Proceedings of the American Academy of Arts and Sciences. 

 Vol. XLVI. No. 3. — September, 1910. 



CONTRIBUTIONS FROM THE JEFFERSON PHYSICAL 

 LABORATORY, HARVARD UNIVERSITY. 



THE MAGNITUDE OF AN ERROR WHICH SOMETIMES 



AFFECTS THE RESULTS OF MAGNETIC TESTS 



UPON IRON AND STEEL RINGS. 



By B. Osgood Peikce. 



