20 



A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



In table 3 the results obtained with jets of a variety of patterns and num- 

 bers are given in detail. They were all fed with hydrant water at 60-70 pounds 

 pressure. In these experiments the jet, /, replaced the phosphorus, the nuclei 

 being actually produced from the spray in the vessel, A, figure i. Details of a 

 simplified form are given in figure 2, where j is the jet to be tested, screwed to a 

 brass pipe, /, joined by gas couplings (unions at U, etc.) to the pipe h from the 

 hydrant. In many of the jets the spray is broken against the sides of the 

 vessel, this being the most efficient mode of comminution. The excess of water 

 is carried off by the cock, k, for which there is a side branch, p, with a special 

 stopcock. When k is closed, the jet may often be used to discharge its own 



FIGURE x. DETAIL (SIMPLIFIED) OF A, FIG. i 



FIGURE 3. FORMS OF IMPINGING JETS. 



nuclei into the condenser without the intervention of the Mariotte flask, M, 

 figure i. 



The types of jets used are shown in figure 3 in cross section, and the num- 

 bers in the table correspond to those of the figure. In No. i , two parallel eighth- 

 inch lead pipes emit jets from their sides in such a way as to impinge on each 

 other nearly at right angles. It was not possible to completely or continually 

 shatter both jets mutually in this way. In No. 2, radial jets from a quarter- 

 inch lead pipe impinge on the walls of the receiver ; in No. 8 the pipe has been 

 thinned. In No. 3 two capillary adjutages produce jets which impinge on each 

 other, and the same is the case, with evident modifications, in Nos. 4 and 7. In 

 No. 6 an oblique lead buffer has been added, while in No. 9 the jets issue from a 

 finely perforated copper plate, and impinge turbulently on the pool of water 

 below. In addition to these, ordinary lava tips (No. 5) and other steatite jets 

 were used. 



The holes were usually pricked with fine cambric needles. Of all the jets, 



