On the motion of Liquids through short JUfflux Tubes. 187 



ticularly when the diameter of the efflux tube is pretty large in 

 relation to that of the tube which serves as reservoir; then, 

 again, under like conditions, these phseuomena do not rigorously 

 reproduce themselves in successive experiments ; and lastly, they 

 are influenced by a number of small and almost inappreciable 

 circumstances, such as the more or less perfect polish of the 

 efflux tube, the purity of the liquid, the cleanness of the sides of 

 the reservoii', &c. 



The experiments of M. Savart, so far as recorded, are intended 

 to illustrate, — 



1. The influence of the chai'ge. 



2. That of the diameter of the efflux tube. 



3. That of its height. 



4. That of the diameter of the reservoir, supposing it first to 

 be cylindrical and concentric with the efflux tube, then cylin- 

 drical and of small diameter at its inferior part, or cylindrical 

 and of large diameter at its superior part. 



1. The influence of the Charge. 



The cylindrical efflux tubes consisted each of a simple plate of 

 brass, in the centre of which was a circular aperture perpendi- 

 cular to the two parallel faces ; or at the centre of such a plate, 

 a small cylindrical tube was soldered. Every precaution was 

 taken that the plate in contact with the liquid and the efflux tube 

 itself were perfectly clean and polished ; that the latter was quite 

 cylindi'ical, and exactly jjerpendicular to the polished face of the 

 plate. 



The tubes which sei-ved as reservoirs were of glass, their dia- 

 meters varied from 30 to 165 millimetres ; they were chosen as 

 cylindrical as possible, and the extremity of each in contact with 

 the plate was ground so that the plane of the latter was pei-pen- 

 dicular to the axis of the cylinder. The plate and glass cylinder 

 were joined by guin-mastic applied hot, care being taken that it 

 did noi penetrate into the interior of the glass tube, and that 

 the axes of the efflux and glass tubes were coincident. 



On experimenting, the glass tube was fixed in a vertical posi- 

 tion by means of an immoveable support, the efflux tube was 

 clysed in order to fill the glass one with water, and after allow- 

 ing the whole to rest quiet for a quarter of an hour, the efflux 

 tube was opened, and the observations commenced. In all casea 

 the experiments were repeated several times, until there was no 

 longer any uncertainty either as to the tones produced, their 

 intensity, or their corresponding charges. 



The first experiment was made with a glass tube 2*66 metres 



02 



