So had they all, in fact, and the Flying Road Racer was soon turned north, following a rough road that ran parallel with the sea-coast. It was now late afternoon, and the shadows were lengthening apace. Before long the swift tropic night would overtake them. Although they had arrived at a determination to continue traveling north till they arrived at a large city, where a telegraph wire could be found, they did not care to risk advancing over the rough, half-formed road in the darkness, so a halt was made where a small stream of fresh water ran down to the sea, and they prepared to spend the night there. It was somewhat chilly and a roaring fire was built around which they seated themselves after the evening meal. All were rather silent and abstracted, and there was no inclination for conversation. The Professor had brought out the silver casket and was examining some queer marks like hieroglyphics on its cover. “I’m sure they have some sort of meaning,” he remarked to Mr. Jesson, “but it’s beyond me to make out what it can be. See if you can do any better.” He handed the box to his brother-in-law to examine. But in the transfer it was fumbled, and before Mr. Jesson could save it the silver casket rolled toward the fire, only stopping when it was embedded in a mass of embers. It was raked out with a stick by Mr. Jesson before it was damaged. He set it aside to cool before examining it, and in the meantime the boys took occasion to observe it more narrowly than they had yet found opportunity to do. “Say, I thought that those knobs on the top were dull-colored!” exclaimed Jack Chadwick suddenly. “Why, so they are!” rejoined Mr. Jesson. “Some sort of inferior stone, I guess. They——” “But they are not dull! Look!” Risking burning his fingers. Jack seized the still warm casket and held it toward his elders. On the cover, embedded in the silver, flashed and winked in the firelight, three magnificent gems, red, blue, green! “Let me look at that a minute. Jack,” exclaimed Professor Chadwick in sharp, excited tones. He took the box from his son, and an instant later his head and Mr. Jesson’s were close together over the rifled silver casket. “Well, gentlemen?” said Ned after a while. “Well,” echoed Professor Chadwick, “we have made a most astounding discovery. These gems which Jack discovered,—for they are genuine, there’s not a doubt of it,—must have been covered with wax of some sort. The heat of the fire, when the box fell into it, melted this substance, and—well, here are three gems worth, conservatively, two hundred and fifty thousand dollars; probably a great deal more.” The listeners looked at him in amazement. “But what were the gems that Herrera took out of the casket, then?” demanded Jack, when he found his voice.