146 FARMERS' INSTITUTES. 



Last of all, geology slio'ws that man came as the grand finale in tins wonder- 

 ful scheme of development. Now all this knowledge as to tlie life of the various 

 ages of the world's history comes through the startling revelations made by the 

 rocks. Are we any more sure of the customs of the people who once made 

 noisy the busy streets of Pompeii because Vesuvius flooded that city with the 

 destroying lava since the historic era? The exhumed coins, instruments and 

 yery buildings are as faithful a recordas that of the most cautious historian. 

 Aye, often a more reliable witness, as they have no prejudice to bias ; no imagi- 

 nation to add its unreal pictures. Biblical history told of great cities which 

 were lost in the destructive warfare of time. Skeptics would not believe the 

 record, and even used the absence of any remains as argument to invalidate the 

 story '^self. Research finds deep under the debris of centuries the remains of 

 the handicraft of the old-time people, and disbelief is utterly dethroned. So 

 these unwritten records of the rocks are no fabrication. They form a, record as 

 certain as truth, as reli.'vble as fact. On the witness stand they know'no preju- 

 dice, and never willfully or otherwise forget. Thus these fossils of the rocks^ 

 long locked in solid vaults, are now brought forth by man's intelligen'e and 

 love of truth, and have told their wonderful story, and have in less than one 

 century convinced the world of iis entire truthfulness. 



Now we see how it is known that our continent commenced in the V-shaped 

 area already referred to, and that Europe as surely arose from an archipelago. 

 These oldest rocks are crystalline, warped and baked, and wholly destitute of 

 fossil remains. They may exhibit no layers which are sure to show in all 

 rocks built up by waves. Hence you can all see and appreciate the kind of 

 testimony which shows that the Upper Peninsula of Michigan reaches back 

 to when time was young. These early rocks were subjected to intense heat 

 "which, with moisture, could act upon gold, silver, iron and copper, and by 

 melting and vaporizing these valuable metals could gather them up wliere- 

 they were dropped in smallest particles from the ocean's waters and bear 

 them to some rock fissure or cavern and mass them in quantity as we see 

 them at M rquette and Keweenaw point to-day. So while tliese old rocks were- 

 all unfertilized by the droppings of centuries of life, and while tlie waves have 

 never been able to plow and harrow them, yet they often are of exceeding value 

 in the costly metals and gems which they hold in their embrace. Tell a geol- 

 ogist of the character of the rocks of our northern Michigan, and he would 

 surely foretell the probable presence of valuable mineral deposits, as did Sir 

 Roderick March ison the rich gold fields of Australia. 



It may be very properly asked how we know what the older, deeper rocks con- 

 tain, and how we can say that such rocks are miles in thickness. Has man 

 bored to the earth's centre that he can speak of the life, remains and general 

 character of these old rock deposits? There are three ways that we can tell of 

 the important secrets which the old rocks have preserved for all these centuries. 

 Occasionally a river like the Colorado, with its vertical banks a mile in height, 

 has cut its channel through the rocks, thus exposing them to view, and giving 

 to man the key to this geological puzzle. Thus the life remains appear and 

 show a wider and wider divergence from the life type of to-day, as they are 

 fTxhumed at a greater distance from the surface. 



Again we often find, as is so well shown in Pennsylvania, that all the rock 

 strata or layers, which, of course, must have been horizontal when first dropped 

 from the grasp of the ocean waves, have been folded or lifted up by some 

 mighty force as we might fold or push up the centre of many sheets of paper. 



