Immediately special trains were sent out, taking United States Marshals, the sheriffs of neighboring counties, officers, and bloodhounds. In a very short time Secret Service men, post-office inspectors, and all the best experts in the service of the government were on the scene. But they were totally unable to discover anything. The turpentine which we had used made the use of the bloodhounds of no benefit to the detectives, and it was not possible to discover the point at which we had left the engine and mail car. Nevertheless the search was not abandoned. It extended itself now in wider directions. The banks throughout the country were notified of the serial numbers of this currency; and the thing which Mooney, wiser than White, foresaw, presently occurred. A clearing house in the southwestern city to which White had gone, notified the Treasury Department at Washington that one of these serial numbers had passed through. The Treasury Department acted at once. It sent two officials to this city to run the matter down. These men were careful, experienced and able detectives. They set on foot every investigation which seemed likely to have any result; but they were not able to discover the source of the note which had been observed by the clearing house. But they remained in charge of the undertaking. Finally fortune favored them. One day, a young girl came in to the post office to deposit part of her salary at the Postal Savings window. A bill which she offered was of the serial numbers of the stolen currency. The post-office clerk who had been instructed to look out for these numbers immediately called the two government detectives to the window. When questioned, the girl said she had gotten this bill from a machinery company as part of her salary. The two detectives went to this company. They found that this particular note had been brought in by one of their drivers who had received it from a man named White. They discovered that this man White had a machine shop in the city. They did not at once undertake to interview White. They shadowed the machine shop until they had an opportunity to get very careful observations of White. They had little data to go on, but they thought he was about the size of one of the bandits described by the mail clerks. They examined the names attached to the note and finally determined they had been made with a rubber stamp. They, then, interviewed all the local stamp dealers, but could find no one who had any knowledge of such a stamp. However, they remained in the city and continued to shadow White. They followed him from place to place, and wherever he made purchases they would go in after him and demand of the storekeeper the note which White had passed, giving another in place of it. They would, then, have the person from whom they had obtained the note write his name on it so that it could later be identified as having been received from this man White.