252 



A. Durward — Temperature Coefficients of 



ture might be sent in a constant flow. The magnetic field 

 about the magnetometer needle was in some cases weakened to 

 make the apparatus more sensitive. 



In measuring many seasoned magnets of a given size I have 

 often found, as has been already said, one or two magnetically 

 much weaker than the average, and these generally had very 

 large temperature coefficients. I have rejected all such as 

 being imperfectly hardened, and have assumed that magnets 

 having high moments and low temperature coefficients are rep- 

 resentative. Kesults obtained with such magnets give smooth 

 curves. 



Table V. 



Table VI. 





Crescent Polished Drill Rod. 



Crescent Polished Drill "Rod. 







Diameter, 



D-64 cm . 





Diametei 



■, 0-81 cm . 







Weight per cm. of length, 2*4 grams. 



Weight per cm. 



of length, 



3 -9 grams. 





o>>2 



2^ *tS 



05 

 09 





C0»O 



a"* 3 AS 



c3 



05 

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a ** 



£ 05 . 

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o cs a 



^a^S? 



2 °B 



05 





a- 



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« y a 

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05 



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££S 



+2 e 1- a> . 



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CD 



a 



a 

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a ° A 



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so 



°oin 

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05 

 05 



a 



a 

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o 



Bf«* 



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^ 2g 



S B *"."S2 



05 15'-) C3 



bc-^o as 



go'- 



a 



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■a°a 



o.'r p ^-^ 

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co a eS-C is 



II 



a 

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05 05 0> 



05 >. a _-^ 



05 P 



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1* 



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3 



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o O p 05 05 



a§ 



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^ 



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a o §S 05 

 2 a u a p 

 05 aS o,*j 



So 





<J 



s 



&H 





<J 



3 



H 



3 



5-0 



0-00114 



0-00057 



6 



13-0 



0-00087 



0-00077 



4 



7-0 



0-0009L 



000049 



8 



17-0 



0-00080 



0-00070 



5 



9-0 



0-00073 



0-00044 



10 



20-0 



0-00073 



0-00064 



6 



11-0 



0-00060 



0-00039 



12 



24-0 



0-00066 



0-00058 



8 



15-0 



0*00043 



0-00030 



15 



29-5 



0-00057 



0-00050 



10 



19-0 



0*00035 



0-00026 



20 



41-0 



0-00040 



0-00037 



12 



23-0 



0-00030 



0-00023 











15 



31-0 



0-00026 



0*00021 











20 



43'0 



0-00024 



0-00020 











