Polychronicon Ranulphi Higden maonachi Cestrensis; together with the English translations of John Trevisa and of an unknown writer of the fifteenth century.
Higden, Ranulf, d. 1364., Trevisa, John, tr. d. 1402., Caxton, William, ca. 1422-1491., Malverne, John, d 1415?, Babington, Churchill, ed. 1821-1889,, Lumby, J. Rawson ed. (Joseph Rawson), 1831-1895.
Page  49, vol.2

De famosis fluminibus. Capitulum quadragesimum sextum.

Alfridus. Thre famous ryueres renneþ þoruȝ Britayne; by þe whiche þre ryueres marchaundis of byȝonde see comeþ in schippes into Bretayne wel nyh oute of alle manere naciouns and londes. Þe*. [These, Cx.] þre ryueres beeþ Themse, Seuarne, and Humber. Þe see ebbeþ and floweþ at þe mouþes of þese*. [the, Cx.] þre ryueres, and departeþ [þe]*. [Added from α. and Cx.] þre prouinces of þe ilondes, as hit were þre kyngdoms, for to wynne;*. [a sondre, Cx., who probably read atwynne (as in β. and γ.); the text seems cor|rupt.] þe þre parties beeþ Loegria, Cambria, and Norþhumbria, þat beeþ Wales, Engelond,*. [myddel Englond, Wales, Cx.] and Northumberlond. ℞.*. [α. omits ℞.] [Þis]*. [Added from α.; these, Cx.] name Temse*. [Themse, α.] semeþ i-made oo name of tweye names of ryueres,*. [two riuers, Cx.] þat beeþ Tame and Ise. For þe ryuer Tame renneþ bysides Dorchestre, and falleþ in Ise; þerfore al þe ryuer from þe first heede anon to þe est see hatte Temse. Temse bygynneþ bysides Tettebury, þat is þre myle by norþ Malmesbury; þere Temse springeþ of a welle and renneþ estward, and passeþe þe Fosse, and departeþ Glowcetreschire and Wilt|schire, and draweþ wiþ hym meny oþer welles stremes,*. [and stremes, Cx.] and wexeþ grete at Grecestre, and passeþ forþ þanne toward Bamptoun,*. [Hampton, Cx.] and so forþ by Oxenforde, by Walyngforde, by Page  51, vol.2 Redynge, and by Londoun. Willelmus de Pontificibus, libro secundo.*. [Reference added from Cx., who has c. (i.e. capitulo) for libro.] At þe hauen of Sandwhiche it falleþ into þe est see, and holdeþ his name fourty myle byȝond Londoun, and departed somtyme*. [in som place, Cx.] bytwene Kent and Essex, Westsex and Mer|cia; þat is as hit were a greet deel of [myddel]*. [Added from α. and Cx.] Engelonde. Seuarn is a ryuer of Bretayne, and hatte Habren [in Britoun, and haþ þat name Habren of Habren],*. [Added from α. and Cx., who has Britons.] þat was Estrildes douȝter. Guedolen þe quene drenched þis Habren þerynne; þerfore þese*. [the, Cx.] Bretouns cleped þe ryuer Habren after þe womman þat was adraynt [þerynne],*. [Added from α. and Cx.] but by corupte Latyn tonge hit hatte Sabryna, Seuarne on Englische. Seuarne byginneþ in þe myddel of Wales, and passeþ first toward þe est anon to Schroesbury, and þan torneþ souþward anon to Brigge-norþ, Wircetre, and Gloucetre, and falleþ in to þe west see besides Brystowe, and departed somtyme*. [departeth in somme place, Cx.] bytwene Engelond and Wales. Willelmus de Pontificibus, libro quarto. Seuarne is swift of streme, fische craft is þere ynne, woodnesse of swolwynge and of whirlynge water casteþ vp and gadereþ to hepe grete hepes of grauel. Seuarne is ofte vppe*. [ofte aryseth, Cx.] and Page  53, vol.2 passeþ þe brynkes.*. [brymmes, α.; ouerfloweth the bankes, Cx.] ℞. Humber haþ þe name of Humber, kyng of Hunes, for he was adreynt*. [drowned, Cx., and so often.] þerynne, and renneþ first a crook out of þe south side of York, and þanne departeþ þe prouince of Lyndeseye*. [Lyndeceie, α.] þat longede somtyme to þe Merces from þe oþer contray Norþumberlond. Trent and Owse*. [Ouse, α.] renneþ*. [and renneþ, MS. (not Cx.)] in to Humber, and makeþ the ryuer ful greet. Tre|uisa. Þe Merces were men as hit were of myddel Engelond, as it is i-seide wiþ ynne.*. [as it shal be sayd here after, Cx.]