an autobiography-第78部分

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For　particulars　and　details；　see　Report　of　Torpedo　Committee。


1839。　A　Double…faced　Wedge…shaped　Sluice…Valve　for　Main　Street　　　　　　　Water…pipes。

The　late　Mr。　Wicksteed；　engineer　of　the　East　London　Water　Company；　having　stated　to　me　the　inconvenience　which　had　been　experienced　from　the　defects　in　respect　of　water…tightness；　as　well　as　the　difficulty　of　opening　and　closing　the　valves　of　the　main　water…pipes　in　the　streets；　I　turned　my　attention　to　the　subject。　　The　result　was　my　contrivance　of　a　double…faced　wedge…shaped　sluice…valve；　which　combined　the　desirable　property　of　perfect　water…tightness　with　ease　of　opening　and　closing　the　valve。

This　was　effected　by　a　screw　which　raised　the　valve　from　its　bearings　at　the　first　partial　turn　of　the　screw；　after　which　there　was　no　further　resistance　or　friction；　except　the　trifling　friction　of　the　screw　in　its　nut　on　the　upper　part　of　the　sluice…valve。　　When　screwed　down　again；　it　closed　simultaneously　the　end　of　the　entrance　pipe　and　that　of　the　exit　pipe　attached　to　the　valve　case　in　the　most　effective　manner。　

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Mr。　Wicksteed　was　so　much　pleased　with　the　simplicity　and　efficiency　of　this　valve　that　he　had　it　applied　to　all　the　main　pipes　of　his　Company。　When　its　advantages　became　known；　I　received　many　orders　from　other　water　companies；　and　the　valves　have　since　come　into　general　use。　The　prefixed　figure　will　convey　a　clear　idea　of　the　construction。　The　wedge　form　of　the　double…faced　valve　is　conspicuous　as　the　characteristic　feature　of　the　arrangement。*　　＇footnote。。。　At　a　meeting　of　the　Institution　of　Civil　Engineers；　May　23；　1883；　when　various　papers　were　read　on　Waterworks；　Mr。　H。　I。　Marten　observed　in　the　course　of　the　discussion：　〃It　has　been　stated　in　Mr。　Gamble's　paper　（on　the　waterworks　of　Port　Elizabeth）　that　the　sluice　valves　are　of　the　usual　pattern。　　The　usual　patterns　of　the　present　day　are　in　wonderful　advance　of　those　of　thirty　or　forty　years　since。　　The　great　improvement　originated　with　the　introduction　of　'the　double…faced　sluice…cock。'　This　sluice…cock；　which　had　now　superseded　every　other　description；　was　the　creation　of　Mr。　James　Nasmyth's　inventive　genius。　Mr。　Marten　said　he　well　remembered　the　first　reception　of　this　useful　invention；　as　he　happened　at　that　time　to　be　a　pupil　of　Mr。　Thomas　Wicksteed。　　He　was　present　when　Mr。　Wicksteed　explained　to　Mr。　Nasmyth　the　want　he　had　experienced　of　a　sluice…cock　for　Waterworks　purposes；　which　should　shut　and　remain　perfectly　tight　against　a　pressure　coming　from　either　side。　　Mr。　Marten　had　a　lively　recollection　of　the　instantaneous　rapidity　with　which　Mr。　Nasmyth　not　only　grasped　but　provided　for　the　requirement；　so　that　almost　by　the　time　Mr。　Wicksteed　had　completed　the　statement　of　his　want；　Mr。　Nasmyth　had　drawn　upon　the　back　of　an　old　letter　a　rough　sketch　of　the　first　double…faced　sluice…cock；　and　in　less　than　an　hour　had　converted　this　rough　sketch　into　a　full…sized　working　drawing；　in　the　preparation　of　which　it　fell　to　Mr。　Marten's　lot　to　have　the　honour　to　assist。　　In　his　'Autobiography'　Mr。　Nasmyth　referred　to　the　conversation　with　Mr。　Wicksteed；　and　introduced　a　print　of　the　drawing　made　upon　the　occasion。　　The　invention　has　been　of　the　greatest　use　to　the　Waterworks　Engineer；　especially　in　connection　with　the　constant　supply　system；　in　which　it　frequently　happened　that　the　pressure　was　sometimes　against　one　face　of　the　sluice…cock；　and　sometimes　against　the　other。〃　See　Proceedings　and　Discussions　of　the　Institution　of　Civil　Engineers；　1883；　pp。　88；　89。　　。。。＇


