PRELIMINARY REMARKS ON GENERAL GEOLOGY. 



Any account of the Geology of Hingham would necessarily be 

 but of little service to the unscientific reader, unless preceded 

 by some remarks upon the several ruck formations of the earth 

 and the periods of their deposition. The advance of knowledge 

 respecting these has been so rapid that the very terms but re- 

 cently used to designate their relative age are not only obsolete to 

 a considerable degree, but often misleading. For instance, it is 

 not long since the word ' ; primitive " conveyed to all students the 

 idea that the rocks so designated, the granites, were the earliest 

 formed of all the earth's strata ; but now it is a well-recognized 

 fact that these have been produced in nearly all periods of geo- 

 logic time. All ideas based upon views taught in the books of 

 a past generation respecting Primitive, Transition, and Secondary 

 rocks should be dismissed from thought as being now but of 

 little or no significance. 



In order that the mind may be receptive of the grand ideas 

 which a knowledge of geological phenomena cannot fail to im- 

 part, it is necessary first of all to disabuse it of the narrow con- 

 ceptions of creation which have too long prevailed among men. 

 It must recognize the sublime truth that the great Power which 

 permeates and controls all matter has been for inconceivable ages 

 evolving from the chaos of things the innumerable worlds that 

 compose the universe ; and in fine must look upon the earth we 

 inhabit, with all its multitude of living and ever-changing forms, 

 as the result of the constant and never-ceasing action of creative 

 energy for not only thousands, but for very many millions of 

 years. 



The calculations relative to the age of the earth have been 

 based upon several grounds, — one astronomical, by estimates of 

 the time which would be required to reduce the sun from the dimen- 

 sions embraced within the orbit of the earth to its present size. 

 This Professor Newcomb makes 18,000,000 years. Add to this 

 the time which he concludes might have passed before the tem- 

 perature of the globe itself would have been reduced so as to 

 allow of the existence of water upon it, 3,845,000 years, and the 

 time estimated by him for the development of the several forma- 

 tions composing the earth's strata, which he embraces within 



