﻿98 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Where 
  the 
  soil 
  foundation 
  is 
  clay, 
  or 
  for 
  any 
  reason 
  difficult 
  to 
  drain, 
  

   the 
  Telford 
  method 
  is 
  used. 
  In 
  this 
  case 
  a 
  course 
  of 
  flat 
  stones 
  about 
  

   six 
  inches 
  deep, 
  set 
  on 
  edge 
  and 
  closely 
  wedged 
  together, 
  is 
  placed 
  upon 
  

   the 
  soil 
  and 
  crushed 
  stone 
  is 
  placed 
  over 
  this 
  four 
  inches 
  thick 
  and 
  rolled 
  

   solid. 
  In 
  good 
  practice 
  it 
  is 
  customary 
  to 
  roll 
  the 
  earth 
  before 
  the 
  stone 
  

   is 
  laid 
  upon 
  it 
  and 
  then 
  roll 
  the 
  stone 
  foundation. 
  The 
  Telford 
  founda- 
  

   tion 
  forms 
  a 
  bridge 
  which 
  prevents 
  the 
  road 
  from 
  sinking 
  in 
  moist 
  soil 
  and 
  

   is 
  rendered 
  completely 
  effective 
  by 
  tile 
  drains 
  on 
  each 
  side 
  of 
  the 
  road. 
  

   After 
  the 
  road 
  is 
  built 
  it 
  must 
  be 
  kept 
  constantly 
  in 
  repair 
  a?id 
  the 
  neglect 
  

   of 
  this 
  principle 
  is 
  to 
  a 
  great 
  extent 
  responsible 
  for 
  the 
  poor 
  roads 
  of 
  the 
  

   United 
  States. 
  

  

  The 
  Macadam 
  and 
  Telford 
  systems 
  above 
  described 
  are 
  necessary 
  

   for 
  roads 
  designed 
  for 
  heavy 
  traffic 
  in 
  all 
  weathers, 
  but 
  roads 
  for 
  

   pleasure 
  driving 
  in 
  summer 
  only, 
  do 
  not 
  need 
  the 
  same 
  expensive 
  prepa- 
  

   ration. 
  

  

  As 
  an 
  example 
  of 
  the 
  methods 
  adopted 
  for 
  the 
  construction 
  of 
  high 
  

   class 
  roads 
  I 
  am 
  permitted 
  by 
  the 
  courtesy 
  of 
  the 
  Massachusetts 
  High- 
  

   way 
  Commission 
  to 
  quote 
  the 
  following 
  extracts 
  from 
  its 
  pamphlet 
  of 
  

   Instructions 
  to 
  engineers^ 
  published 
  in 
  1896: 
  

  

  Gravel. 
  You 
  will 
  use 
  gravel 
  for 
  surfacing 
  the 
  road 
  bed 
  under 
  tel- 
  

   ford 
  ; 
  also 
  for 
  surfacing 
  the 
  sub-grade 
  where 
  the 
  natural 
  soil 
  is 
  clayey, 
  

   loamy, 
  or 
  where 
  ordered 
  under 
  other 
  conditions 
  by 
  the 
  chief 
  engineer. 
  

   The 
  gravel 
  must 
  be 
  practically 
  free 
  from 
  sand 
  and 
  clay. 
  

  

  Broken 
  stone. 
  State 
  highways 
  are 
  divided 
  as 
  follows 
  with 
  reference 
  

   to 
  the 
  broken 
  stone 
  (sizes 
  given 
  are 
  in 
  inches) 
  : 
  

  

  1 
  All 
  trap 
  rock, 
  i 
  bottom 
  ist 
  course 
  to 
  be 
  i^ 
  to 
  2^ 
  ; 
  top 
  course 
  to 
  

   hty^to 
  1%', 
  

  

  2 
  All 
  trap 
  rock, 
  both 
  courses 
  to 
  be 
  i^ 
  to 
  2^ 
  ; 
  

  

  3 
  Local 
  stone 
  other 
  than 
  trap, 
  bottom 
  course 
  to 
  be 
  i^^ 
  to 
  2^ 
  j 
  top 
  

   course 
  to 
  be 
  ^ 
  to 
  1 
  1^ 
  ; 
  

  

  4 
  Local 
  stone 
  other 
  than 
  trap, 
  both 
  courses 
  to 
  be 
  '^ 
  to 
  2^ 
  ; 
  

  

  5 
  Bottom 
  course 
  of 
  local 
  stone 
  other 
  than 
  trap, 
  y^ 
  to 
  2}^; 
  top 
  course 
  

   of 
  trap 
  rock, 
  ^ 
  to 
  1%', 
  

  

  6 
  Bottom 
  course 
  of 
  local 
  stone 
  other 
  than 
  trap, 
  ^ 
  to 
  2^; 
  top 
  course 
  

   of 
  trap 
  rock, 
  1 
  1^ 
  to 
  2^ 
  ; 
  

  

  7 
  All 
  trap 
  rock, 
  bottom 
  course 
  to 
  be 
  j^ 
  to 
  1%', 
  top 
  course 
  to 
  be 
  i^^ 
  

   to 
  2y> 
  ; 
  

  

  8 
  Local 
  stone 
  other 
  than 
  trap, 
  bottom 
  course 
  to 
  be 
  ^ 
  to 
  2}^ 
  ; 
  top 
  

   course 
  to 
  be 
  i^ 
  to 
  2^. 
  

  

  When 
  'local 
  stone 
  other 
  than 
  trap 
  ' 
  is 
  used 
  you 
  must 
  not 
  allow 
  any 
  soft 
  

   or 
  disintegrated 
  rock 
  to 
  go 
  upon 
  the 
  road; 
  all 
  such 
  rock 
  must 
  be 
  rejected 
  

   before 
  breaking. 
  If 
  the 
  contractor 
  fails 
  to 
  remove 
  such 
  rock, 
  immedi- 
  

   ately 
  report 
  the 
  fact 
  in 
  Writing 
  to 
  the 
  chief 
  engineer. 
  

  

  