Chapter II

HOW ICE PERIODS IN THE NORTHERN HEMISPHERE ARE BROUGHT
ABOUT, 37–54

Northern seas during Tertiary age, 37; Gulf Stream during
Tertiary times, 38; the origin of a cold period in the
northern hemisphere, 38; remarks on Gulf Stream and
arctic currents, 39; circulation of arctic waters, 40;
arctic channels during ice age, 41; how the weight of
glaciers in the northern hemisphere attracts the waters
of the southern seas during ice age, 42; Professor
Prestwich on the submergence of European lands, 43;
the great Atlantic tide rips the head-waters of the
Gulf Stream, 44; high sea-level of Atlantic calm
region, 45; tropical Atlantic currents, 46; Sargasso
Sea, 48; arctic and Gulf Stream currents, 49; Pacific
Ocean currents, 50; slow growth of an ice period, 52;
reduction of Cape Horn channel, 53; permanence of
antarctic glaciers elevated above the snow-line during
mild periods, 54.

CHAPTER III.

SPREAD OF GLACIERS DURING COLD EPOCHS, 54–61

Spread of glaciers in tropical zone, 54; Professor Agassiz
on the origin of Galapagos Islands, 55; the bowlders
of Hood’s Island and rookery of Albatross, 56; alpine
flora of Galapagos and tropical America, 57; Mr. J.
Crawford on ancient glaciers in Nicaragua, 58; Cuba and
Republic of Colombia during ice age, 58; destruction
of animal life during glacial age, 59; temperature
of North Atlantic and Mediterranean Sea during ice
age, 60; temperature of ocean during warm epochs, 61;
generative age ascribed to warm eras; Professor Wright
on pre-glacial man, 61.

CHAPTER IV.

THE GLACIERS OF THE TEMPERATE ZONE, 62–75

Professor Hitchcock on the early history of North America,
62; glacial deposits of Nantucket and Martha’s
Vineyard, 63; Professor James Geikie on the glacial
deposits of Northern Italy, 64; California coast ranges
the work of Sierra glaciers, 65; ancient glaciers on
the Pacific slope north of California, 67; Professor
Geikie’s views on the ancient glaciers in the Salt
Lake region, 68; Colorado Cañon, 69; the conglomerate
deposits in the Appalachian district, 69; remarks on
the glacial boundaries in United States during ice age,
70; sands of Florida, 71; ancient ice-sheets of the
plains west of the Mississippi River, 73; the driftless
region of Wisconsin, 74; tropical waters of North
Atlantic chilled during ice age, 75; the drifted snow
of British America and Siberia during ice age, 75.