diameter；　it　was　driven　by　wheel…gearing　like　a　crane　motion；　and
  adapted　to　different　speeds。　　Some　of　his　friends；　on　first　looking　at
  it；　said　he　was　going　〃too　fast；〃　but　he　lived　to　see　work　projected
  on　so　large　a　scale　as　to　prove　that　his　conceptions　were　just；　and
  that　he　had　merely　anticipated　by　a　few　years　the　mechanical　progress
  of　his　time。　　His　large　removable　bar…lathe　was　a　highly　important
  tool　of　the　same　kind。　　It　was　used　to　turn　surfaces　many　feet　in
  diameter。　　While　it　could　be　used　for　boring　wheels；　or　the　side…rods
  of　marine　engines；　it　could　turn　a　roller　or　cylinder　twice　or　three
  times　the　diameter　of　its　own　centres　from　the　ground…level；　and
  indeed　could　drive　round　work　of　any　diameter　that　would　clear　the
  roof　of　the　shop。　　This　was　therefore　an　almost　universal　tool；
  capable　of　very　extensive　uses。　　Indeed　much　of　the　work　now　executed
  by　means　of　special　tools；　such　as　the　planing　or　slotting　machine；
  was　then　done　in　the　lathe；　which　was　used　as　a　cutter…shaping
  machine；　fitted　with　various　appliances　according　to　the　work。
  Maudslay's　love　of　accuracy　also　led　him　from　an　early　period　to
  study　the　subject　of　improved　screw…cutting。　　The　importance　of　this
  department　of　mechanism　can　scarcely　be　overrated；　the　solidity　and
  permanency　of　most　mechanical　structures　mainly　depending　on　the
  employment　of　the　screw；　at　the　same　time　that　the　parts　can　be
  readily　separated　for　renewal　or　repair。　　Any　one　can　form　an　idea　of
  the　importance　of　the　screw　as　an　element　in　mechanical　construction
  by　examining　say　a　steam…engine；　and　counting　the　number　of　screws
  employed　in　holding　it　together。　　Previous　to　the　time　at　which　the
  subject　occupied　the　attention　of　our　mechanic；　the　tools　used　for
  making　screws　were　of　the　most　rude　and　inexact　kind。　　The　screws　were
  for　the　most　part　cut　by　hand：　　the　small　by　filing；　the　larger　by
  chipping　and　filing。　　In　consequence　of　the　great　difficulty　of　making
  them；　as　few　were　used　as　possible；　and　cotters；　cotterils；　or
  forelocks；　were　employed　instead。　　Screws；　however；　were　to　a　certain
  extent　indispensable；　and　each　manufacturing　establishment　made　them
  after　their　own　fashion。　　There　was　an　utter　want　of　uniformity。　　No
  system　was　observed　as　to　〃pitch；〃　i。e。　　the　number　of　threads　to　the
  inch；　nor　was　any　rule　followed　as　to　the　form　of　those　threads。
  Every　bolt　and　nut　was　sort　of　specialty　in　itself；　and　neither　owed
  nor　admitted　of　any　community　with　its　neighbours。　　To　such　an　extent
  was　this　irregularity　carried；　that　all　bolts　and　their　corresponding
  nuts　had　to　be　marked　as　belonging　to　each　other；　and　any　mixing　of
  them　together　led　to　endless　trouble；　hopeless　confusion；　and
  enormous　expense。　　Indeed　none　but　those　who　lived　in　the
  comparatively　early　days　of　machine…manufacture　can　form　an　adequate
  idea　of　the　annoyance　occasioned　by　the　want　of　system　in　this　branch
  of　detail；　or　duly　appreciate　the　services　rendered　by　Maudslay　to
  mechanical　engineering　by　the　practical　measures　which　he　was　among
  the　first　to　introduce　for　its　remedy。　　In　his　system　of　screw…cutting
  machinery；　his　taps　and　dies；　and　screw…tackle　generally；　he　laid　the
  foundations　of　all　that　has　since　been　done　in　this　essential　branch
  of　machine…construction；　in　which　he　was　so　ably　followed　up　by
  several　of　the　eminent　mechanics　brought　up　in　his　school；　and　more
  especially　by　Joseph　Clement　and　Joseph　Whitworth。　　One　of　his
  earliest　self…acting　screw　lathes；　moved　by　a　guide…screw　and　wheels
  after　the　plan　followed　by　the　latter　engineer；　cut　screws　of　large
  diameter　and　of　any　required　pitch。　　As　an　illustration　of　its
  completeness　and　accuracy；　we　may　mention　that　by　its　means　a　screw
  five　feet　in　length；　and　two　inches　in　diameter；　was　cut　with　fifty
  threads　to　the　inch；　the　nut　to　fit　on　to　it　being　twelve　inches
  long；　and　containing　six　hundred　threads。　　This　screw　was　principally
  used　for　dividing　scales　for　astronomical　purposes；　and　by　its　means
  divisions　were　produced　so　minute　that　they　could　not　be　detected
  without　the　aid　of　a　magnifier。　　The　screw；　which　was　sent　for
  exhibition　to　the　Society　of　Arts；　is　still　carefully　preserved
  amongst　the　specimens　of　Maudslay's　handicraft　at　the　Lambeth　Works；
  and　is　a　piece　of　delicate　work　which　every　skilled　mechanic　will
  thoroughly　appreciate。　　Yet　the　tool　by　which　this　fine　piece　of
  turning　was　produced　was　not　an　exceptional　tool；　but　was　daily
