308 Mr. R. H. M. Bosanquet on Electromagnets. 



Bars with P.P. (pole-pieces) with Magnetizing-Force term. 



log n = 1-08160, 



H=A= 69f^ + B-isVcos8, log- =2-57346, 



log/= -16878. 



1 

 33. 



(i. 



Diffs. 



P- 



Diffs. 



Calc. 



Obs. 





Calc. 

 •00589 



Obs. 

 •00593 



-•00004 



0,000 



297 



293 



4- 4 



1,000 



894 



855 



4- 39 



•00364 



•00369 



-•00005 



2,000 



1384 



1250 



4-134 



•00324 



•00332 



-•00008 



3,000 



1767 



1639 



4-128 



•00309 



•00313 



- 00004 



4,000 



2056 



2041 



4- 15 



•00301 



•00301 



•ooooo 



5,000 



2250 



2222 



4- 28 



•00296 



•00297 



- -ooooi 



6,000 



2358 



2381 



- 23 



•00294 



•00294 



•ooooo 



7,000 



2389 



2381 



4- 8 



•00234 



•00294 



•ooooo 



8,000 



2351 



2381 



- 30 



•00294 



00294 



•ooooo 



9,000 



2249 



2326 



- 77 



•00296 



•00295 



4- -ooooi 



10,000 



2091 



2174 



- 83 



•00300 



•00298 



4- -00002 



11,000 



1882 



2041 



-159 



00305 



■00301 



4- -00004 



12,000 



1627 



1754 



-127 



•00313 



•00309 



4- -00004 



13,000 



1339 



1408 



- 69 



•00327 



•00323 



4- -00004 



14,000 



1021 



1031 



- 10 



•00350 



•00349 



4- -00001 



15,000 



707 



595 



4-112 



•00393 



•00420 



-•00027 



16,000 



451 



300 



4-151 



00473 



•00585 



-•00112 



17,000 



179 



207 



- 28 



•008 L0 



•00734 



4- -00076 



18,000 



118 



118 







01102 



•01103 



- -ooooi 



Many rings have been completely examined in my various 

 papers. It is a matter of interest to what extent these sup- 

 port the position that there is an absolute saturation limit, 

 and to what extent they oppose it. 



First, as to Rowland's own measures of the one ring which 

 he examined completely. 1 have reduced them according 

 to my formula at Phil. Mag. xix. p. 340. Although the 

 magnetism is not carried very high, and the fitting has not 

 been as perfectly accomplished as in my more recent calcu- 

 lations, yet it is clear that there is no indication of variation 

 of the saturation limit. This generally shows itself in an 

 excess of the calculated values of fi in the region 33 = 15,000 

 -16,000. 



In all my own determinations the magnetism has been carried 

 up much higher ; and I think in some of the rings discussed 

 at Phil. Mag. xix. pp. 76-79 there is some appearance of this 

 kind. But I have repeatedly submitted nearly all of these to 

 calculation, with the result that the introduction of the variable 

 saturation limit, so as to fit the region in question, invariably 



