OF ARTS AND SCIENCES. 353 



Four liuudred and seventy-third nneetiiig. 



December 13, 1859. — Monthly Meeting. 



The President in the chair. 



Professor James Hall made a detailed communication upon 

 the fossil Crustacea of the genus Eurppterus, DeKay, its spe- 

 cies, and their geological relations ; illustrated by a full suite 

 of specimens, and by drawings. 



Professor Agassiz discoursed upon the morphology of ihe 

 genus Euri/pterus, and its place in the zoological system. He 

 considered it an undoubted member of the family to which 

 Trilobites belong, and of which the genus Limulus is the pres- 

 ent representative. 



Chief Justice Shaw read a paper upon the use of granite 

 as a building material, and upon the introduction of the 

 present mode of working it : — 



The discussions which have recently taken place respecting the Han- 

 cock House have revived my recollections of the history of stone masonry 

 and the use of gi'anite as a building material in Boston, and offer an oc- 

 casion for stating vrhat appears to me to have been an important dis- 

 covery in the art of w^orking granite within a comparatively brief period. 

 It was said, I believe, of a great man of antiquity, as one of his highest 

 claims to the gratitude of his countrymen, that he found the city of 

 brick, and left it of marble. We think that every one feeling just 

 sentiments of pride for the beauty, permanency, and grandeur of the 

 city of his home, in the taste and utility of its public and private 

 buildings, must take a deep interest in knowing the value, cheapness, 

 and excellence of the building materials within its power for practical 

 use. The vast number and magnificence of the granite buildings 

 recently erected in various parts of the city increases the interest we 

 naturally feel, in knowing the steps which have led to this extension 

 of the art, by which granite is brought into use. My main object is to 

 state a fact respecting it which I have never seen stated, which appears 

 to me to be not generally known, and which came to my knowledge 

 under such circumstances as to command my belief. 



It is believed that, although granite has always abounded near Bos- 

 ton, it was not till some time in the earlier part of the last century 



VOL. IV. 45 



