338 



GEOGRAPHICAL EXPLORATIONS AND DISCOVERIES IN 1872. 



flats, and the facility with which they can 

 be irrigated. The Rio Grande is scarcely less 

 infallible than the Nile in its annual swell- 

 ing and recession, and is at its highest when 

 most needed. Rising so near the level of its 

 low banks, the water is easily carried over the 

 fields in earthen aqueducts (not ditches), from 

 which, wherever tapped, the water flows down 

 between the long rows of maize. Rich as they 

 now are, these flats will never need manuring, 

 for the water is laden with a rich argillaceous 

 silt. I never saw water so thick arid soup-like ; 

 it is said to be the heaviest water on the conti- 

 nent, not excepting that of the Mississippi." 



A discovery of great importance was made 

 by the observers of the Signal- Service Office, 

 in November, 1872. From time immemorial 

 the great November atmospheric wave, which 

 breaks upon the coast of England, and is the 

 precursor of the severe storms and gales of the 

 European winter, has excited the attention of 

 scientific men and of experienced seamen. 



Sir John Herschel and others supposed 

 that it was confined to England and West- 

 ern Europe, which it reached from the South 

 Atlantic, and over which it rolled in contin- 

 ued undulations from the last of October to 

 January. But, on the 12th of November, a 

 similar atmospheric wave began to break over 

 the shores of the northwest coast, as shown 

 by the weather-telegrams. By the evening of 

 the 13th it had spread over most of the Pacific 

 States and Territories, Utah, and Nevada, and 

 at midnight was rushing through the passes 

 of the Rocky Mountains. On Thursday, the 

 14th, it descended upon the plains. On Friday 

 morning it extended in unbroken magnitude 

 from Oregon and Washington Territory, east- 

 ward through the great trough or depression of 

 the Rocky Mountain backbone in Idaho and 

 Montana, and stretched thence to the Lower 

 Missouri and Lower Mississippi Valleys and 

 over the western shores of the Mexican Gulf. 

 This discovery will enable meteorologists to an- 

 ti'cipate, by many days, the approach of winter, 

 as it advances from the Pacific coast eastward 

 in the great current of westerly winds. It 

 serves to clear up the old mystery of Ameri- 

 can winter storms, showing that they origi- 

 nate in the Rocky Mountains, upon whose 

 cold and loftiest summits in Nevada, Utah, 

 Colorado, and Southern Wyoming, the vapor- 

 laden air of this wave, coming from over the 

 warm Pacific, is now seen to be condensed in 

 the overwhelming snows of the forty -first 

 parallel. As this vast aerial wave is probably, 

 like the English wave, continued in successive 

 undulations for two or three months, it may 

 assist in explaining the comparatively high 

 temperature and light precipitation in winter 

 along Puget's Sound and eastward. 



We turn next to Mexico, from which, how- 

 ever, we have but small record of either prog- 

 ress or discovery. The altitude of Popo- 

 catepetl, which, like most of the summits of 

 .the Mexican Cordilleras, has been variously 



stated, has been ascertained, by a careful 

 measurement by officers of the School of Engi- 

 neers in Mexico, to be 17,835 feet. This is 13 

 feet more than Humboldt's calculation, and 

 nearly 20 feet less than Oltmann's, while Doll- 

 fus, Sonntag, and Glennie, made it from 100 to 

 160 feet higher. 



In the bulletin of the Societe de Geographic 

 for September, 1872, there is a very elaborate 

 paper by M. A. de Morineau, on the civiliza- 

 tion of Mexico at the commencement of the six- 

 teenth century, in which, from authentic doc- 

 uments as well as from the ruins of their tem- 

 ples, cities, and dwellings, the writer demon- 

 strates that the civilization of the Aztecs, at 

 that period, was nearly equal to that of the 

 Chinese of the present day. A party of natu- 

 ralists visited and ascended, in 1871, the Cofre 

 de Perote, a remarkable mountain on the route 

 between Vera Cruz and the city of Mexico. ' 

 Though not so high as some of the other peaks 

 of Mexico, it is peculiar in not having a coni- 

 cal summit ; the top being in the form of a 

 colossal sarcophagus or chest, whence the 

 name, " The Coffer of Perote." The Mexicans 

 have a legend that Moctezuma, their great 

 emperor and martyr, under the guidance of 

 the Spirit of the Air, deposited his treasures 

 in this gigantic coffer, and that they will re- 

 main there till he comes again, in renewed 

 youth, to resume his sway over Mexico. The 

 height of the mountain, according to the meas- 

 urement of Sefior Lerdo de Tejada, the present 

 learned President of the Mexican Republic, is 

 13,416 feet. These naturalists made it 14,050 

 feet, but their calculations, made from a ba- 

 rometer at the commencement of a violent 

 storm, were not trustworthy. 



The geographical interest in the Central 

 American States centres still in the possibility 

 and practicability of an interoceanic canal. 

 Captain Selfridge's report, while it demon- 

 strated the possibility of such a canal by way 

 of the Atrato and Napipi Rivers, placed the 

 cost of its construction so high (not less than 

 $125,000,000), though- his exploration is con- 

 tinued on the Pacific side, that it seemed best to 

 ascertain whether Honduras, Tehuantepec, or 

 Nicaragua, did not offer equal facilities at a much 

 lower cost. Accordingly, Captain Hatfield was 

 sent out with an exploring-party, by the Secre- 

 tary of the Navy, with orders to examine three 

 routes above the Isthmus of Panama. Mean- 

 time, on the petition of some members of the 

 New York Chamber of Commerce, the Presi- 

 dent appointed, March 13, 1872, Brevet Major- 

 General A. A. Humphreys, U. S. A. ; Prof. 

 Benjamin Peirce, U. S. Coast Survey ; and 

 Captain Daniel Ammen, U. S. N., commis- 

 sioners, "to examine and consider all surveys, 

 plans, proposals, or suggestions of routes of 

 communication, by canal or water communica- 

 tion, between the Atlantic and Pacific Oceans, 

 across, over, or near the isthmus connecting 

 North and South America, which have already 

 been submitted, or which may hereafter be 



