410 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



gen is necessary; that these are impurities as well as the sulphur 

 and phosphorus ; that in the manufacture of steel there is simply 

 a molecular change in the iron ; and that all that is necessary is 

 simply to subject the iron for a considerable time to a tempera- 

 ture just below the melting point, which will so separate the par- 

 ticles as to facilitate this molecular change. After it has once 

 taken that form, it cannot be brought back again to iron. Mr. 

 Dixon says that he will take wrought iron, and without adding 

 any carbon to it, will convert it into steel. 



Mr. Dibben said that he had wrought iron, bought as such, 

 • — Danamora iron, — containing carbon enough to be worked like 

 steel. 



Subject for discussion. — -The subject of " Steel and its uses," 

 was continued for discussion at the next meeting. 



On motion of Mr. Tillman, the Association adjourned, to meet 

 on the second Thursday in September, at 7^ o'clock. 



American Institute, Polytechnic Association, ? 



September 12, 1861. J 



Prof. Mason, on calling the Association to order, delivered a 

 brief and pertinent address, concluding as follows : 



The Farmers' Club and our own Association are now well 

 established, and growing branches of the American Institute, 

 from whose labors the public will justly expect results answer- 

 ing to the increased facilities provided for us, and th? additional 

 work laid out for our accomplishment. It is intended promptly 

 to complete the organization of this branch of the Institute. 

 And it is hoped that the members most active in past years will 

 be ready to continue their labors. 



the geological age of man. 

 Dr. R. P. Stevens said : One of the great lessons of modern 

 geology is that the earth, in its past history, has been the theatre 

 of countless generations of living beings ; that these living 

 organisms have appeared in regular sequence and order of pro- 

 gress from the lower to the higher in the scale of perfection. 

 This grand procession has had well defined eras, marked by the 

 predominance of certain forms of animals. The first has been 

 called the Era of Shell-Fish, when molluscs were the highest 

 types of animated nature. The second has received the name of 



