“A letter carrier drives through the neighborhood with the mail. When he leaves mail in a box he raises a little signal which is attached to it in such a way that it can be seen from the farmhouse. This, you see, takes the place of the postman’s whistle.
“To-day, some trains are given up entirely to the carrying of mail, and all passenger trains that cross the continent carry tons of mail. Not only is the mail carried on trains, but it can be posted on them as well. It is also sorted on the mail-cars; and sacks of mail are thrown off the mail-car and others taken on while the train is going at full speed.”
“I don’t see how mail can be put on a train when it is in motion,” said Edith.
“Beside the track, at the places where mail is to be exchanged, there is a post of wood or iron,” said grandpa. “Fastened to the post there are two cross-arms as far apart as a mail-sack is long. A sack is suspended on hooks between these arms.
“Beside the door of each mail-car there is an arm, or hook of iron. Just before the mail-car reaches the spot where a mail-bag is hanging, the mail clerk inside the car raises this arm. As the train rushes by, the arm pulls the sack from the hooks and holds it.
“The sack is then opened by the mail clerk, and its contents sorted. At the same time that the sack is taken on board, another sack is thrown from the door of the car.
“In 1790 there were but seventy postoffices in the United States. In 1916 the number had increased to over 56,000.
“Our wonderful postal system makes it possible for us to send letters to any part of the civilized world. If properly addressed and stamped they are almost certain to reach their owners safely and promptly, just as Uncle Charles’ letter came all the way from the Arctic Circle to our door.”
—From “How We Travel,” by James F. Chamberlain (adapted).
QUESTIONS