There shall be established no sea or river toll, based on the sole fact of navigation, nor any duty on the goods which happen to be on board the ships. Only such taxes and dues shall be levied as are of the nature of a payment for services rendered to the said navigation. The tariff of these taxes or dues shall admit of no differential treatment. ARTICLE XXVIII. The affluents of the Niger shall in every respect be subject to the same regulations as the river of which they are the tributaries. ARTICLE XXIX. Roads, railways or lateral canals, which shall be established with the special object of supplementing the innavigability or other imperfections of the waterway, in certain sections of the course of the Niger, its affluents, its branches, and its issues, shall be considered, in their capacity of means of communication, as dependencies of the river and shall be open similarly to the traffic of all nations, As on the river, there shall be levied on the roads, railways and canals, only such tolls as are calculated on the expenses of construction, maintenance and administration, and on the profits due to the promoters. In the assessment of these tolls, foreigners and the inhabitants of the respective territories, shall be treated on a footing of perfect equality. ARTICLE XXX. Great Britain undertakes to apply the principles of freedom of navigation annunciated in Articles XXVI., XXVII., XXVIII., XXIX., to so much of the waters of the Niger and its affluent branches and issues as are or shall be under her sovereignty or protectorate. The regulations she will draw up for the safety and control of the navigation, shall be designed to facilitate, as much as possible, the passage of merchant shipping. It is understood that nothing in the engagements thus accepted shall be interpreted as hindering or likely to hinder Great Britain from making any regulations whatever as to the navigation which shall not be contrary to the spirit of such engagements. Great Britain undertakes to protect foreign traders of every nation engaged in commerce in those parts of the course of the Niger, which are or shall be under her sovereignty or protectorate, as if they were her own subjects, provided that such traders conform to the regulations which are or shall be established in accordance with the foregoing. ARTICLE XXXI. France accepts, under the same reservations and identical terms, the obligations set forth in the preceding articles, so far as they apply to the waters of the Niger, its affluents, its branches and its issues, which are or shall be under her sovereignty or protectorate. ARTICLE XXXII. Each of the other Signatory Powers similarly undertake, that they will similarly act in such cases as they exercise or may hereafter exercise, rights of sovereignty or protectorate, in any part of the Niger, its affluent branches or issues. ARTICLE XXXIII.