DEEP SEA RESEARCHES. 368 
duced, and some of its most important discoveries are now announced by Dr. 
‘Carpenter, its originator. One of the first questions its labors contribute to solve 
is the depth and configurations of the ocean basins. 
The prevailing notion of the sea-beds, Dr. Carpenter shows, needs consider- 
able modification, none of them having been carefully outlined, except that of the 
North Atlantic when sounded with a view to laying the first Atlantic cable. 
‘The form of the depressed area which lodges the water of the deep ocean,” he 
says, ‘‘is rather to be likened to that of a flat waiter or tea tray, surrounded by 
an elevated and steeply sloping rim, than that of the ‘basin’ with which it is 
commonly compared ;”” and he adds: ‘‘ The great continental platforms usually 
rise very abruptly from the margins of the real oceanic depressed areas.” 
The average depth of the ocean floors is now ascertained to be about 13,000 
feet. As the average height of the entire land mass of the globe above sea level 
is about 1,000 feet, and the sea area about two and three-fourths times that of the 
Jand, it follows that the total volume of ocean water is thirty-six times that of the 
land above the sea-level. These deductions, seemingly unimportant except to the 
votary of science, are destined perhaps to serve the highest practical purposes of 
deep sea telegraphy. The intelligence now quarried out of the enormous collec- 
tion of later ocean researches shows the modern engineer and capitalist the 
feasibility of depositing a telegraphic cable over almost any part of the ocean’s 
floor, and ought to give new confidence in the success of all such enterprises 
properly devised and equipped. When it is remembered that at the beginning of 
this century La Place, the great mathematician, calculated or assumed the aver- 
age depth of the ocean at four miles (or 8,o00 feet more than Dr. Carpenter de- 
termines it to be from actual survey), and that La Place’s conclusion was the 
received view among scientists until 1850, or later, we get some idea of the ad- 
vance made in this branch of terrestrial physics by modern research. Not less 
interesting is a deduction Dr. Carpenter makes from the deep sea temperature 
observations in the North Atlantic. 
In consequence of the evaporation produced by the long exposure of the 
equatorial Atlantic current, its water contains such an excess of salt as, in spite 
of its high temperature, to be specifically heavier than the colder underflows 
which reach the equator from the opposite Arctic and Antarctic basins; and, 
consequently, it substitutes itself by gravitation for the colder water to a depth of 
several hundred fathoms. ‘‘Thus it conveys the solar heat downward in such a 
manner as to make the North Atlantic between the parallels of 20° and 40°, a 
great reservoir of warmth.” The climatic effect of this vertical transfer of equa- 
torial heat is obvious. If the great heat-bearing currents which enter the North 
Atlantic traversed its bosom as surface currents, they would expend their warmth 
largely in the high latitudes. But, as their heavy and highly heated volumes in 
large measure descend to the deeper strata south of the fortieth parallel, then 
stores of tropical temperature are permanently arrested off our eastern coast, and 
ultimately made subservient to our climate.— Mineteenth Century. 
