the middle of EC, we may perhaps consider 
S and U as corresponding points of strain. 
The side KF is not so conspicuous a line of earthquakes at present, 
though the point F (Crete) is a familiar region, and corresponding 
to S we may take R, the middle point of FK, as representing earth- 
quakes in the Indian Ocean. But apart from modern records, the 
geographical features of ‘this line RF, viz., the Red Sea, the Grecian 
Archipelago, and the Adriatic, are strongly suggestive of crumpling 
into folds at some time in the past. Continuing the line along FC, 
there is an active centre near the middle point T which is not far 
from Iceland; so that S, E, V have corresponding points in R, F, T; 
the former are at present the stronger, but this may not have been 
always so. 
The apex C is not an earthquake centre, but near it, and sym- 
metrically disposed on the sides CD, CA, are the Californian and 
West Indian regions. The symmetry of the whole arrangement round 
the point V (close to Tomsk) will be complete if we may put two 
Antarctic centres at the points P and Q which are in latitude —53° and 
longitudes 55° and 115° East. Milne assigned two Antarctic regions 
near these as a result of observations made during the voyage of the 
“ Discovery ’ (March 14, 1902, to November 28, 1903), but it is doubt- 
ful whether the material is sufficient to locate them exactly. 
As regards the remainder of the map, the symmetrical disposition 
of South Africa and Australia is noteworthy; but as we go northwards 
from them the symmetry disappears, the upper half of the African 
triangle being land, that of the Australian water (though much of it 
not very deep). Superposed on the arrangement symmetrical, about 
the line CK there is at least one unsymmetrical character which may 
be roughly described as a division into land and water hemispheres, 
and as such has been often noted. In the present diagram the salient 
points of this contrast are :— 
(a) Land in the triangle FGK, water in the triangle CDE. 
(b) Water in the middle of land in the triangle ACF, land in the 
middle of water in EKL. 
(c) The absence of land corresponding to South America, on the 
line CD. If a bathy-orographical map be consulted it will, however, 
be found that there is a shallow in this part of the ocean, not very 
different from South America in shape. It is conceivable that a mere 
shift of the earth’s centre of gravity might uncover this ‘ image’ of 
South America. 
Tn a future Report it is hoped to show the actual distribution of 
observed earthquakes on this map; but this will take some little time. 
