Produced by Rontgen Rays. 

 Fig. 5. 



49 



50i 37 MM 

 C2H5CI 100— 



stroke. A key operated by hand was put in parallel with the 

 key which applied the field and held down by hand until the 

 pendulum was approaching the latter on the return stroke. 

 The pendulum key was then quickly closed and the hand key 

 released. 



In this way it was possible to extend the air and carbon 

 dioxide curves to t== 1*06 seconds. The air curve was found 

 to bend very little more, but the carbon dioxide curve became 

 finally only a little steeper than the air curve. 



Am. Jour. Sci.— Fourth Series, Vol. XXXV, No. 205.— January, 1913. 

 4 



