=Benefits of the System.=—The advantages to the post-office department by the adoption of this system have been numerous, and the post-office officials who are familiar with the operation of the tubes frequently speak in high terms of their usefulness. Formerly the mail was transported from one office to the other by a wagon making a trip every half-hour. Considerable time has been saved by the greater speed of transit, but even more time is gained by keeping the mail moving instead of allowing it to accumulate and then despatching it in bulk. With the pneumatic system a letter posted in the sub-post-office will reach its destination just as quickly as if posted at the main office, and sometimes more quickly. Let us take an example, first, with the old wagon service. Suppose that you drop a letter in the sub-post-office; it lies there, say, fifteen minutes waiting for the departure of the next wagon; it is put into a pouch with hundreds of other letters, and ten minutes are consumed in transporting it to the main office. When it arrives there the pouch is thrown on the floor at the entrance of the building; in a few minutes, more or less, a clerk takes the pouch, throws it on a truck and wheels it around to the cancelling machines, where it may lie for five or ten minutes more before being opened, and then perhaps five minutes will elapse before your letter reaches the cancelling machine. It would not be unusual for three-quarters of an hour to elapse from the time you dropped your letter in the office until it was cancelled. Now with the pneumatic tube service forty minutes of this time will be saved; for immediately after you drop your letter in the office it will be despatched through the tube and delivered on the table in front of the cancelling machines. Soon after the tubes were installed the postmaster’s attention was called to an instance where letters from the sub-office were sent through the tube and were despatched to New York City one train earlier than they could have been had the old wagon service been in use. People frequently post letters requesting that they be sent through the tube; of course they would be sent in that way if the request was not made, but it shows that the public recognize the better service. Formerly mail was collected from the street boxes in the banking section of the city and the collectors carried it to the main office. After the tubes were installed this mail was carried to the sub-post-office to be sent through the tube, and the time formerly occupied in walking to the main office was then utilized in having the men face up the letters ready for the cancelling machines,—a double saving in time besides making their labor much lighter and enabling them to do more useful work.