730 THE POPULAR SCIENCE MONTHLY. 



and Sierra Xevada Mountains, and which, commencing within the ter- 

 ritory of the United States as far north certainly as Central Colorado, 

 and perhaps beyond, extends as far south as the Isthmus of Tehuan- 

 tepec ; a north and south length, measuring from the southern fron- 

 tier-line of the United States, of about two thousand miles. Entering 

 the country by the Mexican Central Railway at El Paso, where the 

 plateau has already an elevation of 3,717 feet, the traveler progress- 

 ively and rapidly ascends, though so gradually that, except for a dk- 

 tour, made obligatory in the construction of the road to climb up into 

 the city of Zacatecas, he is hardly conscious of it until, at a point 

 known as Marquez, 1,148 miles from the starting-point and 76 miles 

 from the city of Mexico, the railroad-track attains an elevation of 

 8,134 feet, or 1,849 feet higher than the summit of Mount Washing- 

 ton. From this point the line descends 834 feet into the valley of the 

 city of Mexico, the bottom of which is about 7,300 feet above the sea- 

 level. In fact, as Humboldt as far back as 1803 pointed out, so regu- 

 lar is the great plateau on the line followed by the Central road, and 

 so gentle are its surface slopes where depressions occur, that the jour- 

 ney from the city of Mexico to Santa Fe, in New Mexico, might be 

 performed in a four-wheeled vehicle. 



Starting next from the city of Mexico, and going east toward the 

 Atlantic, or west toward the Pacific, for a distance in either direction 

 of about one hundred and sixty miles, and we come to the edge or ter- 

 minus of this great plateau ; so well defined and so abrupt that in places 

 it seems as if a single vigorous jump would land the experimenter, or 

 all that was left of him, at from two to three thousand feet lower 

 level. Up the side of this almost precipice — tunneling through or 

 winding round a succession of mountain promontories — the Vera Cruz 

 and City of Mexico Railroad has been constructed ; " rising " or " fall- 

 ing" — according to the direction traveled — over four thousand feet, 

 in passing over a circuitous track of about twenty-five miles ; and of 

 which elevation or depression about twenty-five hundred perpendicu- 

 lar feet are comprised within the first thirteen miles, measured from 

 the point where the descent from the edge of the plateau begins. To 

 overcome this tremendous grade in ascending, a sort of double loco- 

 motive — comprising two sets of driving machinery, with the boilers 

 in the center, and known as the " Farlie " engine — is employed ; and 

 even with this most powerful tractor it is necessary, with an ordinary 

 train, to stop every eight or ten miles, in order to keep up a sufficient 

 head of steam to overcome the resistance. In descending, on the 

 other hand, only sufllicient steam is necessary to work the brakes and 

 counteract the tendency to a too rapid movement. As an achievement 

 in engineering the road has probably no parallel, except it may be in 

 some of the more recent and limited constructions among the passes 

 of Colorado ; and, as might be expected, the cost of transportation 

 over the entire distance of 263 miles, from Vera Cruz to the city of 



