belief that it has an atmosphere, 65;
canals of, 67;
gaseous wraps of, 97;
more efficient telescopes required for the study of, 67;
nearer to the earth than other planets, 65.

Marshes,
mangrove, 339;
map of Ipswich, 338;
marine, 336-340;
deposits found in, 336;
of North America, 337;
on the coast of New England, 339;
phenomena of, 167, 168;
tidal, good earth for tillage, 337;
tidal, of North America, 340.

Mercury, 55, 63, 78;
nearest to the sun, 63;
time in which it completes the circle of its year, 55.

Meteorites, 47, 48;
kinship of comets and, 48.

Meteors, 47;
falling, 47;
composition of, 48;
flashing, 39, 40, 47;
speed of, 47;
inflamed by friction with air, 99.

Methods in studying geology, 400.

Milky Way, 45;
voyage along the path of the, 44, 45.

Mineral crusts, 328, 329;
deposits, 308.

Moon, 38, 395-400;
absence of air and water on the, 399;
attended by satellites, 57;
attraction which it exercises on the earth, 62;
curious feature of the, 397;
destitute of gaseous or aqueous envelope, 397;
diameter of the, 399;
imaginary view of the earth from the, 81;
"libration" of the, 398;
made up of circular depressions, 396, 397;
movements of the, 78;
no atmosphere in the, 97;
parting of the earth and, 396;
position of the, in relation to the earth, 62;
tidal action and the, 131;
tides of the, 126, 127;
why does the sun not act in the same manner as the, 78.

Moraines, 216, 218, 229, 230;
map of glaciers and, near Mont Blanc, 217;
movements of the, 216-218;
terminal, 228.

_Moulin_, 219.

Mount AEtna, 288-310;
lava yielding, 290, 293, 294;
lava stream caves of, 292, 293;
more powerful than Vesuvius, 297;
peculiarities of, 291, 292;
size of, 289-291;
turning of the torrents of, 295.

Mountain-building, 90-93, 304;
folding, 86, 87, 90, 365;
attributed to cooling of the earth, 88;
growth, 392;
Swiss falls, 174;
torrents, energy of, 177.

Mountains, 85, 86, 89, 90-93; 174-178;
form and structure of, 86;
partly caused by escape of heat from the earth, 89;
sections of, 87.

Mount Nuova, fo