281 



Panama Canal Zone: Paragraph 



Datum for charts jg5 



Difference in mean sea level at entrances I59 iq2 



Parallax, defined I5 



Parallax inequality 43 



Parallax age , 14g 



Perigee, lunar, defined 43 



Perigean tides I45 



Effect on spring tides 147^ 148 



Mean low and high water of 186 



Perihelion, defined^ 60 



Period of: 



Component 49 



Synodic 54 



Motions of moon and sun. 62 



Seiches 35O 



Phase age I44 



Phases of moon 20 



Phase of component: 



Defined 49 



Computation of initial 91-96 



Polar current curves 487-491 



Potential, tide producing 22-25 



Prediction of: 



Tides 135-138 



Currents 492-498 



Primary current, defined 242 



Amplitude, from surface head and slope 245-247 



Initial phase 248 



Angular lag 254, 373 



Characteristics 255-259 



Distortions 260-277 



In long connecting canal 359-385 



Closed canal 420-432 



Primary tides: 



Defined 359 



Determination of entrance tides 360 



Prism, tidal 295 



Progressive wave 338-344 



Ranges, tidal: 



Defined 4 



Symbols ,158 



Mean, correction for longitude of moons node 171-179 



Relation to harmonic components Appendix II 



Diurnal 4, 152 



Tropic 152 



Recovery head 234, 235 



Reduction factors, F and / 124-128 



Resultant of components 5 1-59 



Retrogressive wave 342, 343 



Reversing tidal currents, defined 5 



Harmonic analysis of 497 



Nonharmonic analvsis of 500-504 



