19IS.] SURFACES OF TELEPHONIC DIAPHRAGMS. 135 



TABLE OF SYMBOLS. 



a =^ Radius of the diaphragm clamping-circle (cm.), 

 an = A phase angle measured around the diaphragm (radians), 

 &^ Thickness of the diaphragm (cm.), 



c = A constant of the material of the diaphragm (cm./second y^ ), 

 flf = Sign of differentiation 



A = Damping constant := n log^ {wjw.^ = r/2w (second"^ ) , 

 ^^ Time-phase (radians), 

 e = Naperian logarithmic base (numeric), 

 / = Fe™'' Impressed simple harmonic moving force on the 



diaphragm (dynes) Z 

 /s = Statical tension (dynes), 

 F = Maximum value of a vibratory force (dynes), 



z=:V" — I (numeric), 

 /re = A Bessel's Function of the nth order (numeric), 

 /' = The first derivative of / with respect to r (numeric), 

 k = A constant of the material of the diaphragm, defined by 



^=(Vw)/c (cm.-^), 

 L = Distance from mirror to scale of explorer (cm.), 

 / = Radius arm of small mirror in explorer (cm.), 

 A = A constant satisfying boundary conditions (numeric), 

 M = Total mass of diaphragm (in Appendix III) (gm.), 

 M=: Magnification factor of explorer (numeric), 

 w =: Equivalent mass of the diaphragm (gm.), 

 /A=Micron, lO"* cm. (cm"*), 



« = Frequency of diaphragm vibration (cycles/second), 

 «o = Resonant frequency of diaphragm vibration (cycles/sec), 

 M= Number of annular rings in equivalent mass theory of App. 

 Ill (numeric), 

 n (Subscript)= Number of nodal diameters (order of Bessel's 

 Function) (numeric), 

 F = Constant of amplitude-magnitude (cm.), 

 77 = 3.1416 (numeric), 

 </> = Angle in the explorer between the plane of mirror and plane 



of diaphragm (deg.), 

 ^=: Young's modulus for diaphragm material (dynes/cm."), 



. r = Frictional resistance to motion of diaphragm , , 



cm./sec. 



