484 



Mr. J. L. W. Gill on the Distribution of 



a small error in placing the coil will give practically no error 

 in the result. 



Table II. 



No. and Description of 

 Specimen. 



1 



S" 



Bmax- 



B x . 



Bmax* 



Bmean- 



Bmean. ' 

 Bmax 



K. 



No. 1. 



51 



1088 



809 



•743 



775 



•713 



•571 



Specimen made up of 





6060 



4511 



•743 



4320 



•711 



•571 



transformer plate, 





10300 



7762 



•753 



7450 



•723 



•585 



section square ; 





12940 



9955 



•768 



9570 



•740 



•594 



0-991 X 0-991 centim. 





14160 



11200 



•791 



10800 



•767 



•621 



1=50 cm. ; d=l-12 cm. 

















No. 2. 



402 



2850 



2143 



•752 



2060 



•724 



•562 



Specimen of soft iron, 





4510 



3389 



•752 



3270 



•726 



•561 



section circular. 





6950 



5177 



•745 



4990 



•719 



•558 



£=30 cm.; d=-976 cm. 





9210 



6920 



•751 



6670 



• r /24 



•561 







12100 



9130 



•7o5 



8810 



•728 



•564 







14580 



11020 



•756 



10620 



■730 



•568 



No. 3. 



1323 



1995 



1502 



•754 



1434 



•720 



•582 



Specimen of soft iron, 





5070 



3764 



•744 



3601 



•710 



•577 



section square. 





7200 



5396 



•750 



5168 



•718 



•579 



l=bl cm. ; ^="700 cm. 





9130 



6865 



•752 



6578 



•720 



•581 







10940 



-8386 



•765 



8050 



•735 



•587 



No. 13. 



58 6 



3270 



2482 



•761 



2405 



•737 



•554 



Specimen made up of 





7370 



5710 



•775 



5460 



•742 



•550 



transformer plate, 





8600 



i -768 



8340 



•745 



•566 



section rectangular. 





14820 



11885 



•803 



11530 



•780 



•597 , 



•222x1-00 cm.; 1- 13 cm. 





15920 



13290 



•834 



1 



13000 



1 



•820 



•628 



I 



If we consider the conditions that will give these results it 

 will be seen that the conditions which will give one result 

 will also give the other. If the induction at different sections 

 of the specimen change proportionately, the results above 

 referred to must follow. From this hypothesis it follows that 

 the functions of the field representing the induction at 

 different sections are similar. The induction at any section 

 may therefore be represented by the equation 



B=K/{H), (2) 



K being a constant depending on the distance of the section 

 from the centre. 

 From equation (2) 



Bi M = I [(K,/(H))i- 6 + (K,flH))"+ . . . (K„/(H))i«] 



C/(fl)) 1 ' 



- (K 1 '' f 4K 1 w +...K,'-' 



