Geodesy, the art of measuring the earth without reference to the heavenly bodies.

God, relation of, to the universe, [258].

Gravitation, laws of, [6]; extends to the stars, [13]; theories of, [253].

Gravity on different bodies, [6], [274].

Helical, rising or setting of a star, as near to sunrise or sunset as it can be seen.

Heliocentric, as seen from the centre of the sun.

Hoosac Tunnel, example of accuracy, [62].

Horizontal pendulum, [272].

Immersion, the disappearance of one body behind another, or in its shadow.

Inclination of an orbit, the angle between its plane and the plane of the ecliptic.