APPENDIX

433

ing  to  drill  a  tapped  hole,  namely,  the  size  and  the
size.  If  a  tap  is  broken  off  in  the  hole  it  can  be  removed  by
means  of  a  Frequently  the  tap  helps  to  prevent
breakage.  The  pilot  of  a  counterbore  should  be
To  allow  for  adjustment  when  fitting  bearings  are
sometimes  inserted.  All  bearings  must  be  made  so  as  to  permit
If  a  babbitt  bearing  it  will  thus  preventing ­
  injury  to  the  shaft.
It  is  a  good  plan  to  pieces  of  machinery  so  that  they
will  go  back  in  the  same  position  if  taken  down  for  some  purpose. ­
  A  good  way  to  such  pieces  is  by  means  of
A  is  put  on  planners  and  shapers  to  prevent  wear  of
the  tool  on  the  return  stroke.
A  worn  gear  should  generally  run  in.......
A  drive  pulley  to  a  follower  gives  a  fast  speed  to
the  follower.
A  pulley  may  be  fastened  to  the  shaft  by  means  of  a
or  a
When  filing  on  a  lathe  the  work  should  revolve  The
file  should  be  fitted  with  a
A  good  cut  for  a  file  which  is  used  for  finishing  work  would
be
When  knocking  a  cutter  out  of  a  collet  it  is  best  to  use  a
in  the  tang  hole.
51.  Spatial  Perception
Description:  See  Chapters  IV,  VI,  XI.  This  test  has  been
enlarged  (1)  by  the  addition  of  new  spaces  (2)  by  using
two  form-boards  instead  of  one.  The  use  of  two  boards,
each  with  a  different  arrangement,  makes  it  possible  to  give
the  same  test  in  two  ways,  but  it  also  makes  it  possible
to  have  the  pieces  arranged  in  exactly  the  same  position
for  every  subject  (Ch.  XI).
Instructions:  These  instructions  are  intended  for  the  original
test  “Pick  up  each  piece,  size  it  up,  and  then  put  it