National Geographic : 1900 Sep
THE WATER SUPPLY FOR THE NICARAGUA CANAL 365 leaving 492 inches as a margin of safety. This is a coefficient of safety of about 91, which ought to be regarded as exceedingly liberal. As an actual fact, no one knows what was the discharge, either maximum, minimum, or mean, from Lake Nicaragua prior to 1898. We do know, however, that the San Juan River has been navigated for a period much longer than the Rivas rainfall record, and that always, within the last generation or more, it has been necessary to transfer freight over the rapids during the dry season and unneces sary to do this during the season of high water. These facts are based not only upon the testimony of such intelligent men as Hon. W. L. Merry, former superintendent of the transit company and now United States Minister to Nicaragua and Costa Rica, but upon the existence of the light-draft steamers and lighters used for these pur poses at that time, which fully bear out the testimony that the reg imen of the San Juan River, and therefore of Lake Nicaragua, has not materially changed within the memory of men now living. If the conclusions drawn by Professor Heilprin are correct, Lake Nicaragua has been only a short time at its present stage, but in this alleged short time it has made a very marked and decided beach throughout the extent of its western coast. How, then, did it manage to leave absolutely no record of its stage twenty or thirty years ago ? But the crowning absurdity involved by Professor Heilprin's theory is that the old Spanishfortifications at Grenada, the wharf, warehouses, and a part of the city, as well as several villages and hamlets around the lake, must have been all constructed under water, since they are now less than 20 feet above the lake level. It is a curious fact that, in order to clinch his argument and show that there is no probability of a recurrence of very wet years to make good the alleged loss from the lake, Professor Heilprin triumphantly quotes from Dr Hayes as follows: " So far as known, there is no evi dence whatever that the rainfall has ever been greater in this region than it is at the present time." This quotation is employed at the close of an article which purports to show conclusively that the water supply to Lake Nicaragua has very greatly declined within a gener ation, and that therefore there is conclusive evidence that the rainfall has been greater in this region than it is at the present time.