St. Germain en Lay (29 March, 1679), whereby the King of Sweden ceded to the elector of Brandenburg all his possessions on the right bank of the Oder, retaining his possession of the left bank, and whereby it was further expressly provided, that the river Oder itself should for ever remain under the Sovereignty of the Crown of Sweden, and that the Elector of Brandenburg should not erect any fortifications upon the bank ceded to him 20. This exceptional arrangement had its origin most probably in the previous dispositions of the Treaty of Westphalia, by which the Sovereignty of the Crown of Sweden over the river Oder was secured for ever, and with which, as forming part of the Public Conventional Law of Europe, the Treaty of St. Germain en Lay was made to accord.

Treaties, whereby a river has been ceded in its entirety (en entier) have been held to transfer not only the possession of the entire channel of the river, but both its banks as inseparable accessories to the river. Thus by the Treaty of Warsaw (18 Sept. 1773), Poland agreed that the entire river Netze should belong to Prussia, and Prussia contended, and was ultimately successful in her contention, that the cession of the entire river implied the cession of the stream and both its banks. By a like interpretation, Sweden having obtained under the Treaty of Osnabruck (24 Oct. 1648) the cession of the entire river Oder from the Emperor of Germany, was held to have acquired thereby possession of a margin of two German miles on the further bank, as an inseparable accessory to

20 La rivière de l'Oder, suivant les dispositions des traités de Westphalie, demeurera toujours en souverainté au Roi et à la couronne de Suède, et il ne sera pas libre au dit Electeur de Bran

denbourg d'ériger aucune forteresse ou de fortifier aucune place dans l'entrevue du Pays qui lui est cédé par le présent Traité.— Dumont, Corps Diplomatique, XIII. p. 408.

the stream. To what extent the use of the land on the bank or banks of a river may be regarded as accessory to the use of the stream, has been a subject of dispute. Prussia, in her dispute with Poland respecting the effect of her cession of the river Netze en entier, went so far as to claim all such portions of the opposite bank as the waters of the river in a state of inundation overflowed, as well as the marshes caused by such inundations, which claim Gunther 2 considers to have been in conformity with usage.

ge

It is obvious however that such a principle, if nerally applied, might lead to great complications. A different and a more definite principle was adopted by Russia in the Treaty of Adrianople concluded with the Ottoman Porte 22 (24 Sept. 1829). By this Treaty, the Porte in effect ceded the river Danube between the Pruth and the Black Sea in its entirety to Russia, for it was provided by Article III, that the frontier line should follow the course of the Danube from the confluence of the Pruth to the St. George's mouth, leaving all the Islands in possession of Russia, and the right bank of the Danube in possession, as heretofore, of the Porte. But it was further agreed that from the point where the St. George's branch separated from the Sulina branch of the Danube, the right bank of the river should remain uninhabited for the distance of two hours 23, and that no establishment of any kind should be formed upon it within that limit. Such a provision, whilst it effectively secured the navigation of the river from any control on the part of the Porte by virtue of its possession of the southern bank of the Danube, did not tend in any way to impair the

21 Gunther, t. II. § 14.

22 Martens, N. R., t. VIII. p. 144.

23 Deux heures,' probably about two German miles, 'Zwei Stünde.'

integrity of the Porte's possession of that bank. On the other hand, the rule of interpretation, whereby the cession of a river en entier implies the cession of both its banks, as contended for by Prussia in the case of the river Netze, might operate to deprive a Nation of an important land-frontier, whilst it has in terms only ceded possession of a water-frontier.

tional Law

great rivers of Europe.

