Havingtakenonboardamonth’srationsforallhands，westarted；and，withastrongbreezeinourfavour，wereachedtheSobatjunctionon16thFebruary，at12。30p。m。
Therewetookinfreshwater，asthatoftheSobatissuperiortotheWhiteNile。Atthisseasontheriverwasabouteightfeetbelowthelevelofthebank。ThewateroftheSobatisyellowish，anditcoloursthatoftheWhiteNileforagreatdistance。BydeadreckoningImadetheSobatjunction684milesbyriverfromKhartoum。
WhenIsawtheSobat，inthefirstweekofJanuary1863，itwasbank-full。Thecurrentisverypowerful，andwhenIsoundedinvariousplacesduringmyformervoyage，Ifoundadepthoftwenty-sixtotwenty-eightfeet。ThevolumeofwaterbroughttotheNilebythisriverisimmense，andthepowerofthestreamissosuperiortothatoftheWhiteNile，thatasitarrivesatrightangles，thewatersoftheNilearebankedup。TheyellowwateroftheSobatformsadistinctlineasitcutsthroughtheclearwaterofthemainriver，andthefloatingraftsofvegetationbroughtdownbytheWhiteNile，insteadofcontinuingtheirvoyage，areheadedback，andremainhelplesslyinthebackwater。
ThesourcesoftheSobatarestillamystery；buttherecanbenodoubtthattheprincipalvolumemustbewaterofmountainorigin，asitiscolouredbyearthymatter，andisquiteunlikethemarshwateroftheWhiteNile。Theexpeditionsoftheslave-huntershaveascendedtheriverasfarasitisnavigable。Atthatpointsevendifferentstreamsconvergeintoonechannel，whichformsthegreatriverSobat。ItismyopinionthatsomeofthesestreamsaretorrentsfromtheGallacountry，whileothersarethecontinuationofthosesouthernriverswhichhavelatelybeencrossedbytheslave-huntersbetweenthesecondandthirddegreesofN。latitude。
TheWhiteNileisagrandriverbetweentheSobatjunctionandKhartoum，andafterpassingtothesouthofthegreataffluentthedifferenceinthecharacterisquicklyperceived。Wenowenterupontheregionofimmenseflatsandboundlessmarshes，throughwhichtheriverwindsinalabyrinth-likecourseforabout750milestoGondokoro。