[367] See Perels, p. 30.
[368] See below, [vol. II. § 84].
IX BOUNDARIES OF STATE TERRITORY
Grotius, II. c. 3, § 18—Vattel, I. § 266—Hall, § 38—Westlake, I. pp. 141-142—Twiss, I. §§ 147-148—Taylor, § 251—Moore, I. §§ 154-162—Bluntschli, §§ 296-302—Hartmann, § 59—Heffter, § 66—Holtzendorff in Holtzendorff, II. pp. 232-239—Gareis, § 19—Liszt, § 9—Ullmann, § 91—Bonfils, Nos. 486-489—Despagnet, No. 377—Pradier-Fodéré, II. Nos. 759-777—Mérignhac, II. p. 358—Nys, I. pp. 413-422—Rivier, I. § 11—Calvo, I. §§ 343-352—Fiore, II. Nos. 799-806, and Code, Nos. 1040-1049—Martens, I. § 89—Lord Curzon of Kedleston, "Frontiers" (Romanes lecture of 1907).
Natural and Artificial Boundaries.
§ 198. Boundaries of State territory are the imaginary lines on the surface of the earth which separate the territory of one State from that of another, or from unappropriated territory, or from the Open Sea. The course of the boundary lines may or may not be indicated by boundary signs. These signs may be natural or artificial, and one speaks, therefore, of natural in contradistinction to artificial boundaries. Natural boundaries may consist of water, a range of rocks or mountains, deserts, forests, and the like. Artificial boundaries are such signs as have been purposely put up to indicate the way of the imaginary boundary-line. They may consist of posts, stones, bars, walls,[369] trenches, roads, canals, buoys in water, and the like. It must, however, be borne in mind that the distinction between artificial and natural boundaries is not sharp, in so far as some natural boundaries can be artificially created. Thus a forest may be planted, and a desert may be created, as was the frequent practice of the Romans of antiquity, for the purpose of marking the frontier.
[369] The Romans of antiquity very often constructed boundary walls, and the Chinese Wall may also be cited as an example.
Boundary Waters.
§ 199. Natural boundaries consisting of water must be specially discussed on account of the different kinds of boundary waters. Such kinds are rivers, lakes, landlocked seas, and the maritime belt.
(1) Boundary rivers[370] are such rivers as separate two different States from each other.[371] If such river is not navigable, the imaginary boundary line runs down the middle of the river, following all turnings of the border line of both banks of the river. On the other hand, in a navigable river the boundary line runs through the middle of the so-called Thalweg, that is, the mid-channel of the river. It is, thirdly, possible that the boundary line is the border line of the river, so that the whole bed belongs to one of the riparian States only.[372] But this is an exception created by treaty or by the fact that a State has occupied the lands on one side of a river at a time prior to the occupation of the lands on the other side by some other State.[373] And it must be remembered that, since a river sometimes changes its course more or less, the boundary line running through the middle or the Thalweg or along the border line is thereby also altered. In case a bridge is built over a boundary river, the boundary line runs, failing special treaty arrangements, through the middle of the bridge. As regards the boundary lines running through islands rising in boundary rivers and through the abandoned beds of such rivers, see below, §§ [234] and [235].