CONTENTS  of  N°  28b.— Fourth  Series 
X.  Researches  on  the  Electromotive  Force  in  the  Contact  of  Metals, 
and  on  the  Modification  of  that  Force  by  Heat.     By  E.  Edlund.  page 
XL  On  a  Simple  Case  of  Resonance.  By  Robert  Moon,  M.A., 
Honorary  Fellow  of  Queen's  College,  Cambridge 
XII.  On  Glacier-motion.      By  Edward  Vansittart  Neale,  Esq.   1< 
XIII.  A  Contribution  to  the  History  of  the  Mechanical  Theory  of 
Heat.     By  Professor  Clausius    1 
XIV.  On  the  Influence  of  Gas-  and  Water-pipes  in  determining  the 
Direction  of  a  Discharge  of  Lightning.     By  Henry  Wilde,  Esq.    . .    1 
XV.  Electrodynamic  Measurements.  By  Professor  Wilhelm 
Weber. — Sixth  Memoir,  relating  specially  to  the  Principle  of  the 
Conservation  of  Energy 1 
XVI.  Notices  respecting  New  Books :— Theory  of  Heat.  By  J. 
Clerk  Maxwell,  M.A.,  F.R.S.,  Professor  of  Experimental  Physics 
in  the  University  of  Cambridge. — Observations  upon  the  Climate  of 
Uckfield  in  the  Weald  of  Sussex.     By  C.  Leeson  Prince    ....    149-1 i 
XVII.  Proceedings  of  Learned  Societies  : — 
Royal  Society: — Prof.  Hornstein  on  a  Periodic  Change  of 
the  Elements  of  the  Force  of  Terrestrial  Magnetism ;  The 
Astronomer  Royal's  Corrections  to  the  Computed  Lengths 
of  Waves  of  Light  published  in  the  Philosophical  Transactions 
of  the  year  1868;  Mr.  J.  E.  Stone's  Experimental  Determi- 
nation of  the  Velocity  of  Sound    , . .  . .      151-U 
Geological  Society  : — Mr.  W.  Carruthers  on  some  supposed 
Vegetable  Fossils ;  Mr.  A.  H.  Green  on  the  Geology  of  part 
of  the  County  of  Donegal ;  Mr.  T.  Login  on  the  most  recent 
Geological  Changes  of  the  Rivers  and  Plains  of  Northern 
India 154-15 
XVIII.  Intelligence  and  Miscellaneous  Articles  : — 
On  the  Spectrum  of  Hydrogen  at  Low  Pressure,  by  G.  M.  Sea- 
broke,  Esq 15 
On  the  Disengagement  of  Heat  when  Caoutchouc  is  stretched, 
by  Professor  E.  Villari 15 
On  Actual  Energy,  by  W.  J.  Macquorn  Rankine,  LL.D.,  F.R.S. 
L.&E J 1 
m*  It  is  requested  that  all  Communications  for  this  Work  may  be  addresse 
post-paid,  to  the  Care  of  Messrs.  Taylor  and  Francis,  Printing  Office,  Re 
Lion  Court,  Fleet  Street,  London. 
