90 Evolution of the Earth. 



Vermont. In the latter State, we visited several of the 

 famous marble quarries, which furnish its people with one 

 of their leading industries. In one of these quarries, at 

 West Rutland, my friend descended three hundred feet be- 

 low the surface, — farther than I cared to climb in an Aug- 

 ust day. On either side through the whole distance were 

 continuous layers of marble, the foundations of which had 

 been built up during the patient centuries out of minute 

 organic remains — the skeletons, so to speak, or the shells 

 rather, of once living animals. Subsequently, the limestone- 

 thus formed was structurally metamorphosed by the action 

 of heat,* so that the evidences of organic life were destroyed. 

 How much deeper the vein extended, I do not know. This 

 formation, in many places, reaches a depth of 2000 feet. 

 These vast beds of limestone and marble, therefore, now 

 just beneath the sloping sides of the Green Mountains, sev- 

 eral hundred feet above the level of the sea, and elsewhere 

 widely distributed over the earth, were formed of deposits 

 Avhich originally lay on the very bed of the ocean. How 

 can we estimate the time required to effect such a transform- 

 ation ? The deposit, through slow-creeping ages, of the 

 shells, their consolidation into rock, the change of structure 

 by the action of heat, if the material be marble, the grad- 

 ual upheaval of the ocean-bed, the elevation of the moun- 

 tain ranges, the slow accumulation of soil above the rock: 

 — verily, "the more thou searchest, the more shalt thou 

 wonder." The great Pyramids of Egypt, the oldest and 

 most enduring products of human art, are built of lime- 

 stone. They embody the results of the patient energy of 

 untold millions of living creatures, besides their human 

 architects and builders. 



Take a little ooze from the bottom of the ocean, dry it 

 and examine it through a microscope, and you will discover 

 that what appeared to be small grains of dust, are so many 

 minute shells — some of them broken, but many of them 

 perfectly formed, all of them of most delicate and symmet- 

 rical proportions. These shells are called Foramenifera. 

 They are crowded together, millions upon millions of them, 



* The Vermont marble is a crystalline limestone, from which all direct ev- 

 idences of animal remains have been destroyed; it is assigned, however, to the 

 lower Silurian or Cambrian division of stratified rocks, and has been identified 

 as belonging to the Chazy limestones of that geological period, of organic ori- 

 gin. Some crystalline limestones may have been formed by chemical processes, 

 without organic intervention. 



