Notwithstanding this overwhelming evidence as to the origin of the mail depredations on this route, there were good reasons for further delay in making the arrest, especially as it seemed unlikely that the person detected would know anything of his real situation for a few days. During this interval, I found it necessary to visit a neighboring city. The reader may judge of my surprise at receiving, two days afterwards, a letter, of which the following is a copy:-- Sir, I have ascertained, no matter how, that you are the "railroad contractor" whom I met in the basement of the hotel in this place a few evenings since, and who partook of my hospitalities afterwards at M----'s saloon. Also that you entertained and perhaps still entertain some doubts of my honesty, as a clerk in the post-office here. I am sorry you had not the candor to say as much to my face, and thus afford me the opportunity of satisfying you as to my standing and character among those who have known me best and longest. You are welcome, sir, to all the advantage you obtained in your underhanded dealings with me on the occasion referred to; if, however, you cannot prostrate private character faster than you can ten-pins, I think I have but little to fear at present. Yours, _not_ very respectfully, THOMAS L----. To J. Holbrook, Special Agent, P. O. Dept. How this clue to my official identity was obtained, I failed to discover at the time, and have been no wiser on that point at any period since. Nor was it of much account, as the information, from whatever quarter derived, came too late to be of any avail, and after he had exposed himself by passing the money which had been placed in the mail to detect him. When he was preparing the above epistle, congratulating himself on my want of skill at prostrating "private character," little did he think that I had already achieved a sweeping "ten-strike" in his own case! The necessary complaint was made, a warrant issued, and the unfortunate young man taken into custody by the U. S. Marshal. I shall never forget the indescribable look which he gave me as he entered the office of the U. S. Commissioner, for a preliminary examination. It was the first time we had met since the memorable roll and supper, and the quondam "railroad contractor" now first appeared to his eye transmuted into the formidable "Special Agent." There was little surprise in his look, but an expression of mortified pride and anger, as he addressed me in a low tone, "I thought I should meet _you_ here!" "Well, Thomas," said I, "I don't know as you will believe me, but, I assure you, I heartily regret that you are brought to this pass, and if the ends of justice could be answered, I should be the first to let you go free." "Perhaps you would," replied he, moodily. "It's easy enough to say so."