  employed　in　the　ordinary　work　of　the　manufactory。
  Like　every　good　workman　who　takes　pride　in　his　craft；　he　kept　his
  tools　in　first…rate　order；　clean；　and　tidily　arranged；　so　that　he
  could　lay　his　hand　upon　the　thing　he　wanted　at　once；　without　loss　of
  time。　　They　are　still　preserved　in　the　state　in　which　he　left　them；
  and　strikingly　illustrate　his　love　of　order；　〃nattiness；〃　and
  dexterity。　　Mr。　Nasmyth　says　of　him　that　you　could　see　the　man's
  character　in　whatever　work　he　turned　out；　and　as　the　connoisseur　in
  art　will　exclaim　at　sight　of　a　picture；　〃　That　is　Turner；〃　or　〃That
  is　Stansfield；〃　detecting　the　hand　of　the　master　in　it；　so　the
  experienced　mechanician；　at　sight　of　one　of　his　machines　or　engines；
  will　be　equally　ready　to　exclaim；　〃That　is　Maudslay；〃　for　the
  characteristic　style　of　the　master…mind　is　as　clear　to　the
  experienced　eye　in　the　case　of　the　finished　machine　as　the　touches　of
  the　artist's　pencil　are　in　the　case　of　the　finished　picture。　　Every
  mechanical　contrivance　that　became　the　subject　of　his　study　came
  forth　from　his　hand　and　mind　rearranged；　simplified；　and　made　new；
  with　the　impress　of　his　individuality　stamped　upon　it。　　He　at　once
  stripped　the　subject　of　all　unnecessary　complications；　for　he
  possessed　a　wonderful　faculty　of　KNOWING　WHAT　TO　DO　WITHOUTthe
  result　of　his　clearness　of　insight　into　mechanical　adaptations；　and
  the　accurate　and　well…defined　notions　he　had　formed　of　the　precise
  object　to　be　accomplished。　　〃Every　member　or　separate　machine　in　the
  system　of　block…machinery　says　Mr。　Nasmyth；　〃is　full　of　Maudslay's
  presence；　and　in　that　machinery；　as　constructed　by　him；　is　to　be
  found　the　parent　of　every　engineering　tool　by　the　aid　of　which　we　are
  now　achieving　such　great　things　in　mechanical　construction。　　To　the
  tools　of　which　Maudslay　furnished　the　prototypes　are　we　mainly
  indebted　for　the　perfection　of　our　textile　machinery；　our
  locomotives；　our　marine　engines；　and　the　various　implements　of　art；
  of　agriculture；　and　of　war。　　If　any　one　who　can　enter　into　the　details
  of　this　subject　will　be　at　the　pains　to　analyse；　if　I　may　so　term　it；
  the　machinery　of　our　modern　engineering　workshops；　he　will　find　in
  all　of　them　the　strongly…marked　features　of　Maudslay's　parent
  machine；　the　slide　rest　and　slide　systemwhether　it　be　a　planing
  machine；　a　slotting　machine；　a　slide…lathe；　or　any　other　of　the
  wonderful　tools　which　are　now　enabling　us　to　accomplish　so　much　in
  mechanism。〃
  One　of　the　things　in　which　Mr。　Maudslay　took　just　pride　was　in　the
  excellence　of　his　work。　　In　designing　and　executing　it；　his　main
  object　was　to　do　it　in　the　best　possible　style　and　finish；　altogether
  irrespective　of　the　probable　pecuniary　results。　　This　he　regarded　in
  the　light　of　a　duty　he　could　not　and　would　not　evade；　independent　of
  its　being　a　good　investment　for　securing　a　future　reputation；　and　the
  character　which　he　thus　obtained；　although　at　times　purchased　at
  great　cost；　eventually　justified　the　soundness　of　his　views。　　As　the
  eminent　Mr。　Penn；　the　head　of　the　great　engineering　firm；　is
  accustomed　to　say；　〃I　cannot　afford　to　turn　out　second…rate　work；〃　so
  Mr。　Maudslay　found　both　character　and　profit　in　striving　after　the
  highest　excellence　in　his　productions。　　He　was　particular　even　in　the
  minutest　details。　　Thus　one　of　the　points　on　which　he
  insistedapparently　a　trivial　matter；　but　in　reality　of　considerable
  importance　in　mechanical　construction　was　the　avoidance　of　sharp
  interior　angles　in　ironwork；　whether　wrought　or　cast；　for　he　found
  that　in　such　interior　angles　cracks　were　apt　to　originate；　and　when
  the　article　was　a　tool；　the　sharp　angle　was　less　pleasant　to　the　hand
  as　well　as　to　the　eye。　　In　the　application　of　his　favourite　round　or
  hollow　corner　systemas；　for　instance；　in　the　case　of　the　points　of
  junction　of　the　arms　of　a　wheel　with　its　centre　and　rimhe　used　to
  illustrate　its　superiority　by　holding　up　his　hand　and　pointing　out
  the　nice　rounded　hollow　at　the　junction　of　the　fingers；　or　by
  referring　to　the　junction　of　the　branches　to　the　stem　of　a　tree。
  Hence　he　made　a　point　of　having　all　the　angles　of　his　machine
  framework　nicely　rounded　off　on　their　exterior；　and　carefully
  hollowed　in　their　interior　angles。　　In　forging　such　articles　he　would
  so　shape　his　metal　before　bending　that　the　result　should　be　the　right
  hollow　or　rounded　corner　when　bent；　the　anticipated　external　angle
  falling　into　its　proper　place　when　the　bar　so　shaped　was　brought　to
  its　ultimate　form。　　In　all