"What does this mean?" he exclaimed aloud. "A round shell of the old-fashioned type instead of the conical ones used nowadays! Why, a shell like this has not been used in any navy for ages!" He had been too excited at the moment of picking up the spluttering shell to note its shape or size, but now he saw at a glance that the one he held in his hand was obsolete and out of date. It was well enough for the old-fashioned smooth-bore guns, but those of modern make had no use for them. As he puzzled over the mystery surrounding the projectile he suddenly heard a whistle from the other side of the embankment. He recognized it as the signal from the insurgent courier, and at once was alive to the importance of carrying out the instructions that had been given him. He hastily dropped the shell upon the ground and sprang up and over the ridge of earth. He gave an answering whistle and soon a form cautiously appeared from among some bushes not far away. "Alto quien va?" called Clif before the newcomer had advanced a step. This was the challenge, meaning, "Who goes there?" The response came promptly: "Cuba!" This is the countersign of the insurgents, and Clif knew that it was the courier who had reached the appointed rendezvous. He called out to him to advance, and in the moonlight appeared the figure of an insurgent soldier, a mambis, as he is called in that country, a figure with which American tars were to become more familiar as the war progressed. His equipment was typical of the insurgent soldier. Beside a pair of linen trousers and a knitted woolen shirt, he wore a short blouse, called mambisa. This was a small shirt-like vest, with pockets front and back, opening at the belt, a handy way of carrying their cartridges devised by them through necessity during the previous ten-years war. A panama hat turned up in front and fastened with a silver star, completed his attire; for as to his feet, they were innocent of a covering. "Rather a summery outfit," thought Clif as he took it in with a glance. But he knew that it was sufficient for the needs of the insurgents in that climate, and that brave hearts beat under the unpretentious mambisa, and brave deeds were done by the poorly equipped soldiers of the army of liberation. The newcomer was effusive in his greeting. "I bring you greeting from our brave general, Gomez," he exclaimed in Spanish. "Greetings to our noble friends and allies." Clif received him cordially, but lost little time in preliminaries. Much more time had already been consumed than he had calculated upon, and he was anxious to have his business over with and return to the flagship with the important dispatches for which he had come. "I am honored by your words," he said, in reply to the other. "Cuban liberty is assured by force of American arms, and at the same time we have our own score to settle with Spain." "It will be done," said the Cuban.