A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



21 



Nos. 2 and 8 were not only the simplest but the most efficient relative to the 

 quantity of water consumed. Adjutages introducing resistances gave inferior 

 restdts, but are needed for special purposes. To change the efficiency at will, 

 the number of holes may be varied from two to fifty. 



5. Results. — In table 3 the description of the jet, the corona produced 

 and its serial number, together with the number of nuclei per cubic centimeter 

 corresponding, are given in each case. Certain data of the aperttire, s, are some- 

 times added for identification. For convenience in comparisons, a brief table 

 of coronas is subjoined to the next table. 



TABLE 3.— NUMBER OF NUCLEI PRODUCED BY DIFFERENT JETS. 



PRESSURE, 60-70 lbs. 



WATER 



It is frequently difficult to place the coronas, and for this reason, several 

 cases, one of which is given in table 4, were investigated by successive exhaus- 

 tions, as explained in the preceding memoir. The identification of the coronas 

 is then more easily possible, beginning with the green corona. The table also 

 contains direct measurements of the successive apertures, with the number of 

 particles computed therefrom. The results show a peculiar periodic discrep- 

 ancy, the nature of which will be treated at length elsewhere.' For the present, 

 the apertures serve merely for the identification of coronas. 



The results obtained for jets will conveniently be discussed in the next 

 section in connection with the electrical data there set forth. Here I need only 

 point out that the maximum nucleation obtainable with jets is obviously de- 

 pendent on their pressure, number, fineness, etc., and probably on the degree 

 with which the air current simultaneously generated has been removed. The 

 presence of this current eventually sweeps out the nuclei as fast as they are 

 generated, and for this reason it makes no difference whether one begins with 



■ Chapter VI. 



