410 



Prof. Ayrton and Mr. Medley on 



so that the light varies only as something like the fourth 

 power of the pressure. 



On the other hand, if we consider the results of the pre- 

 liminary tests recorded in fig. 10<7, we have at the start 



L 100 = 24-8, L 102 = 28-7, L 10 4 = 30, 



so that 



L102 



= 1-16, 



L 



104 



L100 ^100 



while after 100 hours' run 



= 1-21 



so that 



Lioo = 33 # l, Lio2=38 ; Lio4 = 43*3; 

 ?S»=M5, ^f = l-31. 



-I Jinn Lnon 



In this case, then, the law of the seventh power holds roughly 

 not only for the light given out by the three groups at the 

 start but also at the end of the first 100 hours' run. 



The following table gives the analysis of the chief results 

 shown by the curves on figs. 10 and 10 a. 





Preliminary ' 



rests. 



Later Tests. 



Pressure in Volts main- "j 

















tained between Lamp > 



100 



102 



104 



100 



101 



102 



104 



















Duration of Test, in Hours 



110 



110 



110 



1,820 



1,340 



1,820 



460 



Initial Candle Power per 1 

 Lamp J 



8-23 

 4-72 



9-57 

 4-37 



10 

 4-20 



8-77 

 4-79 



8-83 

 4-80 



10-2 

 4 22 



11-27 



3-89 



Initial Walts per Candle... 



Largest Candle-Power "1 



111 



126 



145 



11-67 



1023 



11/67 



135 



Percentage Rise in Can- 1 

















die- Power at the be- I 



350 



31-9 



45-0 



331 



15-5 



144 



19-8 



ginning ) 

















Percentage Rise in Cur- 1 

 rent at the beginning J 



7-55 



4-87 



7'43 



5-87 



4-28 



3-97 



34 



Smallest Watts per 1 

 Candle J 



3-74 



348 



312 



3-82 

 100 



435 



572 ; 957 ; 

 1167. 



43 

 94 



4-68 



No Lamps 

 broken. 



382 

 10-7 



4T2 



242 ; 372 ; 

 516; 540; 

 516; 786. 



3-33 

 12-1 



3-6 



94; 175; 



210; 

 242; 254. 



Average Candle-Power 1 

 per Lamp during whole > 

 run J 



Average Watts per Can- 1 

 die during whole run J 



Lives in Hours of Lamps 1 

 Broken during run ... J 



Lives in Hours of Un- 1 

 broken Lamps f 



Number of Lamps in- J 

 eluded in Striking I 







..A 



1248; 863; 



1340 ; 1340; 



1148; 898; 



165; 222; 







653. 

 6 



1340. 

 3 



772. 

 9 



364 



8 



















