A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



6i 



on exhaustion tinifornily Sp=i'] cm., nearly, so that the precipitate per cub. 

 cm. is w = 4.7Xio"''. Measurements were made to the outer edge of the first 

 ring. In the cohinin marked "coronas," the color of the annuli is specified 

 from within outward, using the abbreviations stated above. The nucleation is 

 marked n' if computed from the aperture 5 standardized with lycopodium, n" 

 if computed from 5 standardized by subsidence measurements, N if computed 

 relatively as a geometric progression, n when the latter is reduced as shown 

 below, and the absolute values corrected for time and exhaustion losses, etc. 

 The initial nttcleation is shown under n^, and corresponds to = 4. The other 

 coefficients, p, referring to time losses, a referring to exhavistion losses, 5 refer- 

 ring to subsidence losses, will be presently explained. Though n is measured 

 for the partially exhausted receiver, a final correction (i/y) need not be added, 

 for the influx of filtered air leaves the nucleation undisttu-bed. The ratio n'/N 

 = 275 5V 10' ''"''' constructed in the chalets shows the wide departure from 

 the constancy which would be anticipated. Diameters of the fog particles are 

 given under d, the accents referring to the method of computation. All data 

 will be fullv disctissed below. 



6. Charts. — The charts show the relations of important quantities in the 

 tables. Thtis r = n'/N may be laid oft' in relation to the numl^er of the exhaus- 

 tion, z, as in figure 5; but, generally, the nucleations, n, and finally the di- 

 ameters, d, of the fog particles, are given in terms of the aperttires, 5, where the 

 angular radius (P = s/ 60. 



7. Tables. — The data investigated for the Welsl^ach burner follow. 



TABLE I.— CONSTANTS OF CORONAS. WELSBACH LAMP. CONDENSATION 

 CHAMBER, 20 cm. BROAD, 25 cm. HIGH, 35 cm. LONG; DISTANCES OF EYE 

 AND SOURCE OF LIGHT FROM CHAMBER, 85 cm. and 250 cm., RESPECT- 

 IVELY; = 22°; BAROM., 75.34cm.; 6p=i6.g; y^.JT, a = .o64; fl = o; 5=2.65; 

 a" = .oo29 (SUBSIDENCE); a' = .0032 (LYCOPODIUM) ; m„= 209000; PHOSPHORUS 

 NUCLEI. ^" = .0029/5; w = 4.7Xio-'^- MEASUREMENT OF i- TO OUTER EDGE 

 OF FIRvST RING. 



