by a particular case of Magnetic Action. 327 



magnet only in position) was 4° 38 / . As respects change of the arc, 

 it will be noticed that, as the distance is decreased, there is a 

 marked decrease of arc when the magnets attract, but a very 

 slight tendency to increase when the magnets repel. 



As respects change of rate, it appears, for a given distance of 

 magnets, that when the adjacent poles were similar, the clock 

 was not retarded to the same extent to which it was accelerated 

 when the poles were unlike. The ratio between the two appears 

 to be somewhat similar to the ratio between the two correspond- 

 ing changes of arc noticed above. 



It will be seen that the distances between the magnets in the 

 different trials were not the same : the fixed magnet was placed 

 at about the desired distance from the pendulum-magnet, and 

 the exact distance afterwards accurately measured. In conse- 

 quence of this a direct comparison of results for a given distance 

 is not possible with the numbers only as given in the preceding 

 Table. To obtain such comparison, the numbers of that Table 

 were laid down graphically, taking the distance of magnets for 

 abscissa, and change of rate as ordinate : curves were then 

 drawn to include all the points. The following Table contains 

 the numbers read off from these curves : — 



Distance 



Lower pole of fixed magnet. 







S. 



N. 



N. 



s. 



between 















adjacent 

 poles of 



Upp 



;r pole of p 



?ndulum-ma 



gnet. 



Mean values 



magnets. 



S. 



S. 



N. 



N. 



of columns 

 3 and 5, 



1 



of columns 

 2 and 4, 













Inci 



ease of hou 



rly gaining i 



ate. 



attraction. 



repulsion. 



in. 



005 



-2 04 



+ 6-25 



s. 



1 -244 



+5-55 



+5-90 



- 2-24 



0075 



— 1 99 



+4-98 



i -237 



+4 35 



+4-67 



-2-18 



010 



-1-94 



+ 4-40 



; -230 



+3-79 



4-410 



-2 12 



0125 



-1-89 



+4-02 



-2-23 



+3-41 



+3-71 



-206 



0-15 



-1 84 



+3-73 



-2-16 



+313 



+3-43 



-200 



0175 



-1-79 



+3-48 



-209 



+2-94 



+3-21 



-1-94 



020 



-1-74 



+326 



-202 



+2-80 



+3-03 



-1-88 



0-25 



-1-63 



+ 2-90 



-1-88 



+2-57 



+273 



-1-76 



30 



-1-52 



+ 2-59 



— 1 75 



+2-36 



+2-47 



-1 64 



0-35 



-1 41 



+233 



-1-64 



+2-16 



+2-24 



-I 52 



0-40 



-1-31 



+ 2 12 



-1-54 



+ 1-97 



+ 205 



-1-42 



0-45 



-1-22 



+ 1-94 



-1-44 



+ 1-80 



+ 1-87 



-1-33 



0-50 



-115 



+ 179 



-1-35 



+ 1-66 



+ 1-73 



-1 25 



0-60 



-102 



+ 1-52 



-119 



+ 1-42 



+ 1-47 



-110 



0-70 



-090 



+ 1-29 



-105 



+ 1-21 



+ 1-25 



-0 97 



0-80 



-078 



+ 111 



-092 



+ 1-04 



+ 107 



-0-85 



0-90 



-0-67 



+096 



-0-80 



+0-90 



+ 0-93 



-0-74 



1-00 



-0-58 



+0-82 



-070 



+0-77 



+ 080 



-0-64 



1-20 



-0-44 ! 



+0-61 



-0-54 



+0-57 



4-0-59 



-0-49 



1-40 



-0-33 



+0-45 



-0'42 



+0-43 



+0-44 



-0-38 



1-60 



-025 1 



+0-34 



-0-33 



+0-34 



+034 



-0-29 



1-80 



-020 i 



+026 



-0-27 



+0-28 



+027 



-0-24 



200 



1 



-017 

 2 



+ 20 



-0 23 



+ 0-23 



+0-22 



-0-20 



~~3~ 



4 



5 



6 



7 



Z2 



