270 Mr. H. A. Rowland on Magnetic Distribution, 



not great. Hence between and 8 inches the resistance of the 

 bar, R, is greater than at succeeding points, and hence a less 

 number of lines of induction pass down the bar from 8 towards 

 than would be given by the formula, which has been adapted 

 to the average value of R at from 9 to 14 inches. In 

 Table II. this same fact shows itself towards the end of the 

 Table, and would probably be more prominent had the Table 

 been carried further. However, in this Table all things have 

 combined to satisfy the formula with great accuracy. 



Table III. 

 Bar *39 inch diameter. at end of bar. 



L. 



Q'e. 



Ob- 

 served. 



Q'e. 



Calcu- 

 lated. 



Error of 



Q'e. 



Q'. 



Ob- 

 served. 



Q'. 

 Calcu- 

 lated. 



Error of 

 Q'. 





 1 

 2 

 3 

 4 

 5 

 6 

 7 

 8 

 9 



10 

 11 

 12 

 13 

 14 

 15 

 16 



197 



163 



160 

 15-8 

 16-5 

 170 

 176 

 18-4 

 19-2 

 203 

 21 8 

 22-8 

 24-8 

 26-8 

 28-8 

 318 



152 

 153 

 15-5 

 15-9 



16 3 

 169 



17 6 

 18-4 

 194 

 205 

 217 

 231 

 247 

 265 

 28-4 

 30-5 



-45 

 -10 



- -5 

 -f "I 



- -2 









 + -2 

 + -2 



+ "3 



- 1 



- -3 



- -4 

 -1-3 



0- 



197 



360 



520 



67-8 



84 3 



101-3 



118-9 



1373 



156-5 



176-8 



1986 



221-4 



246-2 



273-0 



301-8 



333-6 







15-2 



30-5 



460 



61-8 



78-1 



95 



112-6 



130-9 



1503 



170-7 



192-2 



2153 



239-9 



266-4 



294-6 



325 1 





 -4-5 

 -5-5 

 -60 

 -60 

 -62 

 -6-3 

 -6-3 

 -6-4 

 -6-2 

 -61 

 -64 

 -61 

 -6-3 

 -66 

 -72 

 -8-5 



Q'e = 



= 7'6(10-° 3 



7L + 10— 



)37L ); Q / s 



= 89(10-° 3 ' 



7L -io-° 



37L ). 



In Table III. we come across a fact of an entirely different 

 nature from the above. Fig. 2 is the plot of this Table, and 

 gives the values of Q' e at different parts of the rod. 



Fig. 2. 



Distribution at end of bar. 

 The horizontal line in the figure represents values of L, 



