[Illustration: Pl. II. SEASONS.--SUMMER.]

This line of magnetic, or heat activity, consequently varies with the
earth's movements. On the 20th of June the flood of summer heat
overspreads the northern portions of the earth; the sun thence
apparently turns southward, and with its departure the relations of the
line of heat activity change. The city of New York, which on the 20th of
June is found nearest the centre of the solar current (Plate II. b), is,
on the 21st of December, located at its greatest distance from the line
of magnetic or heat intensity (Plate III. b), where the heat-producing
forces are in operation in but low degree.

[Illustration: Pl. III. SEASONS.--WINTER.]

CHAPTER VII.

GRAVITY.

_Its Essential Nature, and its Source._

Gravity is not a separable entity, not a power _per se_. It is but a
production, and an operation, of the same retro-action between sun-core,
and earth-core. This retro-action gives rise to a stupendous magnetic
circuit, as described, in which both sun and earth become the
embodiments of magnetic force, or, in other words, great magnets.[11]

The power thus developed is exercised in preserving the relative
positions of the two bodies, and, on the part of the earth, as we know,
in drawing unto itself all objects within its influence.

The same current, therefore, which lights up our earth, and which gives
to it its requisite supply of heat, at the same time indues it with the
power of attraction.

_Thus is engendered that power known as gravity, which has ever been
acknowledged a profound mystery beyond the comprehension of man._

FOOTNOTES:

[11] Appendix, p. 102.

CHAPTER VIII.

THE ATMOSPHERE.

_A Veritable Ocean._

The great aerial ocean which we call the atmosphere (at the bottom of
which we live, and move, and have our being), is even more vitally
important than has ever been dreamed of in human philosophy.

_How Constituted._

Its tangible constituents, such as clouds, vapors, gases, are well
understood; as well as the modifying influence of those atmospheric
elements upon what we call sunlight, and sun-heat. But the intangible
and vital principle, or basis of the atmosphere, has in a measure
escaped recognition. This principle is vito-magnetic in its ch