Price] 1^0 [Dec 16, 



For the taking of the above stones I had, as far as known, the permission 

 of the owners or tlieir representatives, and for them the University of 

 Pennsylvania and citizens owe thanlis to the City of Philadelpliia, to 

 William Baldwin, Chief Commissioner of Highways, George S. Harris, 

 Dr. Twaddell, J. Clothier, L. Dolby, Samuel C. Bunting, Jr., Albert 

 S. Letchworth and others, who gave them these valuable objects of 

 curiosity and science without charge. The hunting, hauling and building 

 them into a Rockery has been my occupation, with men and carts taken 

 from my quarry for one day or more of the week, from the beginning of 

 June to the end of December, 1881. The purpose of gathering these rocks 

 has been for their preservation, and convenience of study by professors and 

 students, and all interested in the important questions to which they give 

 rise. 



What do these rocks say to us here to-day ? Plainly they show the 

 minerals they contain. But we go back from these to the period of 

 primary rocks, to the granites and other igneous rocks, whose melting and 

 moving power was fire, and whose disintegrations furnished the material 

 for the stratified rocks deposited by later pervading waters ; and these also 

 again, becoming disintegrated by frost, heat and water, also became 

 modifying and different sources for their last granular depositions in 

 strata. We have here from the quarries gneissic rocks, the first strata of 

 the secondary formation ; and we have the transported rocks, also de- 

 posited by water, consisting of materials that have undergone many changes 

 of stratification and re-stratification as well as of attrition. 



In the study of these rocks we pass from a time when no life was on this 

 globe into periods since the beginning, spoken of in the first verse of 

 Genesis, wherein all life has been created ; and therein perceive the 

 methods of the Creator in the structure of this globe. 



The transported rocks demand special explanation. We ask to know 

 what are their compositions ? What their names ? Where were they in 

 the regular order of the geological stratification? Where geographically? 

 How were they torn from their places? How transported to where found 

 round our University? How polished? How lifted upon the hills ? Had 

 we really a great "continental glacier" to bring them here ? Was the 

 world made, peopled, civilized for the repetition of the disaster of the 

 "Great Glacier "? 



These are some of the questions for the mineralogists and geologists, in 

 and out of the University, to answer : it is hoped that they may long 

 incite to interesting and useful study. The objects are the oldest, but the 

 questions are of new presentation. 



Charles E. Hall, of our State Geological Survey, began to observe some 

 of these rocks in 1875, and has partially answered the above questions, 

 according to his observations and convictions at that lime., (See Proceed- 

 ings Amer. Philos. Soc, No. 95, Nov. 1875, p. 633.) He followed Agassiz, 

 Lyell, Geikie, Croll, Dana and Newcomb in placing the south line of the 

 great continental glacier at and below the 40th degree of north latitude. 



