78 



RECORD AND RESULTS OF 



The observations on November 26 and 27, 1860, will be omitted in the following 

 table owing to the break in the series on the 26 th, and the incompleteness on the 

 27th. 



The first two readings, December 24, 1860, require to be changed to conform to- 

 the readings of the day; these readings, after conversion, are 33°.71 find 33°.71; 

 they have been changed into 27°.42 and 27°.42 by the following process of inter- 

 polation: If we compare the readings December 24 at 10'', 11, 12, 1, 2, 3'', with 

 the readings at the same hours on the three days of observation preceding, we find 

 the corrections — 6.31, — 6.47, — 6.64 to be applied to the latter to produce the 

 series on December 24, and applying these quantities to the readings at 9 A. M., 

 we find for that hour, December 24, 26°. 96. Again, the mean reading at 9 A. M., 

 before the break from 5 observations, is 33.34, and from 8 observations, after the 

 break, 27.48, difi'erence — 5.86 ; and applying this to the actual reading December 

 24, 9 A. M., we find the value 27.85 ; the mean of these two values is 27.40. By 

 the same process for 8 A.M., we find 27.44, the mean 27.42 is given in the table. 

 The break in the series amounted therefore to 6°.29, 



The value for noon, February 18, is the mean of the Values for IIP. M. and 1 

 P. M. ; the instrument does not appear to have been permanently disturbed. The 

 incomplete readings of February 25th are omitted. 



Hourly readings of the declinometer at Port Foulke, expressed in degrees and 

 fraction ; increasing numbers denote a movement of the north end of the magnet 

 towards the east. 



I860 



Dec. 



Deo. 



Dec. 



Dec. 



Deo. 31 



Jan. 



Jan. 



Jan. 



Jan. 



Feb. 



Feb. 



Feb. 



March 



1861 



3-4. 



12-13. 



18-19. 



24-25. 



Jan. 1. 



7-8. 



14-15. 



21-22. 



28-29. 



4-5. 



11-12. 



18-19. 



4-5. 



8 A.M. 



33.031 



33°.91 



33°.86 



27°.42 



27°.53 



270.68 



270.63 



270.34 



270.53 



270.64 



270. 06 



270.11 



27°.88 



9 " 



33.24 



33.89 



33.17 



27.42 



27.53 



27.68 



27.71 



26.95 



27.51 



27.66 



27.49 



27.32 



27.70 



10 " 



34.n 



33.87 



33.64 



26.73 



27.32 



27.70 



27.49 



27.08 



27.19 



27.68 



27.46 



27.42 



27.63 



11 " 



33.92 



33.86 



.3.3.76 



27.38 



27.34 



27.71 



27.58 



27.10 



27.25 



27.68 



26.62 



27.36 



27.65 



Noon 



34.07 



33.86 



33.63 



27.72 



27.51 



27.80 



26.70 



27.12 



27.00 



27.17 



27.56 



26.93 



27.24 



1 " 



34.02 



33.87 



33.73 



27.51 



27.08 



27.64 



26.65 



27.30 



27.32 



27.41 



26.99 



26.50 



27.32 



2 " 



34.13 



33.92 



33.56 



27.52 



27.32 



27.66 



27.01 



27.41 



27.27 



27.02 



27.30 



26.35 



27.19 



3 " 



34.00 



33.92 



38.81 



27.64 



26.97 



27.61 



27.08 



27.46 



27.75 



26.97 



27.46 



26.89 



27.17 



4 " 



34.13 



33.84 



33.73 



27.71 



27.41 



27.66 



27.34 



27.39! 27.73 



27.21 



27.19 



27.30 



27.21 



5 " 



34.22 



33.87 



33.84 



27.78 



27.63 



27.59 1 27.14 



27.59 



27.78 



27.59 



27.34 



27 19 



27.47 



6 " 



34.00 33.86 



3.3.76 



27.80 



27.71 



27.61 



27.49 



27.68 



27.80 



27.70 



27.78 



27.21 



27.70 



7 " 



34.20 33.89 



33.96 



27.85 



27.76] 27.66 



27.80 



27.92 



27.89 



27.68 



27.73 



27.56 



27.76 



8 " 



34.37 



33.92 



34.01 27.90 



27.85 27.73 



27.76 



27.94 



27.84 



27.83 



27.86 



27.64 



S7.68 



9 " 



34.41 



33.94 



34.04 



27.97: 27.90 127.88 



27.90 



28.04 



27.84 



27.91 



27.81 



27.66 



27.91 



10 " 



34.41 



33.96 



34.16 



27.98' 27.78 i 28.13 



28.03 



27.87 



27.84 



28.01 



27.98 



27.58 



27.89 



11 " 



34.42 



33.97 



34.13 



27.97 ' 27.78 28.08 



27.92 



27.89 



27.84 



27.92 



27.91 



27.78 



27.83 



Midn't 



34.39 



33.99 



34.04 



27.98 



27.88 1 28.13 



28.07 



27.89 



27.91 



27.83 



28.29 



28.07 



27.94 



1 " 



34.46 



33.99 



33.97 



27.92 



27.83: 28 13 



28.07 



28.01 



27.80 



27.87 



28.54 



27.54 



27.88 



2 " 



34.47 



33.99 



33.84 



27.88 



27.85: 28.07 



28.02 



28.18 



27.81 



28.03 28.01 



27.44 



27.91 



3 " 



34.46 1 33.99 



34.01 



27.83 



27 83: 28.22 



28.20 



28.37 



27.89 



28.26 1 27.99 



27.42 



27.93 



4 " 



34.44 



33.99 



34.18 



28.03 



27.73! 27.93 



27.85 



28.35 



27.84 



28.08 27.44 



27.46 



27.76 



5 " 



34.37 



33.97 



34.04 



28.05 



27.75 i 28.10 



27.70 



28.28 



27.78 



28.09 27.73 27.51 



27.54 



6 " 



34.42 



33. 94 



3.3.86 



28.07 



27.73: 27.98 



27.61 



27.87 



27.75 



27.70 ' 27.68 27.37 



27.70 



*? " 



34.37 



33.87 



33.94 



27.88 



27.68: 27.82 



27.58 



27.63 



27.75 



27.72 27.58 27.25 



27.76 



8 " 



34.36 



33.87 



3.3.86 



27 68 



27.70 27.75 



27.85 



27.37 



27.73 



27.56 27.32 26.84 



27.81 



