4:86 



Mr. Warren De La Hue 



[Jan. 21, 



place through them. 



If the discharge is irregular and 

 the strata indistinct, an alteration 

 of the amount of current makes the 

 strata distinct and steady ; most fre- 

 quently a point of steadiness is pro- 

 duced by the careful introduction of 

 external resistance ; subsequently, with 

 the introduction of more resistance, a 

 new phase of unsteadiness, and still 

 more resistance, another phase of steady 

 and distinct stratification. 



At the same pressure, and with the 

 same current, the diameter of the tube 

 affects the character and closeness of 

 the stratification (Fig. 23), as will be 

 seen when I cause the current to pass 

 in tube No. 161, which contains resi- 

 dual hydrogen. It consists of two 

 portions, one 18 inches long and 1'15 

 internal diameter, the other 17*5 

 inches long and 0*975 inch diameter. 

 The battery I am using consists of 

 4800 cells, and you perceive that 

 whether the terminal in the small 

 tube is positive or negative there is 

 a marked difference in the form and 

 closeness of the strata in the two tubes. 



The greatest heat is developed in 

 the vicinity of the strata. This fact 

 we established most easily when the 

 tube contained only one stratum, or 

 a small number separated by a broad 

 interval. There is reason to believe 

 that even in the dark discharge like 

 that in the neighbourhood of the ne- 

 gative terminal there may be a kind 

 of stratified formation, for we have 

 found a development of heat in part 

 of a tube in which there was no illu- 

 mination except on the terminals. 



There are vacuum tubes made which 

 are not open from end to end, and 

 which consist of a number of separate 

 chambers, some inserted into the others. 

 The induction coil illuminates these 

 very beautifully, but the battery will 

 not do so, as no discharge can take 

 On the other hand, the alternating currents of 



