286 Peirce — Permeabilities and Reluctivities for Steel. 



ing the specimen completely. Investigation showed that 

 there were very slight differences of temper at different parts 

 of the rod, and it seemed best to have the iron thoroughly 

 annealed. This process increased the permeability for almost 

 all excitations, very materially, as a comparison of Tables III 

 and IV will show. 



Table IV. — Annealed Half-Inch Norway Iron Hod in Long 



Solenoid. 



H 



B 







H 



B 



















0-2 



190 







9 



5 14800 



0'5 



395 







10 



14940 



0-8 



1120 







11 



15100 



1-0 



2160 







12 



15360 



1-5 



4600 







14 



15540 



2-0 



6600 







16 



15700 



2-5 



8240 







18 



15900 



3-0 



9480 







20 



16040 



3'5 



10460 







25 



16320 



4-0 



11280 







30 



16520 



4-5 



11980 







. 35 



16740 



5-0 



12560 







40 



16920 



5-5 



13000 







45 



17100 



6-0 



13400 







50 



17220 



6'5 



13700 







60 



17450 



7-0 



13900 







70- 



17630 



7*5 



14100 







80 



17820 



8-0 



14300 







90- 



18020 



8-5 



14490 







100- 



18210 



9-0 



14660 







105- 



18300 



Table V. — Annealed Norway Iron Ho 



d in 3Iassive Y< 





(Free 



length about 80 mm 



) 



H 





B 





I 



295 





21120 





1657 



350 





21550 





1687 



400 





21850 





1707 



450 





22100 





1723 



500 





22220 





1729 



600 





22480 





1741 



700 





22630 





1745 



800 





22770 





1748 



900 





22880 





1749 



1000 





23000 





1750 



1500 





23500 





1751 



1800 





23810 





1751 



2000 





24010 





1751 



2350 





243 



so 





1751 



