Notices  respecting  New  Boohs.  613 
Der  Bau  cles  Fixsternsy  stems,  mit  besonderer  Beriicksiolitig ung  der 
pliotometrischen  Eesultate.  Von  Dr.  Hermann  Kobold,  A.  O. 
Professor  an  der  Universitat  and  Observator  der  Sternwarte 
in  Kiel.  Mit  19  eingedruckten  Abbildungen  und  3  Tafeln. 
Braunscliweig :  F.  Vieweg  und  ISohn.  1906.  Pp.  xii+256. 
["Die  AVissenschaft,"  Heft  11.] 
The  problems  which  are  considered  in  the  present  monograph 
have  long  formed  the  subject  of  much  speculation  on  the  part  of 
astronomers.  It  is  only,  however,  with  the  development  of  the 
recent  powerful  methods  of  research  in  this  field  that  definite 
knowledge  has  taken  the  place  of  vague  conjecture,  and  that  trust- 
worthy conclusions  have  been  arrived  at.  The  author  divides  his 
admirable  account  of  the  present  state  of  the  subject  into  three 
sections.  Section  I.  deals  in  a  general  way  with  types  of  instru- 
ments and  methods  of  observation.  Section  II.  deals  with  the 
results  obtained  up  to  the  present ;  while  Section  III.  contains  an 
account  of  the  conclusions  which  may  be  drawn  from  them. 
Bibliographical  references  are  given  in  an  appendix.  It  may  be 
interesting  to  quote  the  following  sentences  from  the  conclusion, 
in  which  the  author  thus  sums  up  our  knowledge  regarding  the 
structure  of  the  universe  :  "  Throughout  a  finite  space  of  spherical 
form  are  scattered  bodies  of  greatly  varying  mass  and  physical 
state.  Besides  gaseous  nebulas  of  very  low  temperature  there 
occur  bodies  in  the  state  of  greatest  condensation  and  highest 
iacaudescence.  The  arrangement  of  the  individual  masses  is  no 
random  or  uniform  one,  but  they  are  collected  in  heaps  around 
single  concentration  centres,  which,  however,  are  loosely  connected 
with  each  other  and  are  arranged  in  the  form  of  a  large,  many- 
branched  spiral.  In  the  more  remote  parts  of  this  spiral  there 
predominate  the  hotter  and  gaseous  stars,  while  those  more  closely 
related  to  the  sun — which  is  not  far  removed  from  the  centre  of 
the  spiral — also  resemble  it,  on  the  whole,  in  their  physical  state. 
The  sun  has  a  motion  of  translation — shared  by  the  majority  of 
the  nearer  stars — towards  a  point  in  the  milky  way,  which  forms 
the  principal  plane  of  the  entire  spiral." 
Die  Psychischen.  Massmethoden.  Von  Dr.  G-.  P.  Lipps,  Privatdozent 
der  Philosophie  an  der  Universitat  Leipzig.  Mit  6  eingedruckten 
Abbildungen.  Braunschweig :  F.  Vieweg  und  Sohn.  1906. 
Pp.  vii  +  151. 
It  is  but  seldom  that  physicists  devote  much  attention  to  the  study 
of  the  psychical  processes  involved  in  the  making  of  observations. 
True,  they  are  generally  introduced  to  Fechner's  Law  in  connection 
with  photometry,  but  there  their  psychical  studies  may  be  said  to 
begin  and  end.  To  those  with  a  metaphysical  turn  of  mind,  the 
monograph  under  review,  which  forms  No.  10  of  the  series  known 
as  "  Die  Wissenschaft,"  may  be  recommended  as  affording  a 
detailed  account  of  the  subject  and  methods  of  experimental 
psychology. 
