FOR    THE    YEARS    1901-1905,    INCLUSIVE.  213 
Lane  (Alfred  C.) —  Continued. 
14.  Coal  of  Michigan:  its  mode  of  occurrence  and  quality. 
Mich.  Geol.  Surv.,  vol.  8,  pt.  2,  pp.  1-232,  9  pis.,  9  figs.,  map,  1902. 
Describes  the  geologic  occurrence,  composition,  and  mining  of  coal  in  the  Lower  Peninsula 
of  Michigan. 
15.  The  northern  interior  coal  field. 
U.  S.  Geol.  Surv.,  221  Ann.  Rept.,  pt.  3,  pp.  307-331,  2  pis.,  5  figs.,  1902. 
Describes  extent,  geologic  relations  and  structure  of  the  field,  the  character  and  occurrence 
of  the  coal  beds,  the  properties,  composition,  and  development  of  the  coal. 
16.  Variation  of  geothermal  gradient  in  Michigan. 
Abstract:  Science,  new  ser.,  vol.  15,  p.  88,  1902. 
17.  Queneau  on  .size  of  grain  in  igneous  rocks. 
Am.  Jour.  Sci.,  4th  ser.,  vol.  14,  pp.  393-396,  1902. 
18.  Kecent  work  of  the  Geological  Survey  [Michigan]. 
Mich.  Acad.  Sci.,  3d  Rept,,  pp.  38-39,  1902. 
19.  Report  on  certain  lands  leased  for  oil  and  gas  near  Cannel  City,  Morgan  County, 
Kentucky. 
Lansing,  12  pp.,  1902.     (Private  publication,) 
Gives  an  account  of  the  geologic  structure  of  thy  region. 
20.  Notes  on  the  origin  of  Michigan  bog  limes. 
Mich.  Geol.  Surv.,  vol.  8,  pt.  3,  pp.  199-223,  1  pi.,  5  figs.,  1903. 
21.  List  of  localities  and  mills  [manufacturing  Portland  cement]. 
Mich.  Geol.  Surv.,  vol.  8,  pt,  3,  pp.  224-342,  1903. 
Includes  notes  on  the  occurrence  of  marls  and  clays  and  analyses  of  materials  used  in  the 
manufacture  of  cements. 
22.  Studies  of  the  grain  of  igneous  intrusives. 
Geol.  Soc.  Am.,  Bull.,  vol.  14,  pp.  369-384,  5  pis.,  1903. 
Discusses  the  grain  of  augite  in  a  group  of  chemically  similar  diabases. 
28.  Porphyritic  appearance  of  rocks. 
Geol.  Soc.  Am.,  Bull.,  vol.  14,  pp.  385-406,  1903. 
Discusses  the  origin  of  variation  in  texture  of  igneous  rocks  as  the  margin  is  approached. 
24.  Annual  report  of  the  Geological  Survey  of  Michigan. 
Mich.  Miner,  vol.  5,  no.  2,  pp.  16-26,  1903;  reprinted  as  separate,  26  pp.,  1903. 
Discusses  the  occurrence  and  utilization  of  various  economic  products  found  in  Michigan. 
25.  Geological  changes  now  going  on. 
Mich.  Eng.,  pp.  102-105,  1903. 
Describes  erosion  on  lake  shores  and  changes  in  elevation. 
26.  The  economic  geology  of  Michigan. 
Abstract:  Eng.  &  Mg.  Jour.,  vol.  75,  p.  152,  1903;  Science,  new  ser.,  vol.  17,  p.  218,  1903;  Sci. 
Am.  Suppl.,  vol.  55,  p.  22666,  1903. 
27.  Variation  of  geothermal  gradient  in  Michigan. 
Abstract:  Geol.  Soc.  Am.,  Bull.,  vol.  13,  pp.  528-529, 1903. 
Presents  data  regarding  underground  variations  of  temperature. 
28.  The  theory  of  copper  deposition. 
Mich.  Miner,  vol.  6,  no.  2,  pp.  9-11,  no.  3,  pp.  9-11,  1904.     Am.  Geol.,  vol.  34,  pp.  297-309,  1  fig., 
1904. 
Discusses  the  theory  of  copper  deposition  with  especial  reference  to  the  copper-ore  deposits 
of  the  Lake  Superior  region. 
29.  The  science  of  raw  materials. 
Mich.  Miner,  vol.  6,  no.  4,  pp.  9-11,  1904. 
Discusses  scope  and  utility  of  economic  geology. 
30.  P>uilding  and  road  materials. 
Mich.  Miner,  vol.  6,  no.  5,  pp.  9-12,  no.  6,  pp.  9-11,  1904. 
Gives  notes  on  the  occurrence,  character,  and  use  of  materials  for  Portland  cement  and 
cement-brick  manufacture,  and  road  making. 
