248 REPORT— 1867. 



Exp. III. — Bar of Steel from Messrs. John Brown & Co. Mark on 



bar, "B3." 



Before experiment. After experiment. 



Height of specimen 1-002 inch. -832 inch. 



Diameter of specimen -72 inch. .... -748 inch. 



Area of specimen -40715 sq. in -43943 sq. in. 



No, 



of 



Exp. 



Weight laid 



on 



specimen. 



tons. 



16-713 

 20-074 

 23-288 

 26-316 

 29-474 

 32-649 

 35-809 

 39-345 

 41-000 



Weight laid 



on per square inch 



of section. 



lbs. 



91951 

 110440 

 128124 

 144786 

 162516 

 179722 

 197023 

 216465 

 225568 



tons. 

 41-049 

 49-303 

 57-198 

 64-637 

 72-391 

 80-233 

 87-952 

 96-636 

 100-700 



Compres- 

 sion, in 

 inches. 



•010 

 -015 

 •023 

 •029 

 •038 

 •067 

 •096 

 •155 

 •183 



Remarks. 



One very slight 

 crack of outside 

 skin. 



Besults. — Here the strain per square inch (PJ causing rupture is 225,568 

 lbs., or 100-7 tons ; and the corresponding elongation (\) per unit of length 

 is -183. By formula (13). — The -work (u) expended in producing rupture 

 = 20591. 



Exp. IV.— Bar of Steel from Messrs. John Brown & Co. Mark on 



bar, " B 4." 



Before experiment, After experiment. 



Height of specimen 1-01 inch. -739 inch. 



Diameter of .specimen -72 inch. .... -781 inch. 



Area of specimen -40715 sq. in ^47783 sq. in. 



-030 

 •035 

 •053 

 •079 

 -108 

 •157 

 •206 

 •255 



•293 



No cracks. 



Results. — Here the strain per square inch (P^) causing rupture is 225,568 

 lbs., or 100-7 tons ; and the corresponding compression (?J per unit of length 

 is -293. By formula (13). — The work (t() expended in producing rupture 

 =32968. 



