National Geographic : 1891 Apr 30
38 Herbert G. Ogden-Geography of the Land. ever, was not protected by levees, and another large proportion was only partially protected; and while, therefore, the disaster impressed the general public with a belief that the levees were a failure, the facts really point to the contrary. In former notable floods it has not been unusual for one hundred or more miles of levee to be washed away before the flood subsided, but on the recent occasion there was a total length of less than five miles destroyed in some 1,100 miles of levee that had been believed to be safe. This is a remarkable showing, and has naturally in spired the advocates of the system with greater confidence, It points to the possibility of constructing levees at a reasonable expense that will stand the pressure of water for the height that it has been computed necessary to build them. There is a grave doubt, however, in the minds of some as to whether the computed heights, the levees holding intact, will afford sufficient cross-section to carry off the volume of water draining from the catchment basins. Some interesting computations on this sub ject have recently been made by General Greely, the chief sig nal officer,* from observations made during an extended period. The question raised is not a new one, but, considered in the light of the statistics presented, seems to involve the problem of the improvement of the river with increasing difficulties. General Greely's figures indicate that the cross-section of the lower river will only permit carrying to the sea a volume of about sixty cubic miles of water during an ordinary flood season, and that in the extraordinary flood years, such as 1882 and 1890, the volume to be carried down is about eighty cubic miles, showing an excess of about twenty cubic miles over the capacity of the river in a specified time. These figures should be taken in the nature of a warning; and while it must be admitted that the intricacy of the problem precludes precision, their probable relia bility should be carefully studied before an extended levee sys tem is built intended to guarantee protection against exceptional floods. During recent years the complex and perplexing subject of geographic nomenclature has received the careful consideration of a number of the European nations, with a view to reaching a uniformity in treatment and the transliteration of names of un written languages into Roman characters. England, France, and *North American Review, May, 1890.
1891 Mar 28