98 Prof. Maguus's Hydraulic Researches. 



that the water surface will form a greater angle with this plane 

 the smaller the masses of the jets in comparison to that of the 

 water forming the surface, until the angle finally becomes a 

 right angle. It is equally manifest that the water surface makes 

 a small angle with that plane if the mass of the jets prepon- 

 derate, and that if the jets only meet at their edges, the angle 

 almost vanishes. 



The same process which takes place at the first meeting of the 

 jets repeats itself when they pass over each other for the second 

 time, and there partially encounter. But because those parts of 

 the jets which meet at this second place are in the same propor- 

 tion to the entire diameter of the jet as at the first encounter, 

 the second surface, ed^ f, fig. 8, makes the same angle with the 

 first, bcc^d, as this does with the surface parallel to the axes of 

 the jets ab and ap^, and finally the third makes again the same 

 angle with the second. 



25. If the axes of the jets are in the same plane, and if they 

 encounter centrally, but at & small angle, and with moderate 

 velocity, the extent of the surface, which is now at right angles 

 to the original plane of the jets, is only small ; for the particles 

 of water in this surface are only impelled in the direction of the 

 radius with a small force. In that case the thick edges prin- 

 cipally arc formed, as observed above, § 18. These act on each 

 other like two jets, and produce by their encounter a new water 

 surface, which is at right angles to the plane of the edges, that 

 is, at right angles to the direction of the first water surface. 

 This process is repeated until the force employed in spreading 

 out the water so diminishes the force with which the edges act 

 on each other in the third or fourth surface, that no further ap- 

 precia'^'le expansion takes place. 



26.^ The production of the rounded edges of surfaces, their 

 encounter, and the new surfaces produced thereby, together con- 

 stitute the phsenomena which ai*e influential in the remarkable 

 forms assumed by jets issuing from angular openings. 



Experiments with Jets of unequal diameters. 



27. The phsenomena presented by the meeting of two jets 

 issuing jfrom circular openings of different diameters, and whose 

 axes are in the same right line, have been described by Savart, 

 not only when both jets issue at equal pressures, but also when 

 the pressures are unequal. These experiments, described in 

 Savart's interesting treatise Sur le Choc de deux Veines Liquides*, 

 are of minor importance for the present purpose. He has not de- 

 scribed the phfenomena presented by jets of different diameters 

 meeting at an angle ; indeed the subject of the encounter of jets 

 * Annates de Chimie et de Physique, vol. Ixv. p. 257. 



