Prof. Magnus's Hydraulic Researches. 181 



experiments for these jets was cut in a plate at the end of a 

 tube which could receive different inclinations. Savart appears 

 to have employed a similar arrangement for these streams^ as is 

 seen in the drawings which he gives of them*. If the hand be 

 placed on the tube while the sounding body is on the stand on 

 which the tube is fastened, the transversal movements may be 

 plainly felt. These movements give rise to similar ones in the 

 continuous portion of the stream, which, although excessively 

 weak, are sufficient to give different directions to the drops at 

 the moment of their separation ; so that they do not all follow 

 the same curve, but are spread out over a greater space. 



180. Sometimes the " garbe " is transformed into two or three 

 streams which separate from the same point of the original 

 stream, so that the latter is divided into two or three branches 

 which often still show regular swellings. 



181. If such a divided stream be examined by means of the 

 rotating slit, two or three different rovs of drops, all emanating 

 from the same place, are seen, which correspond to the number 

 of branches into which the chief stream has been divided. But 

 at the same time it is seen that the drops of the different rows 

 do not all leave the point of separation at the same time. For 

 if, for instance, two streams are present, it is seen how the two 

 jets are formed of alternating drops ; so that if the drops be re- 

 presented by numbers in the order in which they separate fi'om 

 the continuous part of the stream, the one row contains the drops 

 1, 3, 5, 7, &c., and the other the drops 'Z, 4, 6, 8, &c. Simi- 

 larly when three rows are present. Inasmuch as the drops of 

 the separate rows always follow the same direction in such a 

 manner as to describe the same curves, it follows that the drops of 

 one kind, for instance the even ones, must leave the continuous 

 part of the stream when it is in a definite place, and the odd 

 ones when it has reached another place. Consequently a defi- 

 nite relation must exist between the intervals of time in which 

 the separations follow, and the times of the transverse motions ; 

 so that the intervals between two drops belonging to one and 

 the same branch must be equal to one transverse backwards and 

 forwards movement of the stream. Since both the separation of 

 the drops and the transverse motions of the stream are produced 

 by vibrations of the efflux-orifice, in consequence of the latter 

 being set in motion by the sounding body, not only in the direc- 

 tion of the stream, but also at right angles to it, a simple relation 

 must exist between these motions ; and hence a division of the 

 stream into two branches may easily take place : it is not so often 

 possible to divide the stream into three branches. 



* Atmales ric CItimic >'l di: riiijsiqnc, '2\\i\ scriis, vol. hi. jihilc .'5. 



