INDEX. 



603 



' Peripbractic ' regions, 43, 70 



Pipe, flow of viscous fluid in, 520, 522 



Poiseuille's experiments, 521 



Pressure- equation, 21 



Pressure, resultant, 177 



Pressures on solids in moving fluid, 218 



Progressive waves, 374 



Eeflection of waves, 280 



Resistance of a lamina, 107, 109, 112 



(viscous) to moving sphere, 533 

 Eetardation and acceleration of tides 



(frictional), 501, 502 

 Revolution, motion of a solid of, in 



frictionless fluid, 184, 189, 196 

 Ripples and waves, 447 

 Rotating liquid, 29 



Rotating sheet of water, tides on, 322 

 ' Rotational ' motion, 222 

 Rotation, electromagnetic, 32 

 Rotation of a liquid mass under its own 

 attraction, 580 



Sector, rotation of a circular, 97 



' Secular stability,' 327, 595 



Ship-waves, 403 



4 Simple-source' of sound, 484 



' Simply-connected' regions, 40 



Skin-resistance, 575 



Slipping, resistance to, at the surface 



of a solid, 514, 521 

 Small oscillations, general theory, 266 



relative to rotating solid, 324 

 Smoke-rings, 261 



Solid, motion of, through a liquid, 167 

 4 Solitary ' wave, 418 

 Sound, velocity of, 466 

 Sound-waves, plane, 464, 468 

 energy of, 469 

 general equation of, 480 

 of finite amplitude, 470, 471, 473, 475 

 spherical, 477, 479 

 'Sources' and 'sinks,' 63, 118, 128, 



129, 135 



Source, Simple-, of sound, 484 

 'Speed' defined, 268 

 Sphere, motion of, in infinite mass of 



liquid, 130 

 in liquid bounded by 

 concentric spheri- 

 cal envelope, 132 



Sphere, motion of, in cyclic region, 143, 



217 

 in viscous fluid, 524, 



530, 533 

 Spheres, motion of two, in a liquid, 



139, 205, 206 



Spherical harmonics, see Harmonics. 

 Spherical vortex, 264 

 Spherical mass of liquid, gravitational 



oscillations, 436 

 Spherical sheet of water, waves and 



tides on, 314, 440 

 of air, vibrations of, 489 

 Stability of a cylindrical vortex, 250 

 of a jet, 457, 459 

 of rotating masses of liquid, 326, 



594 

 of a water- surf ace, with wind, 389, 



392, 449 

 of steady motion of a solid in a 



liquid, 178, 188, 189 

 of the ocean, 362 

 ' ordinary ' and ' secular, ' 327 

 Standing waves, 372, 424 

 Stationary waves on the surface of a 



current, 421 



4 Steady motion,' defined, 22 

 general conditions for, 262 

 of a solid in a liquid, 178 

 of a solid of revolution, 190, 196 

 of a viscous fluid, 519, 528, 536 

 Stokes' theorem, 37 

 Stream-function, Lagrange's, 70 



Stokes', 133, 255 

 Stream-lines, 20 



of a circular disk, 153 

 of a circular vortex, 258 

 of a cylinder, 86 



with circulation, 88 

 of a liquid flowing past an oblique 



lamina, 94 



of an eUiptic cylinder, 93, 99 

 of a sphere, 137 

 Stream-lines, of a sphere in viscous 



fluid, 532 



Stream-lines, of a vortex-pair, 80, 246 

 Stresses in a viscous fluid, 512 

 Superficial energy, 442 

 Surface-conditions, 8, 9, 371, 514 

 Surface -distributions of sources and 

 sinks, 65, 66, 235 



