OP ARTS AND SCIENCES. 



467 



TABLE IV. — Dec. 26, 1884. 

 Iron magnetic. 15° C. Heated to red heat and allowed to cool slowly. 



TABLE v. — April 18, 1885. 

 Iron m.agnetic. 18° C. Hardened. 



TABLE VI. — April 20, 1885. 

 Iron masrnetic. 20° C. Softened. 



