Attraction, opposition between modes of, [88]

Attraction, proportion of the mutual motions of, [76]

Balloons, [149], [280]

Balloon, hydrostatic, [159]

Barometer, [169]

Barker's mill, [182]

Battery, electrical, [387]

Berkeley, his ideas of matter, [2]

Boats, why they float, [139]

Boiling point as affected by the pressure of the air, [171]