"Now you know that you can buy a long, narrow stamp which will hurry
your mail along. So, as all mail in this building is put up in many a
small bunch, all with such stamps attract a mailman, who will so wrap a
bunch that that kind of a stamp will show up plainly. Upon its arrival
at a distant point, a boy will grab it, and hurry it to its final
goal. But that stamp will not hurry it as long as it is on that train."