the history and practice of the art of photography-第9节

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d　sold　cameras　fully　equal　to　the　German　and　for　which　Voitlander　instruments　have　been　refused　in　exchange　by　the　purchaser。

The　ordinary　camera　box　（see　fig。　5；　a）　varies　in　size　to　suit　the　tube；　and　is　termed　medium；　half；　or　whole。　Within　the　box　is　a　slide　to　assist　in　regulating　the　focus；　and　in　enlarging　or　diminishing　the　picture。　　In　one　end　of　this　slide　is　a　springed　groove　into　which　the　ground…glass　spectrum　（g　fig。　5）　is　slid；　for　the　purpose　of　more　conveniently　arranging　the　focus。　　After　the　plate　is　prepared　it　is　placed　in　the　holder　partly　seen　at　e；　fig。　5；　and　covered　with　the　dark　slide　f；　fig。　5；　the　spectrum　is　then　withdrawn　and　the　holder　takes　its　place；　and　the　lids　d；　d；　are　closed　after　removing　the　dark　slide　f。　The　plate　is　now　ready　to　receive　the　image；　and　the　cap　c　may　be　removed　to　admit　the　light　into　the　box。

A　camera　constructed　by　Voitlander　is　thus　described　by　Mr。　Fisher。　〃It　is　made　entirely　of　brass；　so　that　variations　of　climate　has　no　effect　upon　it。　　It　is　very　portable　and　when　packed　in　its　box；　with　all　the　necessary　apparatus　and　materials　for　practising　the　Daguerreotype　art；　occupies　but　very　little　space。　It　is　not；　however；　well　adapted　for　the　Calotype　process。〃

〃The　brass　foot　A　（fig。　7。）；　is　placed　on　a　table；　or　other　firm　support；　and　the　pillar　B。　screwed　into　it；　the　body　of　the　camera；　C；　C　is　laid　into　the　double　forked　bearing　D。　D。　The　instrument　is　now　properly　adjusted　by　means　of　the　set　screws；　e；　e；　e；　in　the　brass　foot；　or　it　may　be　raised；　lowered；　or　moved；　by　the　telescope　stand；　and　when　correct；　fixed　by　the　screw　b。　　The　landscape　to　be　delineated　is　viewed　either　through　the　　＇hipho_7。gif＇　small　lens；　g；　or　with　the　naked　eye　on　the　ground　glass　plate　H；　the　focus　being　adjusted　by　the　screw　I。　The　optical　part　of　the　instrument　consist　of　the　small　set　of　achromatic　lenses　already　described。　When　the　portrait　or　view　is　deleniated　on　the　ground　glass　to　the　entire　satisfaction　of　the　operator；　the　brass　cap　L　is　placed　over　the　lens；　and　the　entire　body　is　removed　away　into　the　dark；　taking　care　not　to　disturb　the　position　of　the　stand。　The　body　is　now　detached　at　the　part　H；　and　the　prepared　paper　or　plate　enclosed　in　the　brass　frame　work　introduced　in　its　place；　the　whole　is　again　placed　upon　the　pedestal；　the　brass　cap　L　is　removed；　by　which　the　paper　or　plate　is　exposed　to　the　full　influence　of　the　light；　after　which　the　cap　is　again　replaced。

Mr。　Woodbridge；　of　this　city；　has　constructed　an　instrument　for　taking　full　length　portraits　on　plates　10　by　13　inches；　which　is　worthy　of　some　notice。　It　is　a　double　camera；　consisting　of　two　boxes；　placed　in　a　frame；　one　above　the　other；　and　so　arranged　as　to　slide　easily　up　and　down。　After　the　focus　has　been　adjusted；　on　the　object；　in　both　cameras；　the　plate　is　put　into　the　upper　box；　in　the　manner　already　described；　until　the　superior　portion　of　the　figure　is　complete；　it　is　then　placed　in　the　second　box　and　the　lower　extremities　obtained。　The　adjustment　of　the　instrument　is　so　complete　that　　＇hipho_8。gif＇　a　perfect　union　of　the　parts　is　effected　in　the　picture　without　the　least　possible　line　of　demarkation　being　visible。　　Fig。　8　gives　a　front　view　of　this　instrument。

