207. This tendency of the primary strata to take a uniform direction, has also been observed in other countries. Saussure remarked in the Alps, that the beds of schistus are generally parallel to the chains of mountains composed of them;[104] and this remark is probably applicable to all mountains consisting of primary strata. The general direction, therefore, of the schistus of the Alps, must be confined between W. 10° S. and W. 40° S. In the Pyrenees, the direction of the strata is about W.N.W.[105] If Saussure's rule may be depended on, the schistus of the Altaic, and most of the other great chains in the old continent, are in directions that run considerably to the south of west. The Urals, and perhaps some other of the northern chains, are however entirely different. In the Urals, as we learn not only from the general direction of the chain, but from a section of it in the 10th volume of the Nova Acta of Petersburgh (Tab. 12,) the direction of the strata is nearly from N. to S. This last is probably the direction in the great chains of South America; so that the uniformity of direction in the primary strata, which some mineralogists would extend to those of the whole earth, is certainly imaginary, though there can be no doubt that it extends over very large portions of the earth's surface.[106] [Footnote 104: Voyage aux Alpes, tom. i. § 577.] [Footnote 105: Essai sur la Mineralogie des Pyrenées.] [Footnote 106: It is perhaps unnecessary to observe, that the two propositions, that the intersections of the strata with the horizon are parallel lines; and that they are lines which reserve the same bearing with respect to the points of the compass; are nearly the same thing for tracts of moderate extent, but for large portions of the earth's surface are extremely different. If, for instance, the belt of primary vertical schistus, which traverses the south of Scotland, were to be produced eastward in the same plane, from its northern extremity, where its direction is E.N.E. and its latitude 55° 57', it would cut the meridian always less obliquely as it advanced, till, having increased it longitude about 26° 28', it would be at right angles to the meridian, and its direction of consequence due east and west. This would happen in the parallel of 58° 51', (on the shore of the Gulf of Finland, near Revel,) the strata being now extended about 880 G. miles from the Siccar Point. Conversely, vertical strata, having the same bearing with respect to the meridian, may be in planes very much inclined to one another. A stratum which bears east and west in Cornwall, and one that does the same at the east end of the Altaic, will be in planes, which, if produced, would cut one another at right angles. All this is sufficiently plain from the doctrine of the sphere, and is mentioned here merely as a caution to prevent too hasty conclusions from being drawn from any correspondence of bearing among the strata of remote countries.