230 Mr. J. P. Joule on the Effects of Mag)ietism, 8iX. 

 Experiment 11. Six-inch Pillar. Pressure 82 lbs. 



Experiment 12. Six-inch Pillar. Pressure 1380 lbs. Per- 

 manent magnetism of the pillar to begin with —0*6. 



A comparison of the last columns of the two preceding 

 tables will show that pressure has no sensible effect upon the 

 extent of the elongation. I had not sufficient voltaic force to 

 saturate the short bars, but there appears no reason to doubt, 

 that their elongation, when saturated, would be one-half that 

 of the pillars one foot long, just as the latter were found to 

 experience one-third of the elongation observed in the bars of 

 a yard long employed in the first section. I may remark in 



k 



