CONTENTS  OF  VOL.  XLIII. FOURTH  SERIES.  VII 
Page 
Proceedings  of  the  Royal  Society  : — 
Dr.  W.  Huggins  on  the  Spectrum  of  Encke's  Comet    ....    380 
Mr.  G.  Gore  on  Fluoride  of  Silver 382 
Messrs.  De  La  Rue,  B.  Stewart,  and  B.  Loewy  on  some 
recent  Researches  in  Solar  Physics,  and  a  law  regulating 
the  time  of  duration  of  the  Sun-spot  Period    385 
Dr.  W.  Huggins  on  the  Telescopic  Appearance  of  Encke's 
Comet     390 
Mr.  D.  M'Farlane's  Experiments  made  to  determine  Sur- 
face-conductivity for  Heat  in  Absolute  Measure 392 
On  Calculating-machines,  by  Thomas  T.  P.  Bruce  Warren    . .    396 
On  a  new  method  of  Measuring  the  Velocity  of  Rotation,  by 
Professor  A.  E.  Dolbear     398 
On  a  remarkable  fact  observed  on  the  Contact  of  certain  Liquids 
of  different  superficial  Tensions,  by  G.  Van  der  Mensbrugghe  399 
NUMBER  CCLXXXVIII.— JUNE. 
Prof.  Challis  on  the  Hydrodynamical  Theory  of  Magnetism  . .    401 
Mr.  S.  Sharpe  on  the  Moon  seen  by  the  naked  Eye  ........    427 
Mr.  R.  W.  Atkinson's  Examination  of  the  recent  attack  upon 
the  Atomic  Theory     428 
Mr.  J.  W.  L.  Glaisher  on  the  Relations  between  the  particular 
Integrals  in  Cayley's  solution  of  Riccati's  Equation 433 
Mr.  R.  Moon  on  the  Mode  in  which  Stringed  Instruments  give 
rise  to  Sonorous  Undulations  in  the  surrounding  Atmosphere.  439 
Prof.  R.  Clausius  on  the  Objections  raised  by  Mr.  Tait  against 
his  Treatment  of  the  Mechanical  Theory  of  Heat    443 
M.  F.  Zollner  on  the  Origin  of  the  Earth's  Magnetism,  and 
the  Magnetic  Relations  of  the  Heavenly  Bodies 446 
Notices  respecting  New  Books  : — 
Mr.  J.  H.  Jellett's  Treatise  on  the  Theory  of  Friction  ...    469 
Proceedings  of  the  Royal  Society : — 
The  Astronomer  Royal's  Experiments  on  the  Directive 
Power  of  large  Steel  Magnets,  of  Bars  of  Magnetized  Soft 
Iron,  and  of  Galvanic  Coils,  in  their  action  on  external 
small  Magnets    472 
M.  B.  M.  Jules  Raynaud  on  a  mode  of  Measuring  the 
Internal  Resistance  of  a  Multiple  Battery  by  adjusting 
the  Galvanometer  to  Zero 473 
On  the  Absorption-spectra  of  the  Vapours  of  Selenium,  Proto- 
chloride  and  Bromide  of  Selenium,  Tellurium,  Protochloride 
and  Protobromide  of  Tellurium,  Protobromide  of  Iodine,  and 
Alizarine,  by  D.  Gernez    473 
Demagnetization  of  Electromagnets,   by  Robert  W.  Willson, 
Junior  Class,  Harv.  Coll    475 
The  Source  of  the  Solar  Heat,  by  Maxwell  Hall,  B.A 476 
A  new  Sensitive  Singing-Flame,  by  W.  E.  Geyer 478 
