FROM THE CITY OF MEXICO TO PACHUCA, BY THE HIDALGO AND NORTHEASTERN MEXICAN RAILWAY. FROM TEPA TO PACHUCA, A BRANCH OF THE HIDALGO RAILROAD. FROM SAN AUGUSTIN TO IROLO, A BRANCH OF THE HIDALGO RAILWAY. FROM TEHUACAN TO OAXACA AND PUERTO ANGEL BY WAGON ROAD. 600.00 1968.57 Cúspide.. 1900.00 6233.70 730.00 2395.10 Santo Tomás Jaliera.. 1830.00 6004.14 700.00 2296.67 Ocotlan.. 1720.00 5643.24 680.00 2231.05 Magdalena.. 1700.00 5577.62 600.00 1968.57 San Martin. 1700.00 5577.62 1590.00 5216.71 San Antonio. Hacienda de Ayotla... Rio de Reyes. Tecomavaca Rio Salado.. Campanario.. Paraje Blanco. Rio Seco Chonoslar... Rancho de Urrutia... Don Dominguillo.. Canton de Buena Vista. Llano del Timbre. Ojo de Agua. 580.00 1902.95 Rio Coapa. Tlacuache. 620.00 2034.19 Tepehuaje. ... 660.00 2165.43 San José del Pacifico.. THE VALLEY OF MEXICO'S DRAINAGE.' Mexico is finishing a great work, the drainage of the valley where the capital city is located, which has required for its completion nearly three hundred years and many millions of dollars, and has cost the lives of hundreds of thousands of men. The necessity, importance, 'This article was published in the Engineering Magazine of New York for January, 1895 (vol. viii., No 4), but has since been revised and considerably enlarged. and magnitude of this work, which will be classed among the grandest achievements of men, and the nearness of its completion, induce me to write this paper, which I hope will give some idea of its scope and purpose. I do not pretend to originality, as my work to some extent has been one of compilation from different monographs, which have appeared from time to time, and from some official publications of the Mexican Government. Topographical Conditions of the Valley of Mexico.-The Valley of Mexico is an immense basin, of approximately circular shape with one extreme diameter of about sixty miles, completely bounded by high mountains, and having only two or three quite high passes out of it. No water drains out of the basin. The surface of this valley has a mean altitude above the sea of 7413 feet and an area of about 2220 square miles. Mountain ranges rise on every side, making a great corral of rock containing dozens of villages and hamlets, with the ancient capital in the centre. In times past the fires of volcanoes licked up the earth, and such fires still live in the mammoth Popocatapetl, from whose great crater sulphur fumes and smoke with jets of flame have poured through the centuries. The valley thus hemmed in with solid walls of rock had been an inland sea for many cycles, and during the early existence of man here the salt waters spread over a large extent of the depression. The waters have been gradually lessening by seepage and evaporation, and the Aztec pilgrims coming from the north in the fourteenth century, having received a sign that they were to build their queen-of-the-world city on a small island of the sea, set about building dikes and combating the overflow of the waters. Evaporation is so excessive at certain periods of the year that malaria, consequent on drought, was far more dreaded by the inhabitants than the periodical floods, and thousands perished annually, so that proper drainage was an absolute necessity for the preservation of health. Work done by the Indians.-Nearly fifty years before the discovery of America, which took place in 1492, Netzahualcoyotl, saw the necessity for a drainage canal, and commenced the work in 1450. He constructed an immense dike to divide the fresh from the saltwater lakes of the valley. The City of Mexico was at this time the centre of the Aztec nation, and was built on floating structures, like rafts, on the water in the numerous islets on the margins of the lakes, so that in the event of the water rising or the city being subjected to a state of siege, the whole city would float. Mexico City now occupies the site of the old Aztec capital. The waters of these lakes were liable to disturbances of all kinds; thus it is recorded by Prescott in his History of the Conquest of Mexico: "In 1510 the great lake of Texcoco, without the occurrence of a tempest or earthquake, or any other visible cause, became violently agitated, overflowed its banks, and, pouring into the streets of Mexico, swept off many of the buildings by the fury of its water." When Cortez arrived in Mexico from Spain in 1519 to take possession of the country in the name of the King of Spain, he found, to his great surprise, the defense of the city admirably arranged, and an almost enchanting view of flowering islets forming the floating capital. Little towns and villages lay half-concealed by the foliage, and from the distance these looked like companies of wild swans riding quietly on the waves. A scene so new and wonderful filled the rude heart of the Spaniard with amazement. So astonished was he at the extent of the water of Lake Texcoco that he describes it as "a sea that embraces the whole valley," but upon hearing that it was a lake, with a mean depth of a few yards, he gave orders to cut a way through the dike and destroy the aqueduct of Chapultepec. The central dike dividing the fresh from the salt water lake was of such dimensions as to serve Cortez as a roadway for his army. Prescott, in the work before alluded to, page 297, says: "Leaving the mainland, the Spaniards came on the great dike or causeway, which stretches some four or five miles in length, and divides Lake Chalco from Xochimilco on the west. It was a lance in breadth in the narrowest part, and in some places wide enough for eight horses to ride abreast. It was a solid structure of stone and lime, running directly through the lake, and struck the Spaniards as one of the most remarkable works they had seen in the country." Having cut the dikes and drained the lake, the "floating city" was at once besieged, and where originally stood the great temple of the Aztecs a Christian temple was afterward raised. The Spaniards, finding themselves in complete possession, proceeded to erect the new City of Mexico, and building on the plan adopted by them at home, they cut down the points of the floating islands and by gradual extension soon placed the town below the mean average level of the lake. Hence arose the great difficulties of the drainage of the Valley of Mexico. One of the immense dikes built by King Netzahualcoyotl was ten miles long. It divided Lake Texcoco into two parts. Of the two lakes thus formed one was allowed to remain salt, but the other was freshened by letting only fresh water enter by the streams flowing in, the water for the use of the city being taken from this latter. Little by little the waters have subsided since that period, and have been fought back, until now they are confined to six great lakes-Chalco, Xochi |