Tribune Extras Pamphlet Scries. 



the manner in which the glacial age was ushered 

 in T It is generally assumed that the glaciers com- 

 menced in the Tertiary period, and gradually ex- 

 panded until they reached their maximum size, and 

 covered those parts of the world which hear tho 

 imprint of the agency of ice. But we find on analyz- 

 ing the conditions and phenomena of glacial action, 

 that this assumption of the gradual extension of tho 

 continental glacier is not justified. If it were so, 

 wo should find at tho outer limits of the 

 placier a huge terminal moraine composed of rocks 

 from all tin territory over which the glacier had 

 moved. Suppose the glacier of Greenland to begin 

 to swell and advance south, it would push the 

 bowlders and louse material before it. We should 

 bo ahle to tell how far it had advanced by the 

 mineralopical constituents of its terminal moraine. 

 We find no such thinir anywhere, but we find traces 

 of glacial action within limits that far transcend 

 the region over which such constituents could have 

 been transported. Let us connect what wo know to 

 make a readable history. 



American geologists have taught us that native 

 copper, identical with tho Lake Superior copper, is 

 found all over the Western States to the latitude of 

 40 degrees. Now, we know that tho glacier extend- 

 ed much further south than this, and if it had ex- 

 panded gradually over the country, we should find 

 this Lake Superior copper at its southern limit. 

 On Peuikese, we find pudding-stone that is not 

 found out of Massachusetts. It must have traveled 

 from Roxlmry, while the glacier has been traced to 

 South Carolina. In Nc \v-York, minerals are found 

 in tho drift which are found in place in Canada, 

 but which aro not found in Kentucky, tiiough er- 

 raties are found there. These are loose facts, and 

 must be studied with the utmost accuracy to find 

 how these materials have been transported. Wo 

 must find the north and south limits of these 

 materials. In Canaan. Western Massachusetts, there 

 is a rid.ire from which it is known certain bowlders 

 to the south have been derived. We deduce from 

 this a number of conclusions of great interest. 

 Lake Superior copper is strewn over about 500 miles 

 of latitude.' The distance traveled over by any one 

 sot of bowlders is always much less than tho total 

 extent of the plaeier. In the Alps, where 

 tho glaciers move on steep slopes, and 

 whero tlie slo'.M accelerates the motion of 

 the glacier, tho maximum motion is one 

 foot per "lay; the minimum motion is 

 30 feet per year. If wo only knew the 

 motion per year of the Cieenland glacier we should 

 have a better measure lor our o\vu continental 

 glacier. ''if the An-tie explorers had not met with 

 o'l-tfaclDS we should have he. n aide to apply it now. 

 Since we have no positive data, we cau form some 



idea of their motion by the number of iccberga 

 which the3 T send forth annually; for these icebergs 

 could not exist but for the advance of the glaciers 

 into Baffin's Bay, where their ends are lifted by tho 

 water, broken off, and floated south. We do not know 

 what these icebergs amount to, though it would not 

 be difficult for an observer at the south end of 

 Baffin's Bay to ascertain approximately by counting 

 the number of icebergs that pass a given point annu- 

 ally. 



But we will, to be within bounds, assume that our 

 Contmeatal glacier moved as fast as 100 feet per 

 year. At that rate it would take 50 years for a 

 bowlder of Lake Superior copper to have traveled a 

 mile, and to have traveled to its utmost southern 

 limit, 500 miles, would take 25,000 years; but it 

 probably took a much longer time. If a rock in 

 place south of Lake Superior should be found in the 

 shape of bowlders further south than the southern 

 limit of copper bowlders, it would be an additional 

 evidence in support of this point. 



Although Lake Superior copper is not found south 

 of the 40th parallel, yet there is evidence that tho 

 glacier extended as far south as Charleston, S. C. 

 The interpretation of these facts is that the glacial 

 period came on rather rapidly, through cosmic 

 changes such as have produced other changes in tho 

 geological appearance of tho earth, and wo know 

 that such changes have taken place. The Pyrenees, 

 10,000 feet high, did not exist prior to the 

 cretaceous period. Tho Juras, G.OOO feet 

 high, are not as old as tho Jurassic, and 

 the Alps, 15,000 feet hi eh, were upheaved 

 by tho Tertiary. So wo aro familiar with tho fact 

 that great revolutions have taken place over tho 

 surface of the earth. Causes now operating are not 

 Buih'cient to produce all the geological phenomena of 

 past ages, Lyell to tho contrary notwithstanding. 

 Mountain ranges could not he produced without 

 revolutions which eould not bo measured by causes 

 now operating. These will explain a variety of 

 phenomena, but are inadequate to account for the 

 present aspect of the globe. 



Tho glacial period was comparatively recent, sub- 

 sequent to a time when our earth was much warmei 

 than now, when the rhinoceros inhabited our West- 

 ern prairies, and tho mastodon and elephant roamed 

 over Siberia and the high latitudes of this country. 

 That this tropical state of things was changed 

 rather suddenly is proved by tho fact that mam- 

 moths and other largo animals have been fouii;', 

 frozen in the ice in Siberia, with the flush and skin 

 still on them, and so well preserved that the wolve- 

 and dogs will eat the flesh. A '.rivat climatic change 

 came on very suddenly; these animals became 

 frozen in the ico, and have remained frozen ever 

 since. 



