u 
1&V 
THE 
LONDON,  EDINBURGH,  and  DUBLIN 
PHILOSOPHICAL    MAGAZINE 
AND 
JOURNAL   OF   SCIENCE. 
CONDUCTED  BY 
LORD  KELVIN,  G.C.V.O.  D.C.L.  LL.D.  F.R.S.  <fec. 
JOHN  JOLY,  M.A.  D.Sc.  F.R.S.  F.G.S. 
AND 
WILLIAM  FRANCIS,  F.L.S. 
"Nee  aranearum  sane  textus  ideo  melior  quia  ex  se  fila  gignunt,  nee  noster 
vilior  quia  ex  alienis  libamua  ut  apes."  •    Just.  Lips.  Polit.  lib.  i.  cap.  1.  Not. 
VOL:  ir.^-SJXTH  SERIES. 
c  JANUARY— JUNE -190G^ 
LONDON: 
TAYLOR  AND  FRANCIS,  RED  LION  COURT,  FLEET  STREET. 
SOLD  UY  SIMPKIN,  MARSHALL,  HAMILTON,  KKNT,  AND  CO.,  U>. — T.    AND    T.  CI  IRK, 
EDINBURGH; — SMITH    AND   SON,    GLASGOW  J —  HODQBS,  FIGGIS,    wi>    CO., 
DUBLIN; — VEUVE  J.  BOYVEAU,  PARTS;      am>  tSHBR  and  CO.,  BJ  u    IN. 
84651 
