The value of mountains in the scheme of useful boundary demarcation has been attested in the European war. Towns and villages sheltered behind rocky uplifts have suffered relatively little from the devastation which has marked the struggle in lowlands and plains. The fact is true for the Vosges mountains, the Trentino uplands and the Carpathian region. Although fighting of an exceedingly bitter character was maintained in each of these areas, the loss in property was never extreme. This is one of the many instances where land configuration lends itself advantageously to delimitation work. The need of trustworthy geographical information in partitioning and dividing up territory is obvious. Upon this basis only can boundary revision be satisfactorily pursued. The long borderland of the French language which marks the northern and eastern boundary of French lands from the English Channel to the Mediterranean, lies unruffled by political agitation in its southeastern stretch, where Italian and French become interchangeable languages. Modifications in this section of the political frontier hardly need be considered. Their occurrence, if any, will probably come as peaceful adjustments dictated by economic reasons. To the north, however, the line has a history tainted by deeds of violence. In this stretch it forms the divide between two civilizations, the French and the German. These, although having flourished side by side, are distinctly opposed in spirit and method. Here, beginning north of the Swiss border, frontier changes appear inevitable. In the Vosges uplift, certain facts of geographical import have direct bearing on the international boundary problem. The very occurrence of a mountain in this zone of secular conflict has a significance of its own. Aggression has generally made its way up the steep slope and, since the treaty of Frankfort of 1871, strategic advantages lie on the German side. Moreover the crest line shows French linguistic predominance. [Illustration: _The American Geographical Society of New York_ _Frontiers of Language and Nationality in Europe, 1917, Pl. IX_ PART OF EUROPE SHOWING LANGUAGES having political significance.]