1839。　A　Hydraulic　Mattress　Press；　capable　of　exerting　a　pressure　of　　　　　　　Twenty　thousand　tons。

Being　under　the　impression　that　there　are　many　processes　in　the　manufacturing　arts；　in　which　a　perfectly　controllable　compressing　power　of　vast　potency　might　be　serviceable；　I　many　years　ago　prepared　a　design　of　an　apparatus　of　a　very　simple　and　easily　executed　kind；　which　would　supply　such　a　desideratum。　　It　was　possessed　of　a　range　of　compressing　or　squeezing　　power；　which　far　surpassed　anything　of　the　kind　that　had　been　invented。　　As　above　said；　it　was　perfectly　controllable；　so　as　either　to　yield　the　most　gentle　pressure；　or　to　possess　the　power　of　compressing　to　upwards　of　twenty　thousand　tons；　the　only　limit　to　its　power　being　in　the　materials　employed　in　its　construction。

The　principle　of　this　enormously　powerful　compressing　machine　is　similar　to　that　of　the　Hydraulic　Press；　the　difference　consisting　principally　in　the　substitution　of　what　I　term　a　Hydraulic　Mattress　in　place　of　the　cylinder　and　ram　of　the　ordinary　hydraulic　press。　The　Hydraulic　Mattress　consists　of　a　square　or　circular　water…tight　vessel　or　flat　bag　formed　of　1/2…inch　thick　iron　or　steel　plates　securely　riveted　together；　its　dimensions　being；　say　15　feet　square　by　3　feet　deep；　and　having　semicircular　sides；　which　form　enables　the　upper　flat　part　of　the　Mattress　to　rise　say　to　the　extent　of　6　inches；　without　any　injury　to　the　riveted　joints；　as　such　a　rise　or　alteration　of　the　normal　form　of　the　semicircular　sides　would　be　perfectly　harmless；　and　not　exceed　their　capability　of　returning　to　their　normal　curve　when　the　6…inch　rise　was　no　longer　necessary；　and　the　elevating　pressure　removed。

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The　action　of　this　gigantic　press　is　as　follows。　　The　Mattress　A　A　having　been　filled　with　water；　an　additional　quantity　is　supplied　by　a　force　pump；　capable　of　forcing　in　water　with　a　pressure　of　one　ton　to　the　square　inch；　thus　acting　on　an　available　surface　of　at　least　144　square　feet　surfacenamely；　that　of　the　upper　flat　surface　of　the　Mattress。　　It　will　be　forced　up　by　no　less　a　pressure　than　twenty　thousand　tons；　and　transfer　that　enormous　pressure　to　any　article　that　is　placed　between　the　rising　table　of　the　press　and　the　upper　table。　When　any　object　less　thick　than　the　normal　space　is　required　to　receive　the　pressure；　the　spare　space　must　be　filled　with　a　suitable　set　of　iron　flat　blocks；　so　as　to　subject　the　article　to　be　pressed　to　the　requisite　power。

As　before　stated；　there　may　be　many　processes　in　the　manufacturing　arts　in　which　such　an　enormous　pressure　may　be　useful；　and　this　can　be　accomplished　with　perfect　ease　and　certainty。　　I　trust　that　this　account　of　the　principles　and　construction　of　such　a　machine　may　suggest　some　employment　worthy　of　its　powers。　　In　the　general　use　of　the　Mattress　press；　it　would　be　best　to　supply　the　pressure　water　from　an　accumulator；　which　should　be　kept　constantly　full　by　the　action　of　suitable　pumps　worked　by　a　small　steam…engine。　　The　great　press　would　require　the　high…pressure　water　only　now　and　then；　so　that　it　would　not　be　necessary　to　wait　for　the　small　pump　to　supply　the　pressure　water　when　the　Mattress　was　required　to　be　in　action。


