No. 7. DEPARTMENT OF AGRICULTURE. 24fi 



every cranny, crevice or jjore of the earth or rocks is entered, 

 channels are eaten away, fragments are loosened, rocks broken 

 up and disintegrated, and mountains are destroyed. No rock is 

 free from its corroding influence; no mineral can resist its attack; 

 everything succumbs to the universal force; everything yields be- 

 fore this ceaseless agent. Mountains are sculptured and surfaces 

 denuded, their debris transported into the valley, over the valley, 

 down the valley and thence to its home, the ocean depths. 



Here, throughout the ages, is accumulating the wash from con- 

 tinents more or less remote. Along the coast, the waves break 

 down the cliffs and deposit clean, pure sand. Far out in the deep, 

 come washings from the Kockies, slimes from the richer valleys, de- 

 cayed vegetation and myriads of animal organisms collected by 

 covetous inland waters in their steady journey to the sea and buried 

 under its dark mass to form a soft, black, rusty ooze. Soon it 

 hardens and becomes a layer of rock. 



As the ocean floor is now, so it has remained for ages past; so 

 must it remain for time to come. Though its floor may rise or 

 fall and the level change, the sea is the same yesterday, to-day and 

 forever. 



At some future time the hardened sands at the shore and the lime- 

 stones now in the deep sea will be elevated, just as has happened to 

 the sandstones and the limestones which now form the land on which 

 we tread. West from the South Mountain range, Pennsylvania has 

 been under water, its 38,000 feet of rock crust of the earth having 

 once lain cold and dormant at the bottom of the sea. Prepared 

 throughout, who can say, what unrealizable periods of time, for the 

 use and enjoyment of man with organic and mineral elements for 

 supporting vegetation, these several limestones and sandstones once 

 rose dripping from the sea and were folded into the rolling to- 

 pography of the earth's surface. Grand as were these forces in- 

 volved in uplifting the ocean bottom, no less so is the corroding 

 power of the gently falling rains and snows to which all land every- 

 where yields. Proud mountain domes and ranges acknowledge its 

 supremacy. Valleys fill and the ocean accumulates a fresh sedi- 

 ment. The whole history of the visible land consists of upbuilding 

 and destruction, rebuilding and disintegration by the action of 

 forces which have left gigantic monuments of their mighty power. 

 Of this everlasting contest between the destroying and upbuilding 

 forces of nature, the broken rock and pulverized earth are an ever 

 present witness. 



Such has been the geological history of this State with its varied 

 rock formations and horizontal, and in the eastern half of the State 

 tilted and eroded. Such has been the history of that superficial 

 covering with which we are now most concerned, and throughout 



