Air in interstices of substances, [160]
Air a non-conductor of heat, [302], [304]
Air-pump, [155]
Air-guns, [164]
Animals, coverings suited to climate, [305]
Archimedes, his lever, [229]
Archimedes, his discovery in the bath, [138]
Archimedes and the crown, [143]
Artesian wells, [120]
Aqueducts, [119]