CHAMBERS'S INFORMATION FOR THE PEOPLE. 



ice-masses, whether grinding down the land or 

 grating on the floor of the ocean, or dashing 

 against opposing islands, are seen in the thick 

 clay and sand deposits everywhere around us, 

 inclosing worn stones and gravel ; the scratched 

 and rounded rock-surfaces, often bright and smooth 

 as polished marble ; the 'erratic boulders,' perched 

 on our hill-tops and plains ; and the general wavy 

 outline of all higher ground throughout our land. 

 This glaciation has been ascertained to extend 

 over the whole of Northern Europe and America, 

 and round the shores of the Antarctic Ocean. 



XI. QUATERNARY OR RECENT PERIOD. 



We have now reached the last of the great 

 geological epochs, during which sea and land, 

 plants and animals, were much the same as they 

 are now. This last system has been variously 

 named the Post-tertiary, Quaternary? or Recent. 



The whole system may be divided into two chief 

 periods : 



1. The Prehistoric, or that before history was 

 written. 



2. The Historic, or that since history was 

 written. 



During the whole epoch, there is little or no 

 solid rock, the whole deposits consisting of clay, 

 sand, gravel, mud, peat, and the like. 



Of prehistoric deposits, we find such remains as 

 these : plants of all kinds, all common shells and 

 corals, and common animals, with a few now 

 extinct, such as the long-fronted ox, the gigantic 

 Irish deer a creature ten feet high to the top of 

 its horns the elephant, rhinoceros, hyena, bear, 

 and mammoth, besides human remains in the shape 

 of bones, canoes, ashes, dwellings, and weapons. 



In historical times, we find similar remains, but 

 the deposits are comparatively small, and the 

 plant and animal remains are almost solely those 

 now existing in each country. Men have left 

 traces of themselves in buildings, coins, imple- 

 ments, weapons, and works of art. While peat- 

 bogs have been formed, forests have been sub- 

 merged or cut down, and considerable changes in 

 sea-level have taken place. 



Since the Glacial Period, in the Tertiary, a series 

 of changes has been going on without intermission, 



1 From Latin guaternus, fourth, as coming after the Tertiary. 



accomplished by various causes and in various- 

 ways. The land has changed its level several 

 times both by elevation and depression, the sea. 

 thus alternately encroaching on and retiring from, 

 the land. Whole countries have been gained 

 from the ocean, such as the Fens in England and 

 the greater part of Holland. Old beaches may be 

 distinctly traced, with their cliffs, shores, and 

 shells far above sea-level. Whole forests have 

 been submerged, whose old trunks and fruits are 

 thrown up by every storm. Huge accumula- 

 tions of sand, blown or washed, have been found 

 along its shores. Rivers have been depositing 

 new matter under the ocean at their mouths, 

 increasing the land by the formation of deltas,, 

 sometimes hundreds of miles in extent, laying 

 down fine carse-land along their banks, that now 

 forms the richest soil of the farmer, and leaving 

 terraces far above their present level, to mark 

 their former beds. Many lakes have been formed, 

 others have been gradually silting up from the 

 earthy matter brought down by rivers, while some 

 have become dry, their beds being now waving 

 with corn. Animals have been busy forming new 

 islands and continents, as in the Pacific, where 

 the coral insect leaves its skeleton to form the 

 nucleus of future islands. Igneous agencies have 

 been and are as active as in the olden times in 

 changing the land and throwing out vast deposits 

 of lava and ashes. 



Man. It is an interesting question how far 

 back man extends into these geologic eras, and 

 this important inquiry has of late years received 

 great attention. Striking results have also been 

 arrived at. It seems to be indisputably proved 

 that man existed as far back as the great Glacial 

 Period, at the close of the Tertiary epoch, and 

 that he was contemporary with the hairy rhi- 

 noceros, mammoth, woolly elephants, and other 

 gigantic creatures now long extinct, which he no 

 doubt hunted, as he now does the fox and the 

 deer ; at which period Britain was united to 

 France, where now the sea flows in the Strait of 

 Dover. But this inquiry is yet in its infancy, 

 and it would, therefore, be unwise to make posi- 

 tive statements where our data are insufficient. 

 Enough has, however, been discovered to shew 

 that in our own quiet land men lived for many 

 ages with strange denizens, and under conditions, 

 very different from the present. 



Rocking Stone, Fall river. 



