46 A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



secured by the brass bolts at their ends (see Chapter VII). F is the filtering 

 attachment with a cock, E the exhausting attachment, P the nucleator. Ther- 

 mometers show the temperature both of the air within the chamber and of the 

 water at its bottom. The goniometer is in front and the source of light in the 

 rear of the apparatus, and the exhaustions are made in the way frequently 

 described in these memoirs. 



In the preliminary results, ^ = 4.5 cm. was the pressure decrement on ex- 

 haustion, = 23, the temperature of the saturated air and water. The eye and 

 the light are at distances 85 and 235 cm. from the central plane of the apparatus. 

 Since s for lycopodium is by experiment .75 cm. and ^ = .0032 cm., a = d s = 

 .0024. Hence at 20 d = . 0024/5 and n = 6ms 3 /7ia 3 . 



The results, 5 and s', are constructed in the chart, figure 3, and show the same 

 general character as the results already discussed. Moreover, since s' =1.35, 

 the two sets of data are more nearly in correspondence here than was the case 

 with the cylinder above. Definite results of this character for higher values of 

 dp will presently be given (Chapter VI), after a few incidental questions have 

 been disposed of. 



