This was an exciting moment. My first impulse was to proceed at once to the door, demand admittance, and charge him on the spot with the crime of which I suspected him. But a slight distrust of my physical ability to cope with him single-handed in case of resistance, which would almost certainly follow if my suspicions were correct; and the lateness of the hour, rendering it improbable that I could obtain aid should it be necessary; these considerations prevented me from carrying out my first intention, and when the unconscious object of my scrutiny put out his light and left the depot, I went in an opposite direction to my quarters, determined, however, to give him but one more chance to continue his depredations. The next night he robbed his last mail bag. Obtaining a private interview with the Superintendent of the rail road, I for the first time laid the facts before him, for the purpose of securing some assistance in the prosecution of my plans which he only could render. I wished to provide a place of concealment in that retired part of the depot where the mails had been taken on the preceding evening; and as empty cars were frequently left standing over night upon some of the unoccupied tracks, it was arranged to leave a car near the place mentioned, for my exclusive occupancy. From the "loop-hole" of this "retreat" I could determine with some accuracy the nature of such mysterious movements as I had before witnessed in that vicinity. Lest the baggage room should be chosen this time as the scene of operation, and thus my plans be defeated, a discreet friend was stationed near that point about the time that the mails were brought over from the office, in order to "head off" the suspected functionary. For the purpose of allowing as much time as possible, the conductor of the train, which was to take that mail, had been telegraphed to "come in a little behind time." Certain money packages had been prepared, and everything being in readiness, I took my post of observation in the empty car just before the mails came from the post-office. I had not long been stationed, when I heard the familiar rumbling sound of the baggage truck, and in a moment more the baggage-master appeared, trundling along his load of mails, and coming to a halt upon the platform, within fifteen feet of my watchful eye. That eye saw rapid work for a few moments! Hasty passes of the right hand between the mouth of one of the mail bags (as it appeared in the dim light to be) and the capacious pockets of a sack over-coat, showed clearly for what purpose the mails had been thus taken out of the way, and the well-known click of a mail-lock informed me that the operation was concluded, and that the moment had arrived for action on my part.