The Spanish Pioneers by Charles Fletcher Lummis

At daybreak, on the morning of January 22, Zaldivar gave the signal for the attack; and the main body of the Spaniards began firing their few arquebuses, and making a desperate assault at the north end of the great rock, there absolutely impregnable. The Indians, crowded along the cliffs above, poured down a rain of missiles; and many of the Spaniards were wounded. Meanwhile twelve picked men, who had hidden during the night under the overhanging cliff which protected them alike from the fire and the observation of the Indians, were crawling stealthily around under the precipice, dragging the _pedrero_ by ropes. Most of these twelve were arquebusiers; and besides the weight of the ridiculous little cannon, they had their ponderous flintlocks and their clumsy armor, -- poor helps for scaling heights which the unencumbered athlete finds difficult.

Pursuing their toilsome way unobserved, pulling one another and then the _pedrero_ up the ledges, they reached at last the top of a great outlying pinnacle of rock, separated from the main cliff of Acoma by a narrow but awful chasm. Late in the afternoon they had their howitzer trained upon the town; and the loud report, as its cobble-stone ball flew into Acoma, signalled the main body at the north end of the _mesa_ that the first vantage-ground had been safely gained, and at the same time warned the savages of danger from a new quarter.