“It was Brown’s duty to take certain bags to the lower regions of the Post-office for transmission through the tubes of the Pneumatic Company, which had just been laid down.
“Having overheard all their plans, and made my arrangements accordingly, I concealed myself with one of the watchmen connected with the establishment, in an angle of the wall, where I was free from observation, but able to spring out on a moment’s notice.
“Wareham accompanied Brown from above, and assisted him to carry the bags. No one asked him any questions—it was supposed that he had been told off on the same duty. The room in which the opening to the tube was situated was unoccupied by any one except the workmen connected with the machinery requisite to put the valves in motion.
“Browne and Wareham, thinking themselves alone, commenced the execution of their nefarious project. They hastily untied the neck of the small sacks, and plunging their hands in drew out as many letters as they could conceal about their persons.
“They had taken the precaution to have pockets ingeniously sewn on inside their coats and waistcoats, so that the plunder might be more easily distributed about their bodies.
“If they had crammed and stuffed the two ordinary pockets that every coat possessed, they would have bulged out, and most likely have betrayed them.
“I allowed them to satisfy their rapacity, and waited patiently to see what they would do next.
“The mouth of the pneumatic tube was very like the opening of the boiler of a furnace. The bottom part resembled a miniature railroad, and the idea was strengthened by the car or small waggon, which was driven along at an immense pace by atmospheric pressure.
“The waggon was in readiness for the bags, and when the two thieves had robbed the appointed bag of as much of its precious contents as they thought they could safely carry away with them, Brown raised it up and placed it in the waggon.
“I considered this a good opportunity to make my presence known and make a captive of Brown and his dangerous accomplice.