Notices  respecting  New  Books.  469 
"It  is  remarkable  that  in  this  place,  where  the  unequal  in- 
fluence of  land  and  water  disappears,  as  the  whole  surround- 
ing parts  form  a  nearly  continuous  cover  of  ice,  the  variation 
exactly  coincides  with  the  course  of  the  sun.  This  would  be  an 
important  argument  for  the  derivation  of  the  magnetism  from 
the  sun's  rays." 
The  results  of  Lenz*  point  to  a  similar  relation  of  a  permanent 
distribution  of  temperature  on  the  surface  of  the  earth  to  the 
inner  movement  in  the  glowing  liquid  mass.  The  paper  of  Lenz 
bearing  on  this  question  was  published  under  the  title  of  "  In- 
vestigation of  an  Irregular  Distribution  of  the  Earth's  Magnetism 
in  the  northern  portion  of  the  Gulf  of  Finland." 
In  a  report,  Lamont  says  concerning  the  results  of  this  re- 
search : — 
11  The  paper  of  Lenz,  announced  in  the  Berliner  Berichten,  1 860, 
p.  654,  on  the  local  disturbances  at  the  entrance  of  the  Gulf  of 
Finland,  has  now  appeared,  and  contains  exact  information  about 
the  instruments  and  methods  of  reduction,  the  immediate  results 
of  observations,  and  the  values  calculated  therefrom  for  the  three 
rectangular  magnetic  components.  The  result  is  that  we  have 
to  consider  the  island  of  Jussar-oe  a  great  natural  magnet, 
whose  north  pole  is  to  the  north-west  and  south  pole  to  the 
south-east.  By  this  hypothesis,  however,  the  phenomena  are 
only  explained  in  their  general  character ;  and  if  we  go  into 
details,  we  shall  find  that  the  magnetism  is  irregularly  distributed 
over  the  island  itself;  and  the  abnormal  distribution  is  not 
confiued  to  the  island  and  its  immediate  neighbourhood,  but 
extends  over  a  wide  area.  It  would  be  of  interest  to  continue 
this  research  still  further,  and  especially  to  begin  observations 
on  the  south  coast  of  the  Gulf,  where  the  existence  of  a  local  dis- 
turbance has  been  shown  to  exist.  M.  Lenz  seeks  the  origin 
of  the  disturbance  in  the  huge  beds  of  ice  which  are  found  in 
that  place." 
[To  be  continued.] 
LVIII.  Notices  respecting  New  Books. 
A  Treatise  on  the  Theory  of  Friction.  By  John  H.  Jellett,  B.D., 
Senior  Fellow  of  Trinity  College,  Dublin  ;  President  of  the  Royal 
Irish  Academy.  Dublin  :  Hodges,  Foster,  and  Co.  London  : 
Macmillan  and  Co.      1872.     (8vo.  pp.  220.) 
TN  all  cases  of  equilibrium,  where  a  body  rests  against  one  or  more 
-*-  fixed  surfaces,  it  is  usual  to  assume  that  the  reaction  of  each  fixed 
surface  takes  place  along  the  normal  at  the  point  of  contact.  By 
this  assumption  an  approximate  solution  is  obtained  of  many  ques- 
tions which  become  much  more  difficult,  or  even  insoluble,  if  a  closer 
*  Mem.  de  I'Acad.  de  St,  Petersboury,  vol.  iii.  pp.  1-38, 
