ACADEMY OF SCIENCES. pe 
ing others to immense heights. Earth’s surface, to-day, bears unmistakable 
evidence, to every thoughtful student, that eruptive catastrophes have mate- 
rially changed its geological features—especially the levels. Many areas, 
formerly submerged, are now dry, and known as alluvial formations. Seas 
have changed position, and rivers acquired new courses. New land has been 
formed, and mountain ranges reared by upheaval. Recent deep-sea sound- 
ings of the U. S. steamer Tuscarora—commander, Belknap—clearly illustrate 
how largely the bed of the Pacific Ocean—once but an extended valley, run- 
ning, perhaps, from the Arctic to the Caribbean Sea—may have augmented its 
area by a comparatively moderate depression. During the glacial period, im- 
mense icebergs were produced at the poles, and as they increased in bulk, 
during a succession of cold winters, they accumulated an enormous volume of 
water—human life is considered to have been extant at this period—and when 
a succession of warm summers, produced by the perpendicularity of the 
earth’s axis to the plane of the ecliptic, succeeded in reducing these huge accu- 
mulations of polar ice, its volume retired, covering many valleys not previously 
submerged. This could have given rise to the legend of a Flood, which may 
have occurred, but could not have been universal, for a sufficient amount of 
water does not exist to cover the highest mountains, and submerge the entire 
earth. 
A sudden and eruptive convulsion of earth’s crust during the tertiary, near 
the close of the cretaceous period, whether separate or conjointly with a flood, 
must necessarily have destroyed a large majority of partially developed men, 
struggling to evolve the higher human types. Portions of Asia, Africa, and 
Australia are supposed to have been elevated; while Europe, the extreme north- 
ern portions of America, the Caribbean Sea, and the beds of certain oceans were 
depressed. The eftects must have been most forcible around the poles and 
south of the equator. Dead river beds which cross the highest mountain 
ranges oi the Pacific Coast, and yield so largely of gold to hydraulic washing, 
clearly confirm radical changes in the physical conditions and levels of this 
coast. 
The surviving remnants of these catastrophes, in Asia, Africa, Yucatan, 
and a few scattering tribes of North America, thenceforth appear as the pro- 
genitors of all living nations. It is only from this period that we can hope 
to trace the early history of humanity. Previous beings, if in harmony with 
physical conditions, must have been generally in the incipient stages of hu- 
man eyolution. In Central America alone, we find ruins, whose hoary an- 
tiquity seem to claim for its inhabitants the earliest civilization of which any 
traces remain. It is fair to infer that the pyramids of Yucatan were antedi- 
luvian and escaped inundation, as did the cities of Palenque and Copan. 
These elaborately constructed cities of Central America exhibit conceptions 
of beauty which, as early specimens of a gradually unfolding art, appear to 
antedate all similar structures extant. 
Plausible grounds of inference exist, that the earliest manifestations of cul- 
ture known to us, was among the primitive settlers of Central America, who, 
having acquired mechanical invention, art, and the rudiments of scieuce. 
Proc. Cav. AcaD. Sci., Vou. VI.—9. 
