386 



OUTER AND INNER LINES 



my. 1 " When an enemy is in front of El Penon, the communica- 

 tion between it and troops on the other routes is only by way of the 

 city of Mexico itself; in other words, the American troops being at 

 Ayotla, Genera] Santa Anna's forces at El Penon were one day's 

 march distant from those at Mexicalzingo, three from those under 

 General Valencia, and would have been about four days' march from 

 troops thrown forward on the Chalco route. Fords on these differ- 

 ent routes were by no means within supporting distances of each 

 other. Holding the position that General Scott then did, it would have 

 required, of an equal enemy, four times his own force, to have op- 

 posed successfully his further advance. The Mexican forces were 

 not numerically equal to this, and, accordingly, they were concen- 

 trated at the threatened point. It is evident that as long as the 

 American troops were in front of El Penon, the enemy necessarily 

 held to their position. In moving off, the former could gain one 

 day the start. This brought the only difficult parts of the Chalco 

 route actually nearer General Scott than the Mexican chief. If to 

 this we add the delay necessary in moving heavy artillery and break- 

 ing up from a fortified position, it would seem that, instead of over- 

 sight, it was rather impossible for General Santa Anna to meet our 

 forces sooner than he did." 



The description of the various routes to the capital has necessa- 

 rily acquainted the reader with the important Mexican defences on 

 the north, the east, and the north-east of the capital, both by milita- 

 ry works hastily thrown up after Santa Anna's retreat from Cerro 

 Gordo, and by the encampment of large bodies of soldiery. We 

 thus, already know a part, of the external line of defences at El 

 Penon, Mexicalzingo, Tezcoco, Santiago Zacualco, and the Pass 

 north of Tenepantla. But in addition to these, there are others 

 that must be noticed on the south and west of the capital, which it 

 should always be recollected is situated in the lap of the valley, but 

 near the western edge of the gigantic rim of mountains. 



Along the Chalco route there were no more fortifications, but 

 west of lakes Chalco and Xochimilco, a line of entrenchments had 

 been commenced, connecting the fortified hacienda, or massive stone 

 plantation house of San Antonio, about six miles south of the city, 

 with the town of Mexicalzingo. West of this hacienda, the Ped- 

 regal, a vast, broken field of lava, spread out along the edge of the 



*See the admirable Map and Memoir of Lieutenant M. L. Smith, and Brevet Cap- 

 tain E. L. F. Hardcastle, published in the Senate Document, No. 11 of the first ses- 

 sion of the 31st Congress: 1849 '50. 



