Strabo Geography 4.1.14

[14] Toulouse is situated upon the narrowest part of the isthmus which separates the ocean from the sea of Narbonne; the breadth of the [isthmus], according to Posidonius, being less than 3000 stadia. The perfect similarity maintained throughout this country both in respect to its rivers, and to the exterior and interior sea, ¹ appears to us worthy of especial notice, as we have said before. This, on reflection, will prove to be one main cause of the excellence of this country, since the inhabitants are enabled mutually to communicate, and to procure from each other the necessaries of life; this is peculiarly the case at the present time, when on account of their leisure from war they are devoting themselves to agriculture and the pursuits of social life. In this we are persuaded that we behold the work of Providence; such a disposition of these regions not resulting from chance, but from the thought of some [intelligence]. The Rhone, for instance, is navigable to a considerable distance for vessels of heavy burden, which it is capable of transmitting through various districts of the country by means of other rivers which fall into it, and are likewise fitted for the navigation of large vessels. To the Rhone succeeds the Saone, ² and into this latter river falls the Doubs; thence the merchandise is carried by land to the river Seine; whence it is transported to the ocean and the [countries of the] Lexovii and Caleti, ³ the distance thence to Britain being less than a day’s journey. The navigation of the Rhone being difficult on account of the rapidity of its current, the merchants prefer to transport in waggons certain of their wares, which are destined for the Arverni, ⁴ and the river Loire, ⁵ notwithstanding the vicinity of the Rhone in some places, but the road being level and the distance not far, (about 800 stadia,) they do not make use of water carriage on account of the facility of the transport by land, from thence the merchandise is easily conveyed by the Loire. This river flows from the Cevennes into the ocean. From Narbonne the voyage to the Aude ⁶ is short, but the journey by land to the river Garonne longer, being as much as 700 or 800 stadia. The Garonne likewise flows into the ocean. Such is what we have to say concerning the inhabitants of the Narbonnaise, who were formerly named Kelts. In my opinion the celebrity of the Kelts induced the Grecians to confer that name on the whole of the Galatae; the vicinity of the Massilians may also have had something to do with it. ⁷