145. It was formerly the policy of Nations to con- Convensider rivers, equally with mountains, to be natural as to the barriers, and to regard them as turned to the most useful purpose when employed as lines of international demarcation. Thus Grotius, borrowing a term of Law from the Civilians, writes, "But in any doubt of the bounds of a State, those lands that reach to some river are to be reckoned as arcifinious, because nothing is so proper to distinguish jurisdiction as that which is of such a nature that it is not easily passed over24" The exclusive right to the use of a river has been accordingly maintained with great jealousy by Nations, as an important international right, seeing that a river might under such circumstances be converted into a fortified frontier. The Conventional Law of Europe has, in modern times, been adapted to larger and less selfish views. Thus the great navigable rivers of the Continent, which in their passage to the Ocean intersect various lands, sometimes passing through Territory in the exclusive possession of one and the same Nation, at another time forming a common boundary between the Territories of two or more Nations, and of which the navigation has been heretofore in some parts totally impeded, and in others so burdened with tolls, that they had ceased to be profitable as highways of commerce, are now regarded as the instruments of Nature to cement the peaceful 24 De Jure B. et P., L. II. c. 3. §. 17. 2.

The Thalweg or Midchannel of a River the

of Conter

relations of mankind, by facilitating their mutual intercourse. It was one of the most beneficial arrangements of the Congress of Vienna, that the Powers there assembled agreed, that the navigable rivers which traversed or separated their respective States, should be open for commercial purposes to the navigation of vessels of all Nations, from the places where they became navigable to their mouths, subject to an uniform system of police and tolls, to be settled by common accord 25. The Treaty of Paris 26, (30 March 1856,) has applied to the river Danube and its mouths the same rule of law which had been applied by the Christian Powers assembled at Vienna to the rivers within their respective Territories, and has recorded that this arrangement with the Ottoman Porte forms part of the Public Law of Europe. The Right of Empire over any of the great navigable rivers of Europe has thus ceased to confer any exclusive privilege upon the Nation which enjoys that Right; on the contrary, each Riverain State is under a conventional obligation to remove all obstacles to Navigation which may arise in the bed of the river within its Territory, and to maintain the banks and towing paths, and other accessories to the Navigation, in such a condition as will most favour the circulation of the Merchant Vessels of all Nations.

§ 146. If the opposite banks of a navigable river are in the possession of two Nations, and neither Nation can prove that itself, or the Nation from which Boundary it may have derived its title, was established on the one bank prior to the occupation of the other bank by the other Nation, each will have a Right of Empire and Dominion over the river as far as the midchannel or Thalweg. "Pour ce qui est des fleuves et 25 Martens, N. R. II. p. 428. p. 776.

minous

States.

26 N. R. Général XV.

lacs frontières, dont la rive opposée est également occupée, leur milieu, y compris les îles que traverse la ligne du milieu, sépare ordinairement les territoires. Au lieu de cette ligne on a nouvellement choisi pour frontière le Thalweg, c'est à dire le chemin variable que prennent les bateliers, quand ils vont aval, ou plutôt le milieu de ce chemin". 26 Grotius and Vattel speak of the middle of the river as the line of demarcation" between two jurisdictions, but modern publicists and statesmen prefer the more accurate and more equitable boundary of the Midchannel. If there be more than one channel of a river, the deepest channel is the Midchannel for the purposes of territorial demarcation; and the boundary line will be the line drawn along the surface of the stream corresponding to the line of deepest depression of its bed. Thus we find in the Treaty of Argovie, (17 Sept. 1808,) concluded between the Grand Duchy of Baden and the Helvetic Canton of Argovie, that the Thalweg, or water-frontier line, is defined to be "the line drawn along the greatest depth of the stream," and as far as bridges are concerned, "the line across the middle of each bridge." The islands on either side of the Midchannel are regarded as appendages to either bank; 29 and if they have once been taken possession of by the Nation to whose bank they are appendant,

26 Klüber, Droit des Gens, $133.

27 Grotius, L. II. c. 3. § 18. Vattel, L. c. 22. § 266.

28 Martens, N. R. T. I. p. 140. 29 Such is the general law, but by treaty the midchannel may be made the water-boundary, yet all the islands in the river belong to one Power. Thus by the Convention of 9 Feb. 1776, between

28

the King of Poland and the Empress Maria Theresa, all the islands in the river Vistula, within the limits of the Convention, with the exception of that in which the town of Casimir is situated, were ceded to her Imperial and Royal Majesty, whilst half the bed of the river was declared to belong to each Power. Martens, Recueil, T. II. p. 127.