uently fifteen
degrees of its meridians revolve hourly; therefore, by multiplying the
breadth of any number of degrees of longitude by fifteen, we have the
hourly motion of that part of the earth's surface round the axis; as,
for example, in lat. 45 deg., a degree of long. is 48-3/4 English miles
wide, within a trifling fraction. From these elements, it results that
particles of matter on lat. 45 deg. on the surface of the earth, revolve
about 630 miles hourly: this is nearly the mean motion, as the maximum
at the equator is a fraction less than 1,040 miles hourly, and
decreasing along the meridians, until it becomes 0 at either pole."

From this hypothesis he reasons that atmospheric and oceanic masses are
moved along with the decumbent nucleus with a velocity decreasing from
the equator to the poles; and if the least retardation operates on the
atmospheric and oceanic waters, a counter-current will be formed,
flowing with the greatest rapidity where the retardation is greatest.
This, he says, occurs along the equator, where the horary motion is at
its maximum; and thus the tropic current is formed. This current
receives volume and velocity from another cause, which is thus
explained: "Immediately under the sun, or where the beams of that
luminary are direct, a vacuum is produced, into which the circumambient
air rushes; and as this vacuity is carried westward along the equator,
upwards of 1,035 miles hourly, an atmospheric current follows, which,
acting on the ocean waters, impels them westward, and adds force and
mass to the tropic current. In the Atlantic Ocean, from the peculiar
structure of its shores, a very remarkable phenomenon--the Gulf
Stream--is produced. South America, in form an immense triangle, is
based on the Pacific, and protrudes its perpendicular angle into the
Atlantic at south latitude 6 deg.. This salient point is Cape St. Roque,
from which the continent extends to the northwest, crosses the equator,
and stretches beyond the northern tropic, forming in the Gulf of Mexico
an immense reservoir. Here the continent again turns at right angles,
and continues northeast into the northern polar circle. The very deep
indenting of the American Continent in the Gulf of Mexico, and the long
line of coast from its recesses into the southern section of the torrid
zone, is in a peculiar manner calculated to produce that very reflux,
which constitutes the largest whirlpool on the globe."

Much more does this ing