LIVING TORPEDOS IN BERLIN. 511 



and Halske, each of which has a resistance of 10,000 Siemens 

 Units, and the coils of which are wound so as to be free from 

 induction, as this might perhaps not be without importance here. 

 By closing and opening a rubbing key which bridged the rheostat, 

 its resistance was excluded or admitted at pleasure. I so conducted 

 the experiment, that I sent through the preparation alternately a 

 current of few Groves without the great additional resistance and 

 one of many Groves with this resistance, and repeated it in homo- 

 dromous and heterodromous direction alternately; the number of 

 the Groves and the additional resistance being so arranged, that the 

 current without resistance did not too much exceed that with 

 resistance. Series such as the following were obtained, in which 

 the notation requires no further explanation 1 . There were 50 turns 

 for the galvanometer P, and 5000 turns for the galvanometer /S at 



zero distance. 



I. 



2. Torp. Fresh. L. 19 mm. OC + 0-0128. i' Per. 

 CT o 



X. 8. I -410 I +155 | -210 | +20 II XXX. t +59 | -32 | +29 | -io II 

 P. 1 114 | 143 j 115 | 141 || I 75 | 74 | 78 | 77.5 j| 



Without additional resistance. With resistance. 



I -63 t +9 I -5i t +8 

 4, 118 | 143 i 118 j 149 



Without resistance. 



II. 



New Preparation. C + 0-02 24. i' Per. 

 The same period of closing. 



X. S. t +100 | -92 t +141 I -3i [ XXX. t +80 I -55 t + 52 | -37 j| 

 P. | 187 i 146 | 184 i 148 II I 82 i 80 | 82 j 81.5 || 



Without resistance. With resistance. 



X. t +57 I -57 T - I -34 

 | 184 | 156 I 188 I 157-5. 



Without resistance. 



III. 



7. Torp. Second day. OC reversed, 0-0031. i f Per. 

 The same period of closing. 



X.-S. t +88 I -35 f +70 | -65 || XL.-t +39 I -<*3 t +I 5 | -77 || 

 P. 1 134 i 189 | 119 I 94 I] I 92 I 88 | 90-5 | 89-5 H 



Without resistance. With resistance. 



X. t +26 I -42 I ( -Trace -38 



| 1+7 



I 105 I 95-5 I !4-5 4 94-5 

 Without resistance. 



These series fulfil the condition laid down, with sufficient exact- 



1 For explanation see Appendix to No. XII. 



