156 



NATURAL SCIENCE NEWS. 



PENIKESE — A Reminiscence. 



By One of its Pupils. 



Copyright secured 1895. 

 view. Hitherto, the theories respecting the geologi- 

 cal formation of the earth, as held by Wernes, were 

 that all this material had been brought together by 

 water and flood; the Scottish school of scientists 

 maintained that it had all been accomplished by vol- 

 canic action. A violent feud ensued. Leopold Von 

 Buch asserted that both were right. He gave to 

 geology its present shape. I was then a student. 

 Being at the foot of the Jura, I saw rocks in places 

 where it was impossible for water to carry them. 

 The thought came to me that glaciers transported 

 rocks in Switzerland, and why not here also? I 

 thought: why might not glaciers occur in other coun- 

 tries than Switzerland? I went to other countries 

 and studied the evidence. I found that the rocks 

 which glaciers moved were polished, or rough and 

 scratched. Water rocks were hollowed in soft spots, 

 thus making prominent the hard places. Ice pro- 

 duces a smooth surface. Pebbles worn by water are 

 smooth like a hammered surface — but dull, not 

 shiny; ice polishes the surfaces and scratches them. 

 If the ice goes in one direction all the creases will 

 run in one direction. Loose pebbles scratched by 

 ice and by water are also different. Erratic boulders 

 are always found in connection with loose materials 

 which are scratched and polished. Loose materials 

 are not stratfied. I found out these facts in my 

 study in Germany, France, and in other countries. 

 I went to England, and there found evidence of this 

 glacial action. I was with a friend — a Mr. Buckland 

 — and we were at first alone in our theory. 



"The conclusion we reached was, that at one time 

 the globe was much colder than it is at present. In 

 science one should never suggest anything for which 

 there is not some foundation. The glacial period 

 must have been posterior to the geological period 

 when mastodons and elephants inhabited the whole 

 globe and the climate was more tropical than it is 

 now. We estimated that ice was once 10,000 to 

 12,000 feet deep all over the globe. It is chiefly in 

 temperature that changes occur. If ever our island 

 (Penikese) was below the sea, why not find the same 

 rolled pebbles and low-tide marine animals? No sea 

 has been beating here, for we find no sand or loam 

 has been washed away. All the loose materials re- 

 main in place. The greater part of the local pecu- 

 liarities, such as depressions and inequalities, will 

 have been produced by rain. Glacial action will ex- 

 plain the peculiarities we see on land here. There 

 is nothing so hard to protect as a man's intellect. 

 We can get no patents on our investigations." 



The same subject follows in his next, or fifth lec- 

 ture: 



"A geological period or age ago, the surface of the 

 earth was covered with boulders; this was before 

 there were either plants or animals to be found upon 

 it. Now to understand and to translate the trans- 

 portation of glacial rocks we must understand the 

 formation of glaciers. The idea of glacial motion 

 originated with the peasants of Switzerland. A civil 

 engineer, Verner by name, and a peasant, Chapantea, 

 however, got much of the credit for field observation 

 which I had myself done. In 1837 no geologist ad- 

 mitted that rocks were moved by glaciers; most of 

 them admit it now, though in a somewhat modified 

 condition. The early scientists who were interested 

 in and studied into this subject, were Schenchter, 

 who also first described several fossil fishes; Horace 



Benedict de Saussure, who published his travels in 

 the Alps, and who first described glaciers; Chap- 

 antea, who studied them considerably and published 

 articles upon them; and myself, Professor Forbes, 

 and Mr. Tyndall, who, lately, described their physi- 

 cal constitution, action, etc. Of these Mr. Tyndall's 

 work is the best. We now come to the question, 

 What is a glacier? 



"Glaciers are composed of different materials ac- 

 cording to the positions selected for investigation. 

 On mountain top they are mere snow fields; deeper, 

 they are composed of ice crystals, the ice becoming 

 more and more compact as you go downwards; until 

 the bottom is clear, solid ice. Snow when re- 

 solved into fine granules is called neve: where this 

 changes to ice is called 'the limit of perpetual snow.' 

 Physical geographies are incorrect in their state- 

 ments of the snow-level on the Straits of Magellan 

 and many other places. Similar conditions are found 

 at the same line of perpetual snow; they are also 

 similar in the same number of degrees distant in dif- 

 ferent localities. Glacial ice differs from common 

 ice, — the first is composed of ice crystals melted to- 

 gether and can be reduced to powder, the latter is 

 formed in layers. Glaciers possess a motion in them- 

 selves which is both an upward and a downward mo- 

 tion; it is greatest in the middle, and least upon the 

 edges. Moving ice, therefore, exerts a great power.- 

 As the glacier moves, it collects a large quantity of 

 loose materials which it carries along with it. Part 

 of this material over-crowds itself and forms a low 

 line of rocks on either side of the glacier: these lines 

 are called lateral moraines. When two glaciers or 

 two arms of the same glacier unite, they continue as 

 one, while their lateral moraines unite and form a 

 medial moraine. The bottoms of glaciers, then, be- 

 ing covered with rocks, act like an immense rasp. 

 In passing over walls of rocks, or open faces of ex- 

 posed ledges, both the upper faces of the under 

 rocks, and the under faces of the upper rocks, which 

 are in the glacier, are scratched and scarred alike. 

 Yet the rocks which are in the glacier will still be an- 

 gular above where only the ice covers them. Now 

 the continual motion of the ice pushes forward the 

 larger rocks, and at the same time all the loose ma- 

 terial is gronnd still finer; and each pebble rounded 

 in a manner which is never produced by water. 

 Thus the moraines are ground more and more as 

 they advance, so that, whatever their shape may at 

 first be they come out, at the end of the glacier, 

 rounded material, and when the glacier begins to 

 melt and to recede they are deposited as single or 

 successive terminal moraines. These are crescent- 

 shaped ridges or walls of rock and loose material. 

 If small glaciers will accomplish so much, what 

 might not large ones do?" 



In his sixth and seventh lectures he still continues: 



"When a glacier meets with an obstacle it breaks 

 and forms crevices. You will find no crevices in 

 neve. The more compact the ice the deeper and 

 broader these are. In a hot day the sides of the 

 glaciers melt and form small brooks. These are 

 sometimes too wide to cross. They carry with them 

 an immense amount of rubbish, which fills up many of 

 the cavities and gaps, and makes pot-holes and new 

 excavations. Sometimes one of these brooks will 

 traverse the whole length of a glacier. 



"The geological phenomena connected with glacial 

 action is extraordinary. There are boulders upon 

 the Jura which, in mineral character, have been 

 (To be continued.) 



