



MAGNETIC 



OBSERVATIONS 







Set 5. Deflections. Distance 1.3 foot 



B. 



E. 



30° 36' 30" 



37' 40" 



47° 



" 



W. 



7 20 40 



21 40 



45 



W. 



E. 



30 39 40 



40 10 



43 



" 



W. 



7 24 00 



24 40 



43 



105 



Mean 



44.5 



2u = 230 15' 55' 



2m = 23 15 35 



11= 11 37 53 



The mean result of set 1 and set 2 is 6.9654 at 47°, and of set 2 and set 3, 6.9653 

 at 46.5 ; if we correct these for torsion, and use Ig i^k (for Z 1) ^ 1.19212, and Igm, 

 (for Z 1) = 9.37310, the vibrations give X^ 1.355 and 1.355. For the deflections 

 we use Igm (for Z 6) 9.49164 and 9.49178 (the value of m being 0.310 at 50°) and 

 find jr= 1.349 and 1.372. The mean value of the four determinations is 1.358. 



The magnetic moment of Z 6 appears to be very nearly constant, which is due 

 to the age of the magnet; at 50° Fah. we have 0.308, 0.315, 0.311, 0.309, and 

 0.308 as found at Cambridge, Port Foulke, Netlik, Godhavn, and Washington, 

 respectively. 



Godhavn, Disco Island, Greenland. August and September, 1861. 

 Station in the garden at the rear of the Inspector's house. 





Set 1. Vibrations. 



Z 6 suspended. September 7, 1861. 







2" 28" 42= 



300 



2" 55" 25' 



26" 43'.0 





10 



29 34.5 



310 



56 19 



26 44.5 



Observed time of 



20 



30 28.5 



320 



57 12.5 



26 44.0 



300 vibrations, 1604».08 



30 



31 22 



330 



58 06 



26 44.0 



Time of one, 5.3469 



40 



32 15.5 



340 



59 00 



26 44.5 





50 



33 09 

 37 35.5 



350 

 200 



59 53.5 

 2 46 30 



26 44.5 





100 



26 44.08 







Arc: 207 and 4 



02 at 



Temperatu 



re, 38° 





261 339 " 200 



288 312 " 350 vib's. 



Set 2. Vibrations. Temperature, 38°. 









3'^ 28" 30 





300 





3^ 



55" 14' 





26"= 



44'.0 







10 



2« 24 



310 





56 07 





26 



43.0 



Observed time of 



20 



30 17 



320 





57 01 





26 



44.0 



300 vibrations, 1603'.58 



30 



31 11 



330 





57 54 





26 



43.0 



Time of one, 5.3453 



40 



32 04.5 



340 





58 48 





26 



43.5 





50 



32 57 

 37 25 



350 

 200 





59 41 

 3 46 19.5 



26 



44.0 





00 



26 



"T3758^ 





Arc : 185 and 425 at 













257 347 " 200 









280 320 " 3 



50 vib's. 









Set 3. Deflections. 



Z 1 suspended. 



Z 6 deflecting. 1 



Distance 1 foot. 



E. 



E. 



2440 20' 



40" 



21' 



40" 



46° 







" 



W. 



205 30 



40 



31 



40 



47 





2w = 39° 04' 10' 



w. 



E. 



245 16 



00 



17 



00 



47 









W. 



205 58 



00 



58 



20 



46 







E. 



E. 



244 19 



20 



20 



20 



46 







" 



W. 



205 28 



20 



29 



10 



46 





2W-39 58 20 



W. 



E. 



245 17 



50 



18 



40 



45 







" 



W. 



204 12 



40 



12 



40 



45 





















Mean 







. 46 





M= 19 45 38 



During the above set a strong wind was blowing which disturbed the magnet 

 a little. 



14 July, 1865. 



