A. deF. Palmer^ Jr. — Condensation in the Steam Jet. 253 



cessive positions of the limit of condensation correspond to 

 constantly increasing values of the velocity Y^ and a point C is 

 finally reached at which Y^ is equal to Y^ and the curve be- 

 comes an horizontal straight line. This character is maintained 

 until, for some unknown reason, condensation entirely ceases at 

 D and the original phenomenon repeats itself, producing the 

 curve DE identical with the upper part of AB. At E con- 

 densation again takes place and the representative point moves 

 along the line EF in all respects similar to BC. It is quite 

 possible that, as indicated at F, the cessation of condensation 

 may take place before the point at which Y2=Yi is reached, but 

 however this may be, the curves lying between two successive 

 beginnings of condensation should be repeated so long as the 

 conditions remain the same. The figure shows two possible 

 forms, B C D E and E F G, but does not assume to represent 

 an actual case, which would probably consist of an indefinite 

 repetition of the same form. 



Obviously Yj can never be less than the value of Y, corre- 

 sponding to the lowest points of the curve, and if a definite 

 horizontal portion could be determined from the observations 

 its height above the axis would give the absolute value of the 

 velocity of condensation under the given conditions. The 

 observations above recorded, probably on account of the rela- 

 tively large interval between them, give no definite evidence 

 of this portion of the curve, but an attempt was made to deter- 

 mine a lower limit for Yj by the calculation of Y^ for the 

 lowest observed points corresponding to the same pressure. It 

 was, however, found impossible to accomplish this, with more 

 than a very rough degree of approximation, on account of the 



