418 E. Merritt — Certain Peculiarities in Behavior of a 



The effect described above was noticed in 1884 by Yiolle * 

 while using a thermopile to investigate the radiation of molten 











y^*~* 



150. 















b ^y 







100. 



/+ 



.- 







A 



sy 









50. U 











/ / 



t 1 











Art 



\ s* 1 



o\ 



•"-^ 2 



Seconds. 



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platinum and silver. Numerous observations of successive 

 maxima and minima are given in his paper ; but no explana- 

 tion of the phenomenon is offered. Messrs. Eubens and Ritter 

 have observed a similar phenomenon with a peculiar form of 

 bolometer which they used for quantitative measurements of 

 electromagnetic waves : + and numerous experiments that have 

 been made in the laboratory of Cornell University svith a 

 bolometer of the ordinary type, and with a number of different 

 galvanometers and thermopiles, seem to show that this be- 

 havior is not peculiar to any one instrument, but is always 

 observed when a bolometer or thermopile, in circuit with a 

 galvanometer, is suddenly exposed to radiant heat. My 

 attention was first called to the phenomenon in 1888, while 

 engaged in an investigation of the energy of the light from 

 incandescent lamps. In a paperj published during the fol- 

 lowing year I called attention to the fact, which at that time 

 rested only upon experimental grounds, that the first throw of 

 the needle, under the circumstances described above, bears a 

 constant ratio to the final deflection, this ratio being indepen- 

 dent of the intensity of the radiation to which the pile is 

 exposed. 



* "Sur l'etalon absolu de la lumiere." Annates de Chirnie er de Physique. VI. 

 iii. p. 373. 



f •' Bemerkung zu den Hertz'schen Versuchen fiber Strahlen electrischer Kraft." 



Wied. Ann., vol. si. p. 63. 



X ■■ Some Determinations of the Energy of the Light from Incandescent Lamps," 

 this Journal, vol. xxxvii. p. 1*37. 



