The  blast  was  secured  by  a  fan,  and  the  valve-gear  was
worked  by  cams  instead  of  eccentrics.  This  engine  made
the  round  trip  at  a  cost  of  $16,  doing  the  work  of  42  horses,
which  had  cost  $33  per  trip.  The  engine  cost  $4,500,  and
was  designed  by  Phineas  Davis,  assisted  by  Ross  Winans.
Mr.  Miller,  on  his  return  from  the  Liverpool  &  Man-
chester trial,  ordered  a  locomotive  for  the  Charleston  &
Hamburg  Railroad  from  the  West  Point  Foundery.  This


STEAM-LOCOMOTION   ON   RAILROADS.  21 1

engine  was  guaranteed  by  Mr.  Miller  to  draw  three  times
its  weight  at  the  rate  of  10  miles  an  hour.  It  was  built
during  the  summer  of  1830,  from  the  plans  of  Mr.  Miller,
and  reached  Charleston  in  October.  The  trials  were  made
in  November  and  December.
This  engine  (Fig.  60)  had  a  vertical  tubular  boiler,  in
which  the  gases  rose  through  a  very  high  fire-box,  into
which  large  numbers  of  rods  projected  from  the  sides  and
top,  and  passed  out  through  tubes  leading  them  laterally
outward  into  an  outside  jacket,  through  which  they  rose  to
the  chimney.  The  steam-cylinders  were  two  in  number,
8  inches  in  diameter  and  of  16  inches  stroke,  inclined  so  as
to  connect  with  the  driving-axle.  The  four  wheels  were  all
of  the  same  size,  4£  feet  in  diameter,  and  connected  by


Fio.  60.— The  "  Best  Friend,"  1830.
coupling-rods.  The  engine  weighed  4£  tons.  The  "  Best
Friend,"  as  it  was  called,  did  excellent  work  until  June,
1831,  when  the  explosion  of  the  boiler,  in  consequence  of  the
recklessness  of  the  fireman,  unexpectedly  closed  its  career.
212  THE    MODERN   STEAM-ENGINE.
