“Oh, that’s quite easy,” said Aline, “and so you mark them all like this—
“Arthur Melland wishes to notifie the good people in the Lothians of the lasting excellence of his wares. His pack is regularly filled with all the newest materials and, too, all is most marvellously finished in design.
and then cut them out.”
“Yes,” said Ian, “and the only other thing necessary is that the paper should first be neatly ruled with quarter inch squares, and each of the key letters carefully written in a square. It does not matter about the others. But then when the receiver gets the letter he knows that the squares to be cut must be exactly an even number of quarter inches from the edge of the paper.”
“I hope I shall remember it if needful,” Aline said.
“I don’t,” said Audry.
“Why not?” exclaimed the others in astonishment.
“Because I hope it won’t be needed and that would certainly be simpler.”