MAGNETIC OBSERVATIONS. 



95 



The horizontal force X, and the magnetic moment m of magnet Z 6\ are obtained 

 from the formulae 



T' X ^ 



0-» 



* In addition to the above observations at Washington, I have made the following with the 

 magnets exchanged, from which we obtain an independent result. 



Experiments op Depiections. June 14, 1862. Magnet Z 1 deflecting at right angles to magnet 



Z 6 suspended. Deflecting distance 1-.3 foot (correction + 0.0003). 



The record and order of observations are the same as in the set of deflections given in the 



text, and are here given in a more condensed form 



Set 1. 













11 



■51" 





Temp. 86° Fah. 



U1° 48' 20 ' 

 E. E. 247 49 20 



50' 

 50 



19" 

 30 



w. 



242° 

 242 



13' 

 14 



48"' 

 10 



14' 

 14 



25" 

 50 



2u =5° 35' 16".2 



247 48 40 



50 



20 

























242 



12 



00 



12 



45 





247 48 25 



49 



20 



w. 



242 



10 



00 



•10 



30 





W. E. 247 47 20 



48 



20 





242 



10 



00 



10 



50 



2i«=5 37 20.3 



Line of detorsion 211° 













1" 25" 



Temp. 80° 



Set 2. Distance 1 



foot. 











Ih 40m 



Tgmp. 91° 



251° 06' 10" 

 E. E. 251 07 00 



06' 

 08 



40" 

 00 



w. 



238° 

 238 



51' 

 51 



00" 

 00 



51' 

 51 



20" 

 40 



2« = 12° 10' 22" 



251 08 30 



09 



20 

























238 



57 



10 



57 



00 





W. E. 251 12 00 



13 



00 



w. 



238 



57 



00 



58 



20 



2m = 12 15 12 



251 12 59 



14 



00 





238 



58 



00 



59 



20 

















2 



•40"; 



at temp. 92° 



From these deflections we find P ■■ 



-0.01365 and Ig — = 8.73381 



Experiments op Vibration. June 16, 1862. 



Magnet Z 1 suspended. 



Temp. 



No. of 







vib'ns. 



Time. 







5" 17" 



52'. 



20 



20 



23.5 



40 



22 



55.8 



60 



25 



27.0 



80 



27 



58.8 



100 



30 



30.3 



150 



36 



49.0 



170 



39 



21.8 



190 



41 



52.5 



210 



44 



24.0 



230 



46 



55.8 



250 



49 



27.8 



70-: 



■72'= 



Inertia rin 



Extreme 



scale 

 readings. 



240 

 and 



365 



C. Chronometer 1287, gains 6' a day. 



265 

 and. 

 330 



150 vibrations 

 at 710. 



Mean 



18" 57'.0 

 58.3 

 56.7 

 57.0 

 57.0 

 57.5 



18 57.25 



Observed time of 150 vib'ns, 1137'-25 

 Time of one vibration, 7.5816 



Correction for rate, — 0.0004 



7.5812 

 and when corrected for torsion and 

 referred to 89°. 7 Fah. 



/(7r.= = 1.76132 



