sheet of paper as a blank sample I gave Markham, enclosed in that same envelope, stamped, to give to Mr. Dawes up at the novelty works when he went there again. Mr. Dawes asked for a sample of one linen letter paper. If he wanted a lot, he was to write the amount on the sheet, and mail to us."
"Well," continued Frank," somehow Markham made paste—probably out of a piece of bread. He compiled that letter."
"But how did he get it mailed?" suggested Bob.
"Suppose he was a prisoner, and threw it from a window into the road, chancing its discovery and mailing by some passer-by."
"That's so," nodded Darry. "I believe you are correct in your conclusions, Frank. As to the mailing lists, which Markham also had with him, that's a later mystery to develop."
"Now then," spoke Frank, "I think I can also figure out something else. I believe that Dale Wacker followed Markham. He was probably right on his heels when Markham entered this building. Markham saw him, got scared, and, to evade him, ran up to the third floor. There he found no rooms open to hide in. He was cor-