Fig。　9　represents　Talbot's　Calotype　Camera；a　very　beautiful　instrument。

The　copying　camera　box　has　an　extra　slide　in　the　back　end；　by　which　it　may　be　considerably　lengthened　at　pleasure。

II。CAMERA　STAND。The　best　constructed　stands　are　made　of　maple　or　blackwallnut　wood；　having　a　cast　iron　socket　（a；　fig。　　12；）　through　which　the　sliding　rod　b　passes；　and　into　which　the　legs　c；　c；　with　iron　screw　ferules　are　inserted。　The　platform　d　is　made　of　two　pieces；　hinged　together；　as　at　e；　and　having　a　thumb　screw　for　the　purpose　of　elevating　or　depressing　the　instrument。　　＇hipho_9。gif＇

III。　MERCURY　BATH。Fig。　13　gives　a　front　view　of　the　mercury　bath　now　in　general　use　in　this　country　for　mercurializing　and　bringing　out　the　picture。　　It　is　quite　an　improvement　on　those　first　used。　To　make　it　more　portable　it　is　in　three　pieces；　a　b　and　c；　having　a　groove　e　on　one　side　to　receive　the　thermometre　tube　and　scale　by　which　the　proper　degree　of　heating　the　mercury　is　ascertained。　Into　the　top　are　nicely　fitted　two　or　three　iron　frames；　with　shoulders；　for　the　plate　to　rest　in；　suitable　for　the　different　sizes　of　plates。　The　bath　is　heated　by　means　of　a　spirit　lamp　placed　under　it。　From　two　to　four　ounces　of　highly　purified　mercury　are　put　into　the　bath　at　a　time。

IV。　PLATE　BLOCKS　AND　VICES。There　are　several　kinds　of　this　article　in　use；　I　shall　describe　the　two　best　only。

Fig。　10　gives　an　idea　of　the　improvement　on　the　English　hand　block。　The　top　a　is　perfectly　flat　　＇hipho_10。gif＇　and　smootha　little　smaller　than　the　plate；　so　as　to　permit　the　latter　to　project　a　very　little　all　aroundhaving　at　opposite　angles　c　c　two　clasps；　one　fixed　the　other　moveable；　but　capable　of　being　fastened　by　the　thumb　screw　d；　so　as　to　secure　the　plate　tightly　upon　the　block。　This　block　turns　upon　a　swivle；　b；　which　is　attached　to　the　table　by　the　screw　c；　This　block　is　only　used　for　holding　the　plate　while　undergoing　the　first　operation　in　cleaning。　　＇hipho_11。gif＇

Fig。　11；　shows　the　form　of　Lewis'　newly　patented　plate　vice；　which　for　durability；　simplicity　and　utility　is　preferable　to　all　others。　It　consists　of　a　simple　platform　and　arm　of　cast　iron；　the　former；　a；　having　a　groove；　d；　in　the　centre　for　fixing　the　different　sizes　of　plate　beds；　eand　the　latter　supporting　the　leaves；　e　f。　On　this　vice　which　is　secured　to　a　table；　or　bench；　the　plate　receives　its　finishing　polish　with　rouge；　or　prepared　lampblack。　Mr。　Lewis　gives　the　following　directions　for　its　use。　　〃As　the　cam　wears　tighten　it　with　the　adjusting　screw　（g）　so　as　to　allow　the　lever　（f）　to　fall　back　into　a　horizontal　position；　the　plate　being　in　its　place　at　the　time。　　Oil　the　wearing　parts　occasionally。〃

Some　Daguerreotypists；　however；　use　a　foot　lathe　with　buff　wheels　of　various　forms；　but　this　vice　is　sufficient　for　all　ordinary　purposes。

V。　COATING　BOXES。The　usual　form　for　iodine　and　　＇hipho_12。gif＇　　＇hipho_13。gif＇　bromine　boxes　is　see；　at　figs。　14　and　15。　　They　are　far　superior　to　those　in　use　with　the　English　operators。　Each　consists　of　a　wooden　box　（a；）　having　firmly　embeded　within　it　a　stout　glass　jar　（c）；　the　edges　of　which　are　ground。　Over　this　is　placed　the　sliding　cover　b；　double　the　length　of　the　box；　one　half　occupied　by　a　piece　of　ground　glass　（e）；　tightly　pressed　upon　the　glass　pot　by　a　spring　（i）　beneath　the　cross　bar　g；　and　fits　the　pot　so　accurately　that　it　effectually　prevents　the　escape　of　the　vapor　of　the　iodine；　bromine　or　other　accelerating　liquid　contained　therein。　The　other　half　of　the　lid　is　cut　through；　shoulders　being　left　at　the　four　angles　for　the　different　sizes　of　frames；　designed　to　recieve　the　plate　while　undergoing　the　coating　process。　When　the　plate　is　put　into　the　frame；　the　cover　b　is　shoved　under　the　second　lid　h　and　when　coated　to　the　proper　degree；　it　resumes　its　former　position　and　the　plate　is　placed　in　the　holder　of　the　camera　box。　　To　test　the　tightness　of　the　box；　light　a　piece　of　paper；　put　it　into　the　pot　and　cover　it　with　the　sliding　lid。　The　burning　paper　expels　the　air　from　the　pot；　and　if　it　be　perfectly　tight　you　may　raise　the　whole　box　by　the　lid。

VI。　GLASS　FUNNELS。Are　a　necessary　article　to　the　Daguerreotypist；　for　filtering　water；　solutions；　&c。　　＇hipho_14。gif＇

VII。　GILDING　STAND。For　nervous　persons　the　gilding　stand　is　a　useful　article。　　It　is　adjusted　to　a　perfect　level　by　thumb　screws　placed　in　its　base。

VIII。　SPIRIT　LAMPS。The　most　useful　and　economical　of　those　made　are　the　Britania；　as　they　are　less　liable　to　break；　and　the　tube　for　the　wick　being　fastened　to　the　body　by　a　screw　renders　it　less　liable　to　get　out　of　order　or　explode。　Glass　is　the　cheapest；　and　for　an　amateur　will　do　very　well；　but　for　a　professed　artist　the　Britania　should　always　be　obtained。

IX。　　COLOR　BOX。These　are　generally　found　on　sale　at　the　shops；　and　usually　contain　eight　colors；　four　brushes　and　a　gold　cup。　The　artist　would；　however；　do　well　to　obtain；　all　the　colors　mentioned　in　the　last　chapter　of　this　work；　and　be　sure　to　get　the　very　best；　as　there　are　various　qualities　of　the　same　color；　particularly　carmine；　which　is　very　expensive；　and　the　cupidity　of　some　may　induce　them　to　sell　a　poor　article　for　the　sake　of　larger　profits。　　＇hipho_15。gif＇

STILL。Daguerreotypists　should　always　use　distilled　water　for　solutions；　and　washing　the　plate；　as　common　water　holds　various　substances　in　solution　which　detract　very　materially　from　the　excellence　of　a　photograph；　and　often　gives　much　trouble；　quite　unaccountable　to　many。　For　the　purpose　of　distilling　water　the　apparatus　represented　at　Fig。　16　is　both　convenient　and　economical。

It　may　be　either　wholly　of　good　stout　tin；　or　of　sheet　iron　tinned　on　the　inside；　and　may　be　used　over　a　common　fire；　or　on　a　stove。　A　is　the　body；　which　may　be　made　to　hold　from　one　to　four　gallons　of　water；　which　is　introduced　at　the　opening　b；　which　is　then　stopped　by　a　cork。　The　tube　d　connects　the　neck　a　of　the　still　with　the　worm　tub；　or　refrigerator　B；　at　e；　which　is　kept　filled　with　cold　water　by　m