160 



NATUBAL SCIENCE NEWS. 



PENIKESE— A Reminiscence. 



By One of its Pupils. 



Copyright secured 1895. 

 traced to the Alps; and at the foot of the Alps is a 

 pudding-stone which is found in the Jura. There is 

 no doubt as to where it came from. Professor Guyot 

 has done more than any other man in studying erratic 

 phenomena. He has proved, that what is in reality 

 done between the Alps and the Jura has been done 

 by glaciers and not by water sweeping up the plains. 

 Water would leave transverse ridges of rocks, while 

 those which occur are in longitudinal ridges, and 

 must have been caused by glaciers from the Alps. 

 How, then, while Switzerland was so cold could 

 England and other countries have been so warm. / 

 think that the whole globe was covered with ice. I 

 have found traces of glacial action everywhere in 

 mountainous districts that I have searched. In the 

 White Mountains, north of Franconia mountains, is 

 a ridge of thirteen plain morraines. They occur on 

 all sides of the mountains, also. There are signs in 

 New York, Ohio, Maine, New Hampshire, Massa- 

 chusetts, as far as British America, and still other 

 places. Everywhere is evidence of a great glacial 

 sheet, of immense thickness, passing over mountains 

 five and six thousand feet high, which left boulders 

 of a similar nature upon their tops and each of their 

 sides. I think that the ice in some places must have 

 been at least fifteen thousand feet thick. It moved 

 in a North-South direction. In Siberia, Asia, and in 

 the United States, gigantic animals were found im- 

 bedded in the ice, in perfect preservation, and show- 

 ing the contents of the stomach, — proving that they 

 must have been overpowered suddenly, — perhaps by 

 frost. I think that our large and small rivers are the 

 result of the melting of these glaciers. 



"Drift phenomena must be studied locally. There 

 must have occurred local ice which distributed itself 

 in plains different from that which came down from 

 the mountains. The idea that the glacial period was 

 simply an extension of the Arctic ice is nullified by 

 the fact that at the southernmost limit of that ice 

 sheet is a large moraine. The drift wanes in dis- 

 tinctness from north southward. This period, there- 

 fore, was not an enlargement of the northern glaciers. 

 In America are intimations of local glaciers, but they 

 are few; for example, in the White Mountains, on the 

 cost of Maine, and especially at Mt. Desert. The 

 characteristic of drift in America is that it extends 

 over a plain evenly, and without indications of lat- 

 eral moraines. The hills on the borders of Lake 

 Superior are scarred over their whole surface: slope and 

 summit. Indications that this action has been even 

 from north southward is, that the south side of the 

 rocks is not polished, but the boulders are rough and 

 unmarked. In some places there are deviations of 

 much less extent running from 20° to 30 0 , sometimes 

 almost at right angles with the main line: these are 

 indications of local glaciers — these often run north- 

 west and southeast. Another peculiarity of Ameri- 

 can glaciers is that most of our boulders are rounded 

 — those of Europe and Scotland are angular; where 

 we have circumscribed glaciers we have rounded 

 boulders. We seldom find median moraines in 

 America. The Arctic glaciers encroach largely upon 

 the sea. Our continent has once extended into the 

 sea in the shape of a drift. The level at which the 

 drift extended over all these islands was the same. I 

 think that these islands were once mainland. Local 

 glaciers have been described in many localities, es- 

 pecially by Professor Dana; but they are the effect of 



a great northern drift and not from local causes, as 

 might be implied." 



Toward the last of the session he returned to the 

 subject and gave us his final lecture upon this won- 

 derful subject. He says: 



"Perhaps the most important feature of glacial 

 action is found in the terminal moraine. It contains 

 a mineralogical collection from all the region around, 

 which comes from the upper regions and falls or is 

 detached by the ".glaciers, and all pushed together 

 toward this terminal point of the ice. To examine 

 these moraines and trace the specimens found to 

 their real or probable bed rock is a most important 

 labor of the geologist. That glacial action was once 

 carried on to an extent much greater than could have 

 been possible had the period begun with 'an enlarge- 

 ment of the Arctic glacier. Thus we find copper 

 identical with Lake Superior copper in Michigan, In- 

 diana and Iowa, and even as far as 500 miles south of 

 its origin, having distinct marks of glacial agency 

 upon it. The rate at which glaciers moved in Amer- 

 ica is not certain. In the Alps, where the slope adds 

 to the inclination, the maximum motion per day is 

 one foot; the minimum thirty inches per year. Let 

 us assume that our glacier moved 100 feet a year, — 

 and it will take fifty years for the boulder to go one 

 mile or 25,000 years for it to reach its present po- 

 sition." 



[It has often struck me as a curious fact that in es- 

 timating geological time Professor Agassiz (as well 

 as others) makes no account of the fact that were the 

 motion or the glacier thirty inches a year the period 

 would be forty times that amount or 1,000,000 years; 

 if, on the other hand, the motion were faster, the 

 time would decrease in proportion. The rate of 

 time necessary to accomplish a given object may not 

 always correspond with the numerical calculations of 

 writers. Experiments in the chemical laboratory 

 are sufficiently numerous to show the different actions 

 of the same substance under different circumstances, 

 to make us pretty careful as to how we lay down a 

 law upon insufficient evidence. Hence, our given 

 geological time must be more or less hypothetical 

 under any circumstances.] 



"Large animals being found imbedded in the ice 

 are evidence of its coming quickly. It is not likely 

 that a snow storm capable of freezing large animals 

 in Siberia and North America would be limited to 

 one particular region. It would be graded according 

 to latitude. The question is, how much was there m 

 the coldest latitude; how much in the warmest? Let 

 no one fail to urge upon the members of any expe- 

 dition to the Arctic regions the importance of ascer- 

 taining the motion of Arctic icebergs and glaciers. 

 This motion can be ascertained by the amount of ice- 

 bergs which float away from their extreme southern 

 limit. " 



It is thus that we learn the first principles of gla- 

 cial action. How careful our instructor is to distin- 

 guish facts as truths; and possibilities, only, he weaves 

 into theories, which he is very careful to impress 

 upon us are possibilities. In a letter made public 

 some years since, he said: "The office of Science is 

 not to record possibilities, but to ascertain what na- 

 ture does," again — as far as one "deals with mere ar- 

 guments of possibilities or even probabilities, with- 

 out a basis of fact," he says, that one "departs from 

 the true scientific method." These words are as true 

 today as they were the day they were uttered; they 

 will be as true a thousand, yes, ten thousand years 

 hence: Living truths that never die. 



{To be continued.) 



