102 Professor A. E. H. Love [March 6, 



order to reproduce the actual shape. As the heights and depths are 

 not known everywhere, we use the same process in a rough kind of 

 way, by treating all the land as at one height, the parts of the sea 

 that are less than 1000 fathoms deep as at one depth, those that are 

 between 1000 and 2000 fathoms deep as at a second depth, those that 

 are more than 8000 fathoms deep as at a third depth. By this rough 

 process we can get a suggestion as to the best kind of combination, 

 and tlien we can modify it so as to get a better fit. 



The first harmonic gives us elevation over one hemispliere, depres- 

 sion in the other. In the best fit I have found, the centre of the ele- 

 vated hemisphere is in the Sudan, not far from Wady Haifa. The 

 hemisphere includes practically the whole of the Arctic, Atlantic and 

 Indian Oceans, Europe, Asia and Africa. Its boundary runs just 

 north of Bering's Strait, cuts across North America to a point near 

 Cape Hatteras, and cuts across South America from a point near the 

 mouth of the Amazon to a point near the mouth of the Rio de la 

 Plata. The depressed hemisphere includes practically the whole of 

 the Pacific Ocean, the greater part of North and of South America, 

 Central America and the West Indies, the Antarctic continent, Aus- 

 tralia and New Guinea. [Maps of these hemispheres were shown by 

 slides.] I described earlier the situation of the elevations and depres- 

 sions yielded by the second harmonic according to the best fit that I 

 have found. The third harmonic gives us a central region of eleva- 

 tion of an oval shape, occupying parts of Europe, Asia and Africa, a 

 sort of stalk of an unsyinmetrical pear-shaped figure. This is sur- 

 rounded on all sides by a zone, in which the third harmonic gives us 

 depression — a sort of waist for the pear. The Arctic, Atlantic, and 

 Indian Oceans are in the waist, and so also are the southern and 

 western extremities of Africa, northern and western Europe, and a 

 great part of Asia. The crown of the pear is in the south-western 

 Pacific, and the protuberant ring contains all but the most north- 

 easterly parts of North America, all South America, except the eastern 

 extremity of Brazil, the Antarctic continent, all Australia except the 

 most westerly part, and New Guinea. The boundary between the 

 waist and the protuberant ring of the pear runs near to the boundary 

 between the elevated and depressed hemispheres of the first harmonic. 

 [Maps illustrating the position of the stalk, waist, etc., of the pear- 

 shaped figure were shown by slides.] 



Any one of the harmonics by itself gives depression in some wide 

 tract of actual continent and elevation in some large ocean, and the 

 same is true of any combination of two. When the three are com- 

 bined it is found that almost every bit of actual continent is included 

 in the region of computed elevation, and that the boundary of this 

 region runs everywhere near to the actual boundary of the continental 

 region. The computed elevation is found to exceed 10 per cent, of 

 its maximum value in three regions, which coincide roughly with (i) 

 Europe, Asia and Africa, (ii) North and South America, (iii) Parts of 



