Jack agreed with Needham that Tom and Gerald were not likely to be in the neighbourhood, and the boat being dropped astern, to be in readiness should they or the spy appear, the Supplejack continued her course up the river. The increasing daylight enabled Jack to see his way, and of course a sharp lookout was kept on the shore.

The brig continued on for some distance, neither cavalry nor artillery being seen. A few foot soldiers were observed trudging along, and occasionally country people appeared on the high ground, but none of them came down to the beach.

The appearance of the banks varied considerably in different places; in some they were sloping and were covered with trees and shrubs, in others they consisted of high earthy cliffs with the open plains of the Pampas reaching to the edge of their summits. Frequently the telescope revealed projecting from the cliffs the bones of the megatherion, mastodon, milodon, and other huge antediluvian animals, of which, however, neither Jack nor Terence knew the names. Sometimes they were so distinct that they were remarked by the men, who wondered how such strange animals could have found their way there.

“They cannot have gone and buried themselves,” sagaciously observed Bill Lizard, the boatswain’s mate.

“For my part, howsomedever, I cannot think that anybody would have taken the trouble to bury them,” answered Needham. “It’s a pity we have not got Mr Scrofton on board; he would have told us all about it, no doubt.”

The ship’s company, however, had soon other matters to engage their attention. The brig was now approaching that part of the river where the deep channel runs under the lofty and perpendicular cliffs of San Lorenzo. The bed is as wide as in other places, but on the eastern side is a line of islands extending for several miles, and forcing the current over to the west. It was still doubtful, however, whether the enemy had observed the brig, or would venture to attack her if they had.

Terence had gone aloft to be able to get a better view over the plain, when he made out several horsemen, and what he at first took for carts in the far distance, but which as they emerged from a cloud of dust partially concealing them he discovered were field-pieces. There could be little doubt that the Supplejack would not escape without being fired at. Fortunately there was a good stiff breeze, and under all sail she stood boldly up the clearly defined channel. The ensign was flying at the peak, and Jack ordered one to be hoisted at each masthead, to show the enemy that he intended to fight as long as the masts stood, or his vessel remained above water.

The brig had not got far, however, when six field-pieces, dragged by horses, with a considerable body of men, were seen some way ahead approaching the edge of the cliffs. Jack was not left long in doubt as to their object, for bringing their guns to bear on the brig, the Spaniards opened fire, their shot whizzing over the brig, a few only passing through her sails.

Needham had got his beloved Long Tom elevated as much as possible, the two carronades loaded with canister, and the rockets were ready in their stands.

“Let them learn what Long Tom can do,” said Jack. Needham fired but the shot flew over the heads of the enemy; the gun was quickly again loaded. After the next shot two or three of the horses were seen plunging wildly, and one of the guns appeared to have received some damage—the distance was too great to ascertain what it was. The brig made rapid way, the next shot buried itself in the cliff; it was evident that Long Tom could do no more for the present. The carronades were now fired, and a flight of rockets sent the horsemen galloping out of the way, while the gunners scampered off or threw themselves on the ground; a second flight of rockets and another dose of canister kept them from returning till the brig had neared the cliffs; so close indeed was she that her mainyard almost touched them, while the enemy, who by this time had returned, could not sufficiently depress their guns to send a shot down on her decks, neither did the riflemen approach sufficiently near the edge to fire into her; probably having a wholesome dread of the rockets or bullets which might be sent in return from the daring little vessel.