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On Resistance to Electric Current 



632] Tube 14. 



[CALIBRATION OF TUBES.] 



col. = 2-45. 

 40-6 inc. = 28-5 gr. 

 4-26 = 3 gr. 



12-2 inches of tube next to bend contain \ part of 

 of that in col. 42-5 long. 



col. = 3-25 gr. 



4-67 



After it was measured 7 inches were cut off from straight end, and the 

 numbers in the first col. are the distances from the shortened end. A new bend 

 was also made 12-8 from new end, and the part where the tube is equal to tube 

 14 is at 10-3 from D. 



633] Jan. 1781. The following tubes were measured over again by intro- 

 ducing a col. $ and measuring its length in 3 different places, the beginning of 

 the I st col. being at J inch from bend, and the beginning of the second at the 

 end of the first. Another column was afterwards introduced whose length was 

 pretty nearly equal to the sum of the 3 former, and weighed. 



634] The two following tubes were measured by stopping up the end near 

 bend and weighing them with different quantities of $ in them, and measuring 

 the distance of the top of the column from straight end, whence it was found 



that in 



long beginning 1448 



at \ inch = 2777 



from bend 4033 



long beginning 270 

 at \ inch from 543 

 bend weighed 881 



14-8 



N 12 a col. 28-6 

 42-8 



3-17 



N 20 a col. 6-27 

 9.97 





