gel road, which left the San Antonio causeway near the tête du pont, and continued up the valley of the Churubusco river, in a south-westerly course, by way of Cojohuacan, or Coyoacan, as it is now usually written, and San Angel, to the factory of Magdalena, about nine miles from Churubusco.
General Worth halted his column at a hacienda, within fifteen hundred yards of the enemy's works at San Antonio, and Captain Mason, assisted by Lieutenants Stevens and Tower, all of the corps of engineers, was sent forward to reconnoitre, supported by Captain Thornton with his company of the 2nd dragoons. The Mexican batteries opened on the party, when they came within range; the first shot killing Captain Thornton, and severely wounding the guide. No practicable route, even for infantry, could be discovered to turn the position on the right, and none on the left, except by crossing the pedregal. An assault in front could only be made by battering in breach, and the use of scaling-ladders and fascines. In the meantime a reconnaissance was made by Captain Lee and Lieutenant Beauregard, of the engineers, of a mule path leading through the pedregal, and intersecting the San Angel road about four miles directly west from San Augustin. Lieutenant Colonel Graham, with the 11th infantry, and Captain Kearny, of the 1st dragoons, with his troop, covered the reconnaissance. A large body of observation was discovered in that direction, with the advance corps of which the supporting party had a successful skirmish. A second reconnaissance of this route was made in the morning of the 19th, and Major J. L. Smith, the senior engineer officer with the army, also made a careful examination of the different approaches to the city. These reconnaissances rendered
