220       M.  E.  Edlund's  Researches  on  the  Electromotive 
Calculating  these  experiments  in  the  usual  way,  we  obtain 
£=0-1419  and 
a =2093. 
The  two  following  experiments  were  made  with  15-minute 
intervals  between  the  observations. 
Exp.  31.  Intensity  =  tan  36°. 
Exp.  32.  Intensity  =  tan  20°. 
Deviations. 
Deviations. 
10-03 
6-80 
9-48 
4-78 
10-80 
5-90 
10-40 
5-38 
9-58 
Mean  .  .  572 
Mean  .  .  10-06 
Hence  we  obtain  £  =  0'8067  and  a,=16-53. 
The  passage  of  the  positive  current  from  lead  to  copper  occa- 
sioned a  cooling. 
Copper-Bismuth. 
Exp.33.  Intensity  =  tan  8°  20'. 
Deviations. 
11563 
111-50 
116-78 
Mean  .  .  114*64 
Exp.  34.  Intensity  =  tan  12°. 
Deviations. 
157-65 
174-95 
179-98 
Mean  .  .  170-86 
Exp.  35.  Intensity  =  tan  5°  15'. 
Deviations. 
75-65 
71*78 
62-90 
Mean     .     .     70*11 
Calculating  these  experiments  in  the  usual  way,  we  obtain 
£=0and*=783-l. 
If  we  calculate  with  this  value  of  a  the  deviations  for  the  dif- 
ferent intensities  of  the  current,  and  compare  the  results  with 
the  observed  deviations,  we  obtain  : — 
Observed.  Calculated. 
114-64         114-71 
170-86        166-45 
70-11         71-96 
That  /3  was  here  =0,  and  consequently  the  deviations  propor- 
tional to  the  intensities  of  the  current,  results  doubtless  from 
the  intensities  being  relatively  small.  Hence  the  heat  developed 
in  the  wires  is  a  minimum,  and  the  excess  of  temperature  in  the 
