132 



REPORT 1869. 



THIRD SERIES OF EXPERIMENTS. 



COMPEESSrVE STRAIN. 



Exp. I. (June 1867). — Bar of Steel from the Barrow Haematite Steel and 

 Iron Company. Mark on bar, " H 1." 



Before experiment. After experiment. 



Height of specimen -981 inch -784 inch. 



Diameter of specimen "72 inch -854 inch. 



Area of specimen -4071 sq. in -5728 sq. in. 



No. 



of 



Exp. 



Weight laid 

 on 



specimen. 



Weight laid 



on per square inch 



of section. 



Com- 

 pression, 

 in inches. 



Eemarks. 



1 

 2 



3 



4 

 5 

 6 



7 

 8 

 9 



lbs. 

 37438 

 44966 

 52166 

 58950 

 66022 

 73134 

 80214 

 88134 

 91840 



tons. 



16-713 

 20-074 

 23-288 

 26-316 

 29-474 

 32-649 

 35-809 

 39-345 

 41-000 



lbs. 



91951 

 110440 

 128124 

 144786 

 162156 

 179722 

 197023 

 216465 

 225568 



tons. 

 41-049 

 49-303 

 57-198 

 64-637 

 72-391 

 80-233 

 87-952 

 96-636 

 100-700 



•033 

 -042 

 -050 

 •066 

 •075 

 •100 

 •133 

 -187 

 -200 



No cracks. 



Results. — Here the strain per sqnare inch (Pj)causiug rupture is 225,568 lbs., 

 or 100-7 tons, and the correspond iug compression (/J per unit of length is -2. 

 By formula (13). — The work (m) expended in producing rupture = 22556. 



Exp. II. — Bar of Steel from the Barrow Haematite Steel and Iron Company. 



Mark on bar, " H 2." 



Before experiment. After experiment. 



Height of specimen -971 inch -498 inch. 



Diameter of specimen ^72 inch 1-066 inch. 



Area of specimen -4071 sq. in ^8922 sq. in. 



1 



2 



3 

 4 

 5 

 6 



^- 

 I 



8 

 9 



37438 

 44966 

 52166 

 58950 

 66022 

 73134 

 80214 

 88134 

 91840 



16-713 

 20-074 

 23-288 

 26-316 

 29-474 

 32-649 

 35-809 

 39-345 

 41^000 



91951 

 110440 

 128124 

 144786 

 162156 

 179722 

 197023 

 216465 

 225568 



No cracks. 



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

 or 100-7 tons, and the corresponding com.pression (l^ per unit of length is -IS. 

 By formula (13). — The work (m) expended in producing rupture = 50752. 



