Cuito, July 21. The dispatch boit whicb ariived at Mcmpliia iaturday briaga the following: licpurted escape of the rebel gunbn.it correct. Tlie ifíiir took place on tho mbriting of tho I5th. That mcrning, in oonsequence of repnrts brought by retugoes tbat tho Arkansas as about to attempt to rui) the Federal fleet, tho gunboats Uaroudclet, Tyler and tliu ünm Lancaster started up tho Yhzoo líiver to recnnoitri'. Eight milos t'rom tlic inouth they can;e suddouly upon the ArkutiduB, lying uudtr t lie bank. As our boats rt)undi.-'l tho puint, abe opesied upon tliem with ü lpounders. üur boatb returned tho firc, and for a short time a fieros ungogemont eusued. Fu ding the ebttpuel ot' t lie river preventod uccessful mai ocuvreing, thoy gradual Ty droppod down toward thu niouth, the ArkuriSU foUowliig clonely. Ju-t as the latter was passing over the bar the Garaudolet olDsed with lier, intonding to buard. Sho succecded in throwing grupnel on board and getting out ln;r plank, wlien the ArkauMd oponed ber stcani pipe, tbruwing bol water sores i tho plank. Tho Oaruudulet replied in the same marnier. Whüe ; h us cngiod both vo-suls grnundod. Thesbcok separated thein. and tho Arkausa-i succoodud in getting ofF. 4'iic Carundelut reuiaiueU fast for ne.-uly an liour. Tlie Aikausa.s iiiiinediatcly passed down tlie river, the Tylor prcoêding ber, niaintaining a ruiming Iig!i!. witli her great ly Buperiur advensiirj. None of our irunboU.i w:t!i the fleet had hoir steam lip, and the entire floft was so seattered that few eould tire at tlie ArKnnsas as s!ie jasáod without d.inger ot' bitting our own hu.-.ti. Asshe approitclitiil uueh boa s as Quuld saf ly i!o su oponed upon her, but hor plating rcsisted woit ot'tht! sliöt. íáolid .siiut, from Parriigut'i gun boa t Ni. 6 atruck ber fcirboiird l)(iw, passing ttirough uudör ber plating rippitig it oif for a considerable dwtHnce: W bat forther üanwgo wis done was nol ascertaiued The inju cm to oiir Qiset are Ught. Tlic JJviitiiu rooeived a shot uu. ir iho dü of tlie ttfior part on thu larboard id--, kill ing üiiu iiinn. ÏJie Tjler, whiuli aiignga I tlie Arkuuaua ne.-my mi Loar and .1 liujf, luid soven killirj ajid nino 'oaudnd, uinoitg the latter thu pilot, Subuutinu Hunner, uud Ktigineur D.ivís. Tiiu rain Lancaster rt-oeived u simt under iho joilers, causiiiij tlie escape of trut water, acal di ng s. wen, Lhree of tlieui fatully. T'ne oiiiira Pi-d'-ral loss is twelve killed and tif'rucii wuumiod, Bve or six ut' trlinin will die. Tiiü ri'b.'l loss is not known, but is lelievcd to bavu boen o nsid nbli1, as tl.c lot water tren ns uf ili i Uartuulet, ut tlie tinte sim uttrmpwd bourdiug, wcie tiiruwu direttlj iutu her.