All of this sounds much easier than it really is. As a matter of fact, the task of carrying on the business of a single-track road, where it is practically impossible for all trains to run on time, where meeting-points must be provided for all freight-trains, without delaying them unduly, and where the passenger-trains must have always a clear track and opportunity to make up as much time as possible, if they happen to be late, is one of the most delicate and nerve-racking that could be imagined, though under the new double-order system it is not so bad as it was under the old single-order one. The burden of keeping things moving and of getting the trains over the road in the shortest possible time, falls principally upon the dispatcher at headquarters, but every operator along the road bears his part, and an important part. He must keep awake and alert for any orders the dispatcher may wish to send him; he must note the passage of every train and report to the dispatcher the exact moment at which it passed; and he must be sure that the station signals are properly displayed, and that all orders are properly delivered. Upon the faithful fulfilment of these duties does the safety of trains depend; but especially upon the second, for unless the dispatcher knows accurately the exact position of every train, disaster is sure to follow. Only once that night did Allan have any trouble. That was about three o'clock in the morning. There had not been many orders for Byers, for traffic was light, and he had passed the time listening to the orders sent the other operators and studying the time-card and book of rules with which all operators are provided. But at last his sounder began to clatter out the already familiar "-..., -..., B, B," which was the call for Byers. He answered it and took down the following message on his manifold sheet: "Hold extra east, eng. 632, at B." Allan repeated it at once from his copy, and a moment later, "Com 3.10 C R H" was flashed back to him. The "com" meant "complete," showing that the order had been accurately repeated; the "3.10" was the time the order was sent, and the "C R H" were the initials of the superintendent, which are signed to all train-orders. Three copies must be made of every such order, one for the conductor, one for the engineer, and the other for preservation by the operator. This is done by using tissue-paper for the orders--which are usually called "flimsies" for that reason--between the sheets of which carbon-paper has been placed. A steel-pointed instrument called a stylus is used to write with, instead of pen or pencil, in order that the impression through the three sheets may be clear and distinct. A few minutes after Allan had taken the order, the extra east pulled in, and the conductor, Bill Higgins, stalked into the office. "Any orders?" he asked.