Part 28

Hicks's, Principal, investigations on the influence of temperature on gravitation, 184.

Hieroglyphics, Young's work on, 234.

Hobbes, opposition of, to Boyle, 25.

Hollow conductor, Franklin's experiments on, 91; Cavendish's experiments on, 135; Faraday's experiments on, 270.

Honorary degrees conferred on Franklin, 66, 101.

Hooke's law, 229.

Hooke, Theodore, founds the Royal Society, 14.

Huyghens's explanation of double refraction, 219; principle, 218.

Hydrogen, electro-chemical equivalent of, 267.

Ice-pail experiment of Faraday, 270.

Identity of frictional and voltaic electricity, 266.

Induced currents, discovered by Faraday, 259; explained by structure of ether, 304; from earth's action, 262.

Induction coil, 320.

Induction, Franklin's experiments on, 90; self, 142, 306.

Induction machines, principle of, 316.

Insulators for lightning-rods, 96.

Interference, principle of, discovered by Young, 208; spectra of, obtained by Young, 225.

Invisible college, 13.

Jenkin, William, discovery of the "extra current" by, 268.

Joule and Thomson's determination of the heat absorbed by air in expanding, 324.

Joule, Dr., establishment of mechanical theory of heat by, 193, 324.

Joule's law, 324; proof that heat and energy are equivalent, 324; determination of the mechanical equivalent of heat, 325.

Junto Club, formation of the, 51.

Kelland's, Professor, edition of Young's lectures, 212.

Kinnersley commences lecturing, 73.

Kite, Franklin's, 88.

Knobs versus points, 95.

Laboulaye's comments on Franklin, 38.