﻿CONTENTS 
  OF 
  VOL. 
  XVIII 
  

  

  (SIXTH 
  SERIES). 
  

  

  NUMBER 
  cm.— 
  JULY 
  1909. 
  

  

  Pago 
  

  

  Lord 
  Raylei'gh 
  on 
  the 
  Instantaneous 
  Propagation 
  of 
  Dis- 
  

   turbance 
  in 
  a 
  Dispersive 
  Medium, 
  exemplitied 
  bj 
  Waves 
  

  

  on 
  Water 
  deep 
  and 
  shallow 
  1 
  

  

  Dr. 
  J. 
  W. 
  Nicholson 
  ou 
  the 
  Relation 
  of 
  Airy's 
  Integral 
  

  

  to 
  the 
  Bessel 
  Functions 
  6 
  

  

  Prof. 
  Louis 
  T. 
  More 
  on 
  Theories 
  of 
  Matter 
  and 
  Mass 
  17 
  

  

  Mr. 
  R. 
  T. 
  Lattey 
  on 
  the 
  Ionization 
  of 
  Electrolytic 
  Oxygen 
  . 
  . 
  26 
  

  

  Mr. 
  C. 
  G. 
  Abbot 
  on 
  the 
  Theory 
  of 
  the 
  Greenhouse 
  32 
  

  

  Mr. 
  A. 
  H. 
  Gibson 
  on 
  the 
  Steady 
  Flow 
  of 
  an 
  Incompressible 
  

   Viscous 
  Fluid 
  through 
  a 
  Circular 
  Tube 
  with 
  Uniformly 
  

  

  Converging 
  Boundaries 
  35 
  

  

  Dr. 
  R. 
  D. 
  Kleeman 
  on 
  the 
  Determination 
  of 
  a 
  Constant 
  in 
  

  

  Capillarity 
  39 
  

  

  Prof. 
  T. 
  R. 
  Lyle 
  on 
  the 
  Theory 
  of 
  the 
  Alternate 
  Current 
  

  

  Generator 
  45 
  

  

  Prof. 
  L. 
  R. 
  In«j;ersoll 
  on 
  the 
  Magnetic 
  Rotation 
  in 
  Iron 
  Cathode 
  

  

  Films. 
  (Plate 
  I.) 
  74 
  

  

  Prof. 
  A. 
  S. 
  Eve 
  on 
  tlie 
  Amount 
  of 
  Radium 
  present 
  in 
  Sea- 
  

   Water 
  102 
  

  

  Mr. 
  C. 
  A. 
  Sadler 
  on 
  the 
  Transformations 
  of 
  X-Rays 
  ...'... 
  107 
  

   Prof. 
  J. 
  H. 
  Poynting 
  and 
  Mr. 
  G. 
  W. 
  Todd 
  on 
  a 
  Method 
  of 
  

  

  Determining 
  the 
  Sensibility 
  of 
  a 
  Balance 
  132 
  

  

  Mr. 
  G. 
  W. 
  Todd 
  on 
  the 
  Balance 
  as 
  a 
  Sensitive 
  Barometer 
  . 
  . 
  135 
  

   Prof. 
  J. 
  Joly 
  on 
  the 
  Distribution 
  of 
  Thorium 
  in 
  the 
  Earth's 
  

  

  Surface 
  Materials 
  ■. 
  140 
  

  

  Dr. 
  G. 
  A. 
  Blanc 
  on 
  the 
  Di.stribution 
  of 
  Thorium 
  in 
  the 
  Earth's 
  

  

  Surface 
  Materials 
  146 
  

  

  Dr. 
  J. 
  G. 
  Gray 
  and 
  Mr. 
  A. 
  D. 
  Ross 
  on 
  an 
  Improved 
  Form 
  of 
  

   Magnetometer 
  and 
  Accessories 
  for 
  the 
  Testing 
  of 
  Magnetic 
  

  

  Materials 
  at 
  Different 
  Temperatures 
  (Plate 
  11.) 
  148 
  

  

  Prof. 
  W. 
  A. 
  Douglas 
  Rudge 
  ou 
  the 
  Porous 
  Plug 
  Experiment. 
  159 
  

  

  Mr. 
  W. 
  Duddell 
  on 
  a 
  Bifilar 
  Vibration 
  Galvanometer 
  168 
  

  

  Mr. 
  J. 
  Robinson 
  on 
  Konig's 
  Theory 
  of 
  the 
  Ripple 
  Form- 
  

   ation 
  iu 
  Kundt's 
  Tube 
  Experiment 
  180 
  

  

  