184 Loom is — Effects of Changes of Temperature 



on 



mined by several previous observers in the room in which the 

 work was done ; and as there were no local disturbing iron 

 masses, that part of the building being kept free from iron, it 

 may be taken as within one half of one per cent of correct. 



Specimen Calculation. — Magnet No. 9. 



.Length at 18° C. 16'40 cm 



'Mass 3-609e rms 



Period of vibration at 11° C 10'435 sec 



Period of vibration at 99° C 10-812 sec 



L n -= 16-40(1—7X0-000011) _. 16'399 cm 



9 =16-40(1 + 81X0-000011) 16'414 cm 



L^+6 2 __ 3-609 (268-92 + 0-02) 

 - m 12 12 



L * 269 43 



80-883 



I 



w 



80-883 



81-034 



M. = 



M = 



268-91 



= 80-883 + 0-017 80-900 



= 81-034 + 0-017 81-051 



41 „V 4X80-9X98696 



T„ a H ~~ 108-889X0-2 

 4I 99 ' 7T 2 _ 4X81-051X9-8696 

 T 2 H ~ 116-899X0-2 



146-64 



136*80 



The results of this series of experiments are given in the 

 ... . M -M„„ 



s platted 



tauic . aim juguie ± 



as a function of the 



intensity 



;uivc 111 wiinju ,., 



of magnetization. 



Magnets of Sq 



uare Cross- Section. 



(0-l59 cm square). 



Number 



of 

 magnet. 

 3 



Length 



of 

 magnet. 

 21-53 



Moment 

 atll°C. 



M„ 

 232-92 



Moment 

 at 99° C. 



M 99 

 219-88 



M11-M99 



Mn 



0-056 



Intensity 

 of magne- 

 tization. 

 427 



5 



22-00 



207-08 



193-64 



0-065 



372 



9 



16-40 



146-64 



136-80 



0-067 



352 



15 



16-31 



139-76 



129-28 



0-075 



338 



4 



11-23 



94-76 



88-04 



0-071 



333 



6 



10-80 



72-41 



65-72 



0-092 



249 



7 



8-15 



43-04 



38-48 



0-105 



208 



8 



8-17 



40-48 



35-92 



0-112 



196 



13 



5-49 



16-72 



14-44 



0-141 



117 



12 



5-40 



1204 



9-84 



0-220 



88 



B. Experiments on the change in distribution due to change 

 in temperature. — The apparatus employed was suggested by 

 the late Prof. Henry A. Rowland, under whose direction the 

 investigation was conducted, and will be best understood from 

 the diagram in fig. 2. A and B are two cylindrical soft steel mag- 

 nets (Stubb's steel of the same temper as when purchased) 30'l cm 



