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APPENDIX A. 
1. Piezo Electric Constants and Other Properties of Tourmaline 
(a) Chemical Composit ion. 
17 AV 035 9 Fe 0, 2NO >» 2u S10), 68,05, THO. 
(b) Specific Inductive Capacity = 6.75 (A.R.L. measurement) of ‘Black’ Tourmaline. 
(c) Piezo Electric Constants. 
(1) Pressure applied along the electric axis K, = 5.72 x 1078 €,3.u. 
(2) Pressure applied along the optic axis. kp = 0. 
(3) Pressure applied in the 3rd Directione Ky = -0.88 x 107 E.s.u. 
(4) Hydrostatic Pressure. K = Ky Ky ky * -6.6 x 1078 £.5.u, 
and Q = K p A where Q is the charge developed in E.S.U. "p’ is pressure in dynes per 
Sq.in. and A is the area of crysta) free at right angles to electric axis. 
(d) Velocity of Sound in Tourmaline slab. 6000 metres/second (Provisional only) 
(e) Density of Black Tourmaline 3.0 to 3.2 
2, Piezo Electric Constants of Quartz and Rochelle Salt. 
a Quartz 
Ky 6.u5 x 1078 
Ko 0 
ks -6.u5 x 1078 
“Nts ky + Ky + ky 0 
nee 
Rochelle salt responds only to shearing forces and consequently gives no effect on application 
of hydrostatic pressure. 
3- Data Relating to Cathode Ray Oscillograph. 
(a) 
(b) 
Velocity of Cathode Rays. 
v = 5.95 Y v.10" oms/sec. 
where V is the p.d. (in volts) accelerating the cathode rays. 
Voltage Sensitivity of Cathode Ray Oscillograph. 
Deflection§ = 1 A» ( + d) cms. per volt. 
aveod \ (4: 
where | = distance from mid-point of deflecting plates to screen. 
AX = length of deflecting plates. 
d = déstance apart of deflecting plates. 
(C) Meeetane 
According to "Tables of Physteal Constants" published by French Physical Society, the 
composition Is very vartable. 
