Table XL 



Distance 

 from 



No. of 

 sparks. 



Distance 



1 

 Micrometer Eeadings for contact. 





spark-gap 



ipart of the 







Remarks. 











to 



contacts. 



Make. 



Next 



Difif. 



Next 





contacts. 





2-5XHT 6 



Break. 



Make. 



480 





GO cm . 



3 



470 



670 



5xl0~ 6 



\ Thesereadingswere ! 













3-7 Xl0~ 6 





| taken after the con- j 





1 



, 



480 



630 



500 



\ tacts had been pressed 

















| home ; there was al- 





1 



5-0 xKT 6 



490 



620 



3-3 xlO" 6 



510 



J ways a bridge of loose 

 particles which were 





1 



510 



700 



4-7xl0" b 





thus pressed flat into 







, 











the contacts. 





1 



7-5x10 ° 



590 



no co 



lierence. 









1 



„ 



530 



940 



10 xio -6 









1 



10xl0~ 6 

 12-5 X10~ 6 



560 



920 



9 XlO" 6 





f A discharge in tele- 

 | phone at each spark, 

 ' but no coherence. 





10 



570 



no co 



herence. 









7-5 Xl0"" 6 







5 XlO -6 







1 



530 



730 







The next table is for Copper- Fuse-metal for strong steady 

 currents, no radiation. 



Table XII. 



m 

 Resistance 

 in circuit. 



Diff. between make and 

 break Xl0~ 6 cm. 



Remarks. 



1000 



none. 



E.M.F. in circuit is about 2 volts. 



200 



5 to 12*5 





100 



9 to 15 





50 



20 



i 



25 | these soon 



\ get less 

 36 J (oxide?). 



1 A pronounced "snap" occurs when 

 > the contacts are separated — not 

 J noticeable for the high resistances. 



The following is for Platinum-Platinum for strong steady 

 currents. 



Table XIII. 



Resistance 

 in circuit. 



Diff. between make and 

 break XlO" 6 cm. 



Remarks. 



5000 

 200 



100 



incomplete contacts. 



50, 19, 12*5, 7-5, 5, 



125, 9, 



19, 125, 10, 



42, 17, 



\ Between the first and second line 

 | was a pause of ^ min. ; between the 

 }► second and third a pause of 10 

 j mins. Each line shows some 

 ) "fatigue" and each pause some 

 recovery. 



