Mr. R. H. M. Bosanquet on Permanent Magnetism. 257 











Table 



(continued). 











! n 

 463 



r{n) 



TO) 



3 2 



7T 2 



n 

 476 



Tin) 



192 



T(») 



3 2 



7T J 



n 

 489 



r{n) 

 324 



TOO 



3 2 



— n 



IT 2 



462 



65406 



65160-36 



68964 



68870-85 



72872 



72681-07 



464 



224 



65630 



65442-14 



477 



312 



69276 



69160-52 



490 



168 



73040 



72981-65 



465 



240 



65870 



65724-52 



478 



238 



69514 



69450-81 



491 



490 



73530 



73279-84 



466 



232 



66102 



66007-51 



479 



478 



69992 



69741-70 



492 



160 



73690 



73578-63 



467 



466 



66568 



66291-11 



480 



128 



70120 



70033-20 



493 448 



74138 



73878-04 



468 



144 



66712 



66575-31 



481 



432 



70552 



70325-31 ! 



494 



216 



74354 



74178-05 



469 



396 



67108 



66860-13 



482 



240 



70792 



70618-03 ! 



495 



240 



74594 



7447867 



470 



184 



67292 



67145-55 



483 



264 



71056 



70911-35 



496 



240 



74834 



74779-90 



471 



312 



67604 



67431-58 



484 



220 



71276 



71205-29' 



497 



420 



75254 



75081-73 



472 



232 



67836 



67718-22 



485 



384 



71660 



71499-83 1 



498 



164 



75418 



75384-18 



473 



420 



68256 



68005-46 



486 



162 



71822 



71794-98. 



499 



498 



75916 



75687-23 



474 



156 



68412 



68293-32 



487 



486 



72308 



72090-73 



500 



200 



76116 



75990-89 



475 



360 



68772 



68581-78 



488 



240 



72548 



72387-10 











XXXVIII. On Permanent Magnetism. 

 By R. H. M. Bosanquet, St. John's College, Oxford. 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 



I HAVE succeeded in completely determining, to a mode- 

 rate approximation, all the quantities involved in the 

 experiment mentioned in my paper in the March number of 

 the Philosophical Magazine. I propose to give a short sum- 

 mary of the results, reserving a more complete account for a 

 future occasion. 



The external or air resistances were determined by magne- 

 tizing, in the bifilar, arrangements of soft iron similar to the 

 steel. The resistance of the soft iron is small, and is allowed 

 for by Rowland's table. The total resistance is the quotient 

 of ihe magnetomotive force, (47rC?i), by the magnetic induc- 

 tion 23. 



A set of 18 pieces of soft iron similar to the pieces of the 

 compound magnet gave for the total resistance of each piece 

 •454 centim. 



53 = 116 gives from Rowland's table /*= about 400, whence 



— —- = -004 is to be subtracted, and we have for the air resist- 

 ance -450 centimetre, or *47 R. (R is not quite the same in 

 the iron and steel.) 



A long piece of soft iron, similar to the whole magnet joined 

 up, gave 



Total resistance ='339 centim. 



