He remembered that they had turned there and had gone up into a chamber to try to get in through the entrances. But they had found the entrances all blocked, and the men had set to work to make an opening through one of them. Ralph recalled the scene very distinctly. With what desperate energy those men worked, tearing away the stones and dirt with their hands in order to get in the sooner to their unfortunate comrades. He remembered that while they were doing this Robert Burnham had seated himself on a fallen prop, had torn a leaf from his memorandum book and had asked Ralph to hold his lamp near by, so that he could see to write. He filled one side of the leaf, half of the other side, folded it, addressed it, and placed it in the pocket of his vest. Then he went up and directed the enlargement of the opening and crawled through with the rest. Here was the entrance, and here was the opening, just as it had been left. Ralph clambered through it and went down to the fall. The piled-up rocks were before him, as he had seen them that day. Nothing had been disturbed. On the floor of the mine was something that attracted his attention. He stooped and picked it up. It was a piece of paper. There was writing on it in pencil, much faded now, but still distinct enough to be read. He held his lamp to it and examined it more closely. He could read writing very well, and this was written plainly. He began to read it aloud:-- "My DEAR WIFE,--I desire to supplement the letter sent to you from the office with this note written in the mine during a minute of waiting. I want to tell you that our Ralph is living; that he is here with me, standing this moment at my side." The paper dropped from the boy's trembling fingers, and he stood for a minute awe-struck and breathless. Then he picked up the note and examined it again. It was the very one that Robert Burnham had written on the day of his death. Ralph recognized it by the crossed lines of red and blue marking the page into squares. Without thinking that there might be any impropriety in doing so, he continued to read the letter as fast as his wildly beating heart and his eyes clouded with mist would let him. "I have not time to tell you why and how I know, but, believe me, Margaret, there is no mistake. He is Ralph, the slate-picker, of whom I told you, who lives with Bachelor Billy. If he should survive this trying journey, take him immediately and bring him up as our son; if he should die, give him proper burial. We have set out on a perilous undertaking and some of us may not live through it. I write this note in case I should not see you again. It will be found on my person. Do not allow any one to persuade you that this boy is not our son. I _know_ he is. I send love and greeting to you. I pray for God's mercy and blessing on you and on our children. "ROBERT." CHAPTER XXI. A PERILOUS PASSAGE.