KXPERIMENTS WITH IONIZED A IK. 



AA, while a screen cuts off all extraneous light. With this apparatus a lirilliant 

 field of color is obtained, so that minute differences may be detected, and I thus 

 investigated the scale given below between the intense oranges of the first order 



m 



A 



m 



0M 



ng. 7 



w 



J1. 



Fig. 3. 



t 



A 



Fig. 6. 



d 



1 



d- 





^! 



Fig. I. — Color TrnK. 



3^ 



S^ 



'•B 



l^-g- 



4. 



C 



a' 



F"ig- 



iiiO 



Sectional Elevation. 



Fig. 2.— UlFFERKNTlAL CoLOR TUBE. 



Kic. 3.— Color Tube with Influx Pipes. Fig. 4.— Color Tubes in Series. Fig. 5.— Steam Box or 

 Separator. Fig. 6.— Nozzle of Steam Jet. Scale \. Figs. 7. 8.— Charts. Showing the Margins of the 

 OPAguE Field at Different Tf.mperatires and Pressures, for Atmospheric .'\ir. 



and the final greens of the second order, after which the colors are too f.iint for 

 recognition. In the latter case, since low-pressure steam must be employed, an 

 advantage is secured by drilling two or more holes iu the jet ,/'. Figure 1 shows 



