Primary Capacity for Tesla Coils. 



69 



was at the middle, and 65 with the primary at the lower end 

 of the secondary. By means of these curves corrections 

 could be applied to the values of d due to change in L 21 

 caused by the removal of turns from the secondary coil. 



Table I. 



Primary coil over middle of secondary. 



Secondary terminals insulated. 



Primary spark-length = 1 mm. 



p. 



m( = L. 2 GJJj 1 C 1 ). 



n.J)i x . 



Max. distance 

 d in cm. 



0447 



0-740 



1-53 



65-0 ? 



0-166 



0-725 



1-52 



690 



0182 



0-694 



1-53 



670 



0-206 



0-588 



1-65 



63-7 



0-222 



0-608 



1-67 



58-0 



259 



0-553 



1-80 



48-5 



0-276 



0-551 



1-83 



480 



0-307 



0-420 



2-08 



40-0 



336 



0-447 



2-08 



290 



0314 



0-437 



2-10 



40-3 



0-368 



0-310 



2-43 



28-8 



0374 



0-294 



2-50 



23'0 



Table II. 

 Primary at lower end of secondary. 

 Lower terminal of secondary earthed. 

 Primary spark-length = 1 mm. 



k\ 



m(=L 2 C 2 /L 1 C 1 ). 



njn x . 



Max. distance 

 d in cm. 



0-115 



0-830 



1-48 



146 



0-138 



0-793 



1-50 



137 



0-154 



0-619 



1-61 



125 



0-170 



0-580 



1-71 



115 



0-181 



0-560 



1-73 



110 



0-200 



0-585 



1-73 



99 



0-226 



0-470 



1-89 



94 



0-247 



0-553 



1-87 



88 



0-237 



0-480 



1-92 



85 



0-266 



0373 



2-18 



77 



0-325 



0-250 



2-56 



63 



The results obtained are given in Tables I. and II. The 

 first column gives the values of P, the second the values of 

 m required to produce the maximum secondary potential, 

 and the third column the values of the frequency-ratio n 2 \n x 

 when the primary capacity was at the optimum value. The 



