A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



107 



TABLE i. DIAMETERS OF CLOUD PARTICLES. PRELIMINARY RESULTS, 



FIXED PLATE. 



TABLE 2. DIAMETERS OF CLOUD PARTICLES. PLATE ADJUSTABLE. 



Floating globules were often observed in the act of coalescing; but this is 

 much rarer than the passage of a floating droplet over a fixed one without 

 interference. A distinct central bright area shading off into darkness was seen 

 even in the floating globules when axially illuminated by intense light. The 

 larger drops were often metallically green. The colors vanish after long stand- 

 ing, and they are particularly vivid immediately after falling. It was not even 

 now possible, in spite of all precautions in tipping the vessel, to obtain an abun- 

 dant crop of drops at pleasure. 



The results are given graphically on the chart, figure 7, in comparison with 

 the computed data of my earlier experiments (upper curve) as well as with rny 

 later experiments (lower curve). The observed results lie below the former 

 where adiabatic conditions were assumed, and above the more recent experi- 

 ments where the effect of the successive expansions was computed isothermally 

 In other words, the observed diameters are intermediate, but nearer the older 

 results. I will pass over these preliminary data, as they are probably too high 

 because of the difficulty in focussing among others, to resume the subject in con- 

 nection with the results obtained under much more favorable conditions below. 



