266 Researches in the Theory and Calculus of Operations 



whatever magnitude or minitude, consists of an equilibrium 

 between the forces silicic acid and sodium. The entire hol- 

 low cylinder is therefore in equilibrium with itself, and it 

 is also in equilibrium with the forces of the medium (the 

 atmosphere) in which it is immersed, both without and 

 within the cylinder. When the cushion is brought into con- 

 tact with the cylinder, the equilibrium of the points of 

 contact of the cushion and cylinder is disturbed, and this 

 disturbance is propagated in both directions : 1° through 

 the glass, through the medium forming the diameter at 

 that point, and through the portion of the cylinder adjoin- 

 ing P ? where it takes position on the positive conductor P ; 

 and 2 through the cushion, taking position on the negative 

 conductor N". Equilibrium is now re-established in the sys- 

 tem; but if the cylinder be put in continuous rotation, a 

 succession of new instantaneous diameters will be formed, 

 each from a different point of the surface of the cylinder, 

 and producing so many disturbances or transmissions of 

 force, which accumulate upon the respective conductors P 

 and 1ST. 



If the cylinder is a thin sheet, its thickness may be re- 

 garded as constituting one atom formed by the combination 

 of a half-wave of silicic force with a half-wave of sodial 

 force, the nodes being at the two surfaces. Under the in- 

 fluence of the emanation of the glass which sustains the 

 equilibrium of the medium within the barrel, the diameter 

 will act as one atom or dynamical wave, with nodes at the 

 extremities and venter at the centre. The equilibrium at 

 the point of contact of the cushion (the rubber) and the 

 cylinder (the electric or the rubbed) is disturbed; the silicic 

 force of the atom is destroyed, liberating the sodial force, 

 which in its turn destroys the contiguous opposing force 

 of the semidiameter which pressed toward liberating 

 the other half that pressed toward P. At its encounter 

 with the interior surface of the cylinder, this last liberated 



