

Electric Arc with Varying Power-Supply. 



221 



Arc 



Continuous Current Arc. 



Alternating Current Arc, 



length . 

 Inches. 



















Volts. 



Amperes. 1 



Watts. 



M.S.C.P. 



Volts. 



Amperes. 



Watts. 



M.S.C.P. 



tV 



500 ! 



64 



318 



207 



39-8 



56 



221 



155 



1 o 



1 



46-3 



7-7 



355 



267 



37-8 



74 



268 



236 





44-7 



9 3 



417 



370 



37-4 



9-2 



344 



359 





45-1 



12 1 



544 



542 



(violent 



; hissing i 



? current increased) 





45-4 



16-3 



741 



777 













44-2 



201 



890 



1078 











1 3 

 32' 



50-5 



6-7 



336 



257 . 



47-5 



67 



317 



156 



48-9 



7-9 



384 



354 



405 



9-3 



378 



293 





48-0 



96 



459 



490 



39-7 



11-2 



442 



445 





47-0 



124 



583 



738 



, 39-8 



134 



533 



624 





46-4 



16-9 



786 



1119 



; 401 



160 



643 



855 





453 



20-9 



947 



1476 



40-7 



198 



807 



1104 



1 



53-5 



<r0 



323 



290 



43 8 



6-8 



299 



124 



8 



51-0 



7 - 5 



382 



390 



424 



8-6 



362 



241 





52-2 



92 



481 



609 



41-6 



103 



429 



297 





49-5 



123 



609 



901 



41-7 



125 



520 



477 





47-5 



16-8 



796 



1295 



42 1 



146 



616 



579 





47*0 



204 



961 



1761 



422 

 i 40-3 



18-8 

 201 



793 

 811 



846 

 977 



_3_ 



58-0 



57 



333 



237 



: 51 



4-9 



250 



80 



1 6 



546 



74 



386 



353 



! 48-2 



6-3 



304 



132 





52-1 



8-9 



462 



524 



1 45-4 



8-5 



384 



244 





51-2 



11-7 



599 



767 



435 



12-6 



547 



543 





48-8 



16-3 



796 



1219 



1 424 



15-8 



655 



712 





48-8 



20-2 



985 



1669 



42-2 



199 



837 



990 



1 

 4 



64-6 



6-8 



441 



410 



564 



46 



259 



87 



609 



8-7 



527 



683 



53-9 



54 



291 



154 





59-4 



122 



727 



1161 



50-6 



74 



360 



196 





55-9 



154 



863 



1532 



46-0 



107 



490 



432 





57-0 



194 



1104 



2210 



456 



159 



727 



863 



_5_ 



63-0 



8-7 



548 



549 



! 57-9 



8-3 



478 



270 



1 6 



60-8 



10-4 



632 



727 



56-3 



10-5 



617 



382 





59-0 



125 



728 



921 



53-6 



137 



735 



596 





58-5 



149 



871 



1284 



! 49 2 



17-5 



861 



797 





61-1 



18-8 



1150 



1900 



48 9 



21-7 



1062 



1024 



4 



672 



6-8 



459 



350 



1 57*7 



8-1 



470 



238 



1 



62-5 



9-0 



565 



557 



53-2 



11-3 



602 



446 



i 



624 



12-2 



760 



1130 



i 544 



141 



763 



720 



7 



65-8 



100 



655 



621 



I 56-8 



10-5 



593 



407 



1 6 



65-9 



11 -6 



762 



810 



56-6 



13-8 



783 



660 



1 



64-9 



14-3 



927 



1202 



55-6 



18-1 



1003 



1070 



! 

 1 



62-4 



18-9 



1182 



1703 











the same whether the arc is supplied with continuous or 

 alternating currents, pointing to the fact that the power ex- 

 pended in forms o£ energy other than light, e. g. volatiliza- 

 tion o£ carbon, radiation of heat, sound, &c, is exactly the 

 same for similar alternating and continuous arcs. 



For lengths of arc greater than \ in. the ratio of the 

 efficiencies of the continuous and alternating arcs is about 

 3 to 2, agreeing very well with that obtained by Dr. Fleming 

 and Mr. PetaveL 



