Rocks, average composition of, 43; radioactive heat from, 126;
rate of solution of, 36.

Russell, I. C., river supply of sediments, 10.

Rutherford, Sir E., determination of age of minerals, 19, 20; age
of rocks by haloes, 22; derivation of actinium, 226; artificial
halo, 229; number of alpha rays from one gram of radium, 237.

S.

Salt range deposits of India, 134. 135.

Saltness of the ocean due to denudation, 41-46.

Salisbury (and Chamberlin), the Larimide range, 121.

Salmon, Rev. George, on creation, 301.

Satellite, velocity of, in its orbit, 191; method of finding path
of, over a rotating primary, 189 _et seq._; direct and
retrograde, 178; ultimate end of, 178; path of, when falling into
primary, 179; effect of Mars' atmosphere on infalling satellite,
179; stability of close to primary, 180; effects of, on crust of
primary, 180 _et seq._

Schiaparelli, observations on Mars, 165 166.