ith
the Pedregal separating them. Captain Lee, who had already done
excellent engineering service at Vera Cruz and Cerro Gordo, assisted by
Lieutenants Beauregard and Tower of the engineers, had carefully
reconnoitred the position of the enemy, and on the morning of the 19th
the advance from San Augustin began, Captain Lee accompanying the troops
in their arduous passage across the Pedregal. One of those present thus
describes the exploit:

"Late in the morning of the 19th the brigade of which my regiment was a
part (Riley's) was sent out from San Augustin in the direction of
Contreras. We soon struck a region over which it was said no horses
could go, and men only with difficulty. No road was available; my
regiment was in advance, my company leading, and its point of direction
was a church-spire at or near Contreras. Taking the lead, we soon struck
the Pedregal, a field of volcanic rock like boiling scoria suddenly
solidified, pathless, precipitous, and generally compelling rapid gait
in order to spring from point to point of rock, on which two feet could
not rest and which cut through our shoes. A fall on this sharp material
would have seriously cut and injured one, whilst the effort to climb
some of it cut the hands.

"Just before reaching the main road from Contreras to the city of Mexico
we reached a watery ravine, the sides of which were nearly
perpendicular, up which I had to be pushed and then to pull others. On
looking back over this bed of lava or scoria, I saw the troops, much
scattered, picking their way very slowly; while of my own company, some
eighty or ninety strong, only five men crossed with me or during some
twenty minutes after.

"With these five I examined the country beyond, and struck upon the
small guard of a paymaster's park, which, from the character of the
country over which we had passed, was deemed perfectly safe from
capture. My men gained a paymaster's chest well filled with bags of
silver dollars, and the firing and fuss we made both frightened the
guard with the belief that the infernals were upon them and made our
men hasten to our support.

"Before sundown all of Riley's, and I believe of Cadwallader's, Smith's,
and Pierce's brigades, were over, and by nine o' clock a council of war,
presided over by Persifer Smith and counselled by Captain R. E. Lee, was
held at the church. I have always understood that what was devised and
finally determined upon was suggested by Captain Lee; at