DEC. 4, 1923 PROCEEDINGS: WASHINGTON ACADEMY OF SCIENCES 445 
179TH MEETING 
The 179th meeting of the AcapEemy was held jointly with the Geological 
Society of Washington and the Philosophical Society of Washington in the 
Auditorium of the Interior Building, the evening of Wednesday, April 18, 
1923. The program consisted of three addresses dealing with The Taylor- 
Wegener hypothesis. 
The first paper, by Franx B. Taytor, was entitled, The lateral migration 
of land masses. 
One of the most remarkable things on the Earth is the great belt of Ter- 
tiary fold-mountains which forms a nearly complete girdle around the 
globe. It is believed that the distribution of this belt and certain other 
well defined characteristics associated with it furnish the key to the nature 
of the cause which made it. These mountains form a folded and faulted 
margin along the entire southern front of the continent of Eurasia; then 
passing over into North America through the are of the Aleutian Islands, 
which in reality belongs to the Asiatic structure, the belt turns southward 
and forms the Cordilleran ranges through the entire length of the two 
Americas. From the East Indies a branch extends eastward and southward 
around the north and east sides of Australia to New Zealand, but shows only 
as chains of volcanic islands. The ranges of the entire belt are all of sub- 
stantially one age; they were all either greatly augmented or made outright 
in the Tertiary age. 
The salient facts are these, and they have a profound bearing on the nature 
of the cause: (1) The Tertiary ranges which lie along the southern margin 
of Eurasia show many times the strength of those parts which are related 
to the two Americas and to Australia, and this applies to all of the phe- 
nomena associated with them—to the arcuate expression of the ranges and 
the larger earth-lobes, to the rifts in high latitudes, and to the narrow fore- 
deeps. (2) Although the development of subsidiary arcs in the two Ameri- 
cas is much weaker than in Asia, it is much stronger than that associated 
with Australia, where no subsidiary arc-forms are recognizable. (3) The 
cause, whatever its nature, is clearly and strongly related to latitude. The 
continental crust-sheets of Eurasia and North America migrated in southerly 
directions, while at the same time those of South America and Australia 
moved in northerly directions. All of the masses that moved migrated from 
high latitudes toward low latitudes, as though impelled by a force which 
tended to increase slightly the oblateness of the Earth’s figure. (4) The 
Tertiary mountain belt mapped on Mercator’s projection does not give a 
true idea of the relation of the crustal sheet of Eurasia and its marginal 
mountain belt. On a north-polar projection, or better on the land-hemi- 
sphere, one sees that from the Canary Islands to the mountain angle in Alaska 
is about 230° of longitude, or considerably more than half-way around the 
globe. The striking uniformity of strength through this whole distance is 
strong proof that it was the continental crust-sheet which moved southward 
in forming the mountains, rather than the sinking and landward thrust- 
ing of oceanic segments, an idea which would require India and Africa to be 
counted with the sinking masses, whereas Suess says that India and Africa 
remained unmoved during the Tertiary mountain-making. Many separate 
segments would necessarily be involved, but to produce the observed uni- 
- form result they must all act with about equal strength, and with markedly 