1840。　A　Tapping　Square；　or　instrument　by　which　Perfect　Verticality　of　　　　　　　the　Tapping　of　Screwed　Holes　is　insured。

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The　letter　X　shows　how　Screws　are　frequently　made　when　tapped　in　the　old　mode；　the　letter　T　as　they　are　always　made　when　the　Tapping　Square　is　employed。


1840。　A　Mode　of　turning　Segmental　Work　in　the　Ordinary　Lathe

In　executing　an　order　for　twenty　locomotive　engines　for　the　Great　Western　Railway　Company；　there　was　necessarily　a　repetition　of　detail　parts。　　Many　of　them　required　the　labour　of　the　most　skilful　workmen；　as　the　parts　referred　to　did　not　admit　of　their　being　executed　by　the　lathe　or　planing…machine　in　their　ordinary　mode　of　application。　But　the　cost　of　their　execution　by　hand　labour　was　so　great；　and　the　risk　of　inaccuracy　was　so　common　（where　extreme　accuracy　was　essential）；　that　I　had　recourse　to　the　aid　of　special　mechanical　contrivances　and　machine　tools　for　the　purpose　of　getting　over　the　difficulty。　The　annexed　illustration　has　reference　to　only　one　class　of　objects　in　which　I　effected　great　saving　in　the　production；　as　well　as　great　accuracy　in　the　work。　　It　refers　to　a　contrivance　for　producing　by　the　turning…lathe　the　eighty　bands　of　the　eccentrics　for　these　twenty　engines。　　Being　of　a　segmental　form；　but　with　a　projection　at　each　extremity；　which　rendered　their　production　and　finish　impossible　by　the　ordinary　lathe；　I　bethought　me　of　applying　what　is　termed　the　mangle　motion　to　the　rim　of　a　face　plate　of　the　lay；　with　so　many　pins　in　it　as　to　give　the　required　course　of　segmental　motion　for　the　turning　tool　to　operate　upon；　between　the　projections　C　C　in　the　illustration。

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I　availed　myself　of　the　limited　to…and…fro　horizontal　motion　of　the　shaft　of　the　mangle　motion　wheel；　as　it；　at　each　end　of　the　row　of　pegs　in　the　face　plate　（when　it　passes　from　the　exterior　to　the　interior　range　of　them）　in　giving　the　feed　motion　to　the　tool　in；　the　slide　rest；　〃turned〃　the　segmental　exterior　of　the　eccentric　hoops。　This　it　did　perfectly；　as　the　change　of　position　of　the　small　shaft　occurred　at　the　exact　time　when　the　cut　was　at　its　termination；that　being　the　correct　moment　to　give　the　tool　〃the　feed；　or　advance　for　the　taking　of　the　next　cut。　　The　saving；　in　respect　to　time；　was　10　to　1　in　comparison　with　the　same　amount　of　work　done　by　hand　labour；　while　the　〃truth〃　or　correctness　of　the　work　done　by　this　handy　little　application　of　the　turning…lathe　was　absolutely　perfect　I　have　been　the　more　particular　in　my　allusion　to　this　contrivance；　as　it　is　applicable　to　any　lathe；　and　can　perform　work　which　no　lathe　without　it　can　accomplish。　　The　unceasing　industry　of　such　machines　is　no　small　addition　to　their　attractions；　in　respect　to　the　production　of　unquestionably　accurate　work。


1843。　Invention　of　the　Steam　Hammer　Pile…driver。

Described　in　text；　p。　261。


1843。　A　Universal　Flexible　Joint　for　Steam　and　Water…pipes。

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The　chief　novelty　in　this　swivel　joint　is　the　manner　in　which　the　packing　of　the　joints　is　completely　enclosed；　thereby　rendering　them　perfectly　and　permanently　watertight。


1844。　An　Improvement　in　Blowing　Fans　and　their　Bearings。

The　principle　on　which　Blowing　Fans　act；　and　to　which　they　owe　their　efficiency；　consists　in　their　communicating　Centrifugal　action　to　the　air　within　them。

In　order　to　obtain　the　maximum　force　of　blast；　with　the　minimum　expenditure　of　power；　it　is　requisite　so　to　form　the　outside　rim　of　the　Fan…case　as　that　each　compartment　formed　by　the　space　between