540 



Royal Society. 



i Date. 



Nature of Experiment. 



1873. 



; Number 

 Value of first | of 

 effect. I observa- 

 i tions. 



Mean effect,; 

 excl. of 

 first effect 

 ( — denote 

 decrease of 

 resistance). 



Dec. 17. 



„ 18. 



„ 19. 



1874. 



Jan. 7. 



9. 

 10. 

 12. 



13. 



14. 

 15. 

 16. 

 17. 

 20. 

 21. 

 22, 



24; 



26. 

 27. 

 28. 



29. 



30. 



31. 



2. 



3. 



4. 



5. 



6. 

 11. 

 12. 



13. 

 14. 

 16. 



17. 

 18. 

 19. 

 20. 



22. 



24. 



25. 



Feb, 



Metal key left in over nigbt taken out before off. on. off 



magnetism was put on (1) 0-f 34+17 



Metal key left in over night taken out before 



magnetism was put on (1) j 0+54+24 



Metal key left in over night taken out before I 



magnetism was put on (1) J 0+33—18 



The key was taken out before beginning the ex- j 



periments in the morning . No first effect 



The key was taken out before beginning the ex- j 



periments in the morning j Ditto 



The key was taken out before beginning the ex- j 



periments in the morning j Ditto 



The key was taken out before beginning the ex- j 



periments in the morning Ditto 



The key was not taken out until before mag- 

 netizing 0+47+18 { 



The key was taken out (same as Jan. 7) No first effect. 



The kev was not taken out (same as Jan. 12) ... 0+3—6 



Ditto 0+17+11 



The key was taken out (same as Jan. 7) No first effect. 



The key was not taken out (same as Jan. 12) ... 0+28 + 119 

 The connexions had been broken since Jan. 17 . No first effect. 



The key was taken out (same as Jan. 7) 0+7+1 



When the current was constant the key was taken 

 . out, but the magnet was not put on before the 



current had again become constant No first effect. 



The key had been left out since Jan. 22 Ditto 



Same as Jan. 22 Ditto 



Ditto Ditto 



The magnet was put on (2) from this day until 



Feb. 25 



The magnet was put on (2), key left in (same as 



Jan. 12) 0+102+47 



The magnet was put on (2), key left in (same as 



Jan. 12) I 0+219 



The magnet was put on (2), key left in (same as 



Jan. 12) 0+137+161 



The magnet was put on (2), key left in (same as 



Jan. 12) 0+ 47+84 



15 



30 



15 



15 



15 



15 



15 



15 

 Irregular 

 15 

 15 

 15 

 15 

 15 

 15 



15 

 15 

 15 

 15 



The key was taken out and put in after several 

 offs, same as Jan. 22 



The key was taken out (same as Jan. 22) 



A mercury interruptor was used instead of metal 



key 



The mercury interruptor was kept in over night 

 The mercury interruptor was kept in over night 

 New mercurial contact breaker from Elliott 



Brothers used 



Ditto key left in (same as Jan. 12) 



Ditto Ditto. 



One wire only was broken 



One wire only was broken, key left in (same as 



Jan. 12) 



One wire only was broken, key left in (same as 



Jan. 12). I 



One wire only was broken, key left in (same as j 



Jan. 12) j 



One wire only was broken, magnet on (1) 



No first effect 



No first effect. 

 0+7+3 | 



No first effect, 

 Ditto 

 Ditto 



Ditto 

 Ditto 

 Ditto 

 0+11 + 16 j 



No first effect.- 



Ditto 



Ditto 

 Ditto 



15 



15 

 15 

 15 



15 



15 

 15 



31 

 15 

 15 



15 

 15 

 15 

 15 



15 



17 



17 

 15 



-14 



- 9 



+21 



-17 



-19 



-13 



-20 



-18 

 action. 

 -19 



— 2 

 -67 

 —22 

 -44 



-13 

 -11 

 -33 

 -23 



-23 



+25 

 + 16 

 + 11 



+31 



'+"3 



- 3 



+ 3 

 -11 

 -36 



-18 



- 5 



- 7 



- 2 



-13 



12 



