influence of Vibratory Motions. 15 
The volume of the nascent divisions also increases with the 
_ charge (§ 2), and as each division furnishes a detached mass, 
the volume of these masses must likewise increase with the 
charge; now the greater the volumes of these masses, the 
greater must be their horizontal diameters when the same attain 
their maxima and minima; but these greatest and least diame- 
ters are respectively the diameters of the ventral segments and 
nodes ; hence the diameters of both ventral segments and nodes 
ought also to increase with the charge. The limit, however, to 
which this augmentation tends is not a wide one; for the great- 
est volume which the isolated masses can acquire is evidently that 
which they would possess if the translatory motion of the liquid 
were uniform, that is to say, the volume of the spheres into 
which an indefinite cylinder, formed of the same liquid and having 
a diameter equal to that of the contracted section, would resolve 
itself*, 
Again, if the charge does not vary, but a greater orifice is 
employed, the volume of the divisions of the jet, and hence that 
of the detached masses, will also be more considerable ; now the 
greater the masses the less rapid should be the oscillations of 
form, and consequently the greater the space through which 
they descend during one of these oscillations ; thus the length 
of the ventral segments ought to increase with the diameter of 
the orifice. As to the respective diameters of the ventral seg- 
ments and the nodes, it is evident, from what has been already 
advanced, that they will increase at the same time. 
From the present paragraph it will be seen, therefore, that 
the experimental results in No. 5 of paragraph 3 are once more 
the necessary consequences of theory; in the case, of course, of 
vibrations having the same period as those of the note natural to 
the jet. Let us proceed to the Nos. 6 and 7 of paragraph 3. 
§ 10. When the jet is not exposed to the influence of a sono- 
rous instrument, but is received in a vessel placed simply upon 
the ground, the principal cause of the vibrations transmitted by 
the air and the supports of the vessel from which the jet escapes, 
is the shock of the detached masses against the liquid into which 
they fall; it will easily be understood, therefore, that the ma- 
jority of such vibrations will have a period equal to that which 
would result from the shock of the masses in question against a 
stretched membrane, and consequently that their action upon 
the jet is explained by what has already been advanced in the 
preceding paragraphs. The intensity of the vibrations thus pro- 
occupies himself with their length, and in the paragraph which follows we 
have adopted his expressions ; in reality, however, it is manifest that the 
space in question consists of an expansion and two semi-contractions. 
* Second Series, § 74